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Effects of topical applications of meclofenamic acid and ibuprofen on bone loss, subgingival microbiota and gingival PMN response in the primate Macaca fascicularis
Abstract
Nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to alter periodontitis in both animals and humans. This study was initiated in the nonhuman primate (Nhp) model to determine the effect of two NSAIDs on preexisting gingivitis, the conversion of gingivitis to periodontitis, the associated subgingival microbiota, and the gingival PMN response. Eighteen cynomolgus monkeys were divided into three groups and treated on a blind basis with ibuprofen 8%, meclofenamic acid 5%, or placebo applied topically 5 days/week for 20 wk. After 4 wk of treatment, periodontitis was initiated in one quadrant by the placement of silk ligatures. Clinical parameters, bone loss by densitometric analysis of radiographs (CADIA), and cultural microbiology of subgingival plaque were monitored. In situ PMN chemotaxis was assessed by quantitating the PMNs which entered the sulcus in response to a challenge with n-formyl-methionyl-leucyl-phenylalanine (FMLP). No significant differences in the clinical parameters were noted by treatment groups. Radiographic bone loss was detected in all experimental sites in placebo animals as compared with 67% and 44% for ibuprofen and meclofenamic acid animals, respectively. Mean CADIA scores/animal showed a significant loss in bone density for placebo at 6 and 16 wk, no change for ibuprofen animals, and a significant increase in density for meclofenamic acid animals. The microbiota of all groups changed with ligation consistent with previous reports of disease initiation in the Nhp.(ABSTRACT TRUNCATED AT 250 WORDS)
... Topical NSAIDs such as piroxicam [30], ketoprofen [33], flurbiprofen [34] ibuprofen [35], meclofenamic acid [35] administration in the form of cream, gel or dentifrice use have also been advocated due to its lipophilic nature and their quick absorption into periodontal tissue to cause its therapeutic effect with greater efficacy at lower doses and with fewer adverse effects [36]. ...
... Topical NSAIDs such as piroxicam [30], ketoprofen [33], flurbiprofen [34] ibuprofen [35], meclofenamic acid [35] administration in the form of cream, gel or dentifrice use have also been advocated due to its lipophilic nature and their quick absorption into periodontal tissue to cause its therapeutic effect with greater efficacy at lower doses and with fewer adverse effects [36]. ...
... As such, we have employed a non-human primate model of naturally occurring and experimental ligature-induced periodontitis for decades. The disease has been shown to affect a wide array of non-human primate species that demonstrate clinical, microbiological, and immunological features similar to human disease [14][15][16]; exhibit both age and sex differences similar to humans [17,18]; can be altered by mechanical, chemical, and vaccination interventions [19][20][21][22][23]; and enable detailed studies of clinical resolution of periodontal lesions. We have recently reported on gene expression profiles in gingival tissues that enable discrimination of health, disease kinetics, and resolution of the lesions [24]. ...
Although data describe the presence and increase of inflammatory mediators in the local environment in periodontitis vs. health in humans, details regarding how these responses evolve in the transition from health to disease, changes during disease progression, and features of a resolved lesion remain unknown. This study used a nonhuman primate model of ligature-induced periodontitis in young, adolescent, adult, and aged animals to document features of inflammatory response affected by age. Rhesus monkeys had ligatures tied and provided gingival tissue biopsy specimens at baseline, 0.5, 1, and 3 months of disease and at 5 months of the study, which was 2 months post-ligature removal for clinically resolved tissues. The transcriptome was assessed using microarrays for chemokine ( n = 41), cytokine ( n = 45), chemokine receptor ( n = 21), cytokine receptor ( n = 37), and lipid mediator ( n = 31) genes. Limited differences were noted in healthy tissues for chemokine expression with age; however, chemokine receptor genes were decreased in young but elevated in aged samples. IL1A, IL36A, and IL36G cytokines were decreased in the younger groups, with IL36A elevated in aged animals. IL10RA/IL10RB cytokine receptors were altered with age. Striking variation in the lipid mediator genes in health was observed with nearly 60% of these genes altered with age. A specific repertoire of chemokine and chemokine receptor genes was affected by the disease process, predominated by changes during disease initiation. Cytokine/cytokine receptor genes were also elevated with disease initiation, albeit IL36B, IL36G, and IL36RN were all significantly decreased throughout disease and resolution. Significant changes were observed in similar lipid mediator genes with disease and resolution across the age groups. Examination of the microbiome links to the inflammatory genes demonstrated that specific microbes, including Fusobacterium, P. gingivalis, F. alocis, Pasteurellaceae , and Prevotella are most frequently significantly correlated. These correlations were generally positive in older animals and negative in younger specimens. Gene expression and microbiome patterns from baseline were distinctly different from disease and resolution. These results demonstrate patterns of inflammatory gene expression throughout the phases of the induction of a periodontal disease lesion. The patterns show a very different relationship to specific members of the oral microbiome in younger compared with older animals.
... Prostaglandin levels are elevated in inflamed tissues, and prostaglandin E 2 reportedly causes bone resorption in vitro [20,21]. Kornman et al. [22] reported that topically applied ibuprofen in nonhuman primates with periodontal disease significantly inhibited bone loss with no effect on polymorphonuclear leukocyte levels. Thus, ibuprofen is expected to be effective in modulating the initial bone resorption around implants. ...
Purpose:
Some systemic conditions, especially diabetes mellitus (DM), adversely affect dental implant success. This study aimed to investigate the effects of ibuprofen-loaded TiO2 nanotube (ILTN) dental implants in alloxan-induced diabetic rabbits.
Methods:
Twenty-six New Zealand white rabbits were treated with alloxan monohydrate to induce DM. At 2 weeks following DM induction, 3 types of implants (sandblasted, large-grit, and acid-etched [SLA], ILTN, and machined) were placed into the proximal tibia in the 10 rabbits that survived following DM induction. Each type of implant was fitted randomly in 1 of the holes (round-robin method). The animals were administered alizarin (at 3 weeks) and calcein (at 6 weeks) as fluorescent bone markers, and were sacrificed at 8 weeks for radiographic and histomorphometric analyses.
Results:
TiO2 nanotube arrays of ~70 nm in diameter and ~17 μm in thickness were obtained, and ibuprofen was loaded into the TiO2 nanotube arrays. A total of 26 rabbits were treated with alloxan monohydrate and only 10 rabbits survived. The 10 surviving rabbits showed a blood glucose level of 300 mg/dL or higher, and the implants were placed in these diabetic rabbits. The implant stability quotient (ISQ) and bone-to-implant contact (BIC) values were significantly higher in the ILTN group (ISQ: 61.8, BIC: 41.3%) and SLA group (ISQ: 62.6, BIC: 46.3%) than in the machined group (ISQ: 53.4, BIC: 20.2%), but the difference in the BIC percentage between the SLA and ILTN groups was not statistically significant (P=0.628). However, the bone area percentage was significantly higher in the ILTN group (78.0%) than in the SLA group (52.1%; P=0.000).
Conclusions:
The ILTN dental implants showed better stability (ISQ) and BIC than the machined implants; however, these values were similar to the commercially used SLA implants in the 2-week diabetic rabbit model.
... Interestingly, a rather broad variation in expression of the various clusters of genes was noted during early progression. In the nonhuman primate model, extensive studies of clinical measures have demonstrated a general expression of periodontal disease within 1 month post-ligation in nearly all animals although the rate differs for individual animals [42][43][44] . Also, a portion of the animals demonstrate clinical measures that show minimal increases between 1 and 3 months (early responders), while a subset of the animals clearly demonstrate a continued progression of disease, reaching maximum PPD at the 3 month time point, which we defined as "late progression". ...
We used a nonhuman primate model of ligature-induced periodontitis to identify patterns of gingival transcriptomic after changes demarcating phases of periodontitis lesions (initiation, progression, resolution). A total of 18 adult Macaca mulatta (12–22 years) had ligatures placed (premolar, 1st molar teeth) in all 4 quadrants. Gingival tissue samples were obtained (baseline, 2 weeks, 1 and 3 months during periodontitis and at 5 months resolution). Gene expression was analyzed by microarray [Rhesus Gene 1.0 ST Array (Affymetrix)]. Compared to baseline, a large array of genes were significantly altered at initiation (n = 6049), early progression (n = 4893), and late progression (n = 5078) of disease, with the preponderance being up-regulated. Additionally, 1918 genes were altered in expression with disease resolution, skewed towards down-regulation. Assessment of the genes demonstrated specific profiles of epithelial, bone/connective tissue, apoptosis/autophagy, metabolism, regulatory, immune, and inflammatory responses that were related to health, stages of disease, and tissues with resolved lesions. Unique transcriptomic profiles occured during the kinetics of the periodontitis lesion exacerbation and remission. We delineated phase specific gene expression profiles of the disease lesion. Detection of these gene products in gingival crevicular fluid samples from human disease may contribute to a better understanding of the biological dynamics of the disease to improve patient management.
... These changes are not observed with inhibition of inflammation with drugs, including nonsteroidal anti-inflammatory drugs. 99 Taken together, the data suggest that the inflammatory response ...
The last decade has witnessed unparalleled advances in our understanding of the complexity of the oral microbiome and the compositional changes that occur in subgingival biofilms in the transition from health to gingivitis and to destructive periodontal disease. The traditional view, which has held sway for the last 2 decades, that disease is characterized by the outgrowth of a consortium, or consortia, of a limited number of potentially pathogenic organisms, has given way to an alternative paradigm. In this new view, the microbiological changes associated with disease represent whole‐scale alterations to the overall microbial population structure and to the functional properties of the entire community. Thus, and in common with other microbially mediated diseases of the gastrointestinal tract, the normally balanced, symbiotic, and generally benign commensal microbiome of the tooth‐associated biofilm undergoes dysbiosis to a potentially deleterious microbiota. Coincident with progress in defining the microbiology of these diseases, there have been equally important advances in our understanding of the inflammatory systems of the periodontal tissues, their control, and how inflammation may contribute both to the development of dysbiosis and, in a deregulated state, the destructive disease process. One can therefore speculate that the inflammatory response and the periodontal microbiome are in a bidirectional balance in oral health and a bidirectional imbalance in periodontitis. However, despite these clear insights into both sides of the host/microbe balance in periodontal disease, there remain several unresolved issues concerning the role of the microbiota in disease. These include, but are not limited to, the factors which determine progression from gingivitis to periodontitis in a proportion of the population, whether dysbiosis causes disease or results from disease, and the molecular details of the microbial stimulus responsible for driving the destructive inflammatory response. Further progress in resolving these issues may provide significant benefit to diagnosis, treatment, and prevention.
... These results illustrate two biological principles: (1) local environmental conditions impact the composition of the microbiota, and (2) the impact of inflammation on the microbiome is modifiable. These changes are not observed with inhibition of inflammation with NSAIDs or other inhibitors of inflammation (33). ...
The nexus between periodontal inflammation and the polymicrobial biofilm in the gingival sulcus is critical to understanding the pathobiology of periodontitis. Both play a major role in the etiology and pathogenesis of periodontal diseases and each reinforces the other. However, this nexus is also at the center of a significant conundrum for periodontology. For all mucosal polymicrobial biofilms, the most confounding issue is the paradoxical relationship between inflammation, infection, and disease. Despite significant advances made in both periodontal microbiology and periodontal pathobiology, the issue of which comes first, the inflammatory response or the change to a dysbiotic subgingival microbiota, is still debated. In this paper, we present a model for the pathogenesis of periodontitis based on the central role of inflammation and how this modulates the polymicrobial biofilm within the context of the continuum of health, gingivitis, and periodontitis. We propose a new model termed “Inflammation-Mediated Polymicrobial-Emergence and Dysbiotic-Exacerbation” (IMPEDE), which is designed to integrate into and complement the 2017 World Workshop Classification of Periodontitis.
... Six references were excluded because either no quantitative results were reported [22][23][24][25] or the other essential data (N or SD or SEM) could not be obtained. 26,27 Bone quantity. Fifteen of the included references evaluated the effect of topical host-modulating agents on the change of bone quantity with 24 comparisons included in the analysis. ...
Background:
Over the past decades, locally delivered host-modulating pharmacological agents have been extensively investigated to treat periodontitis. Although a small category of agents has been tested in clinical trials, most of them were reported in the animal experiments. This systematic review evaluates the efficacy of local application of currently available host-modulating agents, with or without mechanical removal of plaque, in animal models with periodontitis or periodontal defect.
Methods:
PubMed and Embase were searched on February 11, 2019. The inclusion criteria were: 1) experiments were performed in healthy animals (all ages, sexes, and species) with periodontitis, and 2) outcome data for the local application of host-modulating approaches were presented for bone quantity, bone loss and attachment loss and compared to a vehicle control group. Study characteristics and outcome data were extracted and internal validity was assessed. The efficacy of host-modulating agents was analyzed in a meta-analysis. A standardized mean difference and its 95% confidence intervals for each individual comparison were calculated to estimate the overall effect. Subgroup analyses were conducted on animal species and different types of agents.
Results:
Forty-eight papers were included in the review, of which 42 were included in meta-analysis on bone quantity, bone loss and attachment loss. The results showed that host-modulating therapy significantly increased bone formation (SMD: 2.200 [1.560,2.840], n=24), and decreased bone loss (SMD: -1.659 [-1.969, -1.348], n=51) and attachment loss (SMD: -1.572 [-2.211, -0.933], n=17). No significant subgroup effects were identified, indicating that the effects are similar across species and drug types.
Conclusions:
The current scientific evidence supports the use of local host-modulation therapy in the treatment of periodontitis in experimental animals. Our findings appear robust for various animal models and designs included in this review, which increases our confidence of the translational value of the results to the clinical situation.
... Ibuprofen is a nonsteroidal antiinflammatory drug (NSAID) that inhibits prostaglandin biosynthesis from arachidonic acid exhibiting analgesic, antipyretic, and anti-inflammatory effects (Katzung et al. 2014). Inhibition of alveolar bone loss has been reported to occur in animal studies treated with ibuprofen (Kornman et al. 1990;Offenbacher et al. 1992;Williams et al. 1988). However, there is controversy over the effect of ibuprofen administrated systematically at post-operation of dental implants on bone healing, (Alissa et al. 2009) and materials delivering drugs directly to the bone tissue have been investigated by earlier researchers (Doadrio et al. 2015;Lopes et al. 2013;Paris et al. 2015). ...
Osseointegration was evaluated for the surface of miniscrews with TiO2 nanotube arrays containing drugs in this in-vivo study. The diameter and length of the TiO2 nanotube arrays were about 70 nm and 5 μm, respectively. Recombinant human bone morphogenetic protein-2 (rhBMP-2) or ibuprofen was loaded in the TiO2 nanotube arrays with 12 miniscrews. The 12 drug-loaded miniscrews, 6 miniscrews with no drug-loaded TiO2 nanotube arrays and 6 conventional miniscrews, were placed on the tibias of New Zealand white rabbits. Histological osseointegration was assessed 8 weeks after implantation by measuring the bone-to-implant contact (BIC) ratio. Ibuprofen-loaded miniscrews showed a significantly higher BIC of 71.6% over conventional miniscrews of 44.3% on average. The mean BIC ratios of rhBMP-2-loaded miniscrews and no drug-loaded miniscrews was 24.6% and 60.1%, respectively. Our results suggest that TiO2 nanotube arrays on the surface of miniscrews could be used as carriers of drugs, and loading ibuprofen in TiO2 nanotube arrays may improve osseointegration of miniscrews. However, the effect of rhBMP-2 loaded in TiO2 nanotube arrays on osseointegration of miniscrews was questionable in this pilot study.
... Pemberian antibiotika lokal dan sistemik untuk menghambat pengaruh bakteri pada jaringan periodontal telah banyak digunakan, sedangkan obat yang membantu tubuh dalam reaksi keradangan pada jaringan periodontal belum banyak diperhatikan. Berdasarkan penelitian Kornmann et al. 7 ternyata obat anti-inflamasi nonsteroid dapat menghambat perkembangan periodontitis meskipun terdapat bakteri patogenik yang potensial. Ibuprofen Research Report merupakan salah satu obat anti-inflamasi nonsteroid, derivat dari asam propionat. ...
Bleeding on probing is the first sign of periodontal inflammation. Several cases was companied by gingival enlargement. The most commonly therapeutics are scaling and root planing, including drugs administration, e.g. antiinflammation. Ibuprofen is the one of antiinflammation drug that used on periodontal disease treatment. Nevertheless, the effectivity of ibuprofen has never been known until now. The aim of this study was to know the effectivity administration of ibuprofen after scaling and root planing procedure in gingival enlargement. Samples were divided into 2 treatment regions. Treatment region were given with ibuprofen 400mg 3x1 for 7 days, while the treatment on control region was scaling and root planing only. The result showed that level of pocket depth decreased in treatment region at day 5, whereas level of pocket depth decreased in control region at day 7. It be concluded that ibuprofen decrease effectively bleeding on probing and pocket depth on the treatment of gingival enlargement.
... [41][42][43][44][45][46] However, on cessation of therapy, immediate recurrence of disease occurred thereby requiring its prolonged administration to sustain its therapeutic effects. Topical NSAIDs such as piroxicam, 44 ketoprofen, 47 flurbiprofen, 48 ibuprofen, 49 meclofenamic acid 49 administration in the form of cream, gel or dentifrice use have also been advocated due to its lipophilic nature and their quick absorption into periodontal tissue to cause its therapeutic effect with greater efficacy at lower doses and with fewer adverse effects. 50 Prolonged administration of NSAIDs is cautioned due to its adverse effects including gastrointestinal upset, renal, hepatic and hemorrhage impairment due to nonselective inhibition of COX-1 and COX-2 enzymes. ...
Host Modulation Therapy (HMT) is a treatment concept that reduces tissue destruction and stabilizes or even regenerates inflammatory tissue by modifying host response factors. It has been used for treating osteoporosis and arthritis for several decades. However, its use in dentistry has only been recently reported. The objective of this article is to present a review of the various literatures available on HMT and also its role as adjunct therapy in periodontics. For identifying studies for this review, a PUBMED search was carried out in 2013 for all articles published till December 2012. The search was restricted to English language publications only. Longitudinal prospective and retrospective studies were included in the search. The key words used were: Host Modulation Therapy; Sub antimicrobial dose doxycycline and Non-Surgical Periodontal Therapy. The main outcomes sought were host modulation therapeutics in periodontics. Exclusion criteria included cross sectional studies, short case series as well as studies with short follow-up periods. There is a paucity of literature on HMT in periodontics although the only drug approved by United States Food and Drug Administration (FDA) is a subantimicrobial dose of doxycycline (SDD) with highly predictable results as a host modulating agent in periodontal diseases and also an effective adjunctive therapy in various diseases of periodontium. However, more randomized controlled trials are needed to obtain clinical guidelines on the usage of other host modulating agents as adjunct as well as definite therapy for periodontal diseases. SDD is an effective adjunct therapy when used in dosage of 20mg twice daily for minimum 3 months duration in various periodontal diseases with predictable clinical outcomes. It is also recommended that future clinical research on anti cytokine drugs, chemically modified tetracycline and other HMT agents should be conducted so that new drugs are available with highly predictable results.
... Application of platelet derived growth factor (PDGF) and insulin-like growth factor (IGF-1) into the defect can accelerate healing in this model (Schou et al., 1993). In addition, systemic bisphosphonate, administered at the onset of the surgical procedure, reduces bone resorption without reducing gingival inflammation (Korman et al., 1990;Brunsvold et al., 1992;Weinreb et al., 1994). Osteogenic protein-1 and bone morphogenic protein-2 enhanced periodontal regeneration and created periodontal defects in baboons when applied intrasurgically (Ripamonti et al., 2001). ...
This chapter on the articular, muscle, adipose tissue, and bone diseases of nonhuman primates provides an extensive review on the various naturally occurring conditions of the musculoskeletal system of nonhuman primates with emphasis on diseases seen in laboratory species including those that have arisen in free-ranging, corralled, and conventional laboratory environments. It also includes experimental/induced nonhuman primate models of diseases and conditions affecting the musculoskeletal system including osteoarthritis, inflammatory arthritis, degenerative disc disease, developmental disorders caused by teratogens, microgravity (space flight), osteoporosis, obesity, and calorie restriction. The chapter is extensively revised since the first edition was prepared approximately 15 years ago and now includes references to new discoveries and recent research articles using imaging technologies that have come into common use since the last edition.
... Application of platelet-derived growth factor (PDGF) and insulin-like growth factor (IGF-1) into the defect can accelerate healing in this model (Schou et al., 1993). Systemic bisphosphonate, administered at the onset of the surgical procedure, also reduces bone resorption without reducing gingival inflammation (Kornman et al., 1990;Brunsvold et al., 1992;Weinreb et al., 1994). ...
This chapter presents a discussion on diseases of the musculoskeletal system of nonhuman primates. Clinical features and epidemiology of several diseases such as arthritis, connective tissue disorders, skeletal muscle diseases, bone diseases, and musculoskeletal neoplasia are also discussed in the chapter. Nonhuman primates appear susceptible to the same range of bone inflammation and bone infections as humans do. These diseases include local and hematogenous osteomyelitis, aggressive orofacial granulomatous inflammation, and chronic periodontitis. Osteoporosis is a systemic skeletal disorder characterized by decreased bone mass and microarchitectural deterioration of bone tissues with a consequent increase in bone fragility and fracture susceptibility. Hypertrophic osteoarthropathy is a disorder characterized by bilateral symmetrical subperiosteal new bone formation at the ends of long bones. This condition is most commonly associated with destructive chronic lung diseases or lung tumors. The mechanism of hypertrophic osteoarthropathy associated with intrathoracic lesions is not known, but it is thought to be mediated by neural reflexes.
... Since NSAIDs are lipophilic and are well absorbed into gingival tissues, its topical application is possible. NSAIDs that have been evaluated for topical administration include ketorolac tromethamine rinse and S-ketoprofen dentifrice, [77] piroxicam [78] and meclofenamic acid [79] in inhibiting gingivitis and progression of periodontitis. ...
Traditionally, only antimicrobials have been used as the chemotherapeutic modality for the treatment of periodontitis. Though bacteria are the primary etiologic factors of periodontal diseases, yet the extent and severity of tissue destruction seen in periodontitis is determined by the host immuno-inflammatory response to these bacteria. This increasing awareness and knowledge of the host-microbial interaction in periodontal pathogenesis has presented the opportunity for exploring new therapeutic strategies for periodontitis by means of targeting host response via host-modulating agents. This has lead to the emergence of the field of "Perioceutics" i.e. the use of parmacotherapeutic agents including antimicrobial therapy as well as host modulatory therapy for the management of periodontitis. These host-modulating agents used as an adjunct tip the balance between periodontal health and disease progression in the direction of a healing response. In this article the host-modulating role of various systemically and locally delivered perioceutic agents will be reviewed.
... This is a critical effect since leukotrienes (LTs) and hydroxyeicosatetraenoic acids (HETEs), major products of the LOX pathway, create strong chemotaxis for polymorphonuclear leukocytes (PMNs). 41 This local accumulation of PMNs results in local increases in the levels of PMN-derived proinflammatory mediators/enzymes and further tissue loss. Therefore, omega-3 fatty acid-driven control of the increase in the levels of LTs arising not only from the inflammation itself but also from application of COX inhibitors may provide significant decreases in LT levels. ...
... The same is true of monkey models in doses of up to 7 mg/kg/day (Offenbacher et aL, 1987). Topical application can be equally effective (0.3 mg Flurbiprofen in 1.0 mL of gel per day; Offenbacher ef aL, 1992;or Ibuprofen;Kornman^ a/., 1990). ...
Rational approaches to the prevention of destructive periodontitis should be based on a clear understanding of etiology and pathogenesis. However, we are dealing with a heterogeneous family of diseases in which different factors operate. It is an oversimplification to regard poor oral hygiene, and hence an accumulation of non-specific dental bacterial plaque, as the major risk factor. Epidemiological evidence indicates that host factors are likely to be of overriding importance for the most severe forms. The limitations of nonspecific plaque control are therefore discussed. Specific inhibitors of virulence factors provide a logical approach, but their clinical application awaits improved knowledge. Improvement of general health and resistance to disease by proper nutrition, the avoidance of intercurrent disease, and elimination of smoking and stress-induced risk are encouraged. The genetic basis of susceptibility to periodontitis is increasingly understood, and, while gene therapy is not likely to be a practicable approach to prevention, genetic markers of risk are emerging.
Rhesus monkeys (n = 36) exhibiting a healthy periodontium at baseline were used to induce progressing periodontitis through ligature-placement around premolar/molar teeth. Bacterial samples were collected at baseline, 0.5, 1 and 3 months of disease and at 5 months for disease resolution. The animals were distributed into two groups (18/group): 3-7 years (young) and 12-23 years (adult) and stratified based upon matriline susceptibility to periodontitis (PDS, susceptible; PDR, resistant). 444 OTUs with 100 microbes representing a core microbiome present in ≥75% of the samples were identified. Only 48% of the major phylotypes overlapped in PDS and PDR samples. Different OTU abundance patterns were seen in young animals from PDS and PDR matrilines, with qualitative similarities during disease and relative abundance of phylotypes becoming less diverse. In adults, 23 OTUs were increased during disease in PDS samples and 24 in PDR samples; however, only 5 were common between these groups. Greater diversity of OTU relative abundance at baseline was observed with adult compared to young oral samples from both the PDS and PDR groups. With disease initiation (2 weeks), less diversity of relative abundance and some distinctive increases in specific OTUs were noted. By 1 month there was considerable qualitative homogeneity in the major OTUs in both groups; however, by 3 months there was an exacerbation of both qualitative and quantitative differences in the dominant OTUs between the PDS and PDR samples. These results support that some differences in disease expression related to matriline (familial) periodontitis risk may be explained by microbiome features. This article is protected by copyright. All rights reserved.
We used a nonhuman primate model of ligature-induced periodontitis to identify patterns of gingival transcriptomic changes demarcating phases of periodontitis lesions (initiation, progression, resolution). 18 adult Mulatta macaca (12-22 years) had ligatures placed (premolar, 1st molar teeth) in all 4 quadrants. Gingival tissue samples were obtained (baseline, 2 weeks, 1 and 3 months during periodontitis and at 5 months resolution). Gene expression was analyzed by microarray [Rhesus Gene 1.0 ST Array (Affymetrix)]. Compared to baseline, a large array of genes were significantly altered at initiation (n=6049), early progression (n=4893), and late progression (n=5078) of disease, with the preponderance being up-regulated. Additionally, 1918 genes were altered in expression with disease resolution, skewed towards down-regulation. Assessment of the genes demonstrated specific profiles of epithelial, bone/connective tissue, apoptosis/autophagy, metabolism, regulatory, immune, and inflammatory responses that were related to health, stages of disease, and tissues with resolved lesions. Unique transcriptomic profiles occured during the kinetics of the periodontitis lesion exacerbation and remission. We delineated phase specific gene expression profiles of the disease lesion. Detection of these gene products in gingival crevicular fluid samples from human disease may contribute to a better understanding of the biological dynamics of the disease to improve patient management.
Much attention has focused on the activity of lipopolysaccharides (LPS), in periapical lesions; however, the surface associated material (SAM) from oral bacteria was found to be 100-1000 times more potent in inhibiting mammalian cell division. SAM also significantly inhibited DNA and collagen synthesis by murine calvaria and isolated osteoblasts and had potent bone resorbing activity. However, where the radicular microbial component is small and contained by the local immune response the outcome appears to be a chronic granuloma or a cyst. To test this hypothesis, cyst fluids were investigated for the presence of endotoxin, microorganisms and cytokines. The results showed significantly high concentrations of endotoxin in radicular cyst fluids. All were sterile. Immunoassay showed IL-1a and β in the inflammatory radicular cysts, whereas the developmental keratocysts and follicular cysts only showed IL-1a. All the cyst fluids contained IL-6 and none contained any TNF. The influence of endotoxin and these cytokines on the epithelial cell rests was explored. Endotoxins, IL-1, IL-6 and TNF significantly stimulated keratinocyte proliferation. PGE2 had no effect except at 10μM where it induced cytotoxicity. As epithelial cell rests are undoubtedly influenced by the adjacent connective tissue, the role of fibroblasts was also explored. Fibroblast culture media were shown to have a dose related proliferative effect on keratinocytes. Antibodies against the cytokines IL-1, TNF, IL-6, were used to localise these molecules histochemically in cysts. All radicular cyst epithelia showed positive staining for IL-1 a and ? and IL-6. Keratocysts revealed the presence of IL- 1a and IL-6. It is postulated that growth of radicular cysts involves endotoxin stimulation of the epithelium, the autocrine stimulation of cyst epithelial cell division by IL-1 and IL-6 and the paracrine activity of these cytokines on the fibroblast component of the cyst wall. The consequence of this is osteolysis by fibroblast/inflammatory cell factors such as the eicosanoids.
An increasing body of evidence supports the concept that host-produced PGE2mediates much of the tissue destruction that occurs in periodontal disease. PGE2levels within the crevicular fluid can serve as a static assessment of ongoing disease activity; i.e., rate of attachment loss and bone resorption. New insights into the mechanisms that regulate PGE2synthesis provide an altered paradigm of periodontal disease which places the emphasis on host response, rather than the bacterial etiology, as the principal determinant of disease expression. We describe a PGE2host response model as a hypothetical framework to discuss new, possible explanations for host susceptibility to periodontal disease. J Periodontol 1993;64:432-444.
Periodontitis is an inflammatory disease of the supporting structures of the dentition that is initiated by bacterial that form a biofilm on the surface of the teeth. The pathogenesis of the disease is a result of complex interactions between the biofilm and the host response that results in dysbiosis of the microbiome and dysregulation of the inflammatory response. Current data suggest that the excess inflammation associated with periodontitis is due to a failure of resolution of inflammation pathways. In this review, the relationship between inflammation and microbial dysbiosis is examined in the context of pro-inflammation and pro-resolution mediators and their ability to modify the course of disease. The impact of local oral inflammation on systemic inflammation and the relationship of periodontitis to other inflammatory diseases, including type 2 diabetes and cardiovascular disease is reviewed. Active resolvers of inflammation, including the lipoxins and resolvins, show great promise as therapeutics for the treatment of periodontitis and other inflammatory diseases.
There is increasing interest in how pathways of tissue destruction around dental implants are similar as for teeth and how these pathways can be modulated to slow loss of supporting bone. The purposes of this study were to develop a short-term animal model to study the effect of the nonsteroidal anti-inflammatory drug flurbiprofen, on slowing the rate of induced peri-implant bone resorption. A total of 20 cylindrical titanium implants were placed in 2 beagle dogs using a low-trauma surgical technique. During the 3-month healing period without functional loading of the implants, daily oral hygiene was performed to maintain a Gingival Index of 0 to 0.5. At completion of the healing period, a baseline evaluation was performed which included the uptake of the bone-seeking radiopharmaceutical (BSRU)99mtechnetium-tin-diphosphonate (99mTc-Sn-MDP) in peri-implant bone and standardized radiographs. Peri-implantitis was induced with 4-O silk ligatures, cessation of oral hygiene and soft diet. One beagle was given 0.02 mgikg of flurbiprofen by mouth; the other received a placebo. BSRU and radiographic height of bone were remeasured to calculate the rate of bone loss during the 60-day treatment period. The percent rate of bone loss during the study period was calculated from the radiographs using a computer-assisted method. The radiopharmaceutical uptake for the flurbiprofen-treated implants remained unchanged. However, BSRU for placebo-treated implants was significantly increased from baseline. Radiographic measurements of bone height revealed that the mean rate of bone loss around implants in the flurbiprofen-treated dog (0.066±0.351%/month) was significantly lower than the rate around implants in the placebo-treated dogs (5.729±0.384%/month) over the 60-day treatment period. These data indicate that peri-implant bone loss can be rapidly induced and measured in the beagle and that flurbiprofen. administered orally, can significantly decrease the rate of induced peri-implant bone loss.
Though bacteria are the primary etiologic factor of periodontal diseases, yet the extent and severity of tissue destruction seen in periodontal diseases is determined by the host immuno-inflammatory response to these bacteria. This increasing awareness and knowledge of the host-microbial interaction in periodontal pathogenesis has presented the opportunity for exploiting new therapeutic strategies for periodontitis by means of targeting host response via host modulating agents. Host modulation means supplementing the natural inherent defense mechanisms of the host by modifying or modulating destructive or damaging aspects of the inflammatory host response that develops in the periodontal tissues as a result of the chronic challenge presented by the subgingival bacterial. This chapter discusses the host-modulating role of various systemically delivered (Tetracycline analogues, NSAIDs, lipoxins, resolvins, protectins, maresin, anti-cytokines, bisphosphonates, probiotics, periodontal vaccine and certain nutrients) and locally delivered agents (Enamel matrix proteins, bone morphogenetic protein, platelet derived growth factor, hypochlorous acid and taurine-N-monochloramine and cimetidine). These host-modulating agents are potentially non-invasive, have fewer side effects, do not require complicated application method and tip the balance between periodontal health and disease progression in the direction of a healing response, when combined with conventional treatments aimed at reducing the bacterial burden.
A consistent observation in osteoporosis is bone volume reduction accompanied by increased marrow adipose tissue. No single
cause linking the two phenomena has yet been identified. In a human progenitor cell clone (hOP 7) derived from bone marrow,
however, we have demonstrated that rabbit serum can direct differentiation away from an osteoblast lineage to one of adipocytes.
We now report on whether human serum has a similar effect. Serum was collected from 10 pre- and 10 postmenopausal women and
from the 10 postmenopausal women before and following 6-week hormone replacement therapy (HRT). hOP 7 cells were cultured
with the various sera, and after 7-14 days adipocytogenesis was determined by oil red O staining and lipoprotein lipase (LPL)
and glycerol 3-phosphate dehydrogenase (G3PDH) expression. Incubation with 10% premenopausal serum led to labeling of 10.9%
of cells (P<0.05) with oil red O, whereas application of 10% postmenopausal serum led to a much larger effect, 43.5% labeling (P<0.001 with respect to premenopausal serum). Oil red O positivity was accompanied by loss of type I collagen expression
and increased LPL and G3PDH expression. HRT did not reverse the adipocytogenic effect of postmenopausal serum. In conclusion,
serum from postmenopausal women contains factors that steer hOP 7 bone progenitor cells toward an adipocytic phenotype, irrespective
of HRT. The study suggests a role for serum factors in the development of fatty marrow in postmenopausal osteoporosis.
It was the aim of the study to evaluate the clinical and antibacterial effect of a dentifrice containing an anti-inflammatory plant extract (SB) versus a placebo (PLA) using an experimental gingivitis model. Forty subjects (20 per group) discontinued all oral hygiene measures for four teeth for a period of 21 days using a shield (to generate a possible gingivitis) while they could brush the other teeth normally. After brushing, the shield was removed and teeth were treated with the randomly assigned toothpaste slurry for 1 min. Löe and Silness gingival index (GI), Silness and Löe plaque index (PI), and biofilm vitality (VF%) were assessed at days 0, 14, and 21, respectively. Subjects of the PLA group developed a GI of 0.82 ± 0.342 (day 14) and 1.585 ± 0.218 (day 21), while the data of the SB group were significantly reduced (0.355 ± 0.243 and 0.934 ± 0.342, p < 0.001). While PI was significantly reduced at all follow-up appointments, reductions in VF reached the level of significance only at day 21. The results suggest that the new toothpaste formulation was able to significantly reduce the extent of gingivitis, plaque development, and vital flora.
Gentle extraction of oral bacteria implicated in the pathogenesis of periodontal disease, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, or Eikenella corrodens, with saline removes the extracellular components while leaving the bacteria intact. This readily-solubilized surface-associated material (SAM) has been demonstrated to significantly inhibit DNA and collagen synthesis by murine calvaria at concentrations as low as 10 ng/ml. DNA and collagen synthesis in isolated calvarial osteoblasts were also inhibited by these SAM preparations with similar dose responses. The inhibitory effect of these bacterial expolymers was blocked by 1 microM indomethacin. The potent inhibitory actions on bone synthesis of the SAM from these bacteria may contribute to the alveolar bone loss found in patients with periodontal disease.
This investigation focuses on the changes in the concentrations of cyclooxygenase (CO) products present within the crevicular fluid in naturally-progressing periodontitis in the beagle and the effects of various non-steroidal anti-inflammatory drugs (NSAIDs) on these metabolite levels and disease progression. Six groups of 5-6 beagles with periodontitis were followed for 6 months to determine the pretreatment rate of radiographic bone loss. At baseline, groups of animals were placed on soft chow to promote disease progression. Groups were treated with either placebo, three different formulations of systemic ibuprofen, systemic naproxen or topical flurbiprofen. During the 6-month treatment phase, crevicular fluid (CF) samples and radiographs were taken at regular intervals. Radioimmunoassay of CF samples from untreated animals demonstrated a steady increase in prostaglandin E2 (PGE2) over baseline values. At 1 month, CF-PGE2 levels increased 2-fold over baseline and, by 6 months, had reached a 5- to 6-fold elevation. Crevicular fluid thromboxane B2 (CF-TxB2) levels rapidly reached a 4- to 5-fold peak over baseline at 1 month and subsequently dropped to a 2-fold elevation for the remainder of the study. The rate of bone loss (BLOSS) in untreated animals increased 38% during the 6-month period, as compared to baseline pretreatment BLOSS rates. Overall, there was a significant depression in the CF levels of both PGE2 and TxB2 in all NSAID-treated groups. All NSAID treatments significantly retarded BLOSS, ranging from 21.0-36.9% of the control BLOSS rate. Furthermore, CO activation represents a major regulatory step in bone destruction and may thereby serve as an important site for pharmacological modulation.
This study attempted to evaluate quantitative changes in radiographic density as an indicator of progression of periodontitis. Twenty-one subjects with a history of periodontitis were monitored at baseline, 3, 6, and 9 months using duplicate probing attachment level (PAL) measurements from stents and computer assisted densitometric image analysis (CADIA) of standardized radiographs. Results indicate that the majority of sites exhibited no PAL change during the 9-month period; however, the percentage of sites with loss increased with time. A mean of 6.1% of the sites/patient exhibited probing attachment loss during the study, as compared to a mean of 38.3% of the sites/patient that exhibited a loss of radiographic density. Due to the two dimensional nature of radiographs, density analysis was calculated in terms of radiographic "complexes" of multiple probing sites. There was significantly more density loss at complexes with greater than or equal to 2 mm of attachment loss than at sites with no change in PAL at 9 months; there was no such difference noted at 3 and 6 months. Also, density loss tended to increase as more sites within each complex experienced PAL. Although there was a significant correlation between mean density and PAL changes during the same time interval, there were wide variations at individual sites. This study suggests that there is a complex relationship between density change on radiographs and PAL change. The difficulties inherent in comparing highly sensitive new technologies to relatively imprecise clinical measurements of the attachment level are discussed.(ABSTRACT TRUNCATED AT 250 WORDS)
To assess the clinical efficacy of adjunctive supragingival irrigation with buffered 0.3% acetylsalicylic acid (ASA), 60 patients with periodontitis receiving supportive periodontal therapy were randomly assigned to 1 of 3 home regimens: (1) 1x daily adjunctive supragingival irrigation with 300 ml water immediately followed by 200 ml of buffered 0.3% ASA; (2) 1x daily adjunctive supragingival irrigation with 500 ml water; or (3) normal oral hygiene alone. Clinical parameters were assessed at baseline and 6 months. Irrigator use was measured by timers built into the irrigator units. Results at 6 months showed that both supragingival irrigation with buffered 0.3% ASA and supragingival irrigation with water significantly reduced gingival index scores (median 0.1 and 0.35, respectively) and pocket probing depths (both median 0.26 mm) compared to the control group. In addition, irrigation with water resulted in a significant reduction in bleeding on probing (median 0.13), whereas irrigation with buffered 0.3% ASA had no significant effect on bleeding on probing compared to the control group. The clinical efficacy of irrigation with either ASA or water was found to be positively correlated to initial disease severity and irrigator use. Thus, frequent supragingival irrigation with either 0.3% ASA or water in addition to regular oral hygiene appears to be a beneficial adjunct to periodontal supportive therapy in patients with moderate to severe signs of periodontitis. However, the use of buffered 0.3% ASA as an irrigant does not seem to enhance the clinical efficacy of supragingival irrigation on periodontal health.
Systemic non-steroidal anti-inflammatory drugs (NSAIDs) have been shown to reduce alveolar bone loss in periodontitis. This study assesses the efficacy of a topical NSAID rinse, containing ketorolac tromethamine as the active agent. Adult periodontitis patients (n = 55) were studied in this 6-month randomized, double blind, parallel, placebo and positive-controlled study. Each patient had a least 3 sites at high risk for bone loss as assessed by low dose bone scan. Groups, balanced for gender, were assigned to one of three regimens: bid ketorolac rinse (0.1%) with placebo capsule; 50 mg bid flurbiprofen capsule (positive control) with placebo rinse; or bid placebo rinse and capsule. Prophylaxes were provided every 3 months. Monthly examinations assessed safety, gingival condition, and gingival crevicular fluid PGE2. Standardized radiographs were taken at baseline and at 3 and 6 months for digital subtraction radiography. A significant loss in bone height was observed during the study period in the placebo group (-0.63 +/- 0.11; P < 0.001), but not in the flurbiprofen (-0.10 +/- 0.12; P = 0.40) or ketorolac rinse (+0.20 +/- 0.11 mm; P = 0.07) groups. Nested ANOVA revealed that ketorolac and flurbiprofen groups had less bone loss (P < 0.01) and reduced gingival crevicular fluid PGE2 levels (P < 0.03) compared to placebo. ANOVA suggests (P = 0.06) that ketorolac rinse preserved more alveolar bone than systemic flurbiprofen at the dose regimens utilized. These data indicate that ketorolac rinse may be beneficial in the treatment of adult periodontitis.
We have assessed Macaca fascicularis as a potential model in which to test the efficacy and safety of a vaccine for periodontitis. Twenty-eight animals were surveyed and 20 studied in more detail. Clinical periodontal status was assessed, the subgingival microflora analyzed especially for the presence and proportions of Porphyromonas gingivalis and titers and avidities of serum antibodies reactive with P. gingivalis measured. Probing depths ranged from 0.90 mm to 3.80 mm, Gingival Index scores from 0.00 to 4.00 and Plaque Index scores from 0.00 to 3.00. About 40% of sites bled on probing. The animals manifested a subgingival flora characteristic of the anaerobic gram-negative bacteria found in human periodontal pockets, including Actinobacillus actinomycetemcomitans, P. gingivalis, Bacteroides forsythus, Campylobacter rectus, Prevotella intermedia and Fusobacterium nucleatum. P. gingivalis was detected in 70 of 80 samples studied, ranging from 0.01% to 20% of the total flora. Serum antibody reactive with antigens of P. gingivalis was observed in all animals, with titers ranging from 1.0 enzyme-linked immunosorbent assay (ELISA) unit to 25 ELISA units and avidities from 0.10 M to 2.20 M. Antibody titer and maximum percentage of P. gingivalis were inversely correlated, indicating that a humoral immune response may be effective in reducing P. gingivalis overgrowth. M. fascicularis appears to be an excellent model for use in vaccine development.
The aim of the present study was to assess the influence of a 1-month period of chlorhexidine digluconate (CHX) rinses on the remodelling activity of periodontal tissues adjacent to an extraction wound. From 12 patients assigned to the test group rinsing 2 x daily with 15 ml of 0.12% CHX solution (Peridex) starting 2 days after tooth extraction and from 11 patients assigned to the control group rinsing with a placebo solution, standardized radiographs were available taken immediately after tooth extraction and 1, 2, 3 and 6 months thereafter. Computer assisted densitometric image analysis (CADIA) was applied in order to quantify changes in density during the healing phase after tooth extraction. Regions of interest (ROI) were chosen for CADIA covering supracrestal periodontal soft tissue adjacent to the extraction wound. ROIs were also defined on crestal alveolar bone adjacent to the extraction wound. In the active group, 15/20 sites demonstrated an increase in alveolar bone density between months 1 and 6 (mean CADIA value 6.7 +/- 10.0), whereas in the control group 11/21 sites demonstrated a loss in density (mean CADIA values -1.4 +/- 10.5). Similar observations were made when the ROIs covering supracrestal periodontal tissues were analyzed (mean CADIA values 7.8 +/- 8.4 for the experimental group and -0.3 +/- 10.5 for the control group). These differences were statistically significant (p < 0.04). The digitized series of standardized radiographs were also evaluated for changes in bone height. The distance from the alveolar bone crest to reference points were measured in mm within the baseline: the 1, 2, 3 and 6 month radiographs.(ABSTRACT TRUNCATED AT 250 WORDS)
Several controlled clinical trials have indicated that nonsteroidal antiinflammatory drugs may slow alveolar bone loss in periodontitis. Demonstration of this efficacy is dependent on the development of accurate, sensitive, and specific quantitative methods for the assessment of bony change, such as digital subtraction radiography. Further studies of such methodologies are required to more fully investigate the effect of nonsteroidal antiinflammatory drugs in rheumatoid arthritis.
Periodontitis is a common infectious disease in which the attachment tissues of the teeth and their alveolar bone housing are destroyed, resulting in tooth loss. The gram-negative anaerobic microorganism Porphyromonas gingivalis has been closely linked to severe forms of the disease. We show for the first time that immunization of the primate Macaca fascicularis with killed P. gingivalis in Syntex Adjuvant Formulation-M inhibits progression of periodontal tissue destruction.
This study tested the efficacy of alendronate, a bisphosphate, in reducing alveolar bone loss caused by experimental periodontitis in cynomolgus monkeys. Periodontitis was initiated in adult monkeys by ligating mandibular molar teeth at the cementoenamel junction (CEJ) and subsequently inoculating the ligature with Porphyromonas (Bacteroides) gingivalis. Contralateral, homologous non-ligated teeth served as controls. Animals received, intravenously, either saline (placebo) or alendronate at 0.05 or 0.25 mg/kg every 2 weeks for 16 weeks. After the animals were sacrificed, coronal sections through mandibular molars were subjected to histomorphometrical analysis. No overt side-effects were observed in any of the animals participating in this study. In placebo-treated animals, ligation and inoculation resulted in significant bone loss both at the CEJ and at the furcation. Alendronate at 0.05 mg/kg significantly reduced bone loss associated with the experimental periodontitis at both sites. In contrast, the dose of 0.25 mg/kg was ineffective in attenuating alveolar bone loss in the furcation area and only slightly effective in preventing it at the CEJ area. The results of the histomorphometric analysis correlate closely with those of the radiographic analysis of the same experiment. These data indicate that alendronate could reduce the loss of alveolar support associated with periodontitis and suggest that bisphosphonates, by virtue of their significant inhibitory action on osteoclasts, may become a treatment modality in the battle against alveolar bone destruction during periodontal disease.
Non-steroidal anti-inflammatory drugs (NSAIDs) have been widely researched in an attempt to control periodontal diseases. This double-blind parallel group study investigated the effect of a systemic flurbiprofen preparation (100 mg daily), when combined with toothbrushing on the resolution of experimental gingivitis in human volunteers. 47 volunteers abstained from tooth cleaning for 21 days. On day 21, 23 subjects were prescribed 100 mg of flurbiprofen daily whereas 24 subjects were prescribed placebo. In both groups, toothbrushing was re-introduced and all subjects used the Bass technique for 2 min each day. Both treatment regimens were continued for 7 days. Plaque indices, gingival indices and gingival crevicular fluid flow were assessed at baseline (day 0) and on days 21 and 27. There were no significant differences at p = 0.05 between the groups for plaque indices or gingival crevicular fluid flow. The flurbiprofen group, however, demonstrated greater resolution of gingival inflammation by day 27 when compared to the placebo controls (p = 0.04). The plasma levels of flurbiprofen in the test group showed mean concentrations of flurbiprofen of 4.7 (+/- 2.1) micrograms/ml at 1 h after dosing. After 6 h, this had fallen to 4.4 (+/- 1.6) micrograms/ml. It is concluded that these serum concentrations of flurbiprofen are sufficient to produce significant anti-inflammatory effects in the gingival tissues.
Exogenous PGE1 at pharmacological doses suppresses acute and chronic inflammation manifestations. As periodontitis possesses features of both acute and chronic inflammation, attenuation of periodontal destruction in hamsters was attempted by using 15-M-PGE1, a stable PGE1 analog. The agent was tested at 2 different doses (100 and 150 micrograms/kg/d) and its effects were matched against disease-free and periodontitis-affected animals. No effect was found with the 100 micrograms regimen. In contrast, in the 150 micrograms group, in the gingiva around the first right mandibular molar the pocket epithelium and infiltrated connective tissue (ICT) areas, the mean vascular lumen, the number of PMNLs adherent to blood vessels and infiltrating the ICT were significantly reduced. The number of osteoclasts was markedly diminished as well, but their intrinsic activity was enhanced. Bone formation was totally inhibited in this treatment group. These results indicated that 15-M-PGE1 effectively improved gingival inflammation mostly by reducing edema and PMNL recruitment and controlled alveolar bone destruction by reducing the osteoclast recruitment. From a therapeutic point of view the complete inhibition of formation seems to contraindicate its use.
This 6-month, double-blind, controlled clinical trial determined the efficacy of the non-steroidal anti-inflammatory drug, meclofenamate sodium (Meclomen), as an adjunct to scaling and root planing in the treatment of rapidly progressive periodontitis (RPP). 22 subjects (7 male, 15 female) aged 36.5 +/- 7.88 years with RPP and disease-active sites as determined by pretreatment bone scan had standardized radiographs at baseline and 6 months, and clinical measurements at baseline, 3 and 6 months. Following full-mouth scaling and root planing, subjects were randomly assigned to either a placebo, 50 or 100 mg meclofenamate sodium bid group. Bone change over the 6-month period as assessed by subtraction radiography was the primary efficacy determinant. Specialized software was used to isolate the lesion from the subtraction image and to measure bone change along the root surface. ANOVA using the subject as the unit of analysis revealed a significant dose response (p < 0.001) with the placebo group having a mean bone loss of 0.42 +/- 0.06 mm and the low and high dose groups having mean bone gains of 0.07 +/- 0.05 and 0.20 +/- 0.07 mm, respectively. These findings indicate that meclofenamate sodium may be a useful adjunct in the treatment of rapidly progressive periodontitis.
This clinical trial investigated the influence of short-term ibuprofen therapy on the early phase of the treatment of adult chronic periodontitis. The subjects were 17 patients in good general health referred for specialist periodontal treatment, having moderate chronic adult periodontitis. A series of assessments were made every 2 weeks over an 8-week period, including evaluations of oral hygiene, gingival inflammation and probing pocket depths. All participants received oral hygiene instruction, and following baseline examinations, had half the dentition, chosen at random, treated by scaling and root planing. The patients were randomly distributed into 2 groups, a test group receiving a 14-day course of 800 mg ibuprofen daily, in 4 divided doses, and a control group who did not receive any drug regime. At the 2-week assessment following the drug regime, significantly greater reduction in gingival bleeding, colour and pocketing was detected in the test compared with the control group. The beneficial effects were less evident thereafter. Although clinical application of the regime used in this study would not be justified by these results, further research into anti-inflammatory agents as an adjunct in the treatment of periodontal diseases could be considered, in the light of the beneficial effect on gingivitis in the early phase of periodontal treatment reported.
The inability to examine initiation and progression of periodontal disease and to assess certain therapies in humans has led to a great interest in the use of animal models in periodontal research. Some of the most prominent animals used are non-human primates. This article reviews the characteristics of non-human primate models in periodontal health, in the transition from health to gingivitis to periodontitis, and in experimental gingivitis and periodontitis. Where possible, the results of these studies are compared with results from human studies. Only a few studies have compared in detail the anatomy, physiology, immunology, and tissue interactions in monkeys with those of humans. With the exceptions of differences and variations in size of the dentition, the number of each tooth type as well as larger canines, presence of diastemata between anterior teeth, and an edge-to-edge relationship of the incisors, the dental and periodontal anatomy of non-human primates seem quite similar to that of humans. Clinically healthy gingiva can be established and maintained in non-human primates, and gingivitis as well as periodontitis occur in these animals. It is possible to induce experimental periodontitis by placement of peri-dental silk ligatures or orthodontic elastics as well as by surgical removal of alveolar bone. Although the most appropriate model for studies of periodontal disease pathogenesis in non-human primates appears to involve the application of silk ligatures, some difficulties may occur in establishing periodontal break-down by using this model. Many clinical, histological, microbiological, and immunological characteristics of spontaneous and experimental marginal inflammation in most non-human primates are similar to those in humans. The most significant differences between small non-human primates and humans are the very limited number of lymphocytes and plasma cells in the inflammatory infiltrate of squirrel monkeys (Saimiri sciureus) and marmosets. Therefore, the use of squirrel monkeys and marmosets may not be appropriate in many studies of periodontal disease pathogenesis. The most significant microbial differences between macaque species and humans are a lower proportion of Actinomyces species, the presence of a catalase-producing Prevotella melaninogenica strain, and the high carrier rate for Actinobacillus actinomycetemcomitans in subgingival plaque of macaque species. The significance of these differences is presently unknown. It is concluded that the use of many non-human primate species due to the apparent close anatomic and biologic similarities to humans is appropriate in experimental studies of periodontal disease, provided the use of laboratory animals is requisite and lower species are not applicable.(ABSTRACT TRUNCATED AT 400 WORDS)
Non-steroidal anti-inflammatory drugs (NSAIDs) have been used as systemic and topical preparations to control chronic periodontal disease in both animal and clinical human trials. Equivocal findings have failed to confirm whether any one NSAID is particularly efficacious, although flurbiprofen appears to be one of the most promising. 49 patients were allocated at baseline to test (25) and control (24) groups in a 12-month, controlled clinical trial. The groups were of similar age and sex distributions. During the first 3 months, both groups were given oral hygiene instruction and received scaling and root planning. The test patients were prescribed a 1% w/w flurbiprofen toothpaste to use 2 x daily for the entire 12 months. Control subjects were prescribed a placebo dentifrice. Plaque scores, bleeding scores, crevicular fluid flow, probing pocket depths and attachment levels were assessed at baseline and at 3, 6, 9 and 12 months. Radiographs were taken at baseline and 12 months using a modified intraoral, repositionable film holder. Both the flurbiprofen and placebo showed significant improvements in the clinical parameters over 12 months and there were no significant differences between the groups. Flurbiprofen-treated patients however, demonstrated a significantly greater proportion of sites (8.0%) with bone gain when compared to the placebo group (3.3%). There were no significant differences between the groups in the number of sites showing bone loss or no change. It is concluded that the 1% w/w flurbiprofen toothpaste exerts a small, yet significant effect on bone metabolism in the absence of any apparent effects on clinical parameters.
The non-human primate Macaca nemestrina was evaluated for use as a potential model in periodontal research by study of 16 animals. Using one incisor, premolar, and molar per quadrant, we measured supragingival plaque, severity of gingival inflammation, and pocket depth, and analyzed the subgingival flora. Serum IgG titers and avidities to antigens of Porphyromonas gingivalis (Pg) and Actinobacillus actinomycetemcomitans (Aa) were also assessed. Ten animals were between 13 and 24 years old, and six were between 4 and 5 years old. While mean gingival inflammation scores were significantly higher for older than for younger animals (2.2 vs 1.8, p < 0.05), mean plaque index scores and mean probing depths did not differ significantly. The animals harbored a subgingival microflora considered to be pathogenic for humans including Aa, Pg, Bacteroides forsythus, Prevotella intermedia I and II, Campylobacter recta and Fusobacterium nucleatum. Aa, however, was found only in the younger animals. All of the animals had serum IgG antibodies reactive with antigens of Pg and Aa, and titers for Pg but not for Aa were significantly higher in the older relative to the younger animals (t test p < 0.02). In contrast, antibody avidity did not significantly differ between the two groups. A combined clinical assessment index based on maximum probing depth, gingival index score, and tooth loss was used to assess the overall disease severity. Titers were positively associated with disease severity (Spearman's rank correlation 0.57, p = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)
We studied the capacities of naked and proteincoated monosodium urate (MSU) crystals to stimulate superoxide anion (O2) release by human polymorphonuclear leukocytes (PMN). Uncoated MSU stimulated significant O2 production by cytochalasin B-treated PMN. Precoating MSU with IgG caused an increase in mean O2 production, whereas precoating heated MSU with serum or plasma inhibited O2 release. Unheated MSU crystals, which activate complement to a greater extent than heated crystals, also provoked O2 generation, an effect again abrogated by precoating with serum but not with plasma. Coincubation of unheated MSU and plasma resulted in an enhancement of O2 generation. The results of these experiments support the hypothesis that adsorbed proteins modulate the phlogistic potential of MSU and that the surface activation of humoral mediators contributes to the local inflammatory response.
Abstract Prostaglandins are believed to be important mediators of periodontal inflammation and bone resorption. The purpose of the present blind study was to quantify clinically and histologically the effects of a topically applied non-steroidal prostaglandin synthetase inhibitor, namely a substituted oxazolopyridine derivative (SOPD), on ligature-induced periodontal disease in the squirrel monkey. For a period of 14 days, one group of ligated animals received 2 daily topical applications of the SOPD. A group receiving systemically administered indomethacin served as a positive control while a group receiving only topically applied vehicle served as a negative control. Results indicate that throughout the 14-day period of the study, the SOPD significantly inhibited gingival inflammation and loss of attachment as compared to either the placebo or indomethacin groups. Both indomethacin and the SOPD significantly inhibited bone resorption.
1. The placement of cotton floss ligatures in a position apical to the gingival margin of premolars and molars in young dogs induced an acute inflammatory reaction in the periodontal tissues resulting in loss of connective tissue attachment and alveolar bone. 2. Bone resorption could be observed histologically within 7 days, and radiographically within 2 to 3 weeks after ligature placement. 3. Daily administration of indomethacin interfered with the periodontal tissue response to ligature placement. Indomethacin was shown to (i) delay the onset and to suppress the magnitude of the acute inflammatory reaction, and (ii) decrease the degree of alveolar bone resorption.
The carrageenan air pouch technique in the rat was used to investigate the effects of flurbiprofen, a non-steroidal anti-inflammatory agent, on prostaglandin production and leucocyte migration. tthere is a suggestion that flurbiprofen was capable of inhibiting prostaglandin synthesis at doses lower than those which were effective in reducing leucocyte migration. Therefore, these two effects may reflect independent actions of the drug. The possible clinical relevance of these experiments has been noted since the effects of flurbiprofen on prostaglandin synthesis and leucocyte migration are produced in the rat at peak plasma concentrations which are less than those found in man after a single dose of 50 mg.
(1) The chemotactic activities of thromboxane B2 (TxB2), PGE2, PGF2alpha, the 15-oxo, 15-oxo-13,14-dihydro and 13,14-dihydro metabolites of PGE2, PGF2alpha, and a metabolite of TxB2 for polymorphonuclear leucocytes (PMN) have been investigated. (2) Thromboxane B2 increased the directional migration of rat peritoneal PMN at a concentration of 2.0 micrograms/ml and of human peripheral neutrophils at a concentration of 0.5 microgram/ml. (3) Neither PGE2, PGF2alpha nor their metabolites showed chemotactic activity for rat peritoneal PMN. (4) PGF2alpha and 15-oxo-13,14-dihydro-thromboxane B2 showed no chemotactic activity for human peripheral PMN. (5) The possible role of thromboxane B2 in inflammation is discussed.
Chronic periodontitis, a common disease of microbial origin, is the major cause of tooth loss in adult humans. The disease serves as a convenient experimental model for analysis of many aspects of chronic inflammation. A consideration of currently available data has permitted the formulation of a new concept of the pathogenesis of this disease. The gingival tissues respond within 2 to 4 days to a beginning accumlation of microbial plaque with a classic acute exudative vasculitis which we have termed the initial lesion. This response, which includes loss of perivascular collagen, is comparable to that elicited in most other tissues subjected to acute injury and may be a consequence of the elaboration and release of chemotactic and antigenic substances by microbial plaque. Within 4 to 10 days, the early lesion develops. It is characterized by a dense infiltrate of lymphocytes and other mononuclear cells, pathologic alteration of fibroblasts, and continuing loss of the connective tissue substance. The structural features of the early lesion are consistent with those expected in some form of cellular hypersensitivity, and a mechanism of this kind may be important in the pathogenesis. The early lesion is followed by the established lesion which develops within 2 to 3 weeks and is distinguished by a predominance of plasma cells in the absence of significant bone loss. The established lesion, which is extremely widespread in humans and in animals, may remain stable for years or decades, or it may become converted into a progressive destructive lesion. Factors causing this conversion are not understood. In the advanced lesion, plasma cells continue to predominate although loss of the alveolar bone and periodontal ligament, and disruption of the tissue architecture with fibrosis are also important characteristics. The initial, early, and established lesions are sequential stages in gingivitis and they, rather than the advanced lesion which is manifest clinically as periodontitis, make up the major portion of inflammatory gingival and periodontal disease in humans.
A quantitative clinical and histopathological study of the conversion of chronic gingivitis into a destructive periodontitis was made in 3 Beagle-dogs 4-years of age. This conversion was induced by the placement of a cotton-floss ligature supragingivally around the crown of a tooth. This resulted in enhanced plaque accumulation, a pronounced increase in gingival exudation and rapid formation of periodontal pockets. There was also an overt loss of alveolar bone, attachment and tooth substance (resorption) and an apical displacement of the gingival tissue. The composition of the chronic inflammatory infiltrate was different around ligated and non-ligated teeth, in that the tissues around the former contained a plasma cell-dominated advanced lesion, and around the latter a lymphocyte and plasma cell-rich lesion intermediate between the early and established type.
The levels of prostaglandin E2 were measured by means of radioimmunoassay in 12 clinically normal and 24 chronically inflamed human gingival tissue homogenates. The average values were found to be 16 and 285 pmol/gm wet weight of the normal and inflamed samples, respectively. Addition of estradiol-17beta alone or a mixture of estradiol-17beta and progesterone to incubation media containing normal or inflamed gingiva caused a significant increase in the in vitro synthesis of endogenous PGE2. Increased levels of female sex steroids during pregnancy may enhance gingival inflammation.
Longitudinal data were collected over a period of at least 18 months and up to 3 years on 41 adult periodontitis patients (AAP Type III and IV). Ramfjord attachment level measurements and sampling of crevicular fluid (CF) at each tooth were repeated every 3 months. A mean full mouth CF prostaglandin E2 (MCF-PGE) value was determined for each patient at each visit. The three-month monitoring was continued until a single site demonstrated a statistically and clinically significant attachment loss (ALOSS) episode. Results indicated that in ALOSS patients the MCF-PGE was significantly elevated at the ALOSS visit as compared to previous levels. Furthermore, the sites which had the ALOSS had elevated levels as compared to the contralateral no ALOSS control sites (305.6±56.5 vs. 65.7±6.89 ng/ml, mean ± SEM). One month following treatment the CF-PGE level dropped to 16.9±3.4 ng/ml at the ALOSS sites. Since the MCF-PGE level increases preceding the attachment loss episode, reaches a maximum at the sites which actually undergo ALOSS, and subsides following treatment, the possibility of using the MCF-PGE level to predict an oncoming future ALOSS episode was examined. The ALOSS patients had a MCF-PGE level of 113.4±9.0 ng/ml 6 months prior to the ALOSS episode, which was significantly higher than the no ALOSS patients’MCF-PGE level of 50.1±7.1. Analysis of MCF-PGE levels as a screening test indicate that this measurement has a high degree of sensitivity, specificity, and a predictive value of 0.92–0.95. Thus, this method has significant merit as a diagnostic tool to determine if a patient is in a state of remission or about to undergo an attachment loss episode.
The effect of two non-steroidal anti-inflammatory drugs, indomethacin and flurbiprofen, on the progression of periodontal disease was studied in 16 beagle dogs over a 12-month period. Standardized radiographs were used to measure the rate of bone loss. Following a 6-month pretreatment baseline period, 5 dogs were dosed daily with 1.0 mg/kg indomethacin, 5 dogs were dosed daily with 0.02 mg/kg flurbiprofen, and 6 dogs were dosed with empty gelatin capsules for a 6-month period. In the untreated control dogs, the rate of bone loss in the treatment period significantly increased from baseline. In contrast, the rate of bone loss significantly decreased from baseline in the flurbiprofen-treated dogs. In the indomethacin-treated dogs, rate of bone loss in the treatment period was not significantly different from baseline. The data indicate that both flurbiprofen and indomethacin inhibit alveolar bone loss in beagles compared to untreated controls. The data also indicate that with the dosages employed flurbiprofen is overall more effective.
The effect of the nonsteroidal anti-inflammatory drug flurbiprofen has been studied in the ligature-induced and spontaneous periodontitis model in the rhesus monkey, Macaca mulatta. Twenty-four adult monkeys with incipient periodontitis were divided into three disease-matched groups. Two groups received flurbiprofen at dosages of either 0.27 mg/kg/d or 7.1 mg/kg/d delivered systemically via osmotic minipump. A split-mouth approach was used, placing ligatures on one side and monitoring the progression of periodontitis at regular intervals for 6 months. Clinical measurements included standardized radiographs, Ramfjord attachment level determinations and assessments of redness, edema and bleeding on probing. There was a statistically significant inhibition of attachment loss (p < 0.05), gingival redness (p < 0.05) and bleeding on probing (p < 0.05) in ligatureinduced and spontaneous periodontitis in the flurbiprofen-treated animals at 6 months. Eight of 8 ligated control monkeys lost significant attachment (mean loss of 1.06 mm/site). Only 3 of 15 flurbiprofen-treated ligated monkeys lost any significant attachment, with an overall mean loss of 0.34 mm/site, which was significantly less than the control loss of 1.06 mm/site at p = 4.46 times 10-3. The odds of a control ligated monkey undergoing significant attachment loss in 6 months are elevated 29.3-fold, as compared to the flurbiprofen-treated, cohort monkey group. Flurbiprofen treatment also significantly inhibited spontaneous attachment loss for 6 months as compared to control monkeys, at p < 0.05. These data provide further evidence for the central role of cyclooxygenase products in the progression of periodontal disease. The ability of flurbiprofen to inhibit periodontal attachment loss, even in the presence of gross plaque accumulation, has significant implications for the potential use of flurbiprofen as an adjunctive periodontal therapeutic modality.
The effect of two non-steroidal anti-inflammatory drugs, indomethacin and flurbiprofen, on the progression of alveolar bone loss and on the crevicular fluid (CF) levels of four arachidonic acid metabolites was compared in 16 beagle dogs over a 12-month period. Standardized radiographs were used to measure the rate of bone loss. Radioimmunoassay was used to measure CF levels of PGE2, PGF2α, TxB2 and 6K-PGF1α. Following a 6-month pretreatment baseline period, 5 dogs were dosed daily with 1.0 mg/kg indomethacin, 5 dogs were dosed daily with 0.02 mg/kg flurbiprofen, and 6 dogs were dosed with empty gelatin capsules for a 6-month period. With the administration of either indomethacin or flurbiprofen. the CF levels of PGE2, PGF2α, and TxB2 were similarly significantly decreased; 6K-PGF1α levels were not altered. Indomethacin and flurbiprofen did not have a similar effect on reducing the rate of alveolar bone loss. Flurbiprofen significantly decreased rate of bone loss from baseline whereas indomethacin did not. The data indicate that indomethacin and flurbiprofen inhibit CF arachidonic acid metabolite levels in a similar manner, but not rate of bone loss. The data suggest that flurbiprofen's striking effect on inhibiting rate of bone loss cannot be solely attributed to simple cyclooxygenase inhibition with a reduction in CF prostaglandin levels.
The effect of the non-steroidal anti-inflammatory drug, ibuprofen, on the progression of periodontal disease was studied in 22 beagle dogs over a 13-month period. Standardized radiographs were used to measure the rate of bone loss. Following a 6-month pretreatment baseline period. 6 dogs were treated daily with 4 mg/kg ibuprofen, 5 dogs were treated with 4 mg/kg ibuprofen in a sustained release preparation, 5 dogs were treated with 0.4 mg/kg ibuprofen and 6 untreated dogs served as controls. In the untreated control dogs the rate of bone loss in the treatment period did not change significantly from baseline, although the rate was increased. In both the 4.0 mg/kg and sustained release 4.0 mg/kg ibuprofen-treated dogs the rate of bone loss in the treatment period was significantly less than the pretreatment period rate. In the 0.4 mg/kg ibuprofen-treated dogs the rate of bone loss, although reduced, was not significantly less than the pretreatment rate. When the rate of bone loss in the control dogs was compared with the rate of bone loss in the ibuprofen-treated dogs, all three ibuprofen-treated groups of dogs had significantly less bone loss than the control dogs. The untreated control dogs lost 10 teeth during the treatment period, whereas the 4.0 mg/kg and 0.4 mg/kg ibuprofen-treated dogs lost 6 teeth and the sustained release 4.0 mg/kg ibuprofen-treated dogs lost 2 teeth during the treatment period. The data indicate that a propionic acid derivative, the non-steroidal anti-inflammatory drug, ibuprofen, can significantly inhibit alveolar bone loss in beagles. Sustained release ibuprofen. which gave consistently greater blood levels over 24 h, was overall more effective.
A videobased computer assisted densitometric image analysis (CADIA) system to quantify alveolar bone density changes on standardized dental radiographs was tested. An algorithm was used for grey level correction of a subsequent image to the baseline image. Quantitative information regarding positive and/or negative grey level changes were obtained automatically. Comparison of the ability of CADIA to detect surgically induced bone loss with interpretation of digital subtraction images and conventional radiographic interpretation revealed that CADIA was the most sensitive of the 3 methods, followed by interpretation of digital subtraction images which was considerably more sensitive than conventional radiographic interpretation. CADIA was capable of assessing differences in alveolar bone changes due to periodontal surgery between sites exposed to ostectomy/osteoplasty and control sites and sites exposed to periodontal surgery without ostectomy/osteoplasty. Finally, CADIA was capable of assessing differences in remodeling activity over 4-6 weeks after periodontal surgery between 45 surgical sites and 45 control sites. The system offers an objective method to quantitatively follow alveolar bone density changes over time and appears to be the most sensitive of previously described radiographic interpretation techniques.
Prostaglandins are believed to be important mediators of periodontal inflammation and bone resorption. The purpose of the present blind study was to quantify clinically and histologically the effects of a topically applied nonsteroidal prostaglandin synthetase inhibitor, namely a substituted oxazolopyridine derivative (SOPD), on ligature-induced periodontal disease in the squirrel monkey. For a period of 14 days, one group of ligated animals received 2 daily topical applications of the SOPD. A group receiving systemically administered indomethacin served as a positive control while a group receiving only topically applied vehicle served as a negative control. Results indicate that throughout the 14-day period of the study, the SOPD significantly inhibited gingival inflammation and loss of attachment as compared to either the placebo or indomethacin groups. Both indomethacin and the SOPD significantly inhibited bone resorption.
Prostaglandins have been implicated as possible modulators of normoxic and hypoxic pulmonary tone partly because of studies using cyclooxygenase inhibitors, but these drugs may exert effects that are independent of prostaglandin cyclooxygenase. We evaluated the hemodynamic effects of the acute intravenous administration of 3 cyclooxygenase inhibitor drugs in doses that inhibit prostaglandin synthesis in intact anesthetized dogs: indomethacin 5 mg/kg, meclofenamate 5 mg/kg, and ibuprofen 12.5 mg/kg. During room air ventilation, the administration of indomethacin produced an increase in mean pulmonary arterial pressure (8.0 +/- 1.27 to 13.1 +/- 1.52 mmHg, p less than 0.01) and pulmonary vascular resistance (1.2 +/- 0.23 to 2.7 +/- 0.39, p less than 0.01), whereas meclofenamate and ibuprofen had no effect. Indomethacin given during hypoxic ventilation slightly but insignificantly increased pulmonary artery pressure and pulmonary vascular resistance when compared with hypoxia alone and with the administration of vehicle or meclofenamate. Treatment with indomethacin methacin or meclofenamate 5 mg/kg given subcutaneously twice daily for 2 days had no effect on normoxic or hypoxic pulmonary tone. The combined cyclooxygenase-lipoxygenase inhibitor BW 755C in doses of 25 mg/kg given intravenously did not inhibit hypoxic pulmonary vasoconstriction. We conclude that prostaglandins do not appear to play a major physiologic role in modulating normoxic or hypoxic pulmonary vasomotor tone in intact anesthetized dogs, and that the indomethacin-induced increases in pressure and resistance are independent of inhibition of prostaglandin cyclooxygenase.
We studied the effects of cyclooxygenase inhibitors (indomethacin, meclofenamate, and ibuprofen) on the increases in pulmonary transvascular fluid and protein fluxes that occur after thrombin-induced intravascular coagulation. Each drug-pretreated group was compared with a control group receiving the same amount of alpha-thrombin (alpha-T), the native enzyme used to induce intravascular coagulation. Studies were made in the following groups of anesthetized sheep prepared with lung lymph fistulas: low dose-indomethacin (bolus injection of 5 mg/kg and infusion of 3 mg/kg/h, high-dose indomethacin (bolus injection of 20 mg/kg and infusion of 12 mg/kg/h), meclofenamate (bolus injection of 5 mg/kg and infusion of 3 mg/kg/h), low-dose ibuprofen (bolus of 6.2 mg/kg and infusion of 3.1 mg/kg/h), and high-dose ibuprofen (bolus of 25 mg/kg and infusion of 12.5 mg/kg/h). The concentrations of the arachidonic acid metabolites, thromboxane B2 and 6-keto-prostaglandin F1 alpha, did not increase in the treated groups. Infusion of alpha-T increased the mean pulmonary arterial pressure and pulmonary vascular resistance in the control and treated groups, but to higher levels in the indomethacin and meclofenamate groups. In the control group, alpha-T increased pulmonary lymph flow (Qlym) and lymph protein clearance (Qlym X lymph/plasma protein concentration ratio), a measure of lung vascular permeability. In the indomethacin, meclofenamate, and low-dose ibuprofen groups, alpha-T resulted in delayed increases in Qlym and lymph protein clearance, but these lymph parameters attained the same levels as the control groups. However, the high-dose of ibuprofen significantly attenuated the increases in Qlym and lymph protein clearance after alpha-T.(ABSTRACT TRUNCATED AT 250 WORDS)
To test whether the hydrolytic products of digestion could stimulate vasoactive prostaglandin synthesis in the intestine, the muscularis and mucosa of the rat jejunum were suffused with a bicarbonate-buffered Ringer vehicle containing cyclooxygenase inhibitors (meclofenamate or indomethacin; 3 X 10(-5) M). To evoke blood flow changes, either glucose (56 mM), oleic acid (20 or 40 mM), or sodium arachidonate was added to the mucosal vehicle. Bile salt (taurocholic acid, 10 mM) was added to emulsify oleic acid. Blood flow was calculated (BFc) in submucosal arterioles by use of video microscopy. Neither bile salt nor cyclooxygenase inhibitors altered resting BFc. Neither oleic acid concentration nor solution osmolality altered the magnitude of absorptive hyperemia. After 10 min of glucose, BFc increased 36 +/- 6% with vehicle (n = 16) and 39 +/- 8% with meclofenamate (n = 10). After 10 min of oleic acid, BFc increased 21 +/- 5% with vehicle (n = 17) and 34 +/- 6% with inhibitors (n = 17). In animals exposed twice to the same concentration of oleic acid, the paired difference between the vehicle and inhibitors (19 +/- 7%; n = 9) was significant. Arachidonate alone produced no dose-related (0.06-1.9 mM) effect on BFc (n = 41), but arachidonate (0.3 mM) combined with cyclooxygenase inhibitors (6 X 10(-5) M) produced a significant BFc increase of 35 +/- 7% (n = 6). These observations suggest that the absorption of oleic acid, but not glucose, stimulates the synthesis of a vasoactive metabolite of arachidonate. The mechanism for the differential effect of cyclooxygenase inhibitors is unknown but could involve nonprostaglandin metabolites of arachidonate, such as lipoxygenase or cytochrome P-450 products.
The nonsteroidal anti-inflammatory drug, flurbiprofen, a potent cyclooxygenase inhibitor, significantly decreases the resorption
of alveolar bone in naturally occurring chronic destructive periodontal disease in beagles. This observation indicates that
arachidonic acid metabolites are important in the alveolar bone loss of periodontitis and suggests a use for flurbiprofen
in the management of bone resorption disease.
PGE2 levels in human gingiva from healthy patients and patients with periodontal disease was measured by radioimmunoassay. There was a tenfold elevation of PGE2 levels in diseased as compared with healthy tissue. PGE2 levels of 10−6M or greater were found in purulent exudates from periodontal infections. The results suggest that local PGE2 production may contribute to the inflammatory changes and bone resorption seen in periodontal disease.
Leukotriene E4 (LTE4) appears to be a rather stable product of the lipoxygenase pathway. Its action in the pulmonary circulation is unknown. Therefore we investigated its effect on the circulation of isolated rat lungs perfused with a cell- and plasma-free solution. Synthetic LTE4 in doses from .15 micrograms to 5 micrograms/.25 ml .9% NaCl injected as a bolus in the pulmonary artery during normoxia caused a fast, transient perfusion pressure increase within seconds. This was followed by a slow rise in baseline perfusion pressure (normoxia) over 25 min. In addition, 5 micrograms LTE4 caused edematogenic lung damage. Injection of 1.5 micrograms LTE4 during hypoxic vasoconstriction caused fast, transient pressure rises, similar to normoxic conditions. 6-keto-PGF1 alpha and TXB2 were measured in the lung effluent before and after LTE4 injection. Neither 6-keto-PGF1 alpha nor TXB2 production changed after LTE4 injection. Meclofenamate (.5 micrograms/ml) increased the fast, transient and the slow, sustained pressure rise. We conclude that LTE4 caused direct pulmonary vasoconstriction unrelated to cyclooxygenase products.
The measurement of crevicular fluid PGE (CF-PGE) as an indicator of periodontal disease status was investigated. The association between CF-PGE levels and the PGE content of the adjacent periodontal tissues was found to be highly significant (P=5.3 × 10−6). The high correlation (r=0.925) between the log CF-PGE level and the tissue PGE concentration indicates that CF levels can be used to reliably predict tissue levels. The CF-PGE measurements at each periodontal site were found to be highly reproducible. Samples from adult and juvenile periodontitis patients demonstrated that the mean CF-PGE levels were correlated with disease severity, as determined by mean attachment loss. The mean CF-PGE level in juvenile periodontitis patients was almost three-fold higher than that present in adult periodontitis (144.0 ± 28.0 ng/ml vs 57.5 ± 8.7 ng/ml, mean ± S.E., significant at P = 0.002). The use of CF-PGE concentrations as an indicator of disease activity (i.e. longitudinal attachment loss) cannot be demonstrated by this cross-sectional study. However, the CF-PGE measurement has been demonstrated to be a non-invasive, sensitive, reproducible, and reliable reflection of tissue levels of PGE2. The association of increasing levels of CF-PGE with increased severity and aggressiveness of disease is consistent with PGE as an inflammatory mediator of tissue destruction.
Arachidonic acid is metabolised either by cyclooxygenases to produce prostaglandins and thromboxanes or by lipoxygenases to produce mono-, di- and trihydroxyeicosatetraenoic acids (HETEs). Polymorphonuclear leukocytes (PMNs) release HETEs, including mono- and dihydroxy fatty acids, when exposed to stimuli such as the calcium ionophore A23187 (refs 1, 2). The mono-HETEs are assumed to be of particular importance with respect to effects on leukocyte function because they have been shown to possess both chemotactic and chemokinetic activities towards PMNs and eosinophils. However, we have now shown that the chemokinetic and aggregating activities released from rat and human PMNs exposed to ionophore A23187 (ref. 5) are not due to the release of mono-HETEs but to that of 5, 12-di-HETE (leukotriene B). This compound is active over the concentration range 10 pg ml-1 to 5 ng ml-1.
A number of hydroperoxy (HPETE) and hydroxy (HETE) products of the lipoxygenase pathway of arachidonic acid metabolism are chemotactic and chemokinetic for human neutrophils. We have investigated the relative chemokinetic potency of some of these products on human, rat and rabbit neutrophils. The most potent lipoxygenase product studied was 5,12-dihydroxy-6,8,10-14-eicosatetraenoic acid (5,12-diHETE), which was maximally chemokinetic and chemotactic between 0.1 and 1.0ng/ml for the three species. The 5, 11 and 12-HPETEs and HETEs were chemokinetic, but less active by at least two orders of magnitude, for human and rabbit neutrophils at concentrations between 0.1 and 10micrograms/ml. 15-HPETE and 15-HETE were inactive on human leucoctes, and none of the monosubstituted products studied were chemokinetic for rat neutrophils. These results indicate that 5,12-diHETE may be an important mediator in the local accumulation of leucocytes in the inflammatory response.
The contraction of isolated guinea pig lung parenchymal strips by synthetic leukotrienes (LTs) C4 and D4 was significantly antagonized by 1 μM indomethacin; the concentration-response curve describing the LTE4 contraction was displaced to a lesser degree. Radioimmunoassays of the lung tissue bath fluid after leukotriene contraction demonstrated the presence of significant levels of thromboxane (TxB2) but only low levels of PGF2. The amount of TxB2 was inhibited at each LTE4 concentration by the presence of meclofenamic acid and indomethacin. No analogous antagonism by the cyclooxygenase inhibitors and the LT-induced contraction of guinea pig tracheal smooth muscle occurred; instead an augmentation of the maximal response was observed. This effect on the LT-induced contraction of the trachea appeared to be generic in that the histamine-induced contraction was also potentiated. When given i.v. to anesthetized, spontaneously breathing guinea pigs, LTE4 produced decreases in dynamic lung compliance and increases in pulmonary resistance. These changes in dynamic lung compliance and pulmonary resistance appeared delayed in onset after pretreatment with meclofenamic acid but only the magnitude of dynamic lung compliance was significantly antagonized by meclofenamic acid. This effect was not apparently due to metabolism of the LTE4, since i.v. LTE4 was similarly affected by meclofenamic acid. However, when LTE4 was administered by aerosol, the bronchopulmonary responses were potentiated by pretreatment with meclofenamic acid. These results suggest that leukotriene-mediated bronchoconstriction may occur via direct and indirect mechanisms: (1) a direct one seen via aerosol administration in vivo or on the trachea in vitro and (2) an indirect one, probably mediated by TxA2, observed after i.v. administration in vivo or on the parenchyma in vitro.
The potential diagnostic usefulness of subtraction radiology in dentistry was evaluated by means of an experimental model of marginal periodontitis in cynomolgus monkeys. Beam-guiding, field-limiting, intraoral radiographic instruments were modified to allow construction of appliances which yielded repeatable superimposable radiographic images during the course of a 16-week study. Marginal periodontitis was induced in monkeys by means of circumferential silk sutures tied around mandibular second molar and second premolar cementoenamel junctions, and serial radiographs were taken at weekly intervals for 16 weeks. Control subtraction masks were made from pretreatment radiographs, and bone loss was evaluated by means of elapsed-time films to give the subtraction prints. The subtraction films clearly showed increasing bone loss with time and were produced easily with size O dental films. This technique appears to have considerable potential usefulness in the evaluation of bone-density changes in experimental models of dental diseases as well as in the clinical setting.
Human blood neutrophils exposed to appropriate stimuli aggregate, degranulate and generate superoxide anion (O2-). These responses are anteceded by mobilization of membrane-associated calcium, monitored as a decrease in fluorescence of cells preloaded with chlortetracycline (CTC). We studied the effects, both in vitro and in vivo, of non-steroidal anti-inflammatory agents (aspirin, indomethacin, ibuprofen and piroxicam) on these neutrophil responses to three stimuli: a chemoattractant, N-formyl-methionyl-leucyl-phenylalanine (FMLP); a tumor promotor, phorbol myristate acetate (PMA); and a lectin, concanavalin A (Con A). The effects of these drugs were compared with those of two polyenoic inhibitors of arachidonate metabolism: eicosatrienoic acid (ETI) and eicosatetraynoic acid (ETYA). The pattern of inhibition of neutrophil functions varied both with inhibitor and the nature of the stimulus. Thus, aspirin, piroxicam, ETYA and ETI inhibited neutrophil aggregation, degranulation, and O2- generation in response to FMLP, whereas ibuprofen inhibited only aggregation and degranulation and indomethacin only inhibited aggregation. None of the agents inhibited aggregation or degranulation induced by PMA or Con A: only piroxicam inhibited O2- generation in response to PMA or Con A. ETI and ibuprofen inhibited decrements of CTC fluorescence induced by FMLP, but whereas ETI inhibited the CTC response to PMA or Con A, ibuprofen was without effect. The agents had varying effects on binding of the stimulus [( 3H]FMLP, [3H]Con A), but these did not correlate with neutrophil responses to the ligands. Neutrophils from subjects taking therapeutic doses of ibuprofen, indomethacin, or piroxicam showed profiles of inhibited responses to FMLP similar to those observed with these agents in vitro. These data suggest that, although non-steroidal anti-inflammatory agents may inhibit discrete neutrophil functions both in vitro and in vivo, their effects do not duplicate those of polyenoic inhibitors of arachidonate metabolism. Moreover, since the susceptibility of neutrophils differed not only with respect to each inhibitor, but also to the stimulus, it is unlikely that all neutrophil responses are necessarily linked by a common pathway that is blocked by inhibitors of arachidonic acid metabolism.
In vitro, phorbol myristate acetate (PMA) causes sheep granulocytes to release superoxide. Infused into sheep, PMA causes leukopenia, hypoxemia, pulmonary hypertension, and increased flow of protein-rich lung lymph. Lung lymph thromboxane B2 and 6-ketoprostaglandin F1 alpha levels rise markedly after PMA infusion. To see whether cyclooxygenase products of arachidonic acid mediate the lung vascular responses to PMA, we infused 5 micrograms/kg PMA twice in each of six sheep, once in the presence of sodium meclofenamate and once alone. We varied the order of paired experiments and allowed 4-7 days between experiments. Meclofenamate (5 mg/kg loading dose + 3 mg X kg-1 X h-1 infusion) given alone had no effect on base-line variables. Meclofenamate inhibited or delayed the initial pulmonary hypertension and hypoxemia after PMA but exaggerated the later increase in pulmonary arterial pressure; it prevented any increase in thromboxane B2 and 6-ketoprostaglandin F1 alpha after PMA. Meclofenamate did not affect the degree of leukopenia or the severity of the later hypoxemia nor did it prevent accumulation of granulocytes in the lung. Lung lymph flow was higher with meclofenamate + PMA than with PMA alone, but lymph-to-plasma protein concentration ratio was lower, suggesting that the main effect of meclofenamate on lymph production after PMA was related to the degree of pulmonary hypertension. We conclude that the early increase in pulmonary arterial pressure caused by PMA is mediated by a cyclooxygenase product of arachidonic acid, possibly thromboxane A2, but the later pulmonary hypertension and the increase in pulmonary vascular permeability are not the result of cyclooxygenase products.
Recent data from several laboratories, which suggest that generally accepted concepts relating to the mechanism of action of nonsteroidal, anti-inflammatory drugs (NSAIDs) in rheumatoid arthritis may be incorrect, are reviewed. Over the past decade, most researchers have espoused the idea that NSAIDs act by inhibiting cyclooxygenase, thereby removing prostaglandins, which are thought to be responsible for pain and inflammation. Recent studies demonstrating that prostaglandins have important immunomodulating properties and that NSAIDs actually provide partial correction of several immunoregulatory dysfunctions in patients with rheumatoid arthritis are described. In addition, some NSAIDs inhibit migration along with other monocyte and polymorphonuclear leukocyte functions. Data suggest that these actions are not related to inhibition of cyclooxygenase.
We monitored the in vivo response of human and rat crevicular leucocytes (CL) and fluid (CF) to a chemical challenge in an attempt to develop an in vivo chemotaxis assay. The mesial crevices of #21 and #22 of male dental students (mean GI = 0; crevice depth = 2.3 mm) were washed and air dried. The baseline values for CL (#num;21) and CF (#22) were recorded. CL were collected in 10 μI washes of the crevice and an aliquot immediately counted in a hemacytometer. CF was collected on filter paper strips and measured with a fluid meter. Casein, a nutrient and a standard in vitro chemo-attractant was applied with a calibrated wire loop into each crevice. CL and CF were monitored 15 min later and at 5 min intervals up to 45 min. CL and CF peaked approximately 30 min after the casein challenge; both parameters returned to baseline rapidly thereafter. In rats, a dose-response was obtained when concentrations of 0.01–4.0 mg casein/ml were applied to the gingival crevice. The maximum response of CL and CF occurred at 2.0 mg/ml. The application of buffer alone or Fab protein, which lacks chemotactic activity, produced no rise in CL and CF. We suggest that this crevicular technique can be used to monitor the in vivo response of subjects with defects in leucocyte chemotaxis.
A test group of 22 subjects who had been taking non-steroidal anti-inflammatory drugs for periods in excess of one year were matched with a control group of 22 office workers with reference to age and Plaque Index. It was found that the test group had significantly lower values of Gingival Index and shallower depths of pockets than the control group of subjects. There was a trend also for there to be less loss of attachment in the test group. These results were interpreted as indicating that anti-inflammatory drugs may influence the response of the periodontal tissues to plaque by reducing the prostaglandin concentration in the tissues. The slight decrease in loss of attachment in the test group may also be explained by the reduction in prostaglandin synthesis in the subjects taking anti-inflammatory drugs.
The cultivable subgingival microflora in the cynomolgus monkey, Macaca fascicularis, was monitored during the ligature-induced progression of naturally occurring gingivitis to periodontitis. Clinical and microbiological observations were divided into four stages. Stage I, prior to ligature placement, was characterized clinically by chronic generalized gingivitis and microbiologically by Gram-positive cocci and rods with B. melaninogenicus ss. intermedius the dominant Gram-negative organism. Stage II, 1 to 3 weeks following ligature placement, exhibited slightly greater gingival inflammation but no clinical evidence of attachment loss. The subgingival flora showed a significant increase in motile and surface translocating Gram-negative rods, primarily Capnocytophaga species and Campylobacter sputorum. Stage III, 4 to 7 weeks following ligature placement, revealed increased pocket depth and radiographic evidence of alveolar bone loss. This stage was characterized by a Gram-negative anaerobic flora with B. asaccharolyticus as the dominant cultivable organism. Stage IV encompassed the remainder of the experimental period, 8 to 17 weeks, during which time no further change in the clinical parameters occurred and levels of B. asaccharolyticus decreased.
The subgingival microflora of ligature induced periodontitis in Macaca fascicularis closely resembled that reported for human periodontal disease and the episodic clinical pattern of attachment loss was associated with levels of Gram-negative anaerobes, primarily B. asaccharolyticus.
Aspirin (ASA) and indomethacin are inhibitors of prostaglandin synthesis and reduce bone resorption in tissue culture stimulated by preparations obtained from human gingival tissue. In a retrospective study, we attempted to determine whether ASA or ASA plus indomethacin exert a bone resorption inhibiting effect on human alveolar bone. Dental radiographs of 75 patients with a history of arthritis and long-term ingestion (greater than 5 years) of ASA were compared with dental radiographs of 75 healthy male volunteers from the VA Dental Longitudinal Study (DLS). Proximal bone loss was measured using a Schei Ruler graded on a 10-point scale. The data indicated that the ASA population presented with significantly fewer sites of 10% or greater mesial and distal bone loss than the healthy control population (P less than 0.05). Mean percentage bone loss for the entire dentition was also lower in the ASA group, although the difference was not statistically significant. As there is no evidence to suggest that inhibition of alveolar bone loss is a natural concomitant of the arthritic process, we conclude that the inhibition of bone loss found in this study was due to the chronic ingestion of ASA or ASA and indomethacin.
We compared alterations of pulmonary hemodynamics with the plasma concentrations of thromboxane B2, 6-keto-PGF(1α) and PGF(2α) following intravenous Escherichia coli endotoxin infusion (1 μg/kg) in three groups of awake sheep. Group 1 served as controls. The animals in group 2 were rendered leukopenic (<1000 WBC/mm3) by nitrogen mustard treatment. Group 3 received ibuprofen (12 mg/kg) one hour before endotoxin. After endotoxin infusion, the pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) increased markedly in groups 1 and 2; however, in group 2, the increases of PAP and PVR were half those of group 1. In group 3, only minimal increases of PAP and PVR were measured. In groups 1 and 2, the rise of PAP correlated with an increased plasma TxB2 concentration at 30 minutes after endotoxin (group 1 - from 0.5 ± 0.04 to 16 ± 3 ng/ml; group 2 - from 0.32 ± 0.1 to 5.6 ± 1.2 ng/ml). The peak plasma concentrations of TxB2 were significantly less in group 2 than in group 1. In the sheep in both groups 1 and 2, 20 minutes after endotoxin infusion, consistent pulmonary artery to aortic increases of T x B2 were measured (group 1 Δ 3.7 ± 1.1 ng/ml and group 2 Δ 3.1 ± 0.7 ng/ml). In group 3, plasma T x B2 increased slightly to 240 ± 80 pg/ml. Plasma concentrations of 6-keto-PGF(1α) increased in group 1 from 0.06 ± 0.01 to 0.59 ± 0.12 ng/ml and in group 2 from 0.06 ± 0.01 to 0.58 ± 0.12 ng/ml. In group 3 sheep, plasma concentrations of 6-keto-PGF(1α) remained below the detection limit of the radioimmunoassay. T x A2 is a likely mediator of endotoxin-induced pulmonary hypertension and is generated in large quantities by cells in the lung. Circulating leukocytes contribute substantially to the peak plasma concentrations of thromboxane following endotoxin infusion.
The lipoxygenation of arachidonic acid in basophils, mastocytoma cells, and other leukocytes generates the unstable intermediate 5-hydroperoxy-eicostaetraenoic acid, which is converted in part to a series of complex hydroxy-eicosatetraenoic acids (HETEs) with additional polar substituents and 3 conjugated double bonds. One of the products, 5,12-di-HETE, is chemotactic for human neutrophils in vitro at a concentration as low as 3 ng/ml and evokes a maximal neutrophil chemotactic response at 30 ng/ml, as compared to 1000 ng/ml for 5-HETE and 10,000 to 20,000 ng/ml for 11-HETE and 12-HETE. In contrast, other products in the same series, such as the slow reacting substance 5-hydroxy-6-glutathionyl-eicosatetraenoic acid (leukotriene C), and the platelet-derived 8,9,12-trihydroxy-eicosatrienoic acid and 8,11,12-trihydroxy-eicosatrienoic acid exhibited only marginal neutrophil chemotactic activity. Only 5,12-di-HETE released significant quantities of beta-glucuronidase and lysozyme from the neutrophils, but the maximal level of enzyme release was far less than that for the chemotactic fragment of C5 and the formyl-methionyl peptides.
The preparation of leukocytes free of contaminating erythrocytes by means of sedimentation with dextran and the removal of residual erythrocytes by exposure to hypotonic saline is described. The recovery and ease of preparation compared favorably with methods previously described, with the advantage that all erythrocytes were removed. An evaluation of the leukocytes obtained by this method suggested that they were viable in terms of most of the currently available criteria. No gross changes in cellular respiration or glycolysis were noted in either normal or leukemic preparations. In addition, evaluation by trypan blue staining, ability to decarboxylate orotic acid, or electron microscopy, revealed the leukocytes to be unchanged. Each of these parameters is altered when cells are exposed to grossly unphysiologic conditions, such as 4 minutes exposure to hypotonic saline.
- Waite I.
Enhancement of human mononuclear leukocyte chemotaxis by prostaglandin E2
- McClatchy W