Fig 3- - uploaded by Toshiki Takamizawa
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Representative SEM micrograms of dentin smear layers. Dentin surface prepared with #4000 grit SiC paper at magnifications of (a) 2500× and (b) 20,000×. A longitudinal section of the dentin surface prepared with #4000 grit SiC paper at a magnification of (c) 10,000×. Arrows indicate smear plugs.
Source publication
Objective:
The purpose of this study was to determine the influence of different smear layers on enamel and dentin bond durability of various types of self-etch adhesives.
Methods:
Two universal adhesives, Scotchbond Universal (SU) and Prime & Bond elect (PE); a conventional single-step self-etch adhesive, G-ænial Bond (GB); and two two-step sel...
Citations
... Two-step self-etch adhesives succeed in penetrating different types of smear layers due to the high hydrophilicity of the self-etching primer. In contrast, one-step self-etch adhesives have greater difficulty in penetrating the smear layer and difficulty in forming the hybrid layer with decreased adhesion strength to the dentin [22]. Correct identification of their cause allows not only to choose the most appropriate treatment plan, but also to reduce the progression of already formed lesions and place the patient on a prevention plan [17][18][19]. ...
... Two-step self-etch adhesives succeed in penetrating different types of smear layers due to the high hydrophilicity of the self-etching primer. In contrast, one-step self-etch adhesives have greater difficulty in penetrating the smear layer and difficulty in forming the hybrid layer with decreased adhesion strength to the dentin [22]. ...
Unlabelled:
This scoping review aims to evaluate methods of conservative reconstruction of dental enamel lesions resulting from abrasions and evaluate the effect of diode laser in reducing the symptoms of tooth sensitivity. The cementoenamel junction is more prone to substance loss because the enamel thickness is substantially decreased, resulting in a much weaker enamel-dentin bond.
Methods:
Dental abrasion was examined in the mechanical cause alone. Pubmed, Scopus, and Web of Science were used to discover publications that matched our topic from 1 January 2018 to 20 March 2023. A comparison of various non-carious cervical lesion (NCCL) restoration treatments was generated mostly by mechanical considerations.
Results:
A final number of 11 clinical trials and randomized controlled trials were included in the review for qualitative analysis. Composite resins performed well in clinical trials for the restoration of NCCLs.
Conclusions:
Composite, in its different forms of filling and consistency, preceded by the use of adhesives, is an efficient and effective material for the treatment of NCCLs. Diode laser use prior to NCCL restoration of teeth does not diminish restoration retention rate, may lessen hypersensitivity, and may affect restoration success.
... Previous studies determined that the bonding strength to the enamel of UAs decreased by water-storage or TC,3,35,37 while other studies did not find a significant change.5,38 These conflicting findings may be explained by different experimental setups, such as the testing method, aging time and conditions, and the thickness of the smear layer.27,39 A thicker hybrid layer and resin tags in ER mode may be able to prevent damage caused by mechanical forces under TC.2 ...
Objective:
To investigate the effect of extended air-drying time on the microshear bond strength (MSBS) of universal adhesives to enamel.
Materials and methods:
The distal and mesial specimens from third molars were wet-ground and randomly assigned to three groups according to adhesives tested (n = 60): Clearfil Bond Universal, Gluma Bond Universal, and G-Premio Bond. The adhesives were applied in etch-and-rinse or self-etch modes, followed by air-drying for 5, 15, or 25 s. Composite buildups were constructed and subjected to the MSBS test after 24-h or thermocycling. MSBS results were evaluated using a four-way ANOVA. The thickness of the adhesive layer and the degree of solvent evaporation were further evaluated.
Results:
At 24-h, MSBS of G-Premio Bond significantly improved with the 25 s air-drying in both of the etching modes when compared to the 5 s air-drying. After thermocycling, the extended air-drying did not produce a significant difference on the MSBS, regardless of the application strategy. Extended air-drying (25 s) evaporated almost all of the volatile part of Gluma Bond Universal and G-Premio Bond.
Conclusions:
Extended air-drying times increased solvent evaporation but did not contribute to the bonding effectiveness of the adhesives, regardless of the etching mode.
Clinical significance:
Air-drying applications for more than 5 s had no significant effect on enamel bonding performance of universal adhesives.
... When talking about the stability of the bond strength in the self-etch technique, studies show that only slight drops in bond strength levels are observed using this mode [5] . Other authors mention that the adhesive quality in the self-etching technique is very dependent on the universal adhesive used [17,30,31] , for example, in a study it shows that the Scotchbond Universal adhesive showed greater adhesion strength in a self-etching technique, compared to All-Bond Universal adhesive, which obtained its best performance from an acid etching technique [10] . Another way to improve the adhesive quality in this technique is by using zoledronate-based primers, just before performing the adhesive protocol for this technique as this will cause less degradation of the resin-tooth interface, however in an acid etching technique the use of this type of primer could be counterproductive [32] . ...
Introduction: Adhesive dentistry faces complex clinical situations, which require the dentist to be able to choose the best adhesive protocol offered by universal adhesives. Objective: To present current information about the performance in bond strength according to the etching technique used in universal adhesives, evaluating the total etching technique, selective enamel etching, self-etch technique and bonding used in special clinical situations. Methodology: A search was carried out in the PubMed electronic database using as keywords "universal adhesive", "total etch technique", "selective enamel etching", "self-etch". Results: In the total acid etching technique, the acid gel to be used must be considered, as well as the type of adhesive. Selective enamel etching seeks to obtain that strong anchorage to the enamel that can only be obtained using a phosphoric acid gel, allowing the self-etching quality of the adhesive to act on dentin. The use of the self-etch technique will simplify the clinical steps in the adhesive protocol, however adhesion may decrease consequently. If there is any type of alteration in the substrate to be adhered, the resulting adhesive force could be modified, regardless of the adhesive technique used. Conclusion: Universal adhesives will allow the clinician to choose the adhesive protocol, depending on the clinical situation they are facing, as long as the clinician pays attention to aspects such as the acid gel to be used, the adhesive application time and the conditions of the substrate to adhere.
... After establishing these basic principles, the research group extended fatigue bond strength evaluations to cover many factors with an influence on tooth bonding, such as the influence of acidic functional monomers [34], double coating [35], the oxygen inhibition layer [36,37], shortened application times of adhesive systems [38], the etching mode for universal adhesives [39][40][41], application of different etching agents [42][43][44][45], silver diamine fluoride pretreatment [46], the prismatic structure of enamel [47], surface moisture [48] or smear layer of substrates [49], the use of different adhesive systems [50,51], phosphoric acid pre-etching [52][53][54], selfadhesive restorative materials [55], short fiber resin composites [56], and water storage of specimens [57]. These evaluations did provide new insights, but also raised methodological suggestions and questions from researchers. ...
Numerous laboratory evaluations have been conducted since Dr. Rafael Bowen introduced a method for determining the bond strengths of adhesive systems to dental substrates in 1965. Most of the past studies have been conducted using static bond strength tests, such as shear and tensile bond strength testing with either macro or micro sized specimens. These static bond strength tests are conducted using a monotonically increasing load in which stress is applied continuously until failure occurs. Although the type of stress that develops in static bond strength tests is not typically encountered in clinical situations, over the years clinicians have based their choice of adhesive systems for use in daily practice on the results of such tests. However, some well-known researchers have reported that the results obtained from static bond strength testing may have limited clinical relevance and should not be used only by themselves to make recommendations for clinical use. In clinical situations, restorations undergo cyclic stress during mastication at stress levels well below the breaking stress used in static bond strength tests. Thus, dynamic bond strength tests, using cyclic loading, should be more clinically relevant than static bond strength tests. Over 15 years, a testing method designed to assess fatigue bond strengths of dental adhesive systems has been developed through inter-collegial and international collaborative efforts. This review discusses the development of fatigue bond strength testing methodology, provides both a historical perspective and current information regarding available testing data for all categories of adhesive systems to enamel and dentin and perspectives on the future development of both adhesive systems and testing methods.
... Human dentin was more frequently used (74.7%), followed by human enamel (13.8%), bovine dentin (12.6%), and bovine enamel (2.3%); seven studies investigated both the dentin and enamel substrates [23,25,48,77,88,96,99]. Concerning the surface treatment applied to dentin/enamel prior bonding, the majority of studies used a #600-grit SiC abrasive paper (56.3%) or a sequence of SiC grits (17.0%); the other studies used distinct methods including the application of diamond burs of medium, fine or extra-fine grit size (9.2%), ...
Objectives: This review evaluated the effects of the acidic composition of self-etch (SE) adhesives at the long-term bond strengths to dentin and enamel.
Data: The review followed the PRISMA Extension Statement for network meta-analysis. Studies were identified by a systematic search in PubMed, Web of Science, and Scopus databases.
Study selection: The inclusion criteria were in vitro studies that evaluated bond strength data of samples analyzed at both immediate and long-term (after aging simulation) periods and that were bonded to sound dentin/enamel using SE adhesives, with at least one group of adhesives being based on 10-MDP (10-methacryloyloxy-decyl-dihydrogen-phosphate; control) and the other group being comprised of alternative acidic monomers. Statistical analyses were conducted using two methods: standard pairwise meta-analysis (SPMA) and Bayesian network meta-analysis (NMA). Heterogeneity was assessed by using the Cochran Q test and I² statistics.
Results: From 5220 studies identified, 87 met the eligibility criteria and 83 were meta-analyzed. Seventeen adhesives were based on 10-MDP and 44 systems were based on alternative acids. The resin-dentin/enamel bonds were predominantly reduced after aging (∼84% of cases). From the SPMA findings, the following acidic compositions showed lower bond strength values (effect size: mean difference [MD] with 95% confidence interval [95% CI]) than 10-MDP: 4-META (MD -4.99, 95% CI: -7.21, -2.78; p<0.001); sulfonic acids (MD -9.59, 95% CI -12.19, -6.98; p<0.001); unspecified phosphate esters (MD -8.89, 95% CI -17.50, -0.28; p=0.04); or mixed acids (MD -11.0, 95% CI -13.62, -8.38; p<0.001). The dental bonds were benefited from the presence of 10-MDP upon longer aging (>6 months). From the NMA probabilistic findings, adhesives based on 10-MDP and phosphonic acids ranked as having the best and the worst bonding potential to dentin, respectively. More than one composition (phosphonic acids and mixed acids) ranked similarly to 10-MDP in enamel. The studies scored as having moderate risk of bias (58.6%), followed by low (39.1%) and high (2.3%) risk of bias.
Conclusion: 10-MDP is an outstanding acidic monomer that contributes to higher bonds to dentin at the long-term. In enamel, there is no evidence that one acidic composition prevails over the other.
Clinical significance. The acidic composition of SE adhesives affects the resistance of dental bonds after simulated aging, with 10-MDP playing a significant role in the adhesion to dentin but not to the enamel.
Registration number. This report is registered at the Open Science Framework (osf.io/urtdf).
... 11 In addition, the thickness of the smear layer decreases with the fine grit abrasives. 15,29 Using a finishing bur for the completion of the preparation 30 and the application of additional polishing procedures to preparations 5 have been previously suggested to enhance the wettability and adhesion. However, the use of the polishing disc has a limited extent in posterior complex partial crown preparations. ...
Aim:
The aim of this study was to evaluate the influence of dentin surface preparation with coarse diamond, extra-fine diamond, and polishing discs on the shear bond strength (SBS) of two resin cements (RCs) to dentin.
Materials and Methods:
Sixty-six recently extracted human mandibular third molar teeth that were free of cracks, caries, or restorations were collected. Sixty teeth were used for the SBS test. The occlusal part of the crowns was cut to expose mid-coronal dentin. The teeth were divided into three dentin preparation groups: coarse diamond (Meisinger, Germany), extra-fine diamond, and polishing discs (SofLex, 3MESPE, USA), and further conventional RC combined with a self-etch adhesive (Panavia F2.0/ED Primer II, Kuraray, Japan) or self-adhesive RC (Maxcem Elite, Kerr, USA) subgroups (n = 10). Sixty composite resin blocks were prepared (diameter: 3 mm, height: 4 mm) and bonded to the teeth according to the groups. The SBS test was performed with a universal testing device. Six teeth were used for the observation of prepared dentin surfaces and the resin–cement dentin interfaces using field emission scanning electron microscopy (Mira 3 XMU, Tescan). Statistical analyses were performed using the Mann–Whitney U and Kruskal–Wallis tests (P < .05).
Results:
Panavia F2.0/ED Primer II exhibited significantly higher SBS values for coarse and extra-fine diamond than for the polishing discs (P <.05). Regarding Maxcem Elite, no significant difference was observed for the preparation methods (P > .05). Panavia F2.0/ED Primer II had higher bond strength than Maxcem Elite for the dentin surface prepared with the coarse diamond (P <.05). The differences were not significant for the extra-fine diamond and the polishing disc groups (P > .05).
Conclusion:
The use of polishing discs did not increase the SBS of the RCs to the dentin.
... Active application (rubbing action) of the self-etch adhesive was done for 20 seconds. The penetration of resin monomers found in adhesives can interfere with collagen in the dentin smear (Takamizawa et al, 2018). Scanning electron microscope observations of treated dentin surfaces in self-etch mode showed that, compared to those inactively applied, actively applied adhesives would dissolve a certain amount of the smear layer. ...
Restoration after endodontic treatment is as important as root canal therapy for clinical success. Evolution of adhesive dentistry strongly aided in the conservation of tooth structure and reinforcement of the restored teeth. Self-etch adhesives has evolved aiming to reduce the technique sensitivity and simplifying the steps needed for bonding (one or two steps). Dual cured self-etch adhesives were also introduced to be more chemically compatible with the resin composite restorations. Bulk-fill resin composites has also achieved great popularity due to the ease of application and being more time saving. These materials made the direct restoration of endodontically treated teeth more conservative, time saving and reliable. This research was performed to assess the clinical success of the restorations of the endodontically treated molars with remaining three walls restored using self-etch adhesives and bulk fill resin composite in comparison to conventional nanohybrid resin composite at a time intervals of 1week (baseline) , 3 ,6 and 12 months. In a randomized clinical trial, 40 patients with endodontically treated molars with remaining three walls received a restorative intervention with either (Xtra-Fil) bulk fill resin composite or (Grandio) nano hybrid resin composite applied in incremental technique.
... 4,6,8,11,20,22,23 However, there is no consensus on the effect of SL type on the adhesive performance of self-etch adhesives. Two-step selfetch and strong or semi-strong 1-step self-etch adhesives do not appear to be substantially influenced by the type of SL. 8,24 In contrast, for mild or ultra-mild 1-step self-etch adhesives, the effect of SL type depends on the formulation and pH of the adhesive. Previous studies have reported that thicker SLs have a negative effect of on the bond strength. ...
... The pH values of self-etch adhesives can significantly influence the dissolution of the SL and etching of the dentin surface. 24 Universal adhesives differ from each other in acidity; the bond strength to dentin along with the bond stability have been shown to depend on acidity. 5 Therefore, this study tested universal adhesives with quite different pH values: a semi-strong (GP; pH: 1.5) and an ultra-mild (SB; pH: 2.7) adhesive, as well as the reference mild twostep self-etch adhesive (SE), according to the classification by Van Meerbeek et al. 15 The higher pH of the ultra-mild universal adhesive (SB) would be expected to result in reduced etching ability, be less able to etch different SL types, and reduce demineralization of the dentin surface, which is beneficial for micromechanical interlocking. ...
... However, consistent with the findings of previous studies, SB showed a higher μTBS than the other universal adhesive, GP , for all SL types. 24 This might be explained by the differences in ingredients, such as solvent and functional mono- ...
Purpose: To evaluate the effects of different smear layers on the microtensile bond strength (μTBS) of a reference
two-step self-etch adhesive and two universal adhesives.
Materials and Methods: Mid-coronal dentin of 90 teeth was exposed and divided into three bur groups (coarse diamond, fine diamond, or tungsten carbide). Each bur-prepared group was further divided into three adhesive groups:
Clearfil SE Bond (SE, Kuraray Noritake), Single Bond Universal (SB; 3M Oral Care), and G-Premio Bond (GP, GC).
After adhesive application, 4-mm-thick resin composites were built up. Half of the teeth in each bur-adhesive group
were used in immediate μTBS testing, and the others were tested after thermal aging (n = 5). Rectangular sticks
were prepared using a low-speed diamond saw. For each tooth, 6 central sticks were used in the μTBS test. Statistical analysis was performed using three-way ANOVA and Bonferroni tests (α = 0.05).
Results: SE presented higher μTBS than universal adhesives and SB presented higher μTBS than GP regardless of
dentin surface preparation and thermal aging (p ˂ 0.05). For SE and SB, the tungsten carbide bur demonstrated
higher immediate and aged μTBS than did the extra-fine diamond bur (p ˂ 0.05). The immediate μTBS was similar
for GP with all bur types (p ˃ 0.05); the tungsten carbide and extra-fine diamond burs presented higher μTBS than
did the coarse-diamond bur after thermal aging (p ˂ 0.05).
Conclusion: Dentin surface preparation and adhesive type had significant effects on μTBS. The smear layer created
with an extra-fine diamond or tungsten carbide bur is favorable when mild and ultra-mild self-etch adhesives are used.
Keywords: smear layer, universal adhesive, self-etch adhesives, bond strength, microtensile bond strength.
... Generally, in single-step self-etching adhesives, functional monomers for etching, priming, and bonding are combined in one bottle [30]. Thus, there are worries related to whether these monomers in one-bottle can simultaneously perform the above functions adequately well [31]. ...
... It may derive from sample preparation and different bonding test. The elastic modulus of bonded composites, bonding surface area, the testing mode (shear or micro-shear), and the thickness of the smear layer have been determined to [27,31]. The PA might improve the infiltration of resin monomers and provide more uniform and thicker hybrid layers [33,34]. ...
Objectives
This study aimed to assess the effect of application time on the microshear bond strength (μSBS) of three universal adhesives in demineralized and sound enamel before and after aging.
Materials and methods
Bovine teeth (192) were prepared where buccal surfaces were ground and divided into two groups (sound enamel and demineralized enamel). The specimens in each group were divided into 12 subgroups by combining 3 adhesive agents (All-Bond Universal, Scotchbond Universal, and Tokuyama Universal Bond) × 4 adhesion strategy. Each adhesive was applied with either prolonged (PA) or reduced (RA) application time in etch-and-rinse or self-etch mode. Bonded composites were subjected to μSBS testing after 24-h or 2-year water storage. The results were evaluated using four-way ANOVA and Tukey’s post-hoc test (α = 0.05).
Results
The μSBS of adhesives to sound enamel in both etching modes was mostly similar to demineralized enamel, regardless of application time and aging time. At 24-h, all adhesives with PA in self-etch mode showed higher μSBS when compared with RA, except Tokuyama Universal Bond, but after 2-year aging, no significant difference was found in μSBS between RA and PA. The μSBS of adhesives with PA in etch-and-rinse mode depended on used adhesive and enamel condition compared to RA, regardless of μSBS testing time.
Conclusions
PA of adhesives did not reveal a significant difference in μSBS to enamel, regardless of substrate type and etching mode.
Clinical relevance
After 2-year aging, the bond strength of universal adhesives presented no significant difference between PA and RA treatments.
... Also, it presents a very low inherent adhesion to the underlying hard tissue. Thus, the mechanical properties of the adhesive material-smear complex may be lower than those of an interface without a smear layer, making it a possible cause of bond deterioration [14]. A previous study reported that the smear layer thickness did not affect the bonding strength of glass-ionomer adhesive material with different surface conditioners [15]. ...
This study assessed the effect of different smear layers and surface conditioning on microtensile bond strength to dentin of two different glass-ionomer cements (GICs). Third molar teeth without caries were collected for this study. The crowns of teeth were cut to reveal the mid-coronal dentin surface, and then the specimens were randomly assigned to three groups for surface preparation (#180-grit, 600-grit, and #3000-grit SiC paper). After surface grinding, the specimens were restored by Equia Forte or Fuji II LC (GC, Tokyo, Japan). A buildup of each material was made by free-hand on the dentin surfaces with or without a polyacrylic acid conditioner. GIC/dentin sticks were obtained after 1 week storage and then stressed using a universal testing device. The fractured surfaces were examined by a stereomicroscope. Statistical analyses were performed with three-way ANOVA and Tukey’s post-hoc test (p < 0.05). GIC type and conditioner application had a significant effect on µTBS (p < 0.001). The smear layer conditions did not affect µTBS of the GICs (p = 0.113). Only Equia Forte without conditioner showed significantly higher µTBS on the #3000-grit surface than on #180-grit and #600-grit surfaces. Equia Forte presented significantly lower µTBS than Fuji II LC, with or without conditioner. With conditioner application, both GICs showed significantly higher µTBS on the #180-grit surface. The effect of different smear layers on µTBS was dependent on GIC type and conditioner application. The effectiveness of the conditioner application to the bond strength depended on the smear layer composition.
