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In recent years, extensive studies have been continuously undertaken on the design of bioactive and biomimetic dental implant surfaces due to the need for improvement of the implant–bone interface properties. In this paper, the titanium dental implant surface was modified by bioactive vitamin D3 molecules by a self-assembly process in order to form...
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... The Ti/oxide samples were immersed in the prepared alendronate solution at 22 ± 1 • C for 24 h. The functionalized samples were then dried at 70 • C for 7 h to ensure the chemical stability of the coating [47]. Samples were then rinsed with Milli-Q ® water and absolute ethanol and dried in a nitrogen stream. ...
... The inhomogeneous-layered structure is evident for the Ti/oxide/alendronate surface (Figure 4a), as a consequence of the presence of electrochemically prepared oxide film on the Ti surface. It is well-known that the alendronate coating has no significant effect on the morphology due to its low thickness (one monolayer) [47]. The surface characterization (composition) of Ti/oxide/alendronate samples before and after immersion was performed using ATR-FTIR ( Figure 5). ...
The surface modification of dental implants plays an important role in establishing a successful interaction of the implant with the surrounding tissue, as the bioactivity and osseointegration properties are strongly dependent on the physicochemical properties of the implant surface. A surface coating with bioactive molecules that stimulate the formation of a mineral calcium phosphate (CaP) layer has a positive effect on the bone bonding process, as biomineralization is crucial for improving the osseointegration process and rapid bone ingrowth. In this work, the spontaneous deposition of calcium phosphate on the titanium surface covered with chemically stable and covalently bound alendronate molecules was investigated using an integrated experimental and theoretical approach. The initial nucleation of CaP was investigated using quantum chemical calculations at the density functional theory (DFT) level. Negative Gibbs free energies show a spontaneous nucleation of CaP on the biomolecule-covered titanium oxide surface. The deposition of calcium and phosphate ions on the alendronate-modified titanium oxide surface is governed by Ca2+–phosphonate (-PO3H) interactions and supported by hydrogen bonding between the phosphate group of CaP and the amino group of the alendronate molecule. The morphological and structural properties of CaP deposit were investigated using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and attenuated total reflectance Fourier transform infrared spectroscopy. This integrated experimental–theoretical study highlights the spontaneous formation of CaP on the alendronate-coated titanium surface, confirming the bioactivity ability of the alendronate coating. The results provide valuable guidance for the promising forthcoming advancements in the development of biomaterials and surface modification of dental implants.
... In accordance with the studies by K. Y. Law [53], obtaining a θ value under 90 • highlights the presence of a hydrophilic surface. Therefore, our results align well with the results reported in the literature, and they may indicate that the composite coatings based on MgZnHAp_Ch can be promising candidates for biomedical use due to their hydrophilic surface features [5,41,54,55]. ...
... In accordance with the studies by K. Y. Law [53], obtaining a θ value under 90° highlights the presence of a hydrophilic surface. Therefore, our results align well with the results reported in the literature, and they may indicate that the composite coatings based on MgZnHAp_Ch can be promising candidates for biomedical use due to their hydrophilic surface features [5,41,54,55]. ...
Hydroxyapatite doped with magnesium and zinc in chitosan matrix biocomposites have great potential for applications in space technology, aerospace, as well as in the biomedical field, as a result of coatings with multifunctional properties that meet the increased requirements for wide applications. In this study, coatings on titanium substrates were developed using hydroxyapatite doped with magnesium and zinc ions in a chitosan matrix (MgZnHAp_Ch). Valuable information concerning the surface morphology and chemical composition of MgZnHAp_Ch composite layers were obtained from studies that performed scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), metallographic microscopy, and atomic force microscopy (AFM). The wettability of the novel coatings, based on magnesium and zinc-doped biocomposites in a chitosan matrix on a titanium substrate, was evaluated by performing water contact angle studies. Furthermore, the swelling properties, together with the coating’s adherence to the titanium substrate, were also analyzed. The AFM results emphasized that the composite layers exhibited the surface topography of a uniform layer, and that there were no evident cracks and fissures present on the investigated surface. Moreover, antifungal studies concerning the MgZnHAp_Ch coatings were also carried out. The data obtained from quantitative antifungal assays highlight the strong inhibitory effects of MgZnHAp_Ch against C. albicans. Additionally, our results underline that after 72 h of exposure, the MgZnHAp_Ch coatings display fungicidal features. Thus, the obtained results suggest that the MgZnHAp_Ch coatings possess the requisite properties that make them suitable for use in the development of new coatings with enhanced antifungal features.
... Biomaterials play an important role in orthopaedic and dental implant applications. Pure titanium and its alloys are the most used materials for permanent implants in contact with bone thanks to their fatigue resistance, low elastic modulus, stable chemical properties, and good biocompatibility [1] However, problems such as aseptic loosening and peri-implant microbial infection may lead to implant failure. The typical way of treating infections is antibiotic therapy through oral administration, which can often lead to the development of antibioticresistant bacteria and thus be ineffective, especially if bacteria are able to evolve in the biofilm form [2,3]. ...
... The CPE impedance is defined as Z CPE = 1/[Q(jω) n ], where Q is the frequency-independent constant, n is the CPE exponent representing the degree of non-ideal capacitor behaviour, and ω is the angular frequency [59,60]. The values of the interfacial capacitance, C were calculated using Brug's equation [62], where R s is the solution resistance, and are listed in Table 3: For unmodified titanium alloy, the impedance values of the alloy | solution interface are governed by the surface oxide film that spontaneously forms on the alloy, i.e., the elements in EEC correspond to the structure of bi-layered oxide film [23,[63][64][65][66]. The high/medium frequency time constant (R 1 -CPE 1 ) describes the properties of the outer part of the oxide film, while the low-frequency time constant (R 2 -CPE 2 ) describes the properties of the inner part of the barrier oxide film (schematically shown in Figure 6b). ...
Calcium phosphate-based (CaP) bioceramic materials are widely used in the field of bone regeneration, both in orthopaedics and in dentistry, due to their good biocompatibility, osseointegration and osteoconduction. The formation of CaP coatings on high-strength implant materials such as titanium alloys combines the superior mechanical properties of metals with the osteoconductive properties of CaP materials. In this work, the electrochemically assisted deposition of CaP coatings on the titanium alloy, TiAlNb, which is commonly used commercially as an implant material in orthopaedic devices, was examined. The barrier properties (electronic properties) of unmodified and CaP-modified titanium alloy were tested in situ in a simulated physiological solution, Hanks’ solution, under in vitro conditions of real implant applications using electrochemical impedance spectroscopy (EIS). The morphology and microstructure of the obtained CaP deposit were characterised by scanning electron microscopy (SEM) and chemical composition was assessed by energy dispersive X-ray spectroscopy (EDS) and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). The aim was to investigate the effect of calcium phosphate CaP coating on the corrosion resistance of the titanium TiAlNb alloy and to understand better the deposition process in the production of bioactive functional coatings on metallic implant materials.
... This finding can be explained by the titanium dissolution observed by Katic et al. (2019) [45] during the electrochemical deposition of calcium phosphate on the titanium surface, when the authors found irregularities in the deposition at low cathodic potential, promoting the formation of tiny pores. When the calcium phosphate is deposited after titanium oxidation, this primary layer acts as a possible protection barrier against titanium degradation during the cathodic potentials but with a partial dissolution, explaining the difference between the isolated titanium oxide layer of Ti/TiO 2 and the multi composition coating of Ti/TiO 2 /CaP OCP, which decrease from 0.250 V to 0.058 V. ...
Titanium (Ti) and its alloys are widely used in biomedical applications due to their excellent mechanical properties and biocompatibility. However, they are a concern due to the possibility of cytotoxic effects coming from the degradation products. This degradation occurs by the combined action of corrosion and mechanical wear of these materials, which are released in the biological environment by the biomaterial implanted. The present article aims to investigate a new route to improve electrochemical and tribological performance with surface modification. Regarding the deposition of a protective layer on the surface, it consists of titanium oxide (TiO2) and calcium phosphate (CaP). Both coatings were performed by chronoamperometric methods with titanium oxidation at 1 V and calcium phosphate reduction at −1.5 V. The corrosion and tribocorrosion tests demonstrated the effective combination of TiO2 and CaP layer to protect the Ti substrate. Furthermore, this coating combination reduced corrosion degradation and mechanical wear in PBS, simulating a physiological environment. Additionally, it was observed that this combination of coating decreased the dissipated energy, and consequently, the wear decreased during sliding tests. All these findings indicate the protective behavior of the TiO2 and CaP layer during the tribocorrosion tests.
... Turning now to the photoemission spectra around O 1s atomic levels in alendronate and collagen molecules (Figure 3a,b), the three characteristic fitting components were assigned to oxygen bonded in O=P/O=C (532.4 eV), HO-P (533.7 eV) and HO-C (534.3 eV) configuration [13,46,47], in addition to the O atoms bonded to titanium (peak at BE of 531.0 eV) [13,46]. Some additional contributions are visible in the O 1s spectra (marked with *), reflecting the presence of surface species, most likely in the form of adsorbed water molecules [48] or fluorine contamination [49]. with *), reflecting the presence of surface species, most likely in the form of adsorbed water molecules [48] or fluorine contamination [49]. ...
... Some additional contributions are visible in the O 1s spectra (marked with *), reflecting the presence of surface species, most likely in the form of adsorbed water molecules [48] or fluorine contamination [49]. with *), reflecting the presence of surface species, most likely in the form of adsorbed water molecules [48] or fluorine contamination [49]. ...
... The structure of the electrified implant/artificial saliva interface can be described by an electrical equivalent circuit (EEC) with two time constants that are characteristic for a two-layer oxide film, TiO 2 (inset in Figure 6d) [48,49]. Modelling results are given in Table 1. ...
The success of the osseointegration process depends on the surface characteristics and chemical composition of dental implants. Therefore, the titanium dental implant was functionalised with a composite coating of alendronate and hydrolysed collagen, which are molecules with a positive influence on the bone formation. The results of the quantum chemical calculations at the density functional theory level confirm a spontaneous formation of the composite coating on the titanium implant, ∆G*INT = −8.25 kcal mol−1. The combination of the results of X-ray photoelectron spectroscopy and quantum chemical calculations reveals the structure of the coating. The alendronate molecules dominate in the outer part, while collagen tripeptides prevail in the inner part of the coating. The electrochemical stability and resistivity of the implant modified with the composite coating in a contact with the saliva depend on the chemical nature of alendronate and collagen molecules, as well as their inter- and intramolecular interactions. The formed composite coating provides a 98% protection to the implant after the 7-day immersion in the artificial saliva. From an application point of view, the composite coating could effectively promote osseointegration and improve the implant’s resistivity in contact with an aggressive environment such as saliva.
... For TiO2 flat surfaces with adsorbed PSS and PDADMA polyions, Figure 6b, two time constants are attributed to the outer and inner part of the surface polyelectrolyte coating formed over spontaneous TiO2 oxide film. The EEC employed was previously reported for covered titanium metal materials [51][52][53][54]. ...
... For TiO 2 flat surfaces with adsorbed PSS and PDADMA polyions, Figure 6b, two time constants are attributed to the outer and inner part of the surface polyelectrolyte coating formed over spontaneous TiO 2 oxide film. The EEC employed was previously reported for covered titanium metal materials [51][52][53][54]. ...
In this study, the surface properties of Ti/TiO2 substrate before and after the adsorption of polyelectrolytes were investigated. As model polyelectrolytes, strongly charged polycation poly(diallyldimethylammonium) (PDADMA) and strongly charged polyanion poly(4-styrenesulfonate) (PSS) were used. Initially, the bare titanium substrate was characterized by means of ellipsometry, atomic force microscopy (AFM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and measurements of inner surface potential using crystal electrode (CrE). It was shown that the substrate surface is very smooth with the roughness of 3.5 nm and oxide layer thickness of 3.8 nm. After the adsorption of PDADMA and PSS, polyelectrolyte-coated titanium surface was examined using the above-mentioned methods under the same conditions. It was found that both PDADMA cations and PSS anions form a stable polymeric nanofilm on Ti/TiO2 surface that partially covers the surface, without significant impact on the surface roughness. The corrosion protection effectiveness values indicate that the corrosion properties were greatly enhanced upon polyion adsorption and polyelectrolyte coating formation on the flat TiO2 surface. The obtained results were additionally confirmed by inner surface potential measurements. According to the methods employed, PDADMA nanofilm modification offers enhanced corrosion protection to the underlying titanium material in sodium chloride electrolyte solution.
... Applying bioactive molecules, such as cholecalciferol/vitamin D3 or silicon-doped ti-87 tanium dioxide (Si-doped TiO 2 ) nanotubes, onto titanium dental implants improves the corrosion resistance against aggressive oral cavity fluids and facilitates osteoblastic bone cell adhesion [31][32][33]. Furthermore, titanium implants treated with liquid plasma rich in growth factors (PRGF) mediated efficient osseointegration, bone regeneration, and higher BIC values when compared to the control untreated implant [34][35][36]. ...
Background:
Bioactive chemical surface modifications improve the wettability and osseointegration properties of titanium implants in both animals and humans. The objective of this animal study was to investigate and compare the bioreactivity characteristics of titanium implants (BLT) pre-treated with a novel bone bioactive liquid (BBL) and the commercially available BLT-SLA active.
Methods:
Forty BLT-SLA titanium implants were placed in in four foxhound dogs. Animals were divided into two groups (n = 20): test (BLT-SLA pre-treated with BBL) and control (BLT-SLA active) implants. The implants were inserted in the post extraction sockets. After 8 and 12 weeks, the animals were sacrificed, and mandibles were extracted, containing the implants and the surrounding soft and hard tissues. Bone-to-implant contact (BIC), inter-thread bone area percentage (ITBA), soft tissue, and crestal bone loss were evaluated by histology and histomorphometry.
Results:
All animals were healthy with no implant loss or inflammation symptoms. All implants were clinically and histologically osseo-integrated. Relative to control groups, test implants demonstrated a significant 1.5- and 1.7-fold increase in BIC and ITBA values, respectively, at both assessment intervals. Crestal bone loss was also significantly reduced in the test group, as compared with controls, at week 8 in both the buccal crests (0.47 ± 0.32 vs 0.98 ± 0.51 mm, p < 0.05) and lingual crests (0.39* ± 0.3 vs. 0.89 ± 0.41 mm, p < 0.05). At week 12, a pronounced crestal bone loss improvement was observed in the test group (buccal, 0.41 ± 0.29 mm and lingual, 0.54 ± 0.23 mm). Tissue thickness showed comparable values at both the buccal and lingual regions and was significantly improved in the studied groups (0.82-0.92 mm vs. 33-48 mm in the control group).
Conclusions:
Relative to the commercially available BLT-SLA active implants, BLT-SLA pre-treated with BBL showed improved histological and histomorphometric characteristics indicating a reduced titanium surface roughness and improved wettability, promoting healing and soft and hard tissue regeneration at the implant site.
... It would be interesting to study the possible release of any ion to the surrounding tissue from analyzed dental implants, but it was not evaluated because it was not according to the aim of the study. However, further studies are necessary to study the biological mechanisms involved and the amount of ions that can be released from dental implants as well as the development of new materials and methods that improve the corrosion resistance of the implant surface and prevent the release of potentially dangerous ions [55]. ...
The use of dental implants has been increasing in the last years; however, their chemical composition is an important issue due to the fact that the implant surface may suffer a corrosion process, allowing the possibility of ions being released and resulting in a possible biological response. Thus, the aim of this study was to evaluate the morphological analysis of the surface and chemical composition of different implant types through an energy-dispersive X-ray spectrometry (EDX) system. Eight dental implant models from different manufacturers were analyzed using variable pressure scanning electron microscopy (VP-SEM) and EDX. The chemical composition and general characteristics of the structural morphology in different dental implant surfaces were analyzed randomly. Nitrogen was identified in two samples, while zirconium was observed in only one model. Aluminium was identified in five samples ranging between 4% and 11% of its composition. Regarding the morphological characteristics, two samples from the same manufacturer had the most irregular surface designed to increase the contact surface, while the others revealed their surfaces with roughness at the micrometric level with no major irregularities. In conclusion, despite the morphology of implants being similar in most of the analyzed samples, more than 50% of them, which are brands of implants available on the market, showed aluminium on the implant surface. Finally, STR (Bone level, Roxolid), DENT (Superline) and NEO (Helix GM) could be considered, among the analyzed samples, the safest implants from the point of view that no aluminium was detected in their chemical composition.
... The quantification of the anti-corrosion protection was performed by modeling of EIS data ( Figure 5) using the electrical equivalent circuit (EEC) presented as R s (C 1 (R 1 (CPE 2 R 2 ))); see the inset in Figure 5a. In the case of the as-received implant/artificial saliva interface, the chosen model represents the oxide film of the bi-layered structure formed on the titanium [69,70]. R s is the electrolyte resistance and (R 1 C 1 ) time constant, in the high/middle-frequency region, is associated with the outer part of the oxide layer with R 1 as the resistance and C 1 representing the capacitance of the oxide outer part. ...
Organophosphorus compounds, like bisphosphonates, drugs for treatment and prevention of bone diseases, have been successfully applied in recent years as bioactive and osseoinductive coatings on dental implants. An integrated experimental-theoretical approach was utilized in this study to clarify the mechanism of bisphosphonate-based coating formation on dental implant surfaces. Experimental validation of the alendronate coating formation on the titanium dental implant surface was carried out by X-ray photoelectron spectroscopy and contact angle measurements. Detailed theoretical simulations of all probable molecular implant surface/alendronate interactions were performed employing quantum chemical calculations at the density functional theory level. The calculated Gibbs free energies of (TiO2)10–alendronate interaction indicate a more spontaneous exergonic process when alendronate molecules interact directly with the titanium surface via two strong bonds, Ti–N and Ti–O, through simultaneous participation common to both phosphonate and amine branches. Additionally, the stability of the alendronate-modified implant during 7 day-immersion in a simulated saliva solution has been investigated by using electrochemical impedance spectroscopy. The alendronate coating was stable during immersion in the artificial saliva solution and acted as an additional barrier on the implant with overall resistivity, R ~ 5.9 MΩ cm2.
