Surface characteristics of electrochemically oxidized implants and acid-etched implants: surface chemistry, morphology, pore configurations, oxide thickness, crystal structure, and roughness

PURPOSE: This study was undertaken to investigate surface properties of surface-modified titanium implants in terms of surface chemistry, morphology, pore characteristics, oxide thickness, crystal structure, and roughness. MATERIALS AND METHODS: An oxidized, custom-made Mg implant, an oxidized commercially available implant (TiUnite), and a dual acid-etched surface (Osseotite) were investigated. Surface characteristics were evaluated with various surface analytic techniques. RESULTS: Surface chemistry showed similar fingerprints of titanium oxide and carbon contaminant in common for all implants but also revealed essential differences of the elements such as about 9 at% Mg for the Mg implant, about 11 at% P for the TiUnite implant and about 12 at% Na for the Osseotite implant. Surface morphology of the Mg and TiUnite implants demonstrated a duplex oxide structure, ie, an inner barrier layer without pores and an outer porous layer with numerous pores, whereas the Osseotite implant revealed a crystallographically etched appearance with pits. The diameter and depth of pores/pits was < or = 2 microm and < or = 1.5 microm in the Mg implant, < or = 4 microm and < or = 10 microm in the TiUnite implant, and < or = 2 microm and < or = 1 microm in the Osseotite implant, respectively. Oxide layer revealed homogeneous thickness, about 3.4 microm of all threads in the Mg implants. On the contrary, TiUnite showed heterogeneous oxide thickness, about 1 to 11 microm, which gradually increased with thread numbers. Crystal structure showed a mixture of anatase and rutile phase for the Mg implants. With respect to roughness, Sa showed 0.69 microm in the Mg implant, 1.35 microm in the TiUnite implant, and 0.72 microm in the Osseotite implant. CONCLUSIONS: Well-defined surface characterization may provide a scientific basis for a better understanding of the effects of the implant surface on the biological response. The surface-engineered implants resulted in various surface characteristics, as a result of different manufacturing techniques.     

Resonance frequency and removal torque analysis of implants with turned and anodized surface oxides

The present experimental study was designed to address two issues. The first was to investigate whether oxide properties of titanium implants influenced bone tissue responses after an in vivo implantation time of six weeks. If such a result was found, the second aim was to investigate which oxide properties are involved in such bone tissue responses. Screw-shaped implants with a wide range of oxide properties were prepared by electrochemical oxidation methods, where the oxide thickness varied in the range of 200 nm to 1000 nm. The surface morphology was prepared in two substantially different ways, i.e. barrier and porous oxide film structures. The micropore structure revealed pore sizes of 8 microm in diameter, with a range in opening area from 1.27 microm 2 to 2.1 microm 2. Porosity ranged from 12.7% to 24.4%. The crystal structures of the titanium oxide were amorphous, anatase and a mixture of anatase and rutile type. The chemical compositions consisted mainly of TiO2. Surface roughness ranged from 0.96 microm to 1.03 microm (Sa). Each group of test samples showed its own, defined status with respect to these various parameters. The oxide properties of turned commercially pure titanium implants were used in the control group, which was characterized by an oxide thickness of 17.4 +/- 6.2 nm, amorphous type in crystallinity, TiO2 in chemical composition, and a surface roughness of 0.83 microm (Sa). Bone tissue responses were evaluated by resonance frequency measurements and removal torque tests that were undertaken six weeks after implant insertion in rabbit tibia. Implants that had an oxide thickness of approximately 600, 800 and 1000 nm demonstrated significantly stronger bone responses in the evaluation of removal torque values than did implants that had an oxide thickness of approximately 17 and 200 nm (P < 0.05). However, there were no difference between implants with oxide thicknesses of 17 and 200 nm (P = 0.99). It was concluded that oxide properties of titanium implants, which include oxide thickness, micropore configurations and crystal structures, greatly influence the bone tissue response in the evaluation of removal torque values. However, it is not fully understood whether these oxide properties influence the bone tissue response separately or synergistically.     

Improvement of osseointegration of titanium dental implant surfaces modified with CO ions: a comparative histomorphometric study in beagle dogs

The aim of this study was to compare carbon-oxygen (CO) ion implantation as a surface treatment with diamond-like carbon and commercially treated implants, including double acid-etched (Osseotite), oxidized (TiUnite) and sandblasted and acid-etched (SLA), using machine-turned titanium implants as control. A total of 72 dental implants divided into 6 groups were placed in the mandibles of 12 beagle dogs. Evaluation was performed by conventional light transmission microscopy and environmental scanning electron microscopy (ESEM). The histological results obtained via ESEM demonstrated bone-implant contact percentage (%BIC) for implants treated with CO ion implantation of 61% and 62% at 3 and 6 months, respectively. At the same time points, the values were 48% and 45% for double acid-etched, 46% and 52% for sandblasted and acid-etched, 55% and 46% for oxidized, and 33% and 49% for machine-turned titanium control implants. Values of %BIC were statistically significantly higher in implants treated with CO ion implantation compared to the commercially treated implant group (p=0.002 and p=0.025) and the control implants (p=0.001 and p=0.032) at 3 and 6 months, respectively. No significant differences were observed between the three groups of commercially treated implants. The larger %BIC of the ion-implanted group was observable at an early stage.     

Histologic evaluation of bone response to oxidized and turned titanium micro-implants in human jawbone

PURPOSE: To evaluate the human bone tissue response to 2 surfaces (oxidized or turned) on commercially available titanium implants. MATERIALS AND METHODS: Screw-type turned (control) and oxidized (test) micro-implants were manufactured in the same manner as commercially available turned and oxidized (TiUnite, Br?nemark System) implants. The thickness of the oxide layer of the test implants was on average 10 microm, corresponding to the oxide thickness of the apical part of the TiUnite implant. Twenty patients received 1 test and 1 control micro-implant each during implant surgery. Before placement, the surface topography of the implants was characterized with an optical confocal laser profilometer. After a mean healing period of 6.6 months in the maxilla and 3.5 months in the mandible, the micro-implants and surrounding tissue were removed with a trephine bur. Histologic sections were produced, and the specimens were analyzed histomorphometrically. RESULTS: Surface roughness and enlargement were greater for the oxidized implants than for the turned implants. All micro-implants, except for 2 controls, were found to be clinically stable at the time of retrieval. Histomorphometric evaluation demonstrated significantly higher bone-to-implant contact for the oxidized implants, whether placed in the maxilla or in the mandible. Significantly more bone was found inside the threaded area for the oxidized implants placed in the mandible and maxilla, but there was no difference between implants with regard to position (maxilla or mandible). DISCUSSION: The stronger bone response to the oxidized implants may have contributed to the fact that 2 control implants but no test implants were lost. The reason for these findings may depend on one or multiple differences of the surfaces between test and control implants: (1) the thicker oxide layer itself, (2) increased surface roughness, (3) different surface morphology in terms of porosity, or (4) change in crystal structure. CONCLUSION: The present histologic study in human jawbone demonstrated a significantly higher bone response for anodic oxidized titanium implants than for implants with a turned surface.     

Effects of tooth whitening and orange juice on surface properties of dental enamel

Objective

To study the effects of 6% H₂O₂ activated with LED light on surface enamel as compared to orange juice challenges in vitro.

Methods

A total of 40 human enamel discs were incubated in saliva overnight to allow pellicle formation and then divided into three groups: 15 for whitening treatments, 15 for orange juice immersions and 10 for normal saline controls. Baseline microhardness was measured with a microhardness Knoop indenter (50 g, 10 s) and surface topography was evaluated with a focus-variation 3D scanning microscopy. Enamel discs were treated with H₂O₂ or orange juice for 20 min each cycle for five cycles to simulate daily treatment with the products for 5 days. The discs were stored in saliva between treatment cycles. Microhardness and surface topography were evaluated again after treatments. Changes in microhardness and in surface area roughness (Sa), mean maximum peak-to-valley distance (Sz) and the developed surface area ratio (Sdr) were compared before and after treatments (t-test) and among groups (ANOVA).

Results

Enamel surface hardness decreased by 84% after orange juice immersion but no statistically significant changes were observed in the whitening and control groups. Surface topography changed significantly only in the orange juice group as shown by increased Sa (1.2 μm vs. 2.0 μm), Sz (7.7 μm vs. 10.2 μm) and Sdr (2.8% vs. 6.0%). No such changes were observed in the whitening and control groups.

Conclusion

In comparison to orange juice challenges, the effects of 6% H₂O₂ on surface enamel are insignificant. Orange juice erosion markedly decreased hardness and increased roughness of enamel.     

Improved retention and bone-tolmplant contact with fluoride-modified titanium implants

PURPOSE: The purpose of the present study was to investigate whether a fluoride modification of the titanium surface would have an effect on bone response after implantation. MATERIALS AND METHODS: Titanium-oxide-blasted titanium implants with and without fluoride modification were investigated in a rabbit tibia model. Quantitative analysis of surface roughness, biomechanical interlocking, and in vivo tissue reactions in rabbit bone at 1 and 3 months after placement were compared. RESULTS: The fluoride-modified test implants had a slightly smoother surface (Sa: 0.91 +/- 0.14 microm) than the unmodified control implants (Sa: 1.12 +/- 0.24 microm). Significantly higher removal torque values (85 +/- 16 Ncm vs 54 +/- 12 Ncm) and shear strength between bone and implants (23 +/- 9 N/mm2 vs 15 +/- 5 N/mm2) were measured for the fluoride-modified implants after 3 months. The histomorphometric evaluations demonstrated higher bone-to-implant contact for test implants at 1 month (35% +/- 14% vs 26% +/- 8%) and 3 months (39% +/- 11% vs 31% +/- 6%) after placement. DISCUSSION: Implant surface modification with fluoride may result in morphologic and physiochemical phenomena that are of significance for the bone response. Another possible explanation for the findings in the present study is that a surface modification changes the surface chemical structures to be more suitable for bone bonding. CONCLUSION: Based on the biomechanical and histomorphometric data, the fluoride-modified titanium implants demonstrated a firmer bone anchorage than the unmodified titanium implants. These implants achieved greater bone integration than unmodified titanium implants after a shorter healing time.     

A histomorphometric analysis of the effects of various surface treatment methods on osseointegration

PURPOSE: One major factor in the success and biocompatibility of an implant is its surface properties. The purposes of this study were to analyze the surface characteristics of implants after blasting and thermal oxidation and to evaluate the bone response around these implants with histomorphometric analysis. MATERIALS AND METHODS: Threaded implants (3.75 mm in diameter, 8.0 mm in length) were manufactured by machining a commercially pure titanium (grade 2). A total of 48 implants were evaluated with histomorphometric methods and included in the statistical analyses. Two different groups of samples were prepared according to the following procedures: Group 1 samples were blasted with 50-microm aluminum oxide (Al2O3) particles, and group 2 samples were blasted with 50-microm Al2O3, then thermally oxidized at 800 degrees C for 2 hours in a pure oxygen atmosphere. A noncontacting optical profilometer was used to measure the surface topography. The surface composition of the implants used and the oxide thickness were investigated with Rutherford backscattering spectrometry. RESULTS: The different preparations produced implant surfaces with essentially similar chemical composition, but with different oxide thickness and roughness. The morphologic evaluation of the bone formation revealed that: (1) the percentage of bone-to-implant contact of the oxidized implants (33.3%) after 4 weeks was greater than that of the blasted group (23.1%); (2) the percentages of bone-to-implant contact after 12 weeks were not statistically significantly different between the groups; (3) the percentages of bone area inside the thread after 4 weeks and 12 weeks were not statistically significantly different between groups. DISCUSSION AND CONCLUSION: This investigation demonstrated the possibility that different surface treatments, such as blasting and oxidation, have an effect on the ingrowth of bone into the thread. However, the clinical implications of surface treatments on implants, and the exact mechanisms by which the surface properties of the implant affect the process of osseointegration, remain subjects for further study.     

Does implant surface hydrophilicity influence the maintenance of surface integrity after insertion into low-density artificial bone?

ObjectiveTo evaluate the influence of hydrophilicity on the surface integrity of implants after insertion in low-density artificial bone and to determine the distribution of titanium (Ti) particles along the bone bed.MethodsForty-eight dental implants with different designs (Titamax Ex, Facility, Alvim, and Drive) and surface treatments (Neoporos® and Aqua?) were inserted into artificial bone blocks with density compatible with bone type III-IV. Hydrophobic Neoporos® surfaces were obtained by sandblasting and acid etching while hydrophilic Aqua? surfaces were obtained by sandblasting, acid etching, and storage in an isotonic 0.9% NaCl solution. The surface integrity was evaluated by Scanning Electron Microscope (SEM) and the surface roughness parameters (Sa, Sp, Ssk, Sdr, Spk, Sk, and Svk) and surface area were measured with Laser Scanning Confocal Microscopy before and after installation. Bone beds were inspected with Digital Microscopy and micro X-Ray Fluorescence (μ-XRF) to analyze the metallic element distribution along the bone bed.ResultsAcqua? implants had higher initial Sa and a pronounced reduction of Sa and Sp during insertion, compared to NeoPoros® implants. After insertion, Sa and Sp of Acqua? and NeoPoros® implants equalized, differing only between designs of Acqua? implants. Surface damage was observed after insertion, mainly in the apical region. Facility implants that are made of TiG5 released fewer debris particles, while the highest Ti intensity was detected in the cervical region of the Titamax Ex Acqua? and Drive Acqua? implants.SignificancePhysicochemical modifications to achieve surface hydrophilicity created a rougher surface that was more susceptible to surface alterations, resulting in more Ti particle release into the bone bed during surgical insertion. The higher Ti intensities detected in the cervical region of bone beds may be related to peri-implantitis and marginal bone resorption.     

Effects of implant geometry and surface treatment on osseointegration after functional loading: a dog study

summary  The purpose of this study was to evaluate the geometry and surface characteristics of osseointegration after functional loading by radiographic, periodontal and histomorphometric analyses. We analysed three groups of implants with different geometry and surface characteristics using experimental dogs. The control group received Brånemark implants (group 1). Group 2 and group 3 implants each had a 0·5-mm pitch height but differed in surface characteristics. Group 2 implants were machine surfaced and group 3 implants were thermally oxidized at 800 °C for 2 h in a pure oxygen atmosphere. For these experiments, which used a total of four healthy beagle dogs, the implants were randomly installed into the extracted first, second and third premolar positions. The animals received radiographic and clinical periodontal examinations at 6 and 12 months post-loading, and were then killed for histomorphometric analysis. The radiographic analysis showed that mean crestal bone resorption in the control group was greater than that observed in the experimental groups ( P  < 0·05). The percentage of bone-to-implant contact for group 3 (83·7%) was significantly higher than in groups 1 (74·4%) and 2 (75·0%) ( P  < 0·05). Overall, implant geometry and surface treatment affected the rate of crestal bone resorption and bone healing surrounding the dental implants.     

Oxidized, bioactive implants are rapidly and strongly integrated in bone. Part 1--experimental implants

OBJECTIVES: The study presented was designed to investigate the speed and the strength of osseointegration of oxidized implants at early healing times in comparison which machined, turned implants. MATERIAL AND METHODS: Screw-shaped titanium implants were prepared and divided into two groups: magnesium ion incorporated, oxidized implants (Mg implants, n=10) and machined, turned implants (controls, n=10). Mg implants were prepared using micro-arc oxidation methods. Surface oxide properties of implants such as surface chemistry, oxide thickness, morphology/pore characteristics, crystal structures and roughness were characterized with various surface analytic techniques. Implants were inserted into the tibiae of ten New Zealand white rabbits. After a follow-up period of 3 and 6 weeks, removal torque (RTQ), osseointegration speed (DeltaRTQ/Deltahealing time) and integration strength of implants were measured. Bonding failure analysis of the bone-to-implant interface was performed. RESULTS: The speed the and strength of osseointegration of Mg implants were significantly more rapid and stronger than for turned implants at follow-up periods of 3 and 6 weeks. Bonding failure for Mg implants dominantly occurred within the bone tissue, whereas bonding failure for turned implants mainly occurred at the interface between implant and bone. CONCLUSIONS: Oxidized, bioactive implants are rapidly and strongly integrated in bone. The present results indicate that the rapid and strong integration of oxidized, bioactive Mg implants to bone may encompass immediate/early loading of clinical implants.     

Bone reactions to oxidized titanium implants with electrochemical anion sulphuric acid and phosphoric acid incorporation

Background: The importance of the surface properties of implants for a successful osseointegration has been emphasized. It is generally known that bone response to implant surfaces is considerably related to the various surface properties. Purpose: The purpose of this study was to investigate bone tissue reactions to multifactorial biocompatibility of the surface oxide of electrochemically oxidized titanium implants. The ultimate objective was to improve surface quality, resulting in enhancement of clinical outcomes of osseointegrated implants. Materials and Methods: Three different surface types of commercially pure titanium (c.p. Ti) implants were prepared. Turned implants were used for controls and test implants were prepared by the micro arc oxidation (MAO) method, either in sulphuric acid (S implants) or in phosphoric acid (P implants). Implants were inserted in the femur and tibia of 10 mature New Zealand White rabbits. The bone response was evaluated by biomechanical tests, histology, and histomorphometry. The follow‐up time was 6 weeks. Results: The mean peak values of the removal torque showed significant differences between control and test S implants (p =.022) but showed no significant differences between control and test P implants (p =.195) or between test S and test P implants (p =.457). In addition, the histomorphometric comparisons of the bone‐to‐metal contact around entire implants demonstrated 186% increase in S implants (p =.028) and 232% increase in P implants (p =.028) compared with the paired control groups. Quantification of the bone area in the threads did not show any significant differences. Conclusions: The present results suggest that the primary mode of action in strong bone response to S implants is mechanical interlocking, and to P implants, it is biochemical interaction. It is possible that the phosphate groups in the titanium oxide of P implants provide potential chemical bonding sites for calcium ions and hydroxyapatite of the bone matrix during biologic mineralization.     

Immediate loading of dental implants supporting fixed partial dentures in the posterior mandible: a randomized controlled split-mouth study--machined versus titanium oxide implant surface

PURPOSE: A split-mouth study was conducted to compare dental implants with either machined or titanium oxide (TiO) surfaces immediately loaded with fixed partial dentures in the posterior mandible. MATERIALS AND METHODS: Ten patients with bilateral partial edentulism in the posterior mandible received 42 implants; 20 on the test (TiO) and 22 on the control (machined) side. The implants were loaded within 24 hours postsurgery. At implant placement the maximum insertion torque (IT) was recorded. Implant stability quotient (ISQ) was also evaluated at baseline (day 0) and 1, 2, 4, 12, 24, and 52 weeks following implant placement. The radiographic bone level (RBL) change was measured on periapical radiographs at baseline and 12 months after loading. Means for the 2 groups were compared by paired t test. RESULTS: The overall implant success rate was 95%. No implants were lost in the test group; 2 failed in the control group. The difference between the groups in RBL change after 1 year of function was not statistically significant (P = .224). However, average RBL change for machined implants in distal positions was significantly higher than for TiO surface implants in the same position (post-hoc comparison; P = .048). ISQ and peak IT values did not differ between the groups (P = .414 and P = .762, respectively). The high IT necessary to insert the implants did not seem to affect the RBL change (P = .203). CONCLUSIONS: No significant difference was observed between machined and TiO implant surface in terms of RBL change or ISQ, although TiO implants may provide a lower RBL change compared to machined implants when utilized in the distal position. Immediate loading of implants using fixed partial dentures in posterior mandible may be considered as a treatment option if implants are inserted with IT > or = 20 Ncm and ISQ > or = 60 into nonaugmented bone and loaded with light centric occlusal contact.     

Effects of a calcium phosphate coating on the osseointegration of endosseous implants in a rabbit model

Objectives: The aim of the present study was to evaluate a Ca–P coated implant surface in a rabbit model. The Ca–P surface (test) was compared to the titanium porous oxide surface (control) in terms of bone‐to‐implant contact (BIC) and removal torque value. Materials and methods: Two hundred and sixteen dental implants were inserted in the tibia and in the femur of 36 rabbits. One hundred and eight were represented by Ca–P oxidized surface implant and other 108 were titanium porous oxide surface modified implants. Each rabbit received six implants. Animals were sacrificed after 2, 4 and 9 weeks of healing. Each group included 12 rabbits. The femoral implant and the proximal implant of the tibia of each animal were subjected to the histologic analysis and the distal implants of the tibia underwent removal torque test (RTQ). Results: Histological analysis in terms of BIC and RTQ did not revealed any significant difference between the Ca–P oxidized surface and the oxidized surface at 2 and 4 weeks. At 9 weeks, the oxidized surface demonstrated better results in terms of RTQ in the tibia. Conclusion: In conclusion, findings from the present study suggested that the Ca–P coating had no beneficial effect in improving bonding strength at the bone–implant interface either at 2, 4 and 9 weeks. To cite this article:
Fontana F, Rocchietta I, Addis A, Schupbach P, Zanotti G, Simion M. Effects of a calcium phosphate coating on the osseointegration of endosseous implants in a rabbit model
Clin. Oral Impl. Res. 22 , 2011; 760–766
doi: 10.1111/j.1600‐0501.2010.02056.x     

Increased bone contact to a calcium-incorporated oxidized commercially pure titanium implant: an in-vivo study in rabbits

The aim of this study was to evaluate the bone response to an oxidized titanium implant (Ox) and a calcium-incorporated oxidized titanium implant (Ca). A blasted titanium implant (Bl) was used as control. The implants were topographically characterized using an optical interferometer and placed: one in each distal femoral metaphysis and two in each proximal tibial metaphysis in rabbits. The rabbits were killed 12 weeks after implant insertion, and the implants and their surrounding tissues were removed en bloc for histomorphometrical evaluations. Topographical evaluation revealed three different surfaces: average height deviation (S(a), microm) values for Ca:Ox:Bl implants were 0.3:0.6:0.9, developed surface area ratios (%) 17:44:31, number of summits per microm(2) 208:136:118, and core fluid retention index values 1.33:1.33:1.38. The mean percentages of bone contact to the implants placed in the tibia (Ca:Ox:Bl) were 47:30:34 and to the implants placed in the femur (Ca:Ox) 32:20. The mean percentages of surrounding bone area for the implants placed in the tibia were 40:47:37 and for the implants placed in the femur 43:46. A significant increase in bone contact was found for smooth (S(a) <0.5 microm) but more densely peaked calcium-incorporated oxidized implants when compared to slightly rougher (S(a)=0.5-1.0 microm) oxidized or blasted implants.     

The effect of two polishing pastes on the surface roughness of bis-acryl composite and methacrylate-based resins

STATEMENT OF PROBLEM: A highly polished restoration surface is necessary to promote a plaque-free environment. PURPOSE: The purpose of this study was to compare the surface roughness of 3 different bis-acryl composite-based and 3 different methyl methacrylate-based provisional crown and fixed partial denture resins after being polished with aluminum oxide and diamond paste. MATERIAL AND METHODS: Six different materials were used (Iso-Temp, Protemp II, Structer 2, Dentalon Plus, Tab 2000 Kerr, Temdent). A total of 180 specimens were fabricated: 30 specimens of each material using circular stainless steel molds 10 mm in diameter and 2 mm high. Each material was mixed and polymerized according to manufacturer's instructions. The bis-acryl composite specimens were polymerized with a laboratory light-initiating unit for 30 seconds on each side (400 to 525 nm, 75 W quartz-halogen light source). All specimens were kept in a water bath at 37 degrees C for 45 minutes. Ten specimens of each group were left as untreated controls, 10 specimens of each group were polished with the aluminum oxide paste (Composite Polish), and 10 specimens of each group were polished with the diamond paste (Insta glaze). Surface roughness was determined with a profilometer. The data were analyzed with one-way analysis of variance (Post Hoc Scheffe's S test) (P<.001). In addition, the profilometric evaluations photographic images were recorded with a scanning electron microscope to examine the surface roughness after polishing. RESULTS: The mean of the surface characteristics of the bis-acryl composites were 1.33 microm for aluminum oxide and 0.90 microm for diamond polishing paste; the mean of the results of the methyl methacrylate resins were 1 microm for aluminum oxide and 0.50 microm for diamond polishing paste. The difference between the mean values of bis-acryl resins groups and methacrylate-based resin groups were significant (P<.001). The difference between the subgroups of bis-acryl resins group (Iso-Temp, Protemp II, Structer 2) were not significant (P>.05). The difference between the subgroups of methacrylate-based resin group (Dentalon, Tab 2000, Temdent) were not significant (P>.05). CONCLUSION: Within the limitations of this study, single-phase polishing of the bis-acryl composites tested and the methacrylate resins tested with diamond-based paste produced a smoother surface than when polished with aluminum oxide paste.     

Implant Survival and Marginal Bone Loss at Turned and Oxidized Implants in Periodontitis‐Susceptible Smokers and Never‐Smokers: A Retrospective,Clinical, Radiographic Case‐Control Study

Background: Little is known about the long‐term outcome of oxidized surface oral implants, especially in periodontitis‐susceptible smokers. The aim of this study is to determine implant survival and marginal bone loss at turned and oxidized implants in smokers and never‐smokers with periodontitis. Methods: Forty smokers and 40 never‐smokers with experience of advanced periodontal disease, treated with implants 5 years previously, are included in this study. Groups were matched for sex, oral hygiene, and implant distribution, and patients were subgrouped by implant surface type (turned or oxidized). Results: The overall implant survival rate was 96.9% in never‐smokers and 89.6% in smokers. Compared with oxidized implants, turned implants failed more frequently in smokers. In smokers, mean (standard error of the mean) marginal bone loss at 5 years was 1.54 (0.21) mm at turned and 1.16 (0.24) mm at oxidized implants. In never‐smokers, significantly greater bone loss was found at oxidized implants, 1.26 (0.15) mm, than at turned implants, 0.84 (0.14) mm. Oxidized implants demonstrated similar bone loss for both groups. Turned implants lost significantly more bone in smokers. Compared with never‐smokers, the smokers’ likelihood ratio for implant failure was 4.68, 6.40 for turned and 0.00 for oxidized implants. Conclusions: The results of the study underscore the need for prevention and cessation of smoking. Turned implants failed more frequently and lost more marginal bone in smokers. In contrast, oxidized implants showed similar failure rates and bone loss in smokers and never‐smokers. Turned implants displayed less bone loss than oxidized implants in never‐smokers. Oxidized surface implants are more suitable for patients susceptible to periodontitis who smoke.     

Bioactivity of nanostructure on titanium surface modified by chemical processing at room temperature

PurposeRecently, there has been considerable interest in finding novel applications and functions for existing dental materials. We found that, at room temperature and atmospheric pressure, titanium oxide spontaneously generates nanostructures very similar to the “nanotubes” created by TiO₂ sputtering. The aim of this study was to evaluate the ability of this surface to affect the cellular osteogenic differentiation response.MethodsTitanium disks without and with a ‘nanosheet’ deposited on their surface were used as the control and test groups, respectively. Cell culture experiments were performed with SD rat bone marrow cells, which were seeded into microplate wells and cultured in media designed to induce osteogenic differentiation. We measured alkaline phosphatase (ALP) activity, osteocalcin (OCN) production, calcium deposition and Runx2 gene expression to assess the levels of differentiation.ResultsAfter 14 and 21 days, cellular ALP activity was significantly higher in the test group than in the control group. After 28 days, cells in the test group also showed significantly more calcium deposition and OCN production than those in the control group. There was significantly different expression of Runx2 mRNA in the test group compared to the control group after 3 days of culture.ConclusionIn conclusion, these data suggest that titanium implants modified by the application of nanostructures promote osteogenic differentiation, and may improve the biointegration of these implants into the alveolar bone.     

Effects of a cell adhesion molecule coating on the blasted surface of titanium implants on bone healing in the rabbit femur

PURPOSE: One strategy to improve implant osseointegration is to control the quality of the bone reaction at the implant-bone tissue interface using an implant coated with biologically active substances. The purpose of this study was to investigate the effect of a tetra-cell adhesion molecule (T-CAM) coating composed of 4 cell-adhesion molecules-an arginine-glycine-aspartic acid (RGD) sequence, a proline-histidine-serine-arginine-asparagine (PHSRN) sequence, a tyrosine-histidine sequence (YH), and a glutamic acid-proline-aspartic acid-isoleucine-methionine (EPDIM)-on the rough-surfaced titanium implant on peri-implant bone formation in the rabbit femur with poor local bone conditions and minimal primary stability. MATERIALS AND METHODS: Seven T-CAM-coated (blasted/T-CAM) and uncoated (blasted) implants with a rough surface (hydroxyapatite-blasted; Ra = 1.8 microm) were placed in slightly oversized beds of the metaphyses of the right and left femurs of 7 New Zealand White rabbits with light tactile pressure, and minimal primary stability was obtained. To evaluate the effects of T-CAM coating on the peri-implant bone healing response, histomorphometric analysis was performed 8 weeks after surgery. The 2 groups were compared using the Student t test, with a significance level of P < .05. RESULTS: Compared to uncoated blasted implants at 8 weeks of healing, the blasted/T-CAM implants showed a significantly greater amount of bone-implant contact (BIC; P < .01) and new bone formation in the zones 0 to 100 microm and 0 to 500 microm lateral to the implant surface (P < .05) in the medullary space. CONCLUSION: The T-CAM coating on the rough-surfaced titanium implants significantly enhanced peri-implant bone formation in rabbit femurs with poor local bone condition.     

Influence of a nanometer-scale surface enhancement on de novo bone formation on titanium implants: a histomorphometric study in human maxillae

In this prospective randomized controlled clinical study, small titanium implants were placed in posterior maxillae for the purpose of assessing the rate and extent of new bone development. Nine pairs of site evaluation implants were placed in posterior areas of maxillae and retrieved with trephine drills after 4 or 8 weeks of unloaded healing. The amount of bone in linear contact (%) with the implant surface was used to determine the osteoconductive potential of the implant surface. Implant surfaces were dual acid etched (n = 9) (controls) or dual acid etched and further conditioned with nanometer-scale crystals of calcium phosphate (n = 9) (test implants), and the surfaces were compared. The implants and surrounding tissues were processed for histologic analysis. The mean bone-to-implant contact value for the test surface was significantly increased over that of the control implants at both time intervals (P <.01). For the implants/patients included in this study, the addition of a nanometer-scale calcium phosphate treatment to a dual acid-etched implant surface appeared to increase the extent of bone development after 4 and 8 weeks of healing.