Machined Surface Implants Research Articles

Biomechanical Investigation of the Osseointegration of Titanium Implants With Different Surfaces Placed With Allogeneic Bone Transfer.

Allogeneic grafts can be preferred to autogenous grafts in plastic and oral-maxillofacial surgery for vertical and horizontal bone deficiencies. Implant surface properties are an important factor in osseointegration. This study aims to evaluate the osseointegration levels of titanium implants with machined, sand-blasted, and acid-etched (SLA) and resorbable blast material (RBM) surfaces placed together with allogeneic bone tissue transplantations obtained from the tibia bone using biomechanical method. Twenty-five female Sprague-Dawley rats were included in the study. The rats were divided into groups in which machined (n=7), SLA (n=7), and RBM (n=7) surface implants were placed with the transplantation of bone taken from the tibia. Four rats (both left and right tibias) were used as donors. Grafts and implants were surgically placed in the corticocancellous part of the metaphyseal area of the tibia bones of rats. At the end of the 4-week experimental setup, all rats were killed, and the implants and surrounding bone tissue were subjected to biomechanical reverse torque analysis (N/cm). Sand-blasted acid-etched surface implants were observed to have higher biomechanical osseointegration levels than RBM and machined surface implants ( P <0.05). No statistical difference could be detected between the RBM and machined surface implants ( P >0.05). On the basis of the limited results of this study, it can be concluded that the osseointegration levels of SLA surface implants placed with allogeneic bone transplantation may be better than those of machined and RBM surface implants.

Evaluation of bone apposition on surface modified titanium implant in experimental animal model: A systematic review and meta-analysis.

To evaluate the response of peri-implant bone to smooth (machined) surface and surface-modified dental implants in healthy experimental animal models. Systematic electronic search was done for using PUBMED, SCOPUS, WEB OF SCIENCE, and EMBASE databases for potentially relevant records from the last 20 years. Duplicate screening and data extraction were performed to formulate the evidence tables and meta-analysis following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The outcome criteria were: 1. Bone Implant Contact (BIC) in percentage, 2. Removal Torque Values (RTV) in Ncm, 3. Implant stability Quotient (ISQ), Quality assessment was done using the ARRIVE (Animal Research: Reporting of In Vivo Experiments) guidelines and SYRCLE RoB (Systematic Review Centre for Laboratory Animal Experimentation Risk of Bias) tool. Results were expressed as pooled mean difference for the respective groups viz. sandblasted and acid etched, laser modified, acid etched and anodized surface. The surface modified implants revealed somewhat higher BIC over machined surface (P < 0.01). Forest plot were drawn for all the outcome variables. Within the limitations of this study, the authors found a higher degree of osseointegration pertaining to bone to implant interface, RTV, and implant stability quotient (ISQ) with surface modified procedures which seemed to promote bone formation around peri-implant tissue during the early stages of healing. After analyzing all 37 included publications for the outcome of interest (BIC%, RTV, ISQ), a positive outcome was obtained for both subtractive and additive implant surface modifying procedures over machined implant surfaces when the data were pooled together. More advanced research work on healthy animal models needs to be investigated to review the impact of surface modifications on dental implant osseointegration.

Three-Year Evaluation of the Influence of Implant Surfaces on Implant Failure and Peri-implantitis: A Double-Blind Randomized Controlled Trial with Split-Mouth Design.

To compare the onset of peri-implantitis, incidence of failure, and peri-implant marginal bone level changes between implants with a roughened surface and those with a machined/turned surface. All patients needing two dental implants of the same size on the left and right sides of the same arch, and not scheduled for immediate loading, were enrolled between October 2012 and February 2016. The patients were randomly allocated either to Nobel Biocare MKIII or Sweden & Martina Outlink2. Rough-surface implants and machined-surface implants were used from each company. After the preparation of two identical implant sites, each implant (rough or machined of the same group) was randomly allocated to the right and left sides of the same patient, following a split-mouth design. Outcome measures were peri-implantitis onset, incidence of failure, and peri-implant marginal bone level changes. Patients were followed up for 3 years after loading. One hundred fourteen patients were enrolled and treated; nine patients dropped out. Following an intent-to-treat analysis to avoid overestimation, proportions are given related to the initial number of 114 patients. Peri-implantitis incidence was 4.39% for machined implants (5/114), 0.88% for rough implants (1/114), 1.75% in the Nobel Biocare group (2 cases), and 3.51% in the Sweden & Martina group (4 cases). The failure rate was 1.75% in machined implants (2/114), 0.88% in rough implants (1/114), 0.98% in the Nobel Biocare group (1/114), and 1.85% in the Sweden & Martina group (1/114). No statistically significant differences in marginal bone loss were found comparing different surfaces, while marginal bone loss was significantly lower in Nobel Biocare than in Sweden & Martina implants. Based on the results of this study, no significant differences can be demonstrated in either peri-implantitis or failure rate or in marginal bone loss between rough and machined implants. Marginal bone loss was significantly worse in machined-surface Sweden & Martina than in rough-surface Nobel Biocare implants.

Enhancement of Bone Ingrowth into a Porous Titanium Structure to Improve Osseointegration of Dental Implants: A Pilot Study in the Canine Model.

A porous titanium structure was suggested to improve implant stability in the early healing period or in poor bone quality. This study investigated the effect of a porous structure on the osseointegration of dental implants. A total of 28 implants (14 implants in each group) were placed in the posterior mandibles of four beagle dogs at 3 months after extraction. The control group included machined surface implants with an external implant–abutment connection, whereas test group implants had a porous titanium structure added to the apical portion. Resonance frequency analysis (RFA); removal torque values (RTV); and surface topographic and histometric parameters including bone-to-implant contact length and ratio, inter-thread bone area and ratio in total, and the coronal and apical parts of the implants were measured after 4 weeks of healing. RTV showed a significant difference between the groups after 4 weeks of healing (p = 0.032), whereas no difference was observed in RFA. In the test group, surface topography showed bone tissue integrated into the porous structures. In the apical part of the test group, all the histometric parameters exhibited significant increases compared to the control group. Within the limitations of this study, enhanced bone growth into the porous structure was achieved, which consequently improved osseointegration of the implant.

Evaluation of decontamination methods of oral biofilms formed on screw-shaped, rough and machined surface implants: an ex vivo study

BackgroundTo evaluate the effect of several representative decontamination methods of oral biofilms on different implant surfaces.Material and methodsEleven participants wore a hard resin splint carrying 6 rough (GC Aadva® implant; 3.3-mm diameter, 8-mm length) or machined (not commercially available) surface implants for 4 days to accumulate dental plaque naturally on the titanium surfaces of the implants. Apart from surface roughness, the morphology of all implants was identical. After detaching the implants from the splints, the ability of the following decontamination methods—gauze soaked in saline (G), ultrasonic scaler (US), air abrasive (Air), rotary stainless steel instrument (Rot), and Er:YAG laser (Las)—to cleanse the contaminated implant surface for 1 min extra-orally was tested. The control (Cont) group did not receive any decontamination. Scanning electron microscopic (SEM) investigation of one participant’s samples was employed to examine the post-instrumented implant surface for qualitative analysis, and bacterial culture of the remaining 10 participants’ samples was performed to count the number of colony-forming units (CFU) for quantitative analysis. The experimental sequence was initially performed for the rough surface implants and then similarly repeated for the machined surface implants. Bacterial CFU counts among the six groups were analyzed using the Steel-Dwass test, and differences between rough and machined surface implants were determined using the Mann-Whitney U test.ResultsG and Rot eliminated most biofilms on machined surface implants according to SEM analysis. G, Air, and Rot removed significantly more of the biofilms on rough and machined surface implants compared with US according to CFU counts. Moreover, G significantly reduced more biofilms than Las on machined surface implants. The analysis between rough and machined surface implants showed that Cont, G, and US were better able to cleanse biofilms on machined surface implants compared with rough surface implants.ConclusionsGauze soaked in saline and rotary stainless steel instruments may be advantageous for cleansing contaminated implant surfaces based on the qualitative and quantitative analyses. In contrast, air abrasives were not shown to be preferable in the qualitative analyses. Additionally, apart from the Er:YAG laser, the reduction of biofilms assessed in both qualitative and quantitative analyses demonstrated that all decontamination methods were better at cleansing machined surface implants compared with rough surface implants.

Influence of Simvastatin-Strontium-Hydroxyapatite Coated Implant Formed by Micro-Arc Oxidation and Immersion Method on Osteointegration in Osteoporotic Rabbits.

PurposeEnhancing osteointegration of implants in osteoporosis patients is a necessity since implantations frequently fail in these patients. The aim of this work is to study how simvastatin-strontium-hydroxyapatite coated implants perform in rabbits with osteoporosis.Materials and MethodsCrystalline HA and Sr-HA oxide film were prepared through micro-arc oxidation. Surface characterization including morphology, roughness, element composition, phase composition, hydrophilicity were then evaluated. Simvastatin loaded on porous films through immersion, and the effects of coatings on osteointegration in osteoporotic rabbits were investigated. All samples were obtained after 4, 8 and 12 weeks of healing. Some of them were subjected to biomechanical tests and others were subjected to histological and histomorphometric analysis.ResultsCoatings exhibited a microporous network structure with appropriate roughness and high hydrophilicity. Compared to control HA and machined surface implants, simvastatin-Sr-HA coated implants exhibited marked improvements in osteointegration, which is characterized by a quicker mineralization deposition rate, good bone formation mode (large amount of contact osteogenesis and a small amount of distance osteogenesis) and increased bone-to-implant contact and pull-out strength.ConclusionThese biological parameters demonstrate the excellent osteoconductivity of simvastatin-Sr-HA coatings in the osteoporotic state. Overall, this suggests that simvastatin-Sr-HA coatings would be applicable in poor-quality bones of patients experiencing osteoporosis.

Evaluation of the three methods of bacterial decontamination on implants with three different surfaces.

The main goal of the treatment of the peri-implantitis is to decontaminate the surface of the implant, thereby enabling further treatment involving, e.g., guided bone regeneration. Since new implants of the rougher surface were introduced to the common dental practice, decontamination is even more difficult. The aim of the study was to evaluate 3 different methods of decontaminating implants with 3 different surfaces. A total of 30 dental implants with 3 different surface types (machined, sandblasted, and acid-etched (SLA) and hydroxyapatite (HA)-coated) were used in the study. Each group of implants was coated with Escherichia coli biofilm and cultivated. Afterwards, the implants were transferred to the jaw model and treated with a different method: sonic scaler mechanical debridement with a Woodpecker PT5 sonic scaler (1st group), and mechanical debridement with sonic scaler and with the combination with chemical agent Perisolv® (2nd group), and with Er:YAG laser treatment (3rd group). Each implant was treated with the specific method and sent for further microbiological evaluation. The highest level of decontamination was achieved for machined-surface implants and the lowest for HA-coated implants. The method with the highest biofilm reduction was the scaler and Perisolv® group. The highest level of decontamination of HA-coated implants were achieved for Er:YAG laser irradiation method. In the following paper, the superiority of combined chemical-mechanical method of decontaminating the surface of the implant on SLA and machined-surface implants was proved. On the contrary, Er:YAG laser irradiation was reported as the best option for decontamination of the HA-coated implants. In our opinion, it is a significant finding, revealing that the method of peri-implantitis management should be considered in accordance to the type of the surface of the implant (customized to the surface of the implant).

Antimicrobial Efficacy of Different Decontamination Methods as Tested on Dental Implants with Various Types of Surfaces.

BackgroundPeri-implantitis is an inflammatory reaction affecting both hard and soft tissues surrounding dental implants. This pathological condition is caused by a polymicrobial aggressive biofilm that colonizes the implant and abutment surface at the peri-implant crevice level. The present in vitro study evaluated different methods of implant surface decontamination and assessed whether the type of the implant surface influences the results.Material/MethodsThe study was conducted in an in vitro model of peri-implantitis using 30 implants. The implants were divided into 3 equal groups based on the surface characteristics: machined-surface, sand-blasted and acid-etched, and HA-coated. Implants were coated with E. coli biofilm. After an incubation period, they were decontaminated with 4 different methods: sonic scaler application, sonic scaler application with the chemical agent Perisolv® combination, Er: YAG laser treatment, and PDT therapy with methylene blue as a photosensitizer.ResultsThe highest level of decontamination was achieved for machined-surface implants and for the combined chemical-mechanical and Er: YAG laser treatment.ConclusionsThe results of our study suggest that the method of implant decontamination should be customized to the type of implant surface.

A long-term clinical statistical analysis of machined-surface Brånemark implants used in patients undergoing oral and maxillofacial surgery

ObjectiveDental implants are powerful tools for functional recovery after oral and maxillofacial surgery. Although a variety of different types of implant body have been developed, statistical studies have covered the comparatively short period. Dental implants are now being used for longer periods than ever. Patients and methodsHerein, we report our more than 27 years of clinical experience with the objective of re-evaluating the performance of machined-surface Brånemark implants. ResultsA total of 454 machined-surface implants, of which 38 were lost, were investigated. The cumulative overall survival rate was thus 87.2%. A comparison between the upper and lower jaws showed that the survival rate was 89.0% in the mandible and 85.1% in the maxilla, with a significant difference. However, there was no significant difference in the sort of bone in which they were embedded, with 90.0% embedded in existing bone and 82.6% in grafted bone. A four-field-table analysis showed that, in Year 27, the rate of “success” was 26%, with 1% “survival”, 65% “unaccounted for”, and 8% “failure”. ConclusionExtending the follow-up period means that more patients are lost to follow-up, and a range of different methods must therefore be used for an overall assessment to enable the accurate evaluation of therapeutic outcomes.

Effect of a Dietary Supplement on Peri-Implant Bone Strength in a Rat Model of Machined Surface Implants

Effect of a Dietary Supplement on Peri-Implant Bone Strength in a Rat Model of Machined Surface Implants

Histological and histomorphometric studies of the effects of hyaluronic acid on osseointegration of titanium implant in rabbits

Background: One of the unique prosthesis for tooth or teeth replacement is the dental implant. Our attempt is using a biomaterial system that is easily obtained and applicable and has the ability to provoke osteoinductive growth factor to enhance bone formation at the site of application. One of these natural polymers is hyaluronic acid. Material and methods: Sixty machined surface implants from commercially pure titanium rod inserted in thirty NewZealand rabbits. Two implants placed in both tibia of each rabbit. The animals scarified at 1, 2 and 4 weeks after implantation (10 rabbits for each interval). For all of animals the right tibia’s implant was control (uncoated) and the left one was experimental (coated with 0.1ml Hyaluronic acid gel). All sections have been stained with Haematoxylin and Eosin then they were histologically examined and assessed for histomorphometric analysis for counting of bone cells (osteoblast, osteocyte and osteoclast), cortical bone thickness, trabecular width, thread width and marrow space star volume (V*). Results: Histological findings for hyaluronic acid- coated titanium implant revealed an earlier bone formation, mineralization and maturation than that in control groups. Histomorphometric analysis for all bone parameters that examined in this study, showed highly significant difference between control and experimental groups in all healing intervals. Conclusion: Commercially pure titanium endosseous implants coated with hyaluronic acid may be osteocoductive thus accelerating healing process and enhancing osseointegration.

Histological and Histomorphometric Studies of the Effects of Hyaluronic Acid on Osseointegration of Titanium Implant in Rabbits

Background: One of the unique prosthesis for tooth or teeth replacement is the dental implant. Our attempt is using a biomaterial system that is easily obtained and applicable and has the ability to provoke osteoinductive growth factor to enhance bone formation at the site of application. One of these natural polymers is hyaluronic acid. Material and methods: Sixty machined surface implants from commercially pure titanium rod inserted in thirty NewZealand rabbits. Two implants placed in both tibia of each rabbit. The animals scarified at 1, 2 and 4 weeks after implantation (10 rabbits for each interval). For all of animals the right tibia’s implant was control (uncoated) and the left one was experimental (coated with 0.1ml Hyaluronic acid gel). All sections have been stained with Haematoxylin and Eosin then they were histologically examined and assessed for histomorphometric analysis for counting of bone cells (osteoblast, osteocyte and osteoclast), cortical bone thickness, trabecular width, thread width and marrow space star volume (V*). Results: Histological findings for hyaluronic acid- coated titanium implant revealed an earlier bone formation, mineralization and maturation than that in control groups. Histomorphometric analysis for all bone parameters that examined in this study, showed highly significant difference between control and experimental groups in all healing intervals. Conclusion: Commercially pure titanium endosseous implants coated with hyaluronic acid may be osteocoductive thus accelerating healing process and enhancing osseointegration.

Evaluation of the effects of different sand particles that used in dental implant roughened for osseointegration

BackgroundSuccessful dental implant treatment is directly related to osseointegration. In achieving osseointegration, the surface property of the implant is of great importance. Sandblasting is the most commonly used basic method for modifying the surface. Many companies use different sand particles for surface roughening and claim their sand is the best. This leads clinicians to mix their minds in product selection. In this study, we tried to find the appropriate sand material by working objectively without praising any brand. We believe that the results of the study will help clinicians choose the right dental implant. In this study, machined-surfaced implants and implants sandblasted with Aluminum oxide (Al2O3), Titanium dioxide (TiO2) and Silicon dioxide (SiO2) were compared via biomechanical testing.MethodsFor the study, four 2 year-old sheep, weighing 45 kilograms (kg), were used. Eight implants (Al2O3, TiO2, and SiO2 sandblasted implants and machined-surfaced implants), each with different surface characteristics, were inserted into the bilateral tibia of each sheep under general anesthesia. Results of the initial Resonance Frequency Analysis (RFA) were recorded just after implant insertion. The sheep were then randomly divided into two groups, each with 2 sheep, to undergo either a 1-month or a 3-month assessment. At the end of the designated evaluation period, RFA and removal torque tests were performed.ResultsAlthough there were no statistically significant differences between the groups, the implants sandblasted with Al2O3 showed a higher Implant Stability Quotient (ISQ) and removal torque value at the end of the 1st and 3rd month.ConclusionsIn short, the results of the study demonstrate that Aluminum oxide is superior to other sand particles.

Direct Contact Test for Evaluating Bacterial Growth on Machined and Rough Surface Implants: An In Vitro Study.

To use a modified direct contact test (DCT) to evaluate the bacterial growth on 3 commercially available implants. Streptococcus salivarius growth was tested on 1 machined surface and 2 commercial rough surface implants. Seven implants from each group were fixed to the cover of a 96-well microtiter plate. Bacterial suspension was placed on each implant, and the plate was incubated at 37°C for 1 hour to allow the suspension fluid to evaporate. Fresh medium was added to 7 corresponding wells in the microtiter plate, and the cover holding the implants was placed on the plate to enable immersion of the implant. Noncontaminated implant samples served as control. Bacterial growth was monitored spectrophotometrically at 650 nm for 24 hours. There was a significant S. salivarius growth in all groups of test implants compared with the control. There was no significant difference between bacterial growth kinetics on treated and nontreated implant surfaces (P = 0.241). Using the DCT, we found no difference in bacterial growth between machined and rough surface implants.

Enhanced Osseointegration of a Modified Titanium Implant with Bound Phospho-Threonine: A Preliminary In Vivo Study.

Implant surface topography is a key factor in achieving osseointegration. l-Threonine can be chemically and stably bonded to titanium surfaces by phosphorylation. This study investigated the degree of in vivo osseointegration of an implant with a novel o-phospho-l-threonine (p-Thr)-binding surface. MC3T3-E1 cells were seeded on the p-Thr binding surface and machined surface disks, and initial cell attachment was evaluated. p-Thr-binding and machined surface implants were tested in vivo by implantation into the femurs of three male New Zealand white rabbits, and the osseointegration was assessed by measurement of removal torque (RT) and bone-implant contact (BIC) ratio. Initial cell attachment was greater for the p-Thr-binding than for the machined surface implant group (P < 0.05). In addition, RT and BIC values were higher for the p-Thr-binding surface than for the machined surface (P < 0.05). These results indicate that our implant with a p-Thr-binding surface can achieve enhanced osseointegration.

Short dental implants in the posterior maxilla: a review of the literature.

The purpose of this study was to perform a literature review of short implants in the posterior maxilla and to assess the influence of different factors on implant success rate. A comprehensive search was conducted to retrieve articles published from 2004 to 2015 using short dental implants with lengths less than 10 mm in the posterior maxilla with at least one year of follow-up. Twenty-four of 253 papers were selected, reviewed, and produced the following results. (1) The initial survival rate of short implants in the posterior maxilla was not related to implant width, surface, or design; however, the cumulative success rate of rough-surface short implants was higher than that of machined-surface implants especially in performance of edentulous dental implants of length <7 mm. (2) While bone augmentation can be used for rehabilitation of the atrophic posterior maxilla, short dental implants may be an alternative approach with fewer biological complications. (3) The increased crown-to-implant (C/I) ratio and occlusal table (OT) values in short dental implants with favorable occlusal loading do not seem to cause peri-implant bone loss. Higher C/I ratio does not produce any negative influence on implant success. (4) Some approaches that decrease the stress in posterior short implants use an implant designed to increase bone-implant contact surface area, providing the patient with a mutually protected or canine guidance occlusion and splinting implants together with no cantilever load. The survival rate of short implants in the posterior edentulous maxilla is high, and applying short implants under strict clinical protocols seems to be a safe and predictable technique.

The Role of Biomimetic Incubation of Sandblasted Titanium Implants in the Process of Osseointegration: An Experimental Study in Dogs

The aim of the present study was to examine the surface characteristics and values of removal torque of an implant surface subjected to sandblasting with 125 µm Al 2 O 3 particles with a following immersion in biomimetic fluid and to compare that surface with a machined implant surface. Study protocol: Forty-eight conical implants were initially made of second-grade titanium alloy. The diameter of implants was 4 mm at the head and 2.6 at the apex, all implants were of 8 mm length and of large variable thread design. Half of them were subjected to sand blasting and immersion in biomimetic fluid at 37 °C for four weeks with daily replenishment of solution until the moment of placement; another 24 implants were left with untreated machined surface. Three-dimensional roughness values were obtained with the help of confocal laser scanning microscope. Forty-eight implants were implanted in 12 dogs. Twenty-four implants were retrieved after a 6-week healing period following installation, and the remaining 24 were removed upon the completion of 16 weeks, using a torque calibrator ((BTG150CN-S TOHNICHI) with a 20 cN·m - 150 cN·m scale of force registration was applied for the measurements of the removal torque. Results: The mean 3-dimensional roughness value of biomimetically treated implant surfaces was 1.34±0.24 µm and the mean roughness value measured for the machined surfaces was 0.33±0.04 µm (P<0.05). As to the average parameters of maximum peak-trough distance, these were equal to 2.85 for machined and 24.25 for incubated sandblasted implants. Machined implants demonstrated 49.5±10.3 removal torque values after the 6-week healing period. But for the immersed sandblasted implants the same parameter was equal to 72.7±15.98 cN·m. During a 16-week recovery period, these values increased up to 77.5±15.16 cN·m and 89.7±11.83 cN·m for machined and biomimetically treated sandblasted implants, respectively, P<0.05. Conclusion: The present study demonstrated the rapid recovery time for biomimetically incubated sandblasted dental implants in comparison to machined surface implants based on findings of early (6 weeks healing period) removal tests. Although there was established only a 13.4% difference in values of removal torque after a 16-week healing period (instead of 32% after 6 weeks of recovery) between two groups of implants which could be associated with delayed bone integration.

Oxidized Titanium Implants Enhance Osseointegration via Mechanisms Involving RANK/RANKL/OPG Regulation.

The role of implant surface properties for bone formation and bone remodeling, that is, the major events during osseointegration, are incompletely understood. This experimental study aimed to investigate the relation between molecular and morphological patterns at the bone interface for machined and oxidized implants. Machined and anodically oxidized titanium implants were inserted in rat tibiae. The implants and surrounding tissue were retrieved at 1, 3, 6, 14, or 28 days for gene expression, histology, histomorphometry, backscatter scanning electron microscopy, and transmission electron microscopy. Compared with machined-surface implants, a higher degree of mineralized bone was found in contact with the oxidized-surface implants. After 3 days, cells adherent to the oxidized implants demonstrated a markedly higher expression of receptor activator of nuclear factor kappa-B (RANK), receptor activator of nuclear factor kappa-B ligand (RANKL), and osteoprotegerin (OPG). Whereas the OPG expression was higher at the machined implants at 6, 14, and 28 days, a higher RANKL/OPG ratio was detected at the oxidized implants. Between 3 and 14 days, both implants demonstrated a temporal increase in RANKL/OPG, corresponding to the remodeling phase at the bone-implant interface. For both implant types, the RANKL/OPG ratio sharply decreased to a low level after 28 days. The present results show that oxidized implants rapidly promote a high degree of mineralized bone apposition to the surface. As determined by the gene expression data, the mechanisms involve an early induction of osteoclastic differentiation and subsequently more intensive bone remodeling, which accelerates the maturation of the bone-implant interface. The present study suggests that the RANKL/OPG ratio is a sensitive indicator for monitoring the remodeling process during osseointegration.

A 7-year prospective radiographic evaluation of marginal bone level around two different implant systems: a randomized clinical trial.

The aim of this study was to evaluate the change in marginal bone level radiographically around two different implant systems after 7 years of use. Twenty fully edentulous patients were included in the study and randomly assigned to two treatment groups of machined surface implants (Brånemark, n = 40) and rough-surface implants (Xive, n = 40). The implants were early loaded with individual bar-retained overdentures. All patients were treated by the same surgeon and the same prosthodontist. Clinical and radiographic examinations were conducted at the time of implant loading (baseline) and annually for up to 7 years of use. Measurements to the nearest 0.1 mm were taken at the mesial and distal site, and the average values were calculated for each implant. A three-level mixed-effect analysis of covariance (ANOVA) was used to test the significance of the mean marginal bone change in the two implant groups. The study population consisted of 15 women (75%) and five men (25%) with an average age of 61.6 years. A total of 79 of 80 implants integrated successfully. n = 1 Brånemark implant failed after 3 weeks. There was a significant difference (P < 0.001) between the two implant systems at the baseline measurements (0.14 mm Brånemark vs. 0.39 mm Xive) and a highly significant difference for the annual bone loss (0.07 mm [Brånemark] vs. 0.18 mm [Xive], P < 0.001). Both the implant systems are clinically satisfying. Nevertheless, the Brånemark group showed a better radiological performance than the Xive group.

Clinical and Radiologic Experience with Moderately Rough Oxidized Titanium Implants: Up to 10 Years of Retrospective Follow-up

The long-term success of machined-surface implants is well documented, whereas the reliability of the moderately rough oxidized implant surface has not been definitively assessed in the long term. The aim of this retrospective study was to assess the long-term clinical and radiologic outcomes of moderately rough oxidized implants supporting fixed prostheses. Seventy-three consecutive patients needing an implant-supported restoration received 1 to 11 implants each (n=167). All implants (82 cylindric and 85 tapered-body implants) had a self-tapping design and a moderately rough oxidized surface and were immediately loaded (n=48) or loaded after a delay (n=113). Patients were followed for up to 10 years. Outcomes were implant and prosthetic survival rates, peri-implant bone level changes, bleeding on probing, and plaque and gingival indices. One patient (one implant) dropped out. Seventy-two patients (166 implants) were followed for at least 8 years (mean, 8.82 years; range, 8.0 to 10.4 years. No implants or prostheses were lost, resulting in a cumulative implant and prosthetic survival rate of 100% after up to 10 years in function. At the final follow-up, the accumulated mean marginal bone loss values were -1.72±1.53 mm (n=27) and -1.27±1.67 mm (n=44) for cylindric and tapered implants, respectively, with no statistically significant difference. Bleeding on probing was 12.1%. The cumulative plaque score was 19.7%; 83.8% of patients showed normal gingiva, 10.1% displayed mild inflammation, and 6.1% showed moderate inflammation. This retrospective study of 73 patients treated with either cylindric or tapered-body moderately rough oxidized implants and followed for up to 10 years demonstrated good treatment outcomes with regard to implant survival, marginal bone changes, and soft tissue conditions.