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Regulation of cellular function is key to bone formation at endosseous implant surfaces. Osseointegration was "discovered" prior to the discovery of genetic regulation of osteoinduction or characterization of mesenchymal stem cells. Understanding osseointegration in cellular and molecular terms has benefited from genome-wide characterization of this healing process at endosseous implants in vivo. These in vivo studies also demonstrate a role for osteoprogenitor cells and cells involved in immune regulation and osteoclastogenesis. The identification of noncoding RNAs, including microRNAs, as key factors controlling cell function has highlighted the role of microRNAs in cell differentiation control. This review summarizes emerging in vitro and in vivo investigations emphasizing the role of microRNAs in the osseointegration process. Many microRNAs influence key osteoinductive pathways controlling Osterix, runt-related transcription factor 2 (RUNX2), and bone morphogenetic protein (BMP)/SMAD function. Others influence the monocyte/ macrophage lineage. While significant progress has been made in elucidating the mechanisms associated with the regulation of surface modulation of osteoblast differentiation by microRNAs, knowledge gaps are evident in the identification and characterization of microRNAs linked to osseointegration. Given existing knowledge regarding the varied expression of microRNAs and their role in inflammation, it is important to understand how microRNA expression may influence the process of bone accrual at implant surfaces during osseointegration. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this vitro study was to reproduce and evaluate the response of bone and bacteria to traditional and innovative implant surfaces with difference wettability. Materials and Methods: Two hundred fifty-two samples made of grade 4 titanium with different coating (machined [MAC]; double-etched, Ti-AE; zirconium nitride [Ti-ZrN]) were used for this in vitro study. Disks were divided into test (bioactivated using plasma of argon) and control group (untreated). To assess the surface morphology of the specimens, representative images were acquired via scanning electron microscopy (SEM). Murine preosteoblasts (MC3T3-E1) were used to study the biologic response in vitro, while the quantification of protein adsorption was achieved through the incubation of the titanium samples in a 2% solution of fetal bovine serum (FBS) in phosphate-buffered saline (PBS). The sterilized titanium disks were then colonized by bacterial species from a single sputum sample obtained from a healthy volunteer. For every analysis, 24 disks were used (12 for each group). Results: SEM and topographic analyses demonstrated a Sa value of 0.33 (Ti-ZrN), 0.34 (MAC), and 0.62 (Ti-AE). Compared with the control groups, plasma treatment significantly increased the protein adsorption level on all the different titanium surfaces (5.88 ± 0.21 vs 7.85 ± 0.21, 7.13 ± 0.14 vs 9.74 ± 0.65, 4.41 ± 0.62 vs 6.13 ± 0.52, respectively, for MAC, Ti-treated, and Ti-ZrN). Similar behavior was described for cell adhesion (27.67 ± 2.03 vs 58.00 ± 20.13, 116.67 ± 12.02 vs 159.33 ± 8.09, 52.00 ± 4.73 vs 78.33 ± 4.67, respectively, for MAC, Ti-treated, and Ti-ZrN). Plasma treatment significantly augmented the number of CFU only in MAC and ZrN samples. Conclusion: With the limitations of this in vitro study, the following conclusions could be drawn: (1) rough implant surfaces present a higher adhesion and proliferation of preosteoblastic cells and bacterial biofilm; (2) rough implant surfaces benefited the most by the plasma of argon treatment. [ABSTRACT FROM AUTHOR]

Objective: Researchs of the effects of ankaferd blood stopper (ABS) on bone healing metabolism have revealed that it affects bone regeneration positively. The exact mechanism by which this positive effect on bone tissue metabolism is not known. The aim of this study is to biomechanic and biochemical analysis of the effects of the local ABS application on osseointegration of 3 different surfaced titanium implants. Material & Methods: Spraque dawley rats were divided machined surfaced (MS) (n ​= ​10), sandblasted and large acid grid (SLA) (n ​= ​10) and resorbable blast material (RBM) (n ​= ​10) surfaced implants. ABS applied locally during the surgical application of the titanium implant before insertion in bone sockets. After 4 weeks experimental period the rats sacrificed and implants with surrounding bone tissues were removed to reverse torque analysis (Newton), blood samples collected to biochemical analysis (ALP, calcium, P) Results: Biomechanic bone implant contact ratio detected higher in SLA surfaced implants compared with the RBM and controls (P ​

Abstract Background The aim of the current study was the evaluation of initial biofilm adhesion and development on laser-microtextured implant collar surfaces and the examination of effectivity of different biofilm management methods. Methods Initial biofilm formation was investigated on hydrophobic machined and laser-microtextured (Laser-Lok) titanium surfaces and hydrophobic machined and laser-microtextured (Laser-Lok) titanium aluminium vanadium surfaces and compared to hydrophobic smooth pickled titanium surfaces, hydrophilic smooth and acid etched titanium surfaces, hydrophobic sandblasted large grid and acid etched titanium surfaces (titanium Promote) via erythrosine staining and subsequent histomorphometrical analysis and scanning electron microscopic investigations. After decontamination procedures, performed via tooth brushing and glycine powder blasting, clean implant surface was detected via histomorphometrical analysis. Results After 24 h mean initial plaque area was detected in the following descending order: smooth pickled titanium > titanium Promote > hydrophilic smooth and acid etched titanium > Laser-Lok titanium > Laser-Lok titanium aluminium vanadium. The same order was determined after 48 h of biofilm formation. After glycine powder blasting all samples depicted almost 100% clean implant surface. After tooth brushing, Laser-Lok titanium (67.19%) and Laser-Lok titanium aluminium vanadium (69.80%) showed significantly more clean implant surface than the other structured surfaces, hydrophilic smooth and acid etched titanium (50.34%) and titanium Promote (33.89%). Smooth pickled titanium showed almost complete clean implant surface (98.84%) after tooth brushing. Conclusions Both Laser-Lok surfaces showed less initial biofilm formation after 24 and 48 h than the other implant surfaces. In combination with the significant higher clean implant surfaces after domestic decontamination procedure via tooth brushing, both Laser-Lok surfaces could be a candidate for modified implant and abutment designs, especially in transmucosal areas.

Purpose: To assess and compare topographic features and preosteoblastic cell responses of a new hydrothermally treated, calcium-incorporated surface against other commercially available implant surfaces. Materials and Methods: Four different surfaces were the subject of comparison in this study: machined (MC), resorbable blast media (RBM), sandblasted/large-grit/acid-etched (SLA), and calcium-incorporated SLA (Ca-SLA). Surface morphology and roughness were first characterized by scanning electron microscope (SEM) and white light interferometer, respectively. Preosteoblastic MC3T3-E1 cells were then cultured on the titanium surfaces. Cell morphology was observed at 24 hours, 48 hours, 7 days, and 15 days by SEM; differentiation was assessed at 7, 11, and 15 days by assaying alkaline phosphatase (ALP) activity and osteocalcin (OCN) levels. Results: Surface characterization revealed nanotopographic features on Ca-SLA. At topographic analysis, SLA and Ca-SLA showed similar roughness values. Significant differences in cell differentiation parameters were found only at 15 days between the SLA surfaces (both Ca-incorporated and nonincorporated) and MC. Conclusion: Collectively, this study demonstrated that hydrothermal treatment determines the formation of nanotopography without altering the SLA microtopography. Moreover, Ca-SLA and SLA induce MC3T3-E1 cell differentiation at comparable levels. [ABSTRACT FROM AUTHOR]

The release of metal particles and ions due to wear and corrosion is one of the main underlying reasons for the long-term complications of implantable metallic implants. The rather short-term focus of the established in-vitro biocompatibility tests cannot take into account such effects. Corrosion behavior of metallic implants mostly investigated in in-vitro body-like environments for long time periods and their coupling with long-term in-vitro experiments are not practical. Mathematical modeling and modeling the corrosion mechanisms of metals and alloys is receiving a considerable attention to make predictions in particular for long term applications by decreasing the required experimental duration. By using such in-silico approaches, the corrosion conditions for later stages can be mimicked immediately in in-vitro experiments. For this end, we have developed a mathematical model for multi-pit corrosion based on Cellular Automata (CA). The model consists of two sub-models, corrosion initialization and corrosion progression, each driven by a set of rules. The model takes into account several environmental factors (pH, temperature, potential difference, etc.), as well as stochastic component, present in phenomena such as corrosion. The selection of NiTi was based on the risk of Ni release from the implant surface as it leads to immune reactions. We have also performed experiments with Nickel Titanium (NiTi) shape memory alloys. The images both from simulation and experiments can be analyzed using a set of statistical methods, also investigated in this paper (mean corrosion, standard deviation, entropy etc.). For more widespread implementation, both simulation model, as well as analysis of output images are implemented as a web tool. Described methodology could be applied to any metal provided that the parameters for the model are available. Such tool can help biomedical researchers to test their new metallic implant systems at different time points with respect to ion release and corrosion and couple the obtained information directly with in-vitro tests.

Researchs of the effects of ankaferd blood stopper (ABS) on bone healing metabolism have revealed that it affects bone regeneration positively. The exact mechanism by which this positive effect on bone tissue metabolism is not known. The aim of this study is to biomechanic and biochemical analysis of the effects of the local ABS application on osseointegration of 3 different surfaced titanium implants. Spraque dawley rats were divided machined surfaced (MS) (n ​= ​10), sandblasted and large acid grid (SLA) (n ​= ​10) and resorbable blast material (RBM) (n ​= ​10) surfaced implants. ABS applied locally during the surgical application of the titanium implant before insertion in bone sockets. After 4 weeks experimental period the rats sacrificed and implants with surrounding bone tissues were removed to reverse torque analysis (Newton), blood samples collected to biochemical analysis (ALP, calcium, P) Biomechanic bone implant contact ratio detected higher in SLA surfaced implants compared with the RBM and controls (P ​< ​0,05). Phosphor levels detected lower in RBM implant group compared with the controls and SLA (P ​< ​0,05). Additionally; phosphor levels detected highly in controls compared with the RBM implants. According the biomechanical parameters ABS may be more effective in SLA and RBM surfaced implants when locally applied. [ABSTRACT FROM AUTHOR]

Aim: In this study, our aim is to compare the effects of dental implants with nano laser excimer technology surface (NLE) and dental implant surfaces (MTX) with micro-roughened surface on marginal tissues with clinical and radiological data. Methodology: A total of 117 dental implants were followed clinically and radiologically. Clinically; Plaque index (silness-löe), bleeding index in boring, pocket depth were evaluated and recorded one week after the insertion of the healing cap, three months, six months and 12 months after the end of the prosthesis. In the same periods, periapical x-rays were taken with the Rinn Holder method, and the amount of marginal bone loss was measured. The data were analyzed with IBM SPSS Statistics Version 22 package program. Results: There was no loss in the implants included in the study. There was no statistically significant difference between the groups in terms of plaque index, bleeding index values (p>0,05). However, the pocket depth of the dental implant group with nano laser excimer technology surface is significantly lower than the micro-roughened surface group. There are statistically significant differences between the groups in terms of radiological marginal bone loss at 0, 3, 6, and 12 months (p<0,05). Radiological marginal bone loss values of the micro-roughened surface group at 0, 3, 6, and 12 months were significantly lower compared to the same periods of the nano laser excimer technology group. Conclusion: It has been determined that the surface properties of dental implants can be effective on marginal tissues. In addition, we believe that routine checks by dentists who perform dental implant applications will increase the success of dental implants. [ABSTRACT FROM AUTHOR]

In peri-implantitis, treatment lasers are effectively used to enhance implant surfaces' decontamination of bacteria. The type of lasers commonly used and tested in dentistry are Nd:YAG, Er:YAG and diodes. The Er:YAG laser is considered to be effective in removing biofilm from implant surfaces. Photodynamic therapy (PDT), realized with low-level laser therapy (LLLT) and a photosensitizer, seems to have limited efficacy in peri-implantitis management, while diode lasers used with high frequency and power (Wiser, Doctor Smile), performed with hydrogen peroxide 10 vol. 3% (OHLLT), seems to lead to a deep sanitization of implant surfaces, without any thermal effect. The aim of our retrospective controlled study is to compare an oxygen high-level laser therapy (OHLLT) protocol with OHLLT with an Er:YAG laser (Pluser, Doctor Smile) in order to maximize bacterial removal and to evaluate if an Er:YAG laser could improve hard tissue regeneration with respect to OHLLT alone. Two hundred and ten implants affected by peri-implantitis were divided into two groups: 88 implants were treated with OHLLT alone (control group) while 122 underwent OHLLT and Er:YAG treatment (test group). Mean bone loss before (T0) and after treatment (T1) (with a follow-up of 5 years) was registered for all implants. The collected data were analyzed with the Statistical Package for Social Sciences (SPSS) version 11.5. No statistically significant differences were found. In the OHLLT group, we noticed a mean bone loss after treatment of 2.1 mm in the upper arch and 2.4 mm in the mandible. In the OHLLT + Er:YAG group, the results indicate a mean bone loss of 2.0 mm in the upper arch and 2.5 mm in the mandible. Both groups showed a mean bone loss after treatment of 2.3 mm. According to the Kolmogorov–Smirnov test, overall, data followed a normal distribution (value of the K-S test statistic = 0.0912; p = 0.36112). OHLLT plays a central role in enhancing clinical results in peri-implantitis treatment, leading to an effective bacterial decontamination. Our results showed no statistically significant differences between OHLLT and OHLLT + Er:YAG laser; thus, the potential advantageous role of Er:YAG has been downgraded with the analysis of our study. [ABSTRACT FROM AUTHOR]

Background: The aim of the current study was the evaluation of initial biofilm adhesion and development on laser-microtextured implant collar surfaces and the examination of effectivity of different biofilm management methods. Methods: Initial biofilm formation was investigated on hydrophobic machined and laser-microtextured (Laser-Lok) titanium surfaces and hydrophobic machined and laser-microtextured (Laser-Lok) titanium aluminium vanadium surfaces and compared to hydrophobic smooth pickled titanium surfaces, hydrophilic smooth and acid etched titanium surfaces, hydrophobic sandblasted large grid and acid etched titanium surfaces (titanium Promote) via erythrosine staining and subsequent histomorphometrical analysis and scanning electron microscopic investigations. After decontamination procedures, performed via tooth brushing and glycine powder blasting, clean implant surface was detected via histomorphometrical analysis. Results: After 24 h mean initial plaque area was detected in the following descending order: smooth pickled titanium > titanium Promote > hydrophilic smooth and acid etched titanium > Laser-Lok titanium > Laser-Lok titanium aluminium vanadium. The same order was determined after 48 h of biofilm formation. After glycine powder blasting all samples depicted almost 100% clean implant surface. After tooth brushing, Laser-Lok titanium (67.19%) and Laser-Lok titanium aluminium vanadium (69.80%) showed significantly more clean implant surface than the other structured surfaces, hydrophilic smooth and acid etched titanium (50.34%) and titanium Promote (33.89%). Smooth pickled titanium showed almost complete clean implant surface (98.84%) after tooth brushing. Conclusions: Both Laser-Lok surfaces showed less initial biofilm formation after 24 and 48 h than the other implant surfaces. In combination with the significant higher clean implant surfaces after domestic decontamination procedure via tooth brushing, both Laser-Lok surfaces could be a candidate for modified implant and abutment designs, especially in transmucosal areas. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to evaluate the cleaning effectiveness of implant prophylaxis instruments on polished and acid-etched implant surfaces. Materials and Methods: Biofilm layers of Streptococcus mutans were grown on a total of 80 titanium disks; 40 disks were polished and 40 were acid-etched. Five disks of each surface were cleaned using each of seven implant prophylaxis instruments: (1) manual plastic curette, (2) manual carbon fiber-reinforced plastic (CFRP) curette, (3) sonic-driven prophylaxis brush, (4) rotating rubber cup with prophylaxis paste, (5) sonic-driven polyether ether ketone (PEEK) plastic tip, (6) ultrasonic-driven PEEK plastic tip, and (7) air polishing with amino acid (glycine) powder. Ten disks (five of each surface type) served as controls. After cleaning, the surfaces with remaining bacteria were assessed by light microscopy. Statistical analyses of the results were performed with one-way and two-way analyses of variance with Bonferroni-Dunn multiple comparisons post hoc analysis (α = .05). Results: The cleaning effectiveness of the plastic curette was significantly lower than those of all machine-driven instruments on the polished surface. Significantly lower cleaning effectiveness occurred with the CFRP curette compared to the prophylaxis brush and to both oscillating PEEK plastic tips on the polished surface. The rubber cup provided less cleaning effectiveness compared to the ultrasonic PEEK plastic tip and air polishing on the acid-etched surface. Superior results, with less than 4% of the biofilm remaining, were obtained for both oscillating PEEK plastic tips and air polishing on both implant surfaces. The cleaning ability of the prophylaxis brush, rubber cup, and ultrasonic PEEK plastic tip differed significantly between both surface structures. Conclusions: Cleaning effectiveness, ie, less than 4% of the biofilm remaining, was not observed with all tested implant prophylaxis instruments. The cleaning ability of the devices depended on the implant surface structure. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to investigate whether estrogen deficiency interrupts bone healing around titanium implants and to evaluate whether bone healing around implants under a condition of estrogen deficiency is affected by variations in implant surface characteristics. Materials and Methods: Forty-eight female rats were divided into two groups: ovariectomized rats (OVX; n = 24) and sham-operated rats (SHAM; n = 24). Each group was further divided into two groups: a machine-polished implants group and a sandblasted implants group. One implant was placed into the left femur of each rat 84 days after OVX or sham surgery. After 28 or 56 days, the rats were killed, and nondecalcified sections were obtained. Bone-toimplant contact (BIC) and bone area (BA) around the implants were assessed for cortical and cancellous bone. Furthermore, bone density (BD) was evaluated in a 500-mm-wide zone of cancellous bone lateral to the implants. Results: At 28 and 56 days after implantation, no significant differences were found between the OVX and SHAM groups for BIC and BA in cortical bone. BIC, BA, and BD with cancellous bone were lower in the OVX group than in the SHAM group. However, BIC and BA tended to increase with the sandblasted implant surface. Conclusions: Estrogen deficiency affected bone healing and bone density around titanium implants, especially in cancellous bone, but the sandblasted surface has the possibility to improve osseointegration. However, the positive effect of this rough surface is limited at the implant surface. [ABSTRACT FROM AUTHOR]

The aim of the present study was a light and scanning electron microscopy (SEM) evaluation of the peri-implant tissues around sandblasted, acid-etched implants, retrieved from man, after a loading period of 5 and 10 years, respectively. Two implants (Leone Implant System) had been retrieved for a fracture of the prosthetic superstructure respectively after 5 and 10 years of loading. Both implants were stable before retrieval and had been retrieved using a 5-mm trephine bur. One implant was treated to obtain thin ground sections, while the other underwent evaluation under SEM. Compact, mature lamellar bone was present over most of the implant perimeter in close contact with the implant surface and with many remodeling areas. Under SEM, small concavities, completely filled by mineralized bone, were present on the implant surface. The present histologic results showed that these implants were well integrated over the long term, and the peri-implant bone was undergoing continuous remodeling at the interface. [ABSTRACT FROM AUTHOR]

Purpose: Soft and hard tissue responses to experimental peri-implantitis around thin sputter hydroxyapatite (HA)-coated implants were evaluated and compared to the responses to implants with other surface treatments. Materials and Methods: Forty-eight dental implants with four different surfaces-machined (M), sandblasted/acid-etched (SA), 1-µm thin sputter HA-coated (S), and plasma-sprayed HA-coated (P)-were inserted into the mandibles of six beagle dogs. Three months later, experimental peri-implantitis was induced with ligatures to allow plaque accumulation. After a 4-month period of active breakdown, the ligatures were removed, and plaque accumulation continued for 5 additional months (progression period). Radiographic marginal bone levels, probing depths, clinical attachment levels, and modified Gingival Index were evaluated at baseline, after the active breakdown period, and after the progression period. Results: Significant increases in mean probing depths and clinical attachment levels were seen around all implants after active breakdown, but no significant differences were found during the progression period. Radiographic analysis revealed marginal bone loss of 1 to 1.7 mm during the active breakdown period. Additional bone loss occurred during the progression period (M 0.2 mm, SA 0.3 mm, S 0.2 mm, P 0.4 mm). Conclusion: Comparable tissue behavior was demonstrated around dental implants with all four surfaces under peri-implantitis conditions. Thin sputter HA-coated implants possess the favorable osteoconductive properties of calcium phosphate coatings without exacerbating further peri-implant tissue breakdown during the progression of peri-implantitis. [ABSTRACT FROM AUTHOR]

Objective: Human retrieved implants with an intact bone-implant interface play a pivotal role in validating data obtained from in vitro studies and animal experiments. This study presents a histologic and histomorphometric analysis of peri-implant tissue reactions and of the bone-titanium interface in three machined and sandblasted dental implants retrieved after a 5-year loading period. Method and Materials: Three implants, with an intact bone-implant interface, were found in the Archives of the Implant Retrieval Center of the Dental School of the University of Chieti-Pescara, Chieti, Italy. The three implants had been used in a two-stage submerged procedure and loaded as part of a small prosthetic restoration. One implant had been retrieved because of an abutment fracture, while there was a fracture of the connecting screw in the other two. One implant was in the maxilla (sandblasted surface), and two were in the mandible (one with a machined surface and the other with a sandblasted surface). All implants had been processed for histology. Results: All three implants presented mature, compact, lamellar bone at the interface. Many remodeling areas were present in the peri-implant bone, especially inside the implant threads. The bone was always in close contact with the implant surface. The bone-implant contact percentage of the machined implant was 92.7%, while the two sandblasted implants showed bone-implant contact percentages of 85.9% and 76.6%. Conclusion: The present histologic results confirmed that these implants with different surfaces maintained a good level of osseointegration over a 5-year loading period, with continuous remodeling at the interface, and showed high bone-implant contact percentages. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to evaluate the effects of a variety of implant cleaning instruments on different implant surfaces, specifically surface roughness and cleaning efficacy. Materials and Methods: Biofilm layers of Streptococcus mutans were cultivated on titanium disks with four different surface structures (polished, grit-blasted, acid-etched, and acid-etched/grit-blasted). Five disks each were cleaned using nine mechanical implant cleaning instruments or an erbium:yttrium-aluminum-garnet laser. Surface roughness (average, Ra; maximum, Rz) and waviness (Lr) were evaluated by two-dimensional laser profilometry. Surface structure damage and cleaning scores were assessed by scanning electron microscopy. Statistical analyses of the results were performed with one- and two-way analyses of variance and Bonferroni-Dunn multiplecomparison post hoc analysis (α = .05). Results: Ra and Rz values for the acid-etched surfaces and Ra, Rz, and Lr values for the polished and the grit-blasted surfaces showed no significant differences between the different cleaning methods or cleaning instruments compared to the control (not cultured, not cleaned) groups. Significantly lower Ra and Rz values on grit-blasted/acid-etched implant surfaces were found following use of the Sonic-Flex clean with prophylaxis brush and the plastic curette compared to Satelec ProphyMax with Periosoft curette. Ra and Rz values of the different implant structure surfaces before cleaning were significantly different between all implant surfaces except for the polished compared to the acid-etched surfaces. Conclusions: Cleaning effect and alterations of the implant surfaces were strongly dependent on the implant cleaning method used. [ABSTRACT FROM AUTHOR]

Purpose: A high clinical and radiographic level of osseointegration has been reported for early and immediately loaded (IL) implants. The aim of this study was to analyze, histologically and histomorphometrically, the bone-titanium interface of IL and submerged titanium implants that were retrieved at 4 and 8 weeks after placement. Materials and Methods: Four patients underwent rehabilitation of the posterior mandible with fixed prostheses, and an additional implant was inserted distally in the mandible. In two patients, the additional implants were put into nonfunctional immediate loading with a fixed provisional prosthesis on the same day of the implant surgery, whereas in the other two patients, the implants were left submerged. The implant stability quotients at implant insertion were 70 and 67 for the submerged implants and 69 and 77 for the IL implants. Before retrieval, the IL implants were clinically osseointegrated and were not mobile. After 4 and 8 weeks, the four implants (two IL and two submerged) were retrieved with a 5-mm trephine and processed for histologic examination. Results: After 4 weeks, the IL implant showed a bone-implant contact percentage (BIC) of 65.6%, while the BIC for the submerged implant was 54.7%. After 8 weeks, the BIC was 76.2% for the IL implant, while for the submerged implant it was 62.3%. Conclusions: Very high BICs were present after 4 and 8 weeks around both submerged and IL implants, with the latter showing a higher quantity of bone. IL did not impede bone formation in the early healing periods. [ABSTRACT FROM AUTHOR]

Purpose: Implant stability has been identified as a factor that may influence the achievement of osseointegration. The aim of this study was to compare the stability of titanium dioxide grit-blasted (TB) dental implants, with fluoride treatment (FTB) and without, over the first 24 weeks following implant placement. Materials and Methods: Subjects were edentulous patients visiting a university prosthodontics department over a 6-month period seeking mandibular overdentures retained by two implants. Each patient received two implants in the mandible: one TB and one FTB. All implants were placed by the same surgeon. TB implants were placed in the right canine region and FTB implants were placed in the left canine region. Resonance frequency analysis (RFA) was performed at the time of implant placement and at 1, 2, 3, 4, 5, 6, 12, and 24 weeks postplacement. Results: Twenty-seven patients were enrolled. TB implants showed fluctuations in RFA values during the first 6 weeks, whereas the RFA values of FTB implants remained stable throughout the study period. Conclusions: FTB implants did not exhibit the early decreases in RFA values seen in TB implants. Larger studies are necessary to confirm this finding and determine whether this will affect clinical loading protocols. [ABSTRACT FROM AUTHOR]

Human biopsy of immediately loaded implants is the most definitive means to determine the occurrence of osseointegration. This case report discusses the histologic and histomorphometric analysis of the bone-titanium interface in immediately restored implants with and without occlusal contact, retrieved after a healing period of 5 weeks. The two implants had been inserted in the posterior mandible; both were freestanding. One implant had been put into functional loading (in occlusal contact) with a fixed provisional prosthesis on the day of implant surgery (implant A), whereas the other implant was restored without occlusal contact (implant B). Both implants were retrieved with a 5-mm trephine after 5 weeks. Before retrieval, both implants appeared to be clinically osseointegrated, and no mobility was present. Both implants were surrounded by newly formed bone lamellae. In both implants about 0.5 to 1 mm of pre-existing and newly formed bone was found coronal to the implant shoulder, with no resorption of the pre-existing coronal bone. The bone-implant contact percentage in implant A was 51.2% ± 4.5%, whereas in implant B it was 55.1% ± 2.3%. Within the limitations of this study, the histologic findings indicated that no differences were found in the histologic response around immediately restored implants with and without occlusal contact. [ABSTRACT FROM AUTHOR]

Purpose: To compare the torsional strengths and the effects of functional loading on five different implant surface structures. Materials and Methods: This in vivo longitudinal study of 9 months' duration examined osseointegration in 180 stepped cylindric implants placed into the mandibles of 18 healthy sheepdogs. Implants with five different surface structures were placed (n = 36 in each group): (1) smooth surface; (2) deep profile structure (DPS); (3) titanium plasma sprayed (TPS); (4) hydroxyapatite coated; and (5) sol-gel hydroxyapatite coated (SGHA). All implants were investigated under standardized conditions. At uncovering (3 months), half the implants were loaded with prefabricated crowns for 6 months, and the other half remained unloaded. Removal torque values were evaluated at 3, 6, and 9 months after implant placement. The data were analyzed using analysis of variance and Scheffé correction (α < .05). Results: All smooth-surface and SGHA implants failed in succession during the fourth and ninth months of the study. After 3 months the removal torque resistance of DPS, TPS, and hydroxyapatite-coated implants was significantly higher (P < .001) than that seen in the other two groups. Initially, the removal torque resistance of unloaded hydroxyapatite-coated implants was superior, and the decrease during the observation period was not significant. The increase in removal torque resistance under functional loading was not significant for the DPS implants. A significant increase was found in removal torque resistance for the loaded TPS implants (P < .05). The unloaded DPS and TPS implants showed no change in removal torque levels after the closed healing period of 3 months. Conclusions: Successful osseointegration was achieved with DPS, TPS, and hydroxyapatitecoated implants, and smooth-surface and SGHA implants failed. Removal torque resistance was enhanced with controlled functional loading. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this retrospective study was to evaluate the effects of implant dimensions, surface treatment, location in the dental arch, numbers of supporting implant abutments, surgical technique, and generally recognized risk factors on the survival of a series of single-stage Straumann dental implants placed into edentulous arches using an immediate loading protocol. Materials and Methods: Each patient received between 4 and 18 implants in one or both dental arches. Periapical radiographs were obtained over a 2- to 10-year follow-up period to evaluate crestal bone loss following insertion of the definitive metal-ceramic fixed prostheses. Univariate tests for failure rates as a function of age (⩽ 59 years versus ⩾ 60 years), gender, smoking, bone grafting, dental arch, surface type, anterior versus posterior, number of implants per arch, and surgical technique were made using Fisher exact tests. The Cochran-Armitage test for trend was used to evaluate the presence of a linear trend in failure rates regarding implant length and implant diameter. Logistic regression modeling was used to determine which, if any, of the aforementioned factors would predict patient and implant failure. A significance criterion of P = .05 was utilized. Results: Data were collected for 344 single-stage implants placed into 56 edentulous arches (39 maxillae and 17 mandibles) of 43 patients and immediately loaded with a 1-piece provisional fixed prosthesis. A total of 16 implants failed to successfully integrate, for a survival rate of 95.3%. Increased rates of failure were associated with reduced implant length, placement in the posterior region of the jaw, increased implant diameter, and surface treatment. Implant length emerged as the sole significant predictor of implant failure. Conclusion: In this retrospective analysis of 56 consecutively treated edentulous arches with multiple single-stage dental implants loaded immediately, reduced implant length was the sole significant predictor of failure. [ABSTRACT FROM AUTHOR]

Purpose: Prevention of late implant bone loss is a critical component in long-term success of implants. The aim of the present study was to evaluate factors affecting late implant bone loss. Materials and Methods: Three hundred thirty-nine endosseous root-form dental implants placed between April 1981 and April 2002 in 69 patients were analyzed. The implants were categorized based on the following factors: (1) surface characteristics (smooth versus rough), (2) length (short [< 10 mm] versus long [⩾ 10 mm]), width (narrow [< 3.75 mm], regular [3.75 to 4.0 mm], or wide [> 4.0 mm]), (3) the amount of keratinized mucosa (< or ⩾ 2 mm), (4) location (anterior versus posterior; maxilla versus mandible), (5) type of prosthesis (fixed versus removable), and (6) type of opposing dentition. The effects of these factors on clinical parameters, especially average annual bone loss (ABL), were evaluated clinically and radiographically by a blinded examiner. The parameters evaluated were modified Plaque Index, Gin gival Index, modified Bleeding Index, probing depth, and ABL. Results: Shorter implants, wider implants, implants supporting fixed prostheses, and implants in smokers were found to be associated with greater ABL (P < .05). The random intercept mixed effects model showed that implant length was the most critical factor for maintenance of ABL. Conclusions: Shorter implants, wider implants, implants supporting fixed prostheses, and implants in smokers were associated with greater ABL. Implant length was the most significant factor in the maintenance of dental implants. Randomized controlled clinical trials are needed to confirm the results obtained from this retrospective clinical study. [ABSTRACT FROM AUTHOR]

Purpose: A 3-dimensional finite element model was developed to investigate the cause of different cre- stal bone loss patterns observed around sintered porous-surfaced and machined (turned) threaded dental implants used for orthodontic anchorage in a previously reported animal study. Materials and Methods: Twenty-n oded structural solid elements with parabolic interpolation between nodes were used for modeling the bone-implant interface zone. A 3-N traction force acting between either 2 porous-surfaced or 2 machined threaded implants placed in canine premolar mandibular sites and bone profiles observed at initiation and 22 weeks of orthodontic loading were modeled. Results: Higher maximum stresses in pen-implant bone next to the coronal region of the implants were pre- dicted with the machined threaded implants at both the initial and final time points, with the values 20% greater than those predicted after the 22-week loading period. These values were approximately 200% greater than those predicted for the porous-surfaced implants, for which a more uniform stress distribution was predicted. Discussion: The finite element model results indicated that the observed greater retention of crestal bone next to the porous-surfaced implants was attributable to lower peak stresses developing in crestal peri-im plant bone with this design, which decreased the probability of bone loss related to local overstressing and bone micro fracture. Conclusion: The predicted lower stresses were a result of the more uniform transfer of force from implant to bone with the porous-sur- faced implants, which was a consequence of the interlocking of bone and implant possible with this design. INT J ORAL MAXILLOFAC IMPLANTS 2006;21:879-889 [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to evaluate the clinical outcome of delayed or immediately loaded implants of 3 different implant macrodesigns. The hypothesis was that no significant differences in implant success would be observed between immediately and delayed loaded implants. Materials and Methods: Between July 2003 and December 2003, 321 patients were consecutively enrolled for this study. Immediate loading was performed in cases where the implant stability quotient (ISQ) values were > 60 (as determined by resonance frequency analysis) and implant insertion torque was > 25 Ncm. In the case of delayed loading, a submerged technique (2-stage) or a single-stage procedure was used. The following variables were statistically analyzed with logistic regression: implant length, implant diameter, implant type, implant site, insertion torque, ISQ, and type of loading (immediate or delayed). Results: Eight hundred two implants were placed. Immediate loading was chosen for 423 implants and delayed loading for 379 implants. All implants were followed up for a minimum of 12 months after prosthetic loading. Only 3 implants were lost, with an overall success rate of 99.6%. No statistically significant differences were found for any variables between the failures in the 2 groups (immediate loading protocol versus delayed loading). Implants with a crestal bone loss greater than 0.2 mm during the first year of observation (69 cases) were evaluated as a group; within this subset, only ISQ value (P < .004), implant length (P < .002), and implant type (P < .049) had a statistically significant effect on crestal bone resorption. Conclusions: Based upon this study of 802 implants, no significant differences in implant success were observed between the 2 groups. [ABSTRACT FROM AUTHOR]

Purpose: Radiation therapy influence on bone healing around 3 types of endosseous dental implants in dogs was evaluated. Materials and Methods: Implants with 3 different surfaces (A = machined commercially pure titanium screws, B = commercially pure titanium plasma spray-coated cylinders, C = hydroxyapatite [HA] -ceramic coated cylinders) were first implanted unilaterally into the right posterior edentulous mandibles of 7 dogs as nonirradiated controls. After 12 weeks without functional loading and after sequential fluorochrome labeling these implants were retrieved by block dissection. In this same surgery, implants were placed on the contralateral side. Three weeks postimplantation the implant-containing hemimandibles were Cobalt 60 irradiated with the biologic equivalent of 5,000 cGy. Twelve weeks postimplantation and after labeling these irradiated implants were retrieved at sacrifice. On scanning electron, light, and fluorescence microscopic images of undecalcified longitudinal ground sections of the implants with surrounding tissues, percent bone-to-implant contact (% BIC), bone formation, and remodeling were histometrically and subjectively evaluated. Results: Woven bone formation started 1 week after implantation at the implant interfaces on both the nonirradiated and the irradiated sides. Average BICs (total/cortical/spongious bone bed) of 26%/49%/36% for surface A, 46%/48%/64% for surface B, and 81%/83%/78% for surface C were observed. In the irradiated hemimandibles average BICs (total/cortical/spongious bone bed) were reduced to 11%/9%/4% for surface A, 43%/46%/43% for surface B, and 63%/85%/76% for surface C, with increased resorption of peri-implant bone and retarded bone formation after irradiation. Discussion: Reductions of total % BIC in all irradiated implants, though not statistically significant, were significant (P ≤ .05) on implant surfaces A and B in the spongious bone bed. Conclusion: Retarded bone formation on surfaces A and B in the spongious bone bed represented a more radiation-sensitive situation at the time of radiation onset compared to advanced bone formation and maturation at surface C. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the study was to compare the failure rates of implants with either a machined surface or a TiUnite surface used to replace failing implants. Materials and Methods: The files of 578 patients, ie, of all patients who were treated at the Department of Periodontology of the University Hospital in Leuven by means of oral implants during 3 recent consecutive years, were analyzed. The implants included in the study had an observation time ranging from 9 to 49 months. All patients had been provided with Brànemark System implants. Only 2 types of implant surfaces were used: machined and TiUnite. Data collection and analysis focused on the replacement implants, ie, implants placed at sites where the original implants had failed. Data were statistically analyzed by means of Statistica for Windows Software version 5.1; a Fisher exact P test was used. The level of significance was set at P = .05. Results: A total of 41 patients experienced the nonintegration of 58 implants. Of those, 29 implants with a machined surface were replaced by implants with the same surface. Six of the replacement implants failed. Nineteen machined-surface implants were replaced by TiUnite sur- face implants; 1 failed. Ten TiUnite-surface implants were replaced by implants with the same surface; none failed. The difference in failure rate between machined-surface replacement implants and TiUnite replacement implants was statistically significant (P = .05). Discussion: In addition to the usual patient-related compromising factors, replacement of a failing implant involves the challenge of achieving osseointegration in a non pristine bone site. In the present study, implants with TiUnite surfaces were associated with fewer failures than machined-surface implants under the same conditions. Conclusion: An improved implant surface such as TiUnite may offer a better prognosis when a failed implant has to be replaced at the same site. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the present study was to evaluate implant survival rates with immediate implant placement (IIP) into fresh extraction sockets and to determine risk factors for implant failure. Materials and Methods: A retrospective chart review was conducted of all patients in whom IIP was performed between January 1988 and December 31, 2004. Treatment required atraumatic tooth extraction, IIP, and mineralized freeze-dried bone allograft with an absorbable barrier to cover exposed implant threads. implant failure was documented along with time of failure, age, gender, medical history, medications taken, posts urgical antibiotic usage, site of implant placement, and reason for implant failure. Statistical analysis was performed using chi-square and logistic regression analysis methods. Results: A total of 1,925 liPs (1,398 machined-surface and 527 rough-surface implants) occurred in 891 patients. Seventy-one implants failed to achieve integration; a total of 77 implants were lost in 68 patients. The overall implant survival rate was 96.0% with a failure rate of 3.7% prerestoration and 0.3% postrestoration. Machined-surface implants were twice as likely to fail as roughsurface implants (4.6% versus 2.3%). Men were 1.65 times more likely to experience implant failure. implants placed in sites where teeth were removed for periodontal reasons were 2.3 times more likely to fail than implants placed in other sites. Patients unable to utilize postsurgical amoxicillin were 3.34 times as likely to experience implant failure as patients who received amoxicillin. Conclusions: With a 1- to 16-year survival rate of 96%, IIP following tooth extraction may be considered to be a predictable procedure. Factors such as the ability to use postsurgical amoxicillin and reason for tooth extraction should be considered when treatment planning for IIP. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the article was to evaluate the survival rates of TiUnite implants and then compare them to a previous similar study of machined-surface implants. Materials and Methods: This report presents the results of 82 consecutive patients treated since the introduction of Nobel Biocare's TiUnite surface. The patients were treated with complete-arch restorations using bilateral pterygomaxillary implants in edentulous maxillae. A total of 840 implants were placed in immediate extraction or healed sites, with a mean of 10 implants placed per patient. Results: In all, 826 of the 840 implants osseointegrated, for a cumulative survival rate (CSR) of 98.3%. One hundred fifty-eight of 164 pterygomaxillary implants successfully osseointegrated, yielding a 96.3% survival rate. Discussion and Conclusion: The results of this complete-arch maxillary prospective study suggest that Brånemark System TiUnite implants are more predicable than implants with a machined surface. Compared to a similar 1999 study in which the survival rate for machined-surface implants was 92.1%, the present study had a significantly higher survival rate of 98.6% with the TiUnite surface (P < .001). In the pterygomaxillary region, there was an increase of 8% with the TiUnite surface as opposed to the machined surface (P < .001). In addition, 62% of the implants in the present study were immediately loaded, compared to 0% in the machined-surface implant study. The titanium oxide surface appears to assist the healing response of the bone-implant interface. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to radiographically evaluate the effect of a machined titanium coronal collar on the marginal bone around 1-part endosseous dental implants placed at different heights relative to the bone crest. Materials and Methods: Sixty dental implants were placed in edentulous spaces bilaterally in 5 foxhounds. Thirty test implants had a sandblasted, large-grit, dual acidetched surface (SLA) over the entire length of the implant. The other 30 implants (control) had a machined collar around the most coronal 1.8 mm of the implant; an SLA surface covered the remainder of the implant. Both control and test implants were placed at 3 distinct levels relative to the bone crest. Six implants (3 control and 3 test) were randomly placed side by side in each hemimandible. Radiographs were taken at placement (baseline) and monthly for 6 months postplacement using a standardized radiographic template. Results: Fifty-eight of the implants integrated and were analyzed on each proximal surface. Bone loss occurred around all implants over the 6 months of the study. In general, implants placed with the top of the SLA surface above the bone crest had significantly less bone loss than implants with the top of the SLA surface placed flush with the bone level. Apically placed implants had greater bone loss than coronally placed implants. The magnitude of bone loss around paired control and test implants was approximately the same. Discussion and Conclusion: The least bone loss with each implant type was observed when the top of the implant was placed above the alveolar crest. When there was no machined collar, the least distance from the implant top to the bone crest (not, however, the least bone loss) was observed when the top of the implant was level with the bone crest. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was the clinical and radiographic comparison of dental implants with surfaces roughened by anodic oxidation (TiUnite), dual acid-etched implants (Osseotite), and machined implants. Materials and Methods: Seventy-four patients (mean age, 52.8 ± 14.2 years; range, 23 to 80 years; 41 men and 33 women) received 198 dental implants-58 TiUnite implants (25 patients), 52 Osseotite implants (27 patients), and 88 machined implants (22 patients). Clinical measurements and radiographs were evaluated at the time of surgery, at the restorative phase, and 2 years postloading. To account for statistical correlation among multiple implants in the same subject, a "per patient" mode of analysis was conducted. A 1-way analysis of variance of bone loss was conducted by type of implant as well by area of the mouth. In addition, differences in mean bone loss were tested for bone density category, gender, and smoking status using Student t tests. Results: Eighteen TiUnite implants (31.0%) were placed in the maxilla and 40 (69.0%) in the mandible. The Osseotite group included 29 maxillary implants (55.8%) and 23 mandibular implants (44.2%). The machined group included 49 maxillary implants (55.7%) and 39 mandibular implants (44.3%). All 198 implants were considered radiographically and clinically successful. No mobility, signs of infection, or inflammation were detected. Discussion: Implant size, location, bone quality, gender, age, and smoking did not influence the comparative clinical outcomes of the 3 groups (P > .05). A trend toward greater coronal bone loss in the TiUnite group was detected. Conclusion: Within the limitations of the present study, TiUnite, Osseotite, and machined dental implants had similar short-term clinical outcomes. No statistically significant differences in bone loss could be detected among implant groups or among the different regions of the oral cavity. The present data underlined the significance of surgical and prosthetic treatment planning. [ABSTRACT FROM AUTHOR]

Purpose: To investigate detailed surface characterization of oxidized implants in a newly invented electrolyte system and to determine optimal surface oxide properties to enhance the bone response in rabbits. Materials and Methods: A total of 100 screw-type titanium implants were prepared and divided into 1 control group (machine-turned implants) and 4 test groups (magnesium ion-incorporated oxidized implants). Forty implants were used for surface analyses. A total of 60 implants, 12 implants from each group, were placed in the tibiae of 10 New Zealand white rabbits and measured with a removal torque test after a healing period of 6 weeks. Results: For the test groups, the oxide thicknesses ranged from about 1,000 to 5,800 nm; for the control group, mean oxide thickness was about 17 nm. The surface morphology showed porous structures for test groups and nonporous barrier film for the control group. Pore diameter ranged from ⩽ 0.5 μm to ⩽ 3.0 μm. In regard to surface roughness, arithmetic average height deviation (Sa) values varied from 0.68 to 0.98 pm for test implants and 0.55 μm for control implants; developed surface ratio (Sdr) values ranged from 10.6% to 46% for the test groups and were about 10.6% for the control group. A mixture of anatase and rutile-type crystals were observed in the test groups; amorphous-type crystals were observed in the control group. After a healing period of 6 weeks, removal torque measurements in all 4 test groups demonstrated significantly greater implant integration as compared to machine-turned control implants (P ⩽ .033). Discussion: Determinant oxide properties of oxidized implants are discussed in association with bone responses. Of all surface properties, RTVs were linearly increased as relative atomic concentrations of magnesium ion increase. Conclusions: Surface properties of the oxidized implants in the present study, especially surface chemistry, influenced bone responses. The surface chemistry of the optimal oxidized implant should be composed of approximately 9% magnesium at relative atomic concentration in titanium oxide matrix and have an oxide thickness of approximately 1,000 to 5,000 nm, a porosity of about 24%, and a surface roughness of about 0.8 pm in Sa and 27% to 46% in Sdr; its oxide crystal structure should be a mixture of anatase- and rutile-phase crystals. [ABSTRACT FROM AUTHOR]

Purpose: This article provides preliminary clinical results on the Osseotite NT implant, which was developed to simplify surgical procedure and cover an extended range of indications. Placement characteristics of NT and standard Osseotite implants were also compared in an in vitro study. Materials and Methods: The in vitro placement characteristics of NT and standard Osseotite implants of 4.0 mm diameter and 8.5 to 15 mm in length were compared. In addition, a total of 182 NT implants (96 maxillary and 86 mandibular) were placed in 92 patients; of these, 87.9% were placed using a 1-stage technique. The implants were placed in healed sites (43.9%), fresh extraction sockets (37.4%), or recent extraction sites (2 months postextraction) (18.7%). Before restoration, healing times of 3 to 4 months in the mandible and 5 to 6 months in the maxilla were allowed. The entered implant length in the osteotomy site before contacting the bony walls (EILOS) was compared, as well as the number of turns and the time required to seat the implants. Cumulative survival rates (CSRs) were calculated for up to 18 months of follow-up after surgery. Results: The EILOS was between 47.3% and 57.6% of implant length for the NT implants; for the standard implants, it was between 12.0% and 21.2%. With the NT implants, the number of turns and the placement time were reduced by 61% to 64% and 61% to 65%, respectively. In the clinical study, 4 implants failed during the healing period; none failed after prosthesis placement. The CSR was 97.79% for implants placed into fresh or recent extraction sites; in healed sites, the CSR was 98.75%. The cumulative prosthetic success rate was 100%. Discussion: This new implant design is seated with special drills; the drilling sequence requires less time and less torque than that used for standard implants. The low failure rate after prosthetic loading was consistent with that observed for standard Osseotite implants. Conclusion: These preliminary data suggest that the NT implant can be predictable in healed sites and fresh or relatively recent extraction sockets. [ABSTRACT FROM AUTHOR]

To evaluate the biocompatibility and the bone-bonding strength of new titanium alloy materials treated by sandblasting and anodic oxidization, 3 cylindric test pieces having different surface roughnesses were manufactured and implanted into the diaphyses of the femurs of New Zealand white rabbits. Six weeks later, shear loading tests and histologic examination were carried out. Strong interfacial bonding strength and active new bone formation were confirmed in the peripheral area of the test pieces having a surface roughness (Ra = 2.7 μm and Ra = 4.7 μm). Judging from stable fixation to shear loading in bone tissue, it was concluded that group C (Ra = 2.7 μm) had the best surface condition of the 2 groups. Further detailed examination is required to demonstrate that the surface treatment used for group C (a micro rough surface on a macro rough surface structure) can enhance active bone formation and stable fixation in bone tissue. [ABSTRACT FROM AUTHOR]

Purpose: This study was undertaken to evaluate ion beam-assisted deposition (IBAD) of hydroxyapatite (HA) on the grit-blasted surface of endosseous dental implants 6 weeks postplacement. Materials and Methods: A total of 40 implants was placed in the tibiae of 10 New Zealand white rabbits. Twenty implants were grit-blasted only and the other 20 were grit-blasted and coated with HA by the IBAD method. After 6 weeks of healing, the rabbits were sacrificed and removal torque tests, histomorphometry, and morphometric analysis of microtomographic images were performed. Results: The HA-coated group showed significantly higher removal torque, bone-to-implant contact, and bone volume than the other group. Discussion and Conclusion: In a previous study, the authors suggested that HA coating deposited on a machined surface by the IBAD method showed results comparable to or more favorable than the results obtained with a blasted surface. This study indicated that the HA coating produced by the IBAD method was also very effective on the aluminum oxide-blasted surface, as demonstrated by the early formation of osseointegration. Morphometric analysis by microtomography showed some promise in measuring the osseointegration rate. [ABSTRACT FROM AUTHOR]

Purpose: Transitional implants (Tis) were developed as a method of providing fixed provisional restorations for the implant patient who wishes to avoid removable temporary restorations during implant healing. Success of Tis depends on achieving sufficient osseointegrated bone-to-implant contact (BIC) during the provisional prosthesis phase. To date, little data are available on the degree of BIC of these implants in function. The purpose of this study was to histologically evaluate the BIC of TIs following various periods of loading. Materials and Methods: Histologic analysis of 33 immediately loaded implants from 21 patients was performed. All TIs had turned machined surfaces and were made of commercially pure titanium (grade 1). These transitional implants were in function for an average of 10.8 months (range: 6 to 27 months). Before the definitive restoration was provided, all of the TIs were removed with trephine drills and sent for hard tissue histomorphometric analysis. Results: The average percentage of BIC was 52.9% ± 13.81% (range 25.1% to 83%). Discussion: Although TIs are traditionally removed when the definitive implants are restored, the BIC and clinical integration of the TIs in the present study may suggest a change in TI protocol. Studies are indicated to examine long-term use of TIs as sole support or in conjunction with definitive implants in definitive implant-supported restorations. Conclusion: The percentage of BIC achieved with TIs was similar to that documented in the literature for conventional turned, machine-surfaced implants. [ABSTRACT FROM AUTHOR]

Purpose: Implant length, implant surface area, and crown-to-root (c/r) ratio and their relationship to crestal bone levels were analyzed in 2 groups of partially edentulous patients treated with sintered porous-surfaced dental implants. Materials and Methods: One hundred ninety-nine implants were used to restore 74 partially edentulous patients with fixed prostheses. Implants were categorized according to their length ("short" versus "long") and estimated surface area ("small" versus "large"). "Short" implants had lengths of 5 or 7 mm, while "long" implants were either 9 or 12 mm in length. "Small" implants had estimated surface areas of > 600 mm2, while "large" implants had estimated surface areas > 600 mm2. Other data collected included c/r ratio (measured on articulated diagnostic casts), whether or not the implants were splinted, and standardized sequential radiographs. Results: The mean c/r ratio was 1.5 (SD = 0.4; range 0.8 to 3.0), with 78.9% of the implants having a c/r ratio between 1.1 and 2.0. Neither c/r ratio nor estimated implant surface area (small or large) affected steady-state crestal bone levels. However, implant length and whether the implants were splinted did appear to affect bone levels. Long implants had greater crestal bone loss (0.2 mm more) than short implants; splinted implants showed greater crestal bone loss (0.2 mm more) than nonsplinted ones. These differences were statistically significant. Discussion and Conclusions: Sintered porous-surfaced implants performed well in short lengths (7 mm or less) in this series of partially edentulous patients. The data suggested that long implants and/or splinting can result in greater crestal bone loss; longer implants and splinted implants appeared to favor greater crestal bone loss in this investigation. These conclusions are, of course, specific to the implants used and would not be relevant to other implant types. [ABSTRACT FROM AUTHOR]

Purpose: Tissue reactions to 4 different implant surfaces were evaluated in regard to the development and progression of ligature-induced peri-implantitis. Materials and Methods: In 6 male mongrel dogs, a total of 36 dental implants with different surfaces (9 titanium plasma-sprayed, 9 hydroxyapatite-coated, 9 acid-etched, and 9 commercially pure titanium) were placed 3 months after mandibular pre-molar extraction. After 3 months with optimal plaque control, abutment connection was performed. Forty-five days later, cotton ligatures were placed around the implants to induce peri-implantitis. At baseline and 20, 40, and 60 days after placement, the presence of plaque, peri-implant mucosal redness, bleeding on probing, probing depth, clinical attachment loss, mobility, vertical bone loss, and horizontal bone loss were assessed. Results: The results did not show significant differences among the surfaces for any parameter during the study (P > .05). All surfaces were equally susceptible to ligature-induced peri-implantitis over time (P < .001). Correlation analysis revealed a statistically significant relationship between width of keratinized tissue and vertical bone loss (r² = 0.81; P = .014) and between mobility and vertical bone loss (r² = 0.66; P = .04), both for the titanium plasma-sprayed surface. Discussion and Conclusions: The present data suggest that all surfaces were equally susceptible to experimental peri-implantitis after a 60-day period. [ABSTRACT FROM AUTHOR]

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 μm) than the unmodified control implants (Sa: 1.12 ± 0.24 μm). 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. [ABSTRACT FROM AUTHOR]

Purpose: Protocols for quantifying the surface roughness of implants are varied and dependent upon the roughness parameter produced by the particular measurement device. The objective of this study was to examine the accuracy and precision of typical roughness characterization instruments used in the dental implant industry. Materials and Methods: The average roughness (Ra) was measured using 2 common surface characterization instruments: an interferometer and a stylus profilometer. Titanium disks were prepared to represent 4 typical dental implant surfaces: machined, acid-etched, hydroxyapatite-coated, and titanium plasma-sprayed. Repeated measurements from multiple sites on each surface were undertaken to establish statistical inferences. Qualitative images of the surfaces were also acquired using a laser scanning con focal microscope. After surface measurements were conducted, the disks were diametrically cut and cross-sectional profiles were examined using a scanning electron microscope (SEM) as a comparative measure of surface topography. An analysis of variance was applied to isolate the effects of the measurement site, measurement sequence, surface treatment, and instrument type on Ra values. Results: The results indicated that surface treatment (P = .0001) and instrument (P = .0001) strongly influenced Ra data. By design, measurement site (diametrical: P = .9859; area: P = .9824) and measurement sequence (P = .9990) did not influence roughness. In the assessment of individual instrument accuracy, the interferometer was the most accurate in predicting SEM-based roughness (P = .6688) compared with the stylus (P = .0839). As a measure of aggregate precision over all measurements, the most repeatable instrument was the stylus (coefficient of variation [CV] = 0.108), followed by the interferometer (CV = 0.125) and SEM (CV = 0.273). Discussion: These results indicate dependencies in accuracy and precision related to the surface characterization technique. Conclusion: Instrument variability may obscure functional correlations between implant surface topography and osseointegration. [ABSTRACT FROM AUTHOR]

Background: Mechanical scaling is the most common treatment of periodontal and peri-implant tissue infections. Aims: This study aimed to evaluate the effect of mechanical prophylactic therapy on the residual stresses in the implant and hand scaler. Settings and Design: For finite-element analysis, an implant-supported prosthesis was created using modeling software with 3 mm of exposed threads. For simulation of a prophylactic mechanical debridement, the active face of the shank was disposed of in contact with the last thread exposed at a 90° angle. Materials and Methods: In the analysis software, the contacts were defined as rough between the instrument and the implant. The cortical bone was fixed and a load of 10 N was applied to the instrument cable. Two simulations were performed according to the instrument material: stainless steel or Teflon. Von-Mises results were obtained. Statistical Analysis Used: No statistical test was used, but, the 500 higher stress peaks in the implant and in the instrument were analyzed for qualitative comparison. Results: Mechanical prophylactic therapy generates higher residual stress on the implant with a stainless steel instrument. There was no difference between the materials for the active tip of the instrument, and the active portion of the shank was the region which concentrated more stress. Conclusions: It is suggested that hand scalers in Teflon are less damaging to the implant, but more susceptible to deformation and possible early failures.

Several antiseptic agents have been proposed for the treatment of peri-implantitis as a complementary therapeutic strategy in addition to mechanical devices. The aim of this study was to compare six different antiseptics, as well as alternative formulations of the same chemical agent, with respect to their decontamination efficacy and impact on chemical properties of the implant surface. Titanium disks with a micro-rough surface, previously contaminated with Porphyromonas gingivalis and Streptococcus mutans biofilms, were treated for 2 min with different antiseptics (liquid sodium hypochlorite 5.25%, gel sodium hypochlorite 5.25%, liquid chlorhexidine 0.2%, gel chlorhexidine 1%, gel citric acid 40%, and gel orthophosphoric acid 37%) or sterile saline solution (control) and their antibacterial activity as well as their ability to remove biofilm were assessed by viable bacterial count and scanning electron microscopy, respectively. Spectroscopic analysis was also performed on non-contaminated disks after exposure to the antiseptics, in order to detect any change in the elemental composition of the titanium surface. All the antimicrobial formulations examined were effective against P. gingivalis and S. mutans biofilms. SEM analysis revealed however that liquid sodium hypochlorite 5.25% was more effective in dissolving biofilm residues. Spectroscopic analysis detected traces of the antiseptics, probably due to insufficient rinsing of the titanium surfaces. In conclusion, since gel formulations of these antiseptic agents possessed a similar antibacterial activity to the liquid formulations, these may be proposed as alternative treatments given their properties to avoid overflows and increase contact time without significant side effects on the bone. [ABSTRACT FROM AUTHOR]

Objectives: The objective of this study was to evaluate the peri‐implant bone tissue formation around titanium implants with different surface treatments, placed in bone defects filled or not with bone substitute material (BSM). Materials and Methods: Ten animals were divided into two groups according to implant surface treatment. In each tibia, a bone defect was created followed by the placement of one implant. On the left tibia, the defect was filled with blood clot (BC), and on the right tibia, the defect was filled with biphasic hydroxyapatite/β‐tricalcium‐phosphate (HA/TCP) generating four subgroups: BC‐N: blood clot and porous surface; BC‐A: blood clot and porous‐hydrophilic surface; HA/TCP‐N: BSM and porous surface; HA/TCP‐A: BSM and porous‐hydrophilic surface. The animals were submitted to euthanasia 60 days after implant installation. After light‐curing resin inclusion, the blocks containing the implant and the bone tissue were stained and evaluated by means of histomorphometry to assess the percentages of bone implant contact (% BIC). Data was normally distributed and the group differences were examined using the parametric tests of Two‐Way ANOVA. Results: The BC‐A group presented the higher mean value of BIC (46.43%). The HA/TCP‐A group presented the higher mean value of BIC. The porous‐hydrophilic surfaces presented better results of BIC when compared to the porous surface in both conditions of defect filling. No statistically significant differences were found among all groups (95% confidence interval and P <.05). Conclusion: According to histomorphometric analysis, after 60‐days in a rabbit model, hydrophilic and hydrophobic surfaces have the same behavior in the presence or absence of HA/TCP. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to determine the antibiofilm activity of Mentha longifolia essential oil (EO) against biofilms forming on in-vitro implant surfaces. Materials and Methods: Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Candida albicans biofilms were used. Stainless steel and titanium samples were grouped as control, water diluted, no EO addition, and reducing amounts of EO doses. The six microorganisms included in the study were investigated to examine if there were differences between the doses on the implant surfaces. The eradication effect of the EO in samples investigated with electron microscope was classified as 0: none, 1: mild, 2: moderate, and 3: severe. The chemical composition of the EO was determined with gas chromatography. Results: In terms of biofilm formation, no difference was observed between implant surfaces. While S. aureus and C. albicans were observed to be the most susceptible, P aeruginosa was identified as the most resistant. According to gas chromatography M. longifolia EO comprised 61.40% carvacrol and 0.28% thymol. Conclusion: In vitro, M. longifolia EO was shown to be effective against gram negative/positive and fungal biofilms forming on the surface of stainless steel and titanium implants. [ABSTRACT FROM AUTHOR]

Besides bone, two other tissues directly contact an osseous implant and/or attachments to it: epithelium and soft connective tissues including the gingival connective tissue. These tissues have received less attention than bone, but are required because of the transmucosal nature of endosseous dental implant restorations. The attachment and growth of human gingival and periodontal ligament fibroblasts and an epithelial cell line to titanium with various surface textures have been examined. Of the three cell types examined, gingival fibroblasts attached best, followed by periodontal ligament fibroblasts and the epithelial cells. Both fibroblast cell types had more cells attached to control (tissue culture plastic) and smooth titanium than either of two rough surfaces. However, once attached, the fibroblast cells grew well on smooth and rough titanium. Epithelial cells did not attach well to any of the surfaces but after a lag period proliferated on control and smooth titanium, although not on either rough titanium surface. This study demonstrates that, as has been found in vivo, human fibroblast and epithelial cell attachment and proliferation are significantly affected by surface characteristics of titanium. These studies suggest that surface texture could be used to guide specific cell attachment to the dental implant. They also provide an in vitro model in which agents such as inflammatory mediators and growth factors could be examined on specific cell function on titanium with distinct surface characteristics. [ABSTRACT FROM AUTHOR]

This investigation was conducted to determine the effects of an air-abrasive polishing system on various implant surfaces. Four each of the following types of implants were obtained from the manufacturer: Stryker DB (a titanium alloy implant), Denar Steri-Oss (a pure titanium implant), IMZ (pure titanium polished collar/plasma-sprayed body), and IMZ transmucosal implant extensions (highly polished pure titanium). Four samples of each type of implant material were placed in a group to be treated with an air-abrasive polishing system for 0.5, 1, 5, or 10 seconds, for a total of 16 samples. Scanning electron photomicrographs taken of each sample before and after treatment were analyzed by three examiners who were blind to the treatment conditions. They determined if the abrasion on the treated surface was greater than, equal to, or less than the pretreatment control. No perceptible difference was noted between the pretreatment and posttreatment photomicrographs regarding the surface integrity of the implant material surfaces. [ABSTRACT FROM AUTHOR]

When a biological system encounters an implant, reactions are induced at the implant-tissue interface. This article deals with various surface properties that are expected to influence tissue-implant reactions and methods available for implant surface characterization. Surface properties of interest are chemical composition, contamination and cleanliness, microarchitecture and structure, etc. Surface science offers a range of methods for surface characterization, eg, x-ray photoemission spectroscopy (XPS or ESCA) and Auger electron spectroscopy (AES), and preparation, which may be used to optimize implant fabrication with molecular level control. Examples are given from analytical and preparative work by XPS, AES, and electron microscopy on pure and alloyed titanium, with focus on surface oxides on these materials. Results of this type are valuable for basic research concerning implant-tissue reactions as well as production control and implant standardization. [ABSTRACT FROM AUTHOR]

Background: Mechanical scaling is the most common treatment of periodontal and peri-implant tissue infections. Aims: This study aimed to evaluate the effect of mechanical prophylactic therapy on the residual stresses in the implant and hand scaler. Settings and Design: For finite-element analysis, an implant-supported prosthesis was created using modeling software with 3 mm of exposed threads. For simulation of a prophylactic mechanical debridement, the active face of the shank was disposed of in contact with the last thread exposed at a 90° angle. Materials and Methods: In the analysis software, the contacts were defined as rough between the instrument and the implant. The cortical bone was fixed and a load of 10 N was applied to the instrument cable. Two simulations were performed according to the instrument material: stainless steel or Teflon. Von-Mises results were obtained. Statistical Analysis Used: No statistical test was used, but, the 500 higher stress peaks in the implant and in the instrument were analyzed for qualitative comparison. Results: Mechanical prophylactic therapy generates higher residual stress on the implant with a stainless steel instrument. There was no difference between the materials for the active tip of the instrument, and the active portion of the shank was the region which concentrated more stress. Conclusions: It is suggested that hand scalers in Teflon are less damaging to the implant, but more susceptible to deformation and possible early failures. [ABSTRACT FROM AUTHOR]

Implants with rough surfaces are today widely used. It has been speculated that rough surfaces (Ra > 0.2 μm) provide a better “substrate” for retention and accumulation of plaque in terms of area, thickness and colony-forming unit that can eventually lead to peri mucositis and/or peri-implantitis. The aim of this investigation was to evaluate in vivo the plaque accumulation after 48 h on three implant surfaces with different treatments. For this investigation, we used 21 sterilized titanium disks, with a diameter of 8mm and a thickness of 3 mm, provided by the manufacturer: 7 with machined surface, as smooth control, 7 with HA grit sandblasted RBM surface and 7 with Ca++ incorporated in titanium Xpeed surface. One disk for each surface treatment was characterized at time 0 by SEM and AFM to study, respectively, the surface morphology and roughness. The other 18 disks were mounted randomly on three upper acrylic bites in a buccal lateral position, worn for 48 h by three volunteer students for plaque accumulation. After 48 h each disk was removed and analyzed qualitatively and quantitatively by an independent operator, not involved into the study, in order to avoid bias. Data collected were statistically analyzed by one-way ANOVA. The qualitative analysis showed no differences in terms of total plaque accumulation between the surfaces. Data from quantitative analysis using Anova Test showed no significance between all groups. In this in vivo investigation all the surfaces studied promoted plaque formation. The degree of surface roughness seems not to be a critical factor for plaque accumulation. [ABSTRACT FROM AUTHOR]