Osteomyelitis-Induced Sequester of Bovine-Derived Bone Mineral/Host Bone Composite 8 Years Post-Sinus Graft: A Case Report.

INTRODUCTION: Sinus grafts are a safe and predictable treatment for increasing bone volume in the posterior maxilla. Common complications include membrane perforations and postoperative infection. Little is published with regard to late-onset infection except as it relates to periimplantitis. This report presents a case of late sequestration of bovine bone mineral graft fully consolidated within host lamellar bone, 8 years postsinus lift. Histology revealed mature lamellar bone encapsulating well-integrated particles of bovine bone material with evidence of devitalization and marrow spaces filled with a dense neutrophil infiltrate and a filamentous mixed microbial flora. RESULT: A histological diagnosis of osteomyelitis was given on analysis of the integrated bovine bone mineral sequester, 8 years after successful integration and functional loading. CONCLUSIONS: It can be concluded from this case report that there is a potential for breakdown and sequestration of bovine bone mineral/host bone composite grafts long after successful integration and consolidation.

Lopinavir/Ritonavir Monotherapy as Second-line Antiretroviral Treatment in Resource-Limited Settings: Week 104 Analysis of AIDS Clinical Trials Group (ACTG) A5230.

BACKGROUND: The AIDS Clinical Trials Group (ACTG) A5230 study evaluated lopinavir/ritonavir (LPV/r) monotherapy following virologic failure (VF) on first-line human immunodeficiency virus (HIV) regimens in Africa and Asia. METHODS: Eligible subjects had received first-line regimens for at least 6 months and had plasma HIV-1 RNA levels 1000-200 000 copies/mL. All subjects received LPV/r 400/100 mg twice daily. VF was defined as failure to suppress to <400 copies/mL by week 24, or confirmed rebound to >400 copies/mL at or after week 16 following confirmed suppression. Subjects with VF added emtricitabine 200 mg/tenofovir 300 mg (FTC/TDF) once daily. The probability of continued HIV-1 RNA <400 copies/mL on LPV/r monotherapy through week 104 was estimated with a 95% confidence interval (CI); predictors of treatment success were evaluated with Cox proportional hazards models. RESULTS: One hundred twenty-three subjects were enrolled. Four subjects died and 2 discontinued prematurely; 117 of 123 (95%) completed 104 weeks. Through week 104, 49 subjects met the primary endpoint; 47 had VF, and 2 intensified treatment without VF. Of the 47 subjects with VF, 41 (33%) intensified treatment, and 39 of 41 subsequently achieved levels <400 copies/mL. The probability of continued suppression <400 copies/mL over 104 weeks on LPV/r monotherapy was 60% (95% CI, 50%-68%); 80%-85% maintained levels <400 copies/mL with FTC/TDF intensification as needed. Ultrasensitive assays on specimens with HIV-1 RNA level <400 copies/mL at weeks 24, 48, and 104 revealed that 61%, 62%, and 65% were suppressed to <40 copies/mL, respectively. CONCLUSIONS: LPV/r monotherapy after first-line VF with FTC/TDF intensification when needed provides durable suppression of HIV-1 RNA over 104 weeks. CLINICAL TRIALS REGISTRATION: NCT00357552.

Clinical and Histological Efficacy of Digitally Designed CAD CAM Allogenic Bone Blocks. A Prospective Cohort.

The growth in bone reconstructive surgery has been unsurpassed in recent decades. However, most bone regenerative products lack any potential for delivering site-specific morphologically driven augmentation. It was therefore the purpose of this study to evaluate the histological and clinical incorporation of a novel CAD CAM allogenic block bone graft for the reconstruction of complex 3- dimensional alveolar defects. In addition the clinical outcome of dental implants subsequently placed and loaded within these grafts was assessed with up to 5 years in function. Results demonstrated that 4 of the initial 17 blocks failed (23.5%). The remaining 13 blocks plus an additional two replacement blocks were fully or partially incorporated within the recipient bone site (79%). Of the 29 implants placed within the integrated blocks, no failures occurred with up to 5 years in function, with a recorded mean marginal bone loss by implant of -0.5mm.

First-in-Human Pilot Study to Assess Methodology for Using a Mineral-Organic Bone Adhesive for Optimization of Primary Stability and Implant Success for Implants Glued into Immediate Extraction Sockets and Immediately Temporized: Pilot Study.

PURPOSE: To assess the handling properties and clinical function of a new class of material, a so-called mineral-organic bone adhesive (Tetranite; TN), which as yet has no precedent in orthopedic or oral and maxillofacial surgery, for clinically unstable implants placed in immediate extraction sockets and immediately temporized in the anterior maxilla. MATERIALS AND METHODS: A cohort of up to 15 patients requiring between one and four immediate dental implants placed into maxillary extraction sockets from canine to canine were eligible for inclusion. Implants had to be unstable with an insertion torque of < 15 Ncm. Implants were then stabilized using TN, which was allowed to set before reassessing stability using both torque and resonance frequency measurements. Implant stability quotients (ISQs) taken after TN setting were compared to ISQs taken prior to its application, and the implants had to demonstrate resistance to a forward torque of 20 Ncm to be considered stable. ISQs were monitored at 1 week and 1, 3, 7, and 12 months postplacement. In addition, peri-implant tissue health was monitored, adverse events were recorded, and implant success was determined at 1 year postplacement. RESULTS: Eleven patients received a total of 14 implants. Three out of the first six implants failed within 1 month (50%), and thus a protocol amendment was made to remove steps considered potentially destructive to the bonding process. As a result of these amendments, only one further failure was experienced for the next eight implants placed (12.5%). Mean ISQ data averaged for buccolingual and mesiodistal measurements demonstrated a baseline value before TN application of 59.1 Ncm (SD: ± 9.7; range: 40.5 to 73.0). After final setting of the TN, mean ISQ measured 71.9 Ncm (± 6.5; 56.0 to 80.0). At 3 months, just prior to restoration placement, mean ISQ measured 71.0 Ncm (± 6.6; 57.0 to 78.0). Thereafter, the mean ISQ continued to increase at both the 7- and 12-month follow-ups with scores of 78.9 (± 4.6; 72.0 to 84.5) and 80.3 (± 3.8; 74.5 to 85.0), respectively. The surviving 10 implants went on to be fully restored and remained in function beyond the end of the study period to yield a final success rate of 71.4%. CONCLUSIONS: The purpose of a first-in-human study is to demonstrate an extrapolation of preclinical data into the controlled human clinical arena. It is an opportunity to learn what does and does not translate well from experimental data. In that regard, the current pilot study can be deemed a complete success. The implant survival rate of 71.4%, while disappointing, should be considered in light of the protocol amendments identified, the user handling experience learned, and the opportunity to modify the material to better perform in the human patient, as all represent important lessons learned. The notable increase in ISQ sheds light on the nature by which the glue was substituted for bone to yield a stable implant by the end of the study period.

First-in-Human Pilot Study to Assess Methodology for Using a Mineral-Organic Bone Adhesive for Optimization of Primary Stability & Implant Success for Implants Glued into Immediate Extraction Sockets and Immediately Temporized. Pilot Study 1.

PURPOSE: The purpose of this First-in-Human pilot study was to assess the handling properties and clinical function of a new class of material, so-called mineral-organic bone adhesive (Tetranite, TN), that as yet has no precedent in orthopedic or oral & maxillofacial surgery, for clinically unstable implants, stabilized by this bone adhesive, in immediate extraction sockets and immediately temporized in the anterior maxilla. MATERIALS & METHODS: A cohort of up to 15 patients requiring between 1 and 4 immediate dental implants inserted into maxillary extraction sockets from canine to canine could be enrolled to the study. Implants had to be unstable, <15Ncm. Implants would then be stabilized by the use of a TN, which was allowed to set and the stability re-assessed using both torque and resonance frequency. Implant Stability Quotients (ISQ) taken after TN set were compared to ISQs taken prior to its application and the implants had to demonstrate resistance to a forward torque of 20Ncm. ISQs were monitored at 1 week and 1, 3, 7 and 12 months post-placement. In addition, peri-implant tissue health was monitored, adverse events recorded and implant success determined 1-year post-placement. RESULTS: 11 patients received a total of 14 implants. Three out of the first 6 implants failed within one month (50%), subsequent to which a protocol amendment was made to remove steps considered potentially destructive to the bonding process. As a result of these amendments only 1 further failure was experienced for the next 8 implants placed (12.5%). Mean ISQ data averaged for bucco-lingual and mesio-distal measurements, demonstrated a baseline value before TN application of 59.1 (Std Dev: ±9.7; Min: 40.5; Max: 73.0). After final set of the TN, mean ISQ measured 71.9 (Std Dev: ±6.5; Min: 56.0; Max: 80.0). At 3 months, just prior to restoration, mean ISQ measured 71.0 (Std Dev: ±6.6; Min: 57.0; Max: 78.0). Thereafter mean ISQ continued to increase at both the 7- and 12- month reviews with scores of 78.9 (Std Dev: ± 4.6; Min: 72.0; Max: 84.5) and 80.3 (Std Dev: ± 3.8; Min: 74.5; Max: 85.0) respectively. The surviving 10 implants went on to be fully restored and remain in function beyond the end of the study period to yield a final success rate of 71.4%. CONCLUSION: The purpose of a first-in-human study is to demonstrate an extrapolation of pre-clinical data into the controlled human clinical arena. It is an opportunity to learn what does and does not translate well from experimental data. In that regard the current pilot study can be deemed a complete success. The implant survival rate of 71.4%, while disappointing, should be considered in light of protocol amendments identified, user handling experience learned, and the opportunity to modify the material to better perform in the human subject, as all represent important lessons learnt. The notable increase in ISQ sheds light on the nature by which the glue is substituted for bone to yield a stable implant at the end of the study period.

Biologic and Mechanical Stability of Screw-Retained Layered Zirconia Crowns Bonded to CAD/CAM Titanium Abutments Using Angulated Screw Access: A Prospective Closed Cohort Study.

Purpose: To evaluate hard and soft tissue response and mechanical integrity for screw-retained layered zirconia crowns bonded to titanium nitride-coated titanium (TiN) CAD/CAM abutments supported by implants at 1- and 2-year follow-ups. Materials and Methods: A total of 46 patients were restored with a total of 102 free-standing implant-supported layered zirconia crowns, which were bonded to their respective abutments in the dental laboratory and delivered as a one-piece screw-retained crown. Baseline, 1-year, and 2-year data were collated on pocket probing depth, bleeding on probing, marginal bone levels, and mechanical complications. Results: Of the 46 patients, 4 patients with one implant each were not followed-up. These patients were not included in the analysis. Of the remaining 98 implants, due to failed appointments during the global pandemic, soft tissue measurements were recorded for 94 implants at year 1 and 86 implants at year 2, with a mean buccal/lingual pocket probing depth of 1.80/1.95 mm and 2.09/2.17 mm, respectively. Mean bleeding on probing was 0.50 and 0.53 at 1 and 2 years, which represents somewhere between no bleeding and a spot bleed according to the study protocol. Radiographic data were available for 74 implants at year 1 and 86 implants at year 2. The mean marginal bone change from baseline was +0.11 mm mesially and +0.19 mm distally at 1 year and +0.24 mm mesially and +0.16 mm distally at 2 years. The final bone level with respect to the reference point was +0.49 mm mesially and +0.19 mm distally at the end of the study period. Mechanical complications involving a slight misfit of the crown margin were recorded for one unit (1%), porcelain fracture for 16 units (16%), and a loss of preload for 12 units (12%) of < 5 Ncm (< 20% of initial preload). Conclusion: The biologic and mechanical stability of ceramic crowns bonded to CAD/CAM screw-retained abutments using angulated screw access was considered to be high, with overall bone gain, excellent soft tissue health, and only limited mechanical complications related to generally small fractures of the porcelain and a clinically insignificant loss of preload.

Will any dental implant do?

Dental implant treatment is a well-documented technology, but sadly with the passage of time, the vast majority of dental implants sold on the market today have little of their own documentation. All implants are not the same and the consequences of 'look-alike' implants relying on the documentation of others may be far-reaching. This opinion piece highlights concerns identified in the literature and exposes problems that are already occurring in reality.

The Influence of Implant Surface on Maintenance of Marginal Bone Levels for Three Premium Implant Brands: A Systematic Review and Meta-analysis.

PURPOSE: The purpose of this meta-analysis was to evaluate the short- and long-term outcomes for marginal bone level changes around implants that benefit from one of three commercially available implant surface preparations: Astra Tech OsseoSpeed (ATO), Straumann SLA/SLActive (SLA), and Nobel Biocare TiUnite (NBT). MATERIALS AND METHODS: A MEDLINE (full text) search was conducted in July 2019 using the search terms "dental implant," "prospective," "bone level," and either implant surface/brand "TiUnite," "Nobel," "Nobel Biocare" (Nobel Biocare); or "OsseoSpeed," "Astra Tech" (Astra Tech); "Dentsply" or "SLA"; "SLActive" or "Straumann," in different combinations. Additionally, searches in Google Scholar, Elsevier, and Wiley publisher homepages were made. The abstracts were screened for eligibility, according to predefined inclusion and exclusion criteria. Initial screening resulted in 588, 813, and 616 publications for ATO, SLA, and NBT, respectively. The principal outcome measure was change in marginal bone levels at the 1- and 5-year follow-ups. A weighted mean value for the marginal bone level changes (MBLCw) based on the number of implants analyzed in each of the studies and a standard error mean for the MBLCw were calculated (SEMw). A test of the null hypotheses that the MBLC was equal in each pair of the three groups was carried out for all data available at the implant level, using both the Student t test and Wilcoxon rank sum test. A P value below 5% was considered statistically significant. RESULTS: After a full-text analysis and screening, a total of 37 ATO, 23 SLA, and 53 NBT publications qualified for inclusion in the meta-analysis for both the 1- and 5-year data. At the 1-year follow-up, data were available for 2,586 implants for ATO, compared with 1,490 and 3,948 implants for SLA and NBT, respectively. A weighted analysis revealed that mean MBLCw was -0.29 mm (SEMw: 0.0005 mm, SD: ± 0.42 mm) for ATO, compared with -0.83 mm (SEMw: 0.0025 mm, SD: ± 0.36 mm) for SLA and -0.87 mm (SEMw: 0.0006 mm, SD: ± 0.56 mm) for NBT. There was a statistically significant difference between ATO vs SLA (P < .0001), ATO vs NBT (P = .0012), and SLA vs NBT (P = .0488). Data at the 5-year follow-up were available for 1,168, 202, and 1,683 implants from the ATO, SLA, and NBT groups, respectively. Analysis revealed that mean MBLCw was -0.35 mm (SEMw: 0.0038 mm, SD: ± 0.66 mm) for ATO compared with -0.74 mm (SEMw: 0.0154 mm, SD: ± 0.45 mm) for SLA and -1.19 mm (SEMw: 0.0107 mm, SD: ± 0.61 mm) for NBT. There was a statistically significant difference between ATO vs SLA (P = .0024) and ATO vs NBT (P = .0240). The difference between SLA and NBT did not reach statistical significance (P = .0769). CONCLUSION: Based on the current meta-analysis, the null hypotheses could be rejected, and even if all groups demonstrated only a small mean amount of change in marginal bone levels at the 1- and 5-year follow-ups, there was a statistically significant difference between the three implant surface preparations, with the ATO surface showing superior marginal bone maintenance.

Improving biologic predictors of cycling endurance performance with near-infrared spectroscopy derived measures of skeletal muscle respiration: E pluribus unum.

The study aim was to compare the predictive validity of the often referenced traditional model of human endurance performance (i.e. oxygen consumption, VO2 , or power at maximal effort, fatigue threshold values, and indices of exercise efficiency) versus measures of skeletal muscle oxidative potential in relation to endurance cycling performance. We hypothesized that skeletal muscle oxidative potential would more completely explain endurance performance than the traditional model, which has never been collectively verified with cycling. Accordingly, we obtained nine measures of VO2 or power at maximal efforts, 20 measures reflective of various fatigue threshold values, 14 indices of cycling efficiency, and near-infrared spectroscopy-derived measures reflecting in vivo skeletal muscle oxidative potential. Forward regression modeling identified variable combinations that best explained 25-km time trial time-to-completion (TTC) across a group of trained male participants (n = 24). The time constant for skeletal muscle oxygen consumption recovery, a validated measure of maximal skeletal muscle respiration, explained 92.7% of TTC variance by itself (Adj R2  = .927, F = 294.2, SEE = 71.2, p < .001). Alternatively, the best complete traditional model of performance, including VO2max (L·min-1 ), %VO2max determined by the ventilatory equivalents method, and cycling economy at 50 W, only explained 76.2% of TTC variance (Adj R2  = .762, F = 25.6, SEE = 128.7, p < .001). These results confirm our hypothesis by demonstrating that maximal rates of skeletal muscle respiration more completely explain cycling endurance performance than even the best combination of traditional variables long postulated to predict human endurance performance.

Healed Edentulous Sites: Suitability for Dental Implant Placement, Need for Secondary Procedures, and Contemporary Implant Designs.

PURPOSE: The purpose of this retrospective computed tomography study was to evaluate bone availability for dental implant placement, frequency of bone augmentation procedures, frequency of anatomical structures that compromise implant placement, and frequency of implant dimensions, and to determine which edentulous sites would benefit from the use of a sloped implant versus a traditional flat design. MATERIALS AND METHODS: Recorded parameters included the width of the ridge, the buccal and lingual/palatal alveolar bone height in reference to different anatomical landmarks, determination of implant placement, selection of an implant with a flat or sloped top, and need for a secondary bone augmentation procedure. RESULTS: One thousand three hundred seventy edentulous sites were evaluated in 216 patients. Implants could be placed in 60.6% of the total sites, where the coronal portion would be sloped in 59% of sites and conventionally flat in 41%; 39.4% of sites were not adequate for implant placement, where 56.5% needed additional guided bone regeneration procedures and 43.5% required sinus augmentation procedures. The inferior alveolar canal was the most frequent anatomical structure limiting size and/or placement. CONCLUSION: The study indicates that implants can be placed in slightly over half of edentulous sites without a secondary grafting procedure. The possibility of dental implant placement varied according to the volume and morphology of alveolar bone and related anatomical structures. This decreased from anterior to posterior in both arches. The sloped implant design was beneficial. In addition, the sloped implant design resulted in the placement of a longer implant.

Resonance Frequency Analysis: Agreement and Correlation of Implant Stability Quotients Between Three Commercially Available Instruments.

PURPOSE: Purpose: The purpose of this study was to analyze the implant stability quotient (ISQ) values recorded by three commercially available resonance frequency analysis (RFA) instruments from a large cohort of implants in order to determine their accuracy and agreement with one another both for static measurements of ISQ at a given time and for change in ISQ over time. MATERIALS AND METHODS: Materials and Methods: A cohort of n = 210 implants had their primary stability, secondary stability, or both evaluated in both the mesiodistal (MD) and buccolingual (BL) directions by means of ISQ using three different RFA instruments: Osstell ISQ (OISQ), Osstell IDx (OIDX), and the Penguin (PG). ISQ values were recorded both at the time of implant placement and at 3 months postinsertion prior to definitive restoration. All values were tabulated for a blinded statistical analysis using Bland-Altman plots to determine if the outcome values were in agreement both for primary and secondary stability. In addition, a subgroup was evaluated to determine if change in ISQ was also in agreement. An intraclass correlation (ICC) was used to measure the reliability of the measurements for each instrument. RESULTS: Results: Bland-Altman plots confirmed that there was a high agreement for MD values between OISQ and OIDX, with 72.7% of readings being within one ISQ unit and 94.7% within four units. Comparing PG to OISQ, the respective values at one and four units were 15.3% and 82.3%, and comparing PG to OIDX, the respective values were 16.3% and 85.2%. In general, there was a greater uncertainty in the BL values having wider variability and demonstrating less agreement between instruments, with the percentage of readings falling within four units reducing to 85.9% (OISQ vs OIDX), 72.3% (PG vs OISQ), and 74.3% (PG vs OIDX). For change in ISQ over time, 92.3% of values were in agreement to within four units between instruments OISQ and OIDX in the MD direction and 73% in the BL direction. The respective percentage changes of values in agreement within four units for PG vs OISQ were 76.9% and 60.3% and for PG vs OIDX were 80% and 53.8%. The paired t test from mixed effects revealed that there was a significant difference for mean MD values between PG vs OISQ; P = .015 with a mean 0.823 units higher was recorded for PG. Similarly for PG vs OIDX, P = .008 with a mean 0.871 units higher was recorded for PG. For mean BL values between PG vs OIDX, P = .000 with a mean 1.161 units higher was recorded for PG, and finally, for OISQ vs OIDX, P = .005 with a mean 0.597 units higher was recorded for OISQ. However, the maximum upper and lower bound estimated bias between any two instruments was only 1.86 units and 0.46 units both for PG vs OIDX in the BL direction, and it is doubtful that this is of clinical relevance even if statistically significant. ICC revealed that for static MD measurements, there was an 85% reliability between all three instruments (range: 79% to 97%). For BL measurements, the reliability value was 66% (range: 69% to 71%). When considering ICC for changes in ISQ values over time in the MD direction, there was a 70% reliability between all three instruments (range: 58% to 94%). For BL measurements, the reliability value was 58% (range: 46% to 91%). CONCLUSION: Conclusion: Differences exist between instruments to some extent, most notably between the Penguin and the two instruments from Osstell, which showed good agreement to each other. While differences in evaluating ISQ with the PG were statistically significant, they were less than 1.86 units at the upper bound limit, and it is doubtful that this is of clinical relevance. Increased variability and reduced reliability for BL values render these less clinically sound when trying to assess primary stability.

Alveolar Ridge Augmentation with Three-Dimensional Printed Hydroxyapatite Devices: A Preclinical Study.

The objective of this study was to evaluate the effectiveness of precise three-dimensional hydroxyapatite printed micro- and macrochannel devices for alveolar ridge augmentation in a canine model. All grafts induced minimal inflammatory and fibrotic reactions. Examination of undecalcified sections revealed that both types of grafts demonstrated bone ingrowth. The majority of the bone growth into the block graft was into the channels, though a portion grew directly into the construct in the form of small bony spicules. In conclusion, bone ingrowth was readily demonstrated in the middle of the implanted printed devices.

The Influence of Low Insertion Torque on Primary Stability, Implant Survival, and Maintenance of Marginal Bone Levels: A Closed-Cohort Prospective Study.

PURPOSE: The purpose of this study was to evaluate the impact of low insertion torque on primary stability and the short-term clinical outcome of single-tooth implants placed into healed ridges and fresh extraction sockets. MATERIALS AND METHODS: A cohort of n = 30 implants was self-selected on the basis that their insertion torque measured ≤ 20 Ncm. The cohort was closed with the follow-up set at 1 year. Resonance frequency analysis was evaluated in both mesiodistal (MD) and buccolingual (BL) directions at the time of implant insertion and at the time of restoration. Immediate temporization was determined by the esthetic need and a minimum implant stability quotient (ISQ) reading of 55. Implants were definitively restored after approximately 3 months. Implant survival was recorded along with changes in the level of the marginal bone relative to a fixed reference point, at the 1-year follow-up. RESULTS: Twenty-two patients with a total of 30 implants were grouped by insertion torques of < 5 Ncm (spinners), > 5 < 10 Ncm, 10 Ncm, 15 Ncm, and 20 Ncm. One implant was excluded because follow-up data were unavailable. Of the remaining 29 implants, the mean ISQ measured 67 (MD) and 65 (BL) at surgery. The values increased to 80 (MD) and 79 (BL) after a period of 3 months. The survival rate at the end of the 1-year period was 96.7%, including the excluded implant, but 100% for the remaining 29 implants. The frequency of implants demonstrating no marginal bone loss was 71.4%, 0.1 to 0.5 mm bone loss was 21.4%, and bone loss > 0.5 mm (max = 2.82 mm) was only 7.2%. No implants were lost during the functional loading period. Data on immediate temporization revealed no significant difference in ISQ or marginal bone loss values for implants in this group. CONCLUSION: Lower insertion torques yield favorable survival rates with optimal marginal bone levels compared with the accepted norm.

Efficacy of Er:YAG Laser in the Decontamination of Peri-implant Disease: A One-Year Prospective Closed Cohort Study.

A significant number of articles have been published to describe a variety of techniques for the treatment of peri-implant disease, with varying success. Previous reports have presented limited data on the use of lasers for the decontamination of implant surfaces prior to defect augmentation using guided bone regeneration techniques. The current study is a prospective closed cohort study of 20 patients with a follow-up of 1 year. It was established to assess the efficacy of the Er:YAG water-cooled laser following initially promising reports suggesting the laser can decontaminate and sterilize the implant surface and allow for reosseointegration of the affected portion of the implant.

Multiple single-tooth implant restorations in the posterior jaws: maintenance of marginal bone levels with reference to the implant-abutment microgap.

PURPOSE: The purpose of this study was to measure marginal bone loss from the implant-abutment microgap to the bone crest between multiple freestanding implants functionally loaded for up to 7.5 years in the posterior jaws. MATERIALS AND METHODS: Patients consecutively treated for the replacement of missing posterior teeth were included in the study. Using the implant-abutment interface, which was placed level with the crestal bone as a reference point, standardized follow-up radiographs were obtained to evaluate marginal bone loss. Results were subject to statistical analysis using the Wilcoxon rank sum test and the Wilcoxon signed rank test at the 95% confidence level. Additionally, soft tissue and prosthetic complications were recorded. RESULTS: One hundred seventy-three implants in 54 patients were evaluated. Implants were in function for a mean of 37 months (range, 21 to 91 months). One implant failed, for a survival rate of 99.4%. Overall mean marginal bone loss was 0.65 mm (range, 0.0 to 4.8 mm). For the 80 maxillary and 93 mandibular implants, mean marginal bone loss was 0.56 mm and 0.70 mm, respectively. The frequency of bone loss > or = 1.0 mm was 25.0% in the maxilla and 36.0% in the mandible; 23.1% of maxillary implants and 16.7% of mandibular implants demonstrated no bone loss. No significant differences were observed between men and women or between smokers and nonsmokers. The difference between mesial and distal bone levels was statistically significant (P < .001), with respective means of 0.53 mm and 0.76 mm. Recorded prosthetic complications included cementation failure (17.7%), porcelain fracture (7.2%), and abutment screw loosening (2.2%). CONCLUSIONS: Multiple single-tooth implants placed in the posterior jaws perform extremely well. Furthermore, it is possible to retain bone close to the implant-abutment microgap with certain implant designs.

A Classification System for Peri-implant Diseases and Conditions.

Peri-implant bone levels are influenced by pathologic and nonpathologic conditions. The understanding of peri-implant disease has evolved over the past several decades, and the classification of peri-implantitis has been limited to descriptions of disease progression or those involving soft and/or hard tissues (peri-implant mucositis or peri-implantitis). However, no classification system has been established based on etiology. The objective of this study was to identify various etiologies for peri-implantitis and to establish a classification system based on the pathogenesis. The results indicate that the majority of bone loss was related to biofilm, followed by iatrogenic factors, exogenous irritants, absence of keratinized tissue, and extrinsic pathology. The proposed classification system will allow the clinician to properly diagnose peri-implant diseases in relation to etiology. These conditions may respond differently to applied therapies.

A Palatal Approach for a Sinus Augmentation Procedure.

The purpose of this article is to demonstrate an alternative method for sinus augmentation through a palatal approach when complications do not allow the use of traditional approaches. A 50-year-old male patient presented with multiple previous sinus augmentation attempts. A cone beam computed tomography scan revealed bone graft material had consolidated on the buccal aspect of the lateral sinus wall only, preventing implant placement while not allowing access via a conventional lateral window technique to improve the graft bulk. A palatal approach was adopted as an alternative method of sinus entry and is presented in this case report. The authors suggest that a palatal approach technique is a safe and effective method to complete a sinus augmentation where a buccal approach is impractical.

A short-term clinical evaluation of immediately restored maxillary TiOblast single-tooth implants.

PURPOSE: The purpose of this study was to evaluate the short-term clinical outcome of single-tooth implants placed in the maxilla and immediately restored using cementless friction-fit temporary crowns. MATERIALS AND METHODS: Twenty-five patients consecutively referred to a private specialist practice for the replacement of failing or missing maxillary teeth were treated by means of immediate temporization of their single-tooth implants. Where teeth were still present, implants were placed immediately following extraction. Provisional crowns were fabricated on a special friction-fit coping by means of autopolymerizing acrylic resin. Definitive crowns were placed a mean of 4.5 months after surgery. Implant survival was recorded along with the level of the marginal bone relative to a fixed reference point 1 year after placement. Any adverse soft tissue changes were also noted. RESULTS: A total of 28 Astra Tech ST dental implants were placed. The overall survival rate at the end of the study was 96.4% for implants which were in function for periods ranging from 15.7 to 27 months. One patient, a smoker, lost 1 implant within 1 month of surgery. Mean marginal bone loss was 0.40 mm (range 0 to 1.53 mm) 1 year after placement of the implants. Many implants (37.5%) had no observed bone loss. No implants or crowns have been lost during the functional loading period. One implant was associated with an unfavorable recession of soft tissues; however, most maintained an esthetic gingival architecture. Eleven of 28 provisional restorations needed treatment; 6 required replacement during the temporization period, and 5 required cementation because of looseness. The ease of removal of the crowns allowed regular access for irrigation with chlorhexidine and thus maintenance of soft tissue health. DISCUSSION: The need to provide provisional restorations for single-tooth gaps often presents challenges. An immediate temporary partial denture or adhesive prosthesis may be unacceptable or impractical. The current study describes a simple method for the immediate temporization of single-tooth implants. The results did not indicate any negative influence on osseointegration or short-term survival once the implants were functionally loaded. CONCLUSION: Immediate temporization of maxillary single-tooth implants can be both safe and predictable, and it appears that the procedure can yield favorable soft tissue esthetics.

Dental implants placed in extraction sites implanted with bioactive glass: human histology and clinical outcome.

PURPOSE: To evaluate the clinical outcome of implants placed into sites grafted with bioactive glass. MATERIALS AND METHODS: Seventeen consecutively treated patients were referred to a private specialist surgical practice for the repair of dentoalveolar defects, and/or ridge maintenance at the site of extraction sockets, prior to implantation. Bioactive glass available in 1 of 2 forms was utilized as an alloplastic grafting material. Bone cores were trephined out at the time of implantation and processed and examined to evaluate the tissue response under the light microscope. Implant mobility, marginal bone levels, and soft tissue health were all evaluated over a 2- to 3-year follow-up period to determine treatment success. RESULTS: A total of 40 Astra Tech dental implants were placed. The overall success rate at the end of the study was 88.6% for implants that were in function for a mean period of 29.2 months (22 to 24 months). One patient with 5 successful implants died at 18 months after functional loading. At that time the cumulative success rate was 90%. Another patient who was diagnosed with cancer of the large bowel lost 3 implants. If this patient were excluded from the data, the cumulative success rate increases to 96.8%. Mean marginal bone loss measured 0.5 mm mesially and 0.4 mm distally over a maximum follow-up of 36 months. Human histology demonstrated that connective tissue was seen to exist without any inflammatory response, for up to 6 months. Increasing evidence of bone formation was seen in direct relation to the bioactive glass material beyond this time frame. DISCUSSION: The need to repair and augment dentoalveolar defects necessitates the use of autogenous bone or a substitute that may be seen to avoid the additional morbidity of a donor site procedure and without risk of cross infection. The use of bioactive glass has been proposed as a viable bone substitute. The current study draws attention to the long healing time required to achieve even a small amount of new bone incorporation into the graft, as seen histologically. However, the high rate of osseointegration and continued medium-term function of implants placed into these grafted sites would indicate that the use of bioactive glass does not prohibit osseointegration. However, it is likely that the initial integration will have derived from those areas in contact with native bone. CONCLUSION: Implants will survive for up to 3 years in sites grafted with bioactive glass, even when such grafts appear to only slowly conduct new bone growth.