Avoiding implant-related complications in medically compromised patients with or without unhealthy lifestyle/Elevated oxidative stress.

Increased human life expectancy broadens the alternatives for missing teeth and played a role in the widespread use of dental implants and related augmentation procedures for the aging population. Though, many of these patients may have one or more diseases. These systemic conditions may directly lead to surgical complications, compromise implant/bone healing, or influence long-term peri-implant health and its response to biologic nuisances. Offering patients credible expectations regarding intra- and postoperative complications and therapeutic prognosis is an ethical and legal obligation. Clear identification of potential types of adverse effects, complications, or errors is important for decision-making processes as they may be related to different local, systemic, and technical aspects. Therefore, the present review structures the underlying biological mechanisms, clinical evidence, and clinical recommendations for the most common systemic risk factors for implant-related complications.

Bucco-palatal implant position and its impact on soft tissue level in the maxillary esthetic zone.

AIM: The term "buccal implant position" is commonly used but lacks a precise definition and missing a reference point. Considering its major impact on peri-implantitis and esthetic failures the purpose of this study was to find a correlation between bucco-palatal implant positioning and the midfacial soft tissue level of implant crowns using newly defined Emergence-points. MATERIALS AND METHODS: Patients with unilateral single-tooth implant crowns in the region of the central or lateral maxillary incisor were included in this study. Digital intraoral scans were superimposed over a scan of the master cast or the original digital data set and analyzed in a computer planning program. In relation to the corresponding natural tooth, an ideal Emergence-point (EIDEAL -point) was defined from a frontal view. The distance to the real Emergence-point (EREAL -point) of the implant crown was correlated to apical displacement (AD) of peri-implant soft tissue. The distance of the implant shoulder (I-point) to the real Emergence-point (EREAL -point) of the implant crown was also correlated to the AD of peri-implant soft tissue. In cross sections, the horizontal distance between EREAL - and I-point represents the sagittal implant position (SIP), and the vertical distance represents the vertical implant position (VIP). RESULTS: Seventy-three patients met the inclusion criteria. AD ranged from 0 to 3.5 mm (AD = 0.87 ± 1.01), SIP from 0.2 to 5.1 mm (AD = 2.66 ± 1.64). Statistical analysis showed a significant inverse correlation between AD and SIP (ρ = -.55, p < .001). VIP, the implant inclination, time span since implant insertion, and phenotype revealed no significant correlation to AD. CONCLUSION: The more palatal the implant was positioned, the less AD was observed. The position of the implant shoulder should preferably be planned more than 2 mm behind the ideal E-point. This E-point can be used for implant planning as it defines the ideal crown length for prospective planning.

Long-term outcomes of maxillary single-tooth implants in relation to timing protocols of implant placement and loading: Systematic review and meta-analysis.

OBJECTIVES: The aim of the present systematic literature review was to determine whether long-term treatment results with single-tooth implants may differ depending on the timing of implant placement in relation to tooth extraction (immediate IP/early EP/delayed DP) and the timing of prosthetic loading (immediate IL/early EL/delayed DL). MATERIAL AND METHODS: Electronic and manual searches were performed to identify studies reporting on long-term results (survival rate and/or marginal bone resorption after ≥3 years) of maxillary single-tooth implants in the aesthetic zone using defined placement and loading protocols. Comparative trials were subjected to meta-analyses whilst data from single-arm studies were pooled to evaluate differences between timing protocols. RESULTS: A total of 7 controlled trials were considered for meta-analyses: immediate loading was compared to delayed loading in 3 studies on immediate placement (IPIL vs. IPDL, p = .306) and in 2 studies on delayed placement (DPIL vs. DPDL, p = 1.000) whilst 2 studies compared early versus delayed placement with delayed loading (EPDL vs. DPDL, p = .600), however, without significant differences. Pooled data analysis of 29 studies (965 implants) did not show differences between timing of placement or loading as well as marginal bone remodelling. No impact of the one abutment - one time concept, flap design and simultaneous bone or soft tissue augmentation could be established. CONCLUSIONS: Insufficient data are available for meta-analytic comparison of all combinations of implant placement and loading protocols.

Influence of Implant Length and Associated Parameters Upon Biomechanical Forces in Finite Element Analyses: A Systematic Review.

PURPOSE: The aim of this systematic review is to provide an overview of finite element analyses comparing standard and short dental implants concerning biomechanical properties and to detect the most relevant parameters affecting periimplant stress concentrations. MATERIAL AND METHODS: After screening the literature and assessment of studies, 36 studies were included in this review. RESULTS: Eighty-three percent of the studies state that short dental implants have to bear higher stress concentrations compared with standard length implants. At the same time, 44% of articles note that implant diameter can be considered a more effective design parameter than implant length to reduce stress concentrations and to avoid an overload of periimplant bone. Regardless of implant dimension, in all studies, the highest stress concentrations are found in the cortical section around the upper part of the implant. CONCLUSIONS: Unaffected of bone quality, implant diameter is found to play a key role to minimize periimplant stress concentrations. Concerning stress reduction implant length gains increasing relevance with decreasing bone density. Furthermore, splinting of short implants constitute an appropriate tool to avoid crestal overloading.

Single tooth implants in the esthetic zone following a two-stage all flapless approach: A retrospective analysis.

BACKGROUND: Due to chronic inflammation or trauma facial bone is frequently missing after tooth loss in the esthetic zone. As a consequence, procedures to augment or at least to preserve bone are frequently necessary prior to implant placement. PURPOSE: The aim of this retrospective case series is to demonstrate the applicability of a staged all-flapless concept to establish satisfactory implant restorations following situations of partial missing facial bone in the esthetic zone. MATERIALS AND METHODS: Radiological/clinical data of 25 patients were analyzed and an esthetic evaluation of 24 patients was performed. The staged concept included ridge preservation at time of tooth extraction and delayed guided implant placement. Marginal bone loss was measured radiologically and esthetic evaluation was performed based on standardized photographs using the Pink Esthetic Score as well as the Papilla Index. RESULTS: Implant success rate revealed 100%. The mean radiological peri-implant marginal bone loss measured 1.16 mm (SD: 0.16). Regarding the esthetic outcome 71% of patients were evaluated with a Pink Esthetic Score higher or equal to 10 constituting satisfactory esthetics (median pink esthetic score: 10). The mean follow-up time for clinical and radiographic analysis was 1.3 years (SD: 0.6 years) and 1.2 years (SD: 0.6) for esthetic evaluation. CONCLUSION: Although marginal bone loss cannot be avoided, the staged concept of flapless ridge preservation and subsequent delayed flapless guided implant placement carries the potential to improve esthetics of single-tooth implants in the anterior maxilla.

Extra-short (< 7 mm) and extra-narrow diameter (< 3.5 mm) implants: a meta-analytic literature review.

AIM: To review available evidence in scientific literature on oral implants of severely reduced length or diameter. MATERIALS AND METHODS: Electronic and hand searches up to May 2017 were performed in order to identify clinical investigations providing implant survival and/or marginal bone resorption data for extra-short implants < 7.0 mm in length and extra-narrow implants < 3.5 mm in diameter (excluding one-piece mini-implants). RESULTS: A total of 2929 extra-short implants and 3048 extra-narrow diameter implants were investigated in 53 and 29 clinical studies, respectively. Shorter implants between 4.0 mm and 5.4 mm in length showed comparable results to implant lengths of 5.5 mm to 6.5 mm (95.1% vs. 96.4%, P = 0.121) and no difference regarding marginal bone resorption (0.7 mm vs 0.5 mm, P = 0.086). Implant lengths of 5.5 mm to 6.5 mm, however, performed significantly better in the mandible compared with the maxilla (P = 0.010). Smaller diameters between 3.0 mm and 3.25 mm yielded a significantly lower survival rate of 94.3% than wider implants of 3.3 mm to 3.4 mm diameter (97.7%, P < 0.001), while marginal bone resorption did not differ (0.4 mm vs 0.5 mm, P = 0.447). CONCLUSIONS: The results of the present literature review suggest that extra-short and extra-narrow-diameter implants show satisfactory survival rates of around 95% and little marginal bone resorption of around 0.5 mm after a mean follow-up of 3 years. However, implant lengths < 7 mm in the maxilla and < 5.5 mm in the mandible as well as diameters < 3.3 mm may increase early failure rates.

Evaluation of implant esthetics using eight objective indices-Comparative analysis of reliability and validity.

OBJECTIVES: The aim of the present study was to give a detailed analysis on eight proposed implant esthetic indices including a total of 48 parameters with respect to validity and reproducibility as well as its correlation to patients' perception of esthetics. MATERIAL AND METHODS: Standardized intraoral photographs of 189 patients with 189 implant-supported crowns and adjacent peri-implant soft tissue in the esthetic zone (central and lateral incisors, canine, first premolar) served as basis for this evaluation. Eight indices (Papilla Index [PI], Pink Esthetic Score [PES], Implant Crown Aesthetic Index [ICAI], Pink and White Esthetic Score [PES/WES], Complex Esthetic Index [CEI], Implant Aesthetic Score [IAS], Subjective Esthetic Score [SES], and Rompen Index) with a total of 48 parameters were selected. Esthetic evaluation was performed twice by five examiners with an interval of 4 weeks between the evaluations. RESULTS: A total of 1,890 evaluations including eight esthetic indices served as basis for the statistical analysis. Among the overall main scores tested for inter-rater reliability, the highest ρ^inter values were computed for CEI, PES, PI, and IAS scores. By contrast, SES and Rompen showed the worst inter-rater reliability, respectively. The highest level of intra-rater reproducibility was noted for PI, PES, and CEI. The lowest level of intra-rater reproducibility showed Rompen, SES, and ICA. The Papilla Index demonstrated the highest level of inter-rater reliability. The remainder of the single variables (n = 46) did not reach the ρ^inter level of 0.6. The single variables PI mesial, PI distal as well as CEI P4 showed the highest ρ^intra with statistical significance higher than 0.8. The lowest agreement was observed among the variables ICA3, WES5, and IASm2. In general, VAS did not show any good correlation to the esthetic indices proposed so far. The influence of esthetic parameters on subjective patient satisfaction was generally low. CONCLUSION: In conclusion, significant differences regarding reliability and validity could be observed in the present comparison of eight esthetic indices. Objective evaluation of the esthetic outcome of implant therapy inherently fails to reflect subjective patient opinion, however, requires consistency of results to enable between-study comparison and meta-analysis.

The influence of crown-to-implant ratio on marginal bone levels around splinted short dental implants: A radiological and clincial short term analysis.

BACKGROUND: The amount of marginal bone resorption around dental implants is considered to have a significant impact on implant stability as well as implant survival rates. PURPOSE: The aim of this prospective study was to investigate the influence of prosthetic as well as patient specific factors on marginal bone loss around short dental implants. MATERIALS AND METHODS: Seventy-six implants, which supported splinted crowns were included for investigation. All implants were from the same type and had an intraosseous length of 6.5 mm and a diameter of 4.0 mm. Twenty implants were additionally splinted onto longer ones. Measurements of marginal bone loss were performed at a mean of 12.38 months after prosthetic loading and the mean follow-up for clinical evaluation was 20.52 months. RESULTS: Overall two implant failures were recorded, revealing a survival rate of 97.3%. Marginal bone resorption around 72 short implants measured 0.71 mm (SD: 0.74 mm) and was found to have a strong correlation with calculated Crown-to-Implant ratio (r = .71; P < .001). Age, gender, insertion torque, implant surface area, location, position, bone quality, and insertion torque did not influence peri-implant bone loss after one year of loading. CONCLUSION: Within the limitations of the study, it is suggested that Crown-to-Implant ratios should not exceed 1.7 to avoid increased early marginal bone loss.

Immediate Restoration of Immediate Implants in the Esthetic Zone of the Maxilla Via the Copy-Abutment Technique: 5-Year Follow-Up of Pink Esthetic Scores.

BACKGROUND: Implant esthetics may benefit from individualized zirconia abutments copying the emergence profile of the natural tooth and delivered within days after immediate implant insertion. PURPOSE: To investigate the esthetic outcome of the Copy-Abutment technique using the Pink Esthetic Score (PES). MATERIALS AND METHODS: A total of 77 patients with single-tooth implants in the anterior maxilla restored at the day of immediate implant placement using Copy-Abutments and provisional crowns were followed-up after 1 week, 1 month, 4 months, 6 months, 1, 2, 3, 4, and 5 years to assess implant esthetics. RESULTS: PES ranged between 7 and 14 (median: 13) and improved significantly between the 6 month and 1 year follow-up (p < .001), then remained stable up to the fifth year. Significant improvement was seen for the variables PES-6 soft tissue color (p = .002) and PES-7 soft tissue texture (p < .001) up to the 1 year follow-up, while PES-5 alveolar process deficiency deteriorated (p = .016). Mean mucosal recession was 0.26 ± 0.86 mm (range: 0-1.6) after 5 years and not related to gingival biotype. CONCLUSION: Copy-Abutments for immediate restoration of implants in the esthetic zone show satisfactory long-term esthetic outcomes.

Graftless Full-Arch Implant Rehabilitation with Interantral Implants and Immediate or Delayed Loading-Part II: Transition from the Failing Maxillary Dentition.

PURPOSE: To compare long-term survival and marginal bone loss of immediate interantral implants in the nonaugmented maxilla subjected to immediate vs delayed loading. MATERIALS AND METHODS: Graftless maxillary cross-arch rehabilitation was performed in a total of 362 patients in the years 2004 to 2013 (1,797 implants). Of the 240 patients with immediate implants replacing their failing maxillary dentition, 81% were subjected to immediate loading and 19% to delayed loading of their 4 to 6 interantral implants (980 and 235 implants, respectively). Kaplan-Meier survival estimates were computed and marginal bone loss was evaluated in a stratified random sample of 20 patients per group. RESULTS: Thirty-one of 1,215 implants failed within the mean observation period of 3.9 years, and no difference in 8-year survival estimates could be seen between immediate (97.6% [95% CI: 96.7 to 98.6]) and delayed (96.6% [95% CI: 94.3 to 98.9]) loading protocols (P = .359). Mean marginal bone resorption following implant insertion did not differ significantly between the groups (1.5 ± 1.7 mm vs 0.7 ± 1.1 mm, P = .379); however, it was significantly associated with a reduced number of implants (P = .017) and patient history of periodontal disease (P < .001). CONCLUSION: Immediate loading of interantral implants yields satisfactory results in the transition of patients from a failing maxillary dentition to full-arch implant rehabilitation and thus may be favored over delayed loading concepts.

Trends in techniques to avoid bone augmentation surgery: Application of short implants, narrow-diameter implants and guided surgery.

INTRODUCTION: Minimally invasive implantology using reduced implant dimensions as well as virtual treatment planning and CAD/CAM stereolithographic templates has gained popularity in recent years. The aim of the present investigation was to analyze prevailing trends in clinical utilization of these graftless therapeutic options. MATERIAL AND METHODS: A total of 12.865 dental implants were placed in 5.365 patients at the Academy for Oral Implantology in Vienna, of which 5.5% were short (length < 10 mm), 19.5% narrow (diameter < 3.75 mm) and 10.6% template-guided. Application trends were analyzed using linear regression and compared between jaw location and dentition subgroups. RESULTS: Use of short implants and guided surgery increased significantly in all subgroups. Narrow-diameter implants were most frequent in single-tooth gaps (24.1%), however, upward trends could only be observed in partially and completely edentulous patients. Short implants were predominantly used in the mandible (9.9% vs. 2.5%, P < 0.001) while guided surgery was favored in the maxilla (14.2% vs. 5.4%, P < 0.001). CONCLUSION: Short implants (most frequent in partial edentulism) and guided implant surgery (most frequent in complete edentulism) represent uprising and promising surgical approaches to avoid patient morbidity associated with bone graft surgery.

Periimplantitis Treatment: Long-Term Comparison of Laser Decontamination and Implantoplasty Surgery.

PURPOSE: Periimplantitis is the most frequent cause of late implant failure; however, little is known about the long-term success of periimplantitis treatment and the effectiveness of various therapeutic interventions. MATERIALS AND METHODS: A total of 142 patients were referred to the Academy for Oral Implantology in Vienna for the treatment of recurrent periimplantitis around single-tooth implants. Of them, 72 patients (51%) were treated by laser decontamination, 47 patients (33%) by implantoplasty surgery, and 23 patients (16%) by a combination of both approaches. RESULTS: Overall success of periimplantitis therapy was 89% after 9 years of follow-up, and it did not differ significantly between female and male patients (P = 0.426). The number of implant failures that could not be prevented by periimplantitis treatment was 6 after laser decontamination (8%), 6 after implantoplasty surgery (13%), and 4 after a combination of both therapies (17%). Implant loss occurred after 4.9 ± 1.9 years of therapy, on average. No significant difference between the 3 treatment groups could be observed (P = 0.393). CONCLUSION: The present results suggest that success rates of periimplantitis therapy with either laser decontamination or surgical implantoplasty are high. These success rates do not appear to be associated with patient gender or treatment strategy.

Graftless Full-Arch Implant Rehabilitation with Interantral Implants and Immediate or Delayed Loading-Part I: Reconstruction of the Edentulous Maxilla.

PURPOSE: To compare long-term survival and marginal bone loss of late interantral implants in the nonaugmented edentulous maxilla subjected to immediate vs delayed loading. MATERIALS AND METHODS: One hundred twenty-two edentulous patients with implants in native, healed jawbone were subjected to either immediate loading (179 implants) or delayed loading (403 implants) of their four to six interantral implants (part I of 362 graftless maxillary cross-arch rehabilitations performed in the years 2004 to 2013). Kaplan-Meier survival estimates were computed, and marginal bone loss was evaluated in a stratified random sample of 20 patients per group. RESULTS: Fifteen of 582 implants failed within the mean observation period of 4.7 years, and no difference in 8-year survival estimates could be seen between immediate (98.3% [95% CI: 96.4-100.0]) and delayed (96.7% [95% CI: 94.7-98.6]) loading protocols (P = .370). Mean marginal bone resorption following implant insertion did not differ significantly between the groups (1.1 ± 1.3 mm vs 1.4 ± 1.3 mm, P = .490). CONCLUSION: Immediate loading of interantral implants in the nonaugmented edentulous maxilla yields favorable results comparable to delayed loading and may be considered to shorten periods of removable provisional prostheses in maxillary edentulism.

Patient-Perceived Morbidity and Subjective Functional Impairment Following Immediate Transition from a Failing Dentition to Fixed Implant Rehabilitation.

PURPOSE: Failing residual dentition gives rise to patient concerns about the surgical and prosthodontic management of immediate implant rehabilitation. The purpose of this study was to assess subjective patient experiences of full-arch immediate implant loading. MATERIALS AND METHODS: Patients made a transition from poor dentition in the maxilla (25 patients) or mandible (25 patients) to full-arch rehabilitation on the day of extraction using four interantral or interforaminal implants. Provisional restoration was performed, and postoperative pain, swelling, and patient-perceived impairment in the first week was recorded. RESULTS: Absence of pain was reported by 40%, 52%, and 66% of patients, on the day of surgery, on the first day after surgery, and on the second day after surgery, respectively; pain levels decreased significantly (from 1.8 to 0.9, P < .001) and patient-reported swelling decreased from 1.5 to 1.3 (P = .058) on a 10-point scale. Postoperative impairment of everyday life and work (mean score = 1.1) was significantly less pronounced than impairment of food intake (mean score = 2.2; P = .004) or speech (mean score = 1.9; P = .002). Of these patients, 88% would again undergo the procedure without doubt. CONCLUSION: Although patient-perceived morbidity after immediate full-arch implant rehabilitation is low in general, minor masticatory and phonetic impairment should be taken into account.

How meta-analytic evidence impacts clinical decision making in oral implantology: a Delphi opinion poll.

OBJECTIVES: To investigate the impact of meta-analytic evidence in scientific literature on clinical decision making in the field of oral implantology. METHODS: A Delphi opinion poll was performed at the meeting of the "Next Generation" Committees of the Austrian, German and Swiss Societies for Implantology (ÖGI, DGI and SGI). First, the experts gave their opinion on 20 questions regarding routine implant treatment (uninformed decisions), then they were confronted with up-to-date Level I evidence from scientific literature on these topics and again asked to give their opinion (informed decisions) as well as to rate the available evidence as satisfactory or insufficient. Topics involved surgical issues, such as immediate implant placement, flapless surgery, tilted and short implants and bone substitute materials, as well as opinions on prosthodontic paradigms, such as immediate loading, abutment materials and platform switching. RESULTS: Compared to their uninformed decisions prior to confrontation with recent scientific literature, on average, 37% of experts (range: 15-50%) changed their opinion on the topic. When originally favoring one treatment alternative, less than half were still convinced after review of meta-analytic evidence. Discrepancy between uninformed and informed decisions was significantly associated with insufficient evidence (P = 0.014, 49% change of opinion vs. 26% on topics rated as sufficiently backed with evidence). Agreement regarding strength of evidence could be reached for eight topics (40%), in three issues toward sufficiency and in five issues toward lack of evidence. CONCLUSION: Confrontation with literature results significantly changes clinical decisions of implantologists, particularly in cases of ambiguous or lacking meta-analytic evidence.

Scientific Interests of 21st Century Clinical Oral Implant Research: Topical Trend Analysis.

BACKGROUND: Discrimination between ongoing and solved research questions may help to distinguish established dogmas from evidence-based implant dentistry. PURPOSE: The purpose of this study was to investigate topics of interest in the field of oral implant science and evolving thematic trends in clinical studies during the last decade. MATERIALS AND METHODS: Electronic and manual searches of English literature were performed to identify clinical studies on oral implants. Out of 15,695 publications screened, 2,875 clinical investigations were included. RESULTS: Among the most prevalent topics were immediate loading (14.3%), bone substitutes (11.6%), lateral sinus grafting (10.7%), implant overdentures (10.5%), single-tooth implant crowns (8.8%), cross-arch implant bridges (8.0%), immediate implant placement (7.5%), implant surfaces (7.0%), simultaneous implant placement and augmentation (6.4%) as well as guided bone regeneration (5.3%). Significant increase of scientific interest was seen in immediate loading (+6.3%, p < .001), platform switching (+2.9%, p < 0.001), lateral sinus grafting (+2.3%, p = .024), flapless implant surgery (+2.2%, p < 0.001), and guided implant surgery (+1.9%, p = .011), while research on implant overdentures (-6.6%, p = .033) and tooth-to-implant connection (-2.5%, p = .010) was on the decline. CONCLUSIONS: Literature coverage, since the beginning of the 21st century, has seen greater focus on surgical topics compared to prosthodontic issues (p = .005) while only few topics experienced decrease of interest indicating scientific consensus.

Hot Topics in Clinical Oral Implants Research: Recent Trends in Literature Coverage.

This systematic review looks at thematic trends in clinical research publications on dental implants. For this purpose, MEDLINE electronic searches as well as additional hand searches of six main journals in the field were conducted. A total of 2875 clinical studies published between 2001 and 2012 met the inclusion criteria and were subjected to statistical analysis. Hot topics in dental implant literature included immediate loading (14.3%), bone substitutes (11.6%), cross-arch full bridges (8.0%), and immediate implant placement (7.5%). A significant increase in scientific interest for immediate loading (+6.3%, p = 0.001), platform switching (+2.9%, p = 0.001), guided implant surgery (+1.9%, p = 0.011), growth factors (p = 0.014, +1.4%), piezoelectric surgery (+1.3%, p = 0.015), and restorative materials (+0.7%, p = 0.011) was found. A declining scientific interest in onlay grafting (-0.3%, p = 0.042) was recorded. The findings regarding current clinical oral implants research tie in with better-informed consumers and increased patient demands. Our results demonstrate an increasing interest in techniques that avoid complicated procedures such as bone grafting and that reduce treatment duration.

Auto-stop Drilling Device for Implant Site Preparation: In Vitro Test of Eccentric Sensor Position.

PURPOSE: To quantify the reliability of a new drilling system for implant osteotomy characterized by an eccentric sensor that automatically stops the drill upon contact with soft tissue. This safety mechanism aims to minimize surgical trauma to nerves, vessels, and the maxillary sinus mucosa. The benefits of the eccentric sensor position on planar and angulated surfaces were tested in vitro. MATERIALS AND METHODS: Predicted drill protrusion after auto-stop was validated against experiments on four human cadaver mandibles (30 osteotomies with varying angles). Measurement of the drill's exit holes allowed calculation of the amount of drill protrusion, and postoperative computed tomographic scans of the mandibles were acquired to determine the drill's exit angles. RESULTS: Mean drill protrusion into human jawbone was 0.46 ± 0.26 mm and differed significantly from expected drill protrusion, which was based on mathematical modeling, of 0.64 ± 0.3 mm. Detection of bone passage on angulated walls was seen up to 71 degrees. A central sensor position, by contrast, may result in significantly greater drill protrusion into soft tissue (mean difference: 0.55 ± 0.49 mm) that increases with the drill's exit angle (r = 0.93). CONCLUSION: Auto-stop drills may significantly enhance safety for the patient during osteotomy. The benefits of eccentric sensor positioning were particularly apparent when applied on angulated surfaces, whereas drill angulation was not found to influence this safety mechanism.

The Concept of Platform Switching to Preserve Peri-implant Bone Level: Assessment of Methodologic Quality of Systematic Reviews.

PURPOSE: To assess the methodologic quality of systematic reviews on the effect of platform switching upon peri-implant marginal bone loss. MATERIALS AND METHODS: An electronic literature search of several databases was conducted by two reviewers. Articles were considered for quality assessment if they met the following inclusion criterion: systematic reviews that aimed at investigating the effect of platform switching/mismatch on marginal bone levels around dental implants. Two independent examiners evaluated the review publications using two quality-ranking scales (assessment of multiple systematic reviews [AMSTAR] and Glenny checklist). Descriptive statistics were used to summarize the results, and Cohen's kappa coefficients were calculated to appraise interrater agreement of each checklist. RESULTS: Overall, five systematic reviews (including three of them with meta-analysis) were evaluated. The mean AMSTAR score ± standard deviation was 8.4 ± 2.6 (range, 4 to 11), and the mean Glenny score was 10.8 ± 2.9 (range, 6 to 14), showing high statistical correlation (rs = 0.98, P = .005). Cohen interexaminer test yielded values of κ = 0.88 and κ = 0.86 for the AMSTAR and Glenny checklist, respectively. The AMSTAR items rated positive in 78%, whereas 18% met the criteria for "no" and 4% were "not applicable." Only one review article met all criteria. Items of the Glenny checklist rated positive in 73% and negative in 27%. All but one study with the lowest quality scores (finding no difference) demonstrated a clinical benefit of implant platform switching in preserving the peri-implant marginal bone loss. CONCLUSION: According to the quality-ranking scales appraised, substantial methodologic variability was found in systematic assessment of benefits with the platform switching concept to preserve peri-implant bone level. High-quality systematic reviews, however, generally favored platform switching over platform matching.