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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., (© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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 (E IDEAL -point) was defined from a frontal view. The distance to the real Emergence-point (E REAL -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 (E REAL -point) of the implant crown was also correlated to the AD of peri-implant soft tissue. In cross sections, the horizontal distance between E REAL - 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., (© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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., (© 2021 John Wiley & Sons A/S . Published by John Wiley & Sons Ltd.)

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.

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., (© 2018 Wiley Periodicals, Inc.)

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., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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.

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., (© 2017 Wiley Periodicals, Inc.)

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., (© 2016 Wiley Periodicals, Inc.)

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., (Copyright © 2016. Published by Elsevier Ltd.)

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.

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.

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., (© 2015 Wiley Periodicals, Inc.)

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.

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.

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.

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., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Purpose: To compare five different implant treatment protocols in the anterior maxilla, including immediate, early, and delayed implant placement, as well as implant placement in conjunction with simultaneous guided bone regeneration and implant placement 3 months following horizontal autologous bone block grafting., Material and Methods: Aesthetic indices used included the Pink Esthetic Score (PES), Papilla Index (PI), Subjective Esthetic Score (SES), and White Esthetic Score (WES). Subjective evaluation of implant aesthetics was performed using a visual analogue scale (VAS). The VAS consisted of a 10 cm-long line representing the degree of discontent (0%) or satisfaction (100%)., Results: A total of 153 implants in 153 patients (80 women, 73 men) were evaluated after a mean follow-up of 4.5 ± 2.9 years. Mean peri-implant bone loss was 1.6 ± 0.9 mm and not affected by treatment protocol, time after implant placement, or crown length. Papilla presence, by contrast, differed significantly between the protocols: Papilla formation was more pronounced following delayed and immediate implant placement. No statistical significance was found among treatment modalities with regard to PES, SES, or WES. Longer crowns were associated with lower PES and PI ratings and correlated with greater midfacial recession. SES was also influenced by time after implant placement and keratinized mucosa. Patient satisfaction differed significantly among treatment protocols, favoring immediate implant placement. Agreement between objective and subjective aesthetic ratings was low., Conclusion: The present study suggests that comparable clinical, radiological, and aesthetic results can be achieved with all treatment protocols. Gingival recession, however, seems to occur in the long term irrespective of the technique used., (© 2014 Wiley Periodicals, Inc.)

Background: Flapless implant placement using surgical templates may guarantee predictable and esthetic results provided that preplanned implant positions are transfered precisely into surgical reality., Purpose: The study aims to investigate the effect of three-dimensional accuracy in guided implant surgery on the esthetic outcome of single-tooth implants in the anterior maxilla., Materials and Methods: Single-tooth implants for delayed replacement of upper incisors were inserted in 27 patients using stereolithographic templates. Superimposition of postoperative cone beam computed tomography (CBCT) scans allowed assessment of positional inaccuracy at the implant shoulder and apex, as well as angular deviation. Objective evaluation of implant esthetics was performed after a mean follow-up of 2.3 years using the Pink Esthetic Score (PES)., Results: Mean deviation between planned and actual implant position was 0.84 mm at the implant shoulder and significantly correlated to average PES of 12 (p = .031). Inaccuracy toward the buccal side was most frequent (70%). Deviations  ≥  0.8  mm resulted in significantly worse implant esthetics (median PES: 9.5, interquartile range [IQR]: 8-11) compared with more accurate implant positions (median PES: 13, IQR: 12-13, p = .039)., Conclusion: Positional inaccuracy is low in guided implant surgery, but may however significantly compromise implant esthetics in the anterior maxilla., (© 2014 Wiley Periodicals, Inc.)

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.

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.

Prosthodontically driven biomechanical considerations are essential for longterm successful outcomes in dental implant therapy. Correct protocols seek to preclude potential consequences associated with functional and parafunctional occlusal overload such as screw loosening, component fracture, compromised marginal bone maintenance, and the integrity of the induced osseointegration response. Other concerns also need to be addressed, more especially when other implants are selected, for example: bridge insertion torque (BIT) in cases of immediate loading, cantilever length-anteroposterior spread ratio (CL-AP), overall crown-to-implant ratio (oCIR), total bone-to-implant surface area (tBICA), and the status of the opposing dentition. In spite of promising clinical results, evidence-based clinical protocols demand that such biomechanical limits still need to be determined.

Purpose: To test patient- and sinus-related risk factors for an association with intraoperative membrane perforation and postoperative complications after sinus floor augmentation surgery., Materials and Methods: Sinus floor elevation procedures using a lateral approach were retrospectively analyzed for patients' medical history and sinus anatomy on computed tomographic scans. Complications per sinus after membrane elevation and augmentation using a mixture of autologous bone and deproteinized bovine bone substitute (Bio-Oss) were recorded. Logic regression (adjusted using the generalized estimation equation approach) was performed to analyze the influence of patient age, gender, smoking habits, sinus septa, residual bone height, and mesiodistal elevation width., Results: Of 407 sinus grafts in 300 patients (mean age, 56 yr), perforation of the Schneiderian membrane occurred in 35 sinuses (8.6%) and was significantly associated to the presence of sinus septa (odds ratio [OR] = 4.8; P = .002) and decreased residual bone height (OR = 0.01; P < .001). Smoking increased the risk of membrane perforation (OR = 4.8; P = .002), sinusitis (OR = 12.3; P < .001), and wound dehiscence (OR = 16.1; P = .005). Cases of sinus membrane perforation had higher odds for postoperative sinusitis (OR = 10.5; P < .001). The probability of wound dehiscence increased with the size of the elevated area (OR = 3; P < .001)., Conclusion: The results of the study suggest that the presence of sinus septa and residual bone height less than 3.5 mm are the main risk factors increasing sinus membrane perforation rates. There was a higher prevalence for sinusitis in cases of membrane perforation (31.4%) despite intraoperative closure with resorbable membranes (Bio-Guide). Smokers generally exhibited greater chances for complications., (Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: The first year of prosthetic loading is crucial to peri-implant bone levels; however, contributing factors are yet barely understood., Purpose: The purpose of the study is to investigate the influence of patient-, implant-, and prosthetic-related parameters on marginal bone resorption in partially edentulous patients within the first year of prosthetic loading., Materials and Methods: This retrospective multifactorial analysis involved the following influencing factors: patient gender and age, implant diameter, implant location and neck design, insertion torque, insertion depth, splinted versus single-tooth restorations, crown height space, and crown-to-implant ratio., Results: Mean peri-implant bone resorption around 200 dental implants was 0.98 ± 0.76 mm and significantly correlated to higher implant insertion depth (p < .001), whereas no association to prosthetic parameters could be observed., Conclusions: Within the limits of the present analysis, it can be concluded that apical implant positioning may constitute a relevant determinant of early peri-implant bone resorption., (© 2013 Wiley Periodicals, Inc.)

Purpose: The aim of this study is to assess the impact of insertion torque and implant neck design on peri-implant bone levels and gain insights into dynamic crestal tissue alterations by radiological, clinical, and biochemical examinations., Material and Methods: In this prospective trial, a total of 84 implants (four implants in each patient) in the interforaminal region of 21 edentulous mandibles were randomly alternated according to a split-mouth design. Implant placement was performed using different insertion torques (≤20 Ncm vs >50 Ncm). In each group, one machined and one anodized implant neck design (1.5 mm length) was used in the same jaw side. Evaluation of peri-implant tissues involved radiological, clinical examination and immunoassays for interleukin-1β., Results: No significant influence of insertion torque or implant neck design on peri-implant bone level was found. Protein levels of interleukin-1β in the peri-implant crevicular fluid revealed no difference between both insertion torque groups and different neck designs., Conclusion: Interactive effects of insertion torque and neck surface modification may exist; however, no clinically significant differences in marginal bone resorption after 1 year could be observed in the edentulous anterior mandible., (© 2013 Wiley Periodicals, Inc.)

Objectives: Single-tooth replacement of anterior mandibular teeth is frequently complicated by insufficient bucco-lingual bone width and limited mesio-distal space available for implant placement. The aim of the present study was to assess implant esthetics in the partially edentulous anterior mandible., Material and Methods: Esthetic evaluation of 43 anterior mandibular single-tooth implants in 15 women and 28 men was performed using esthetic indices (PES = Pink Esthetic Score, PI = Papilla Index, SES = Subjective Esthetic Score) as well as subjective patients' Visual Analogue Scale (VAS) ratings. Clinical and radiological parameters (implant and crown dimensions, pocket depth, bleeding on probing, plaque, keratinized mucosa, marginal bone level, and distance to adjacent teeth) were tested for influence., Results: Implant esthetics were judged satisfactory (PES ≤10) in 42% of implants compared with a patient satisfaction rate of 87%. Correlation between objective indices (PES/PI: rs  = 0.62, PES/SES: rs  = -0.73, PI/SES: rs  = -0.48) was highly significant (P ≤ 0.001); however, no association to subjective patients' ratings could be observed. Type of prosthetic restoration (single crown vs. tulip-shaped double crowns), mesio-distal crown width as well as anatomic crown length significantly affected esthetic scores. Patients' judgment, by contrast, could not be associated to any prognostic factor., Conclusion: Subjective patient satisfaction with implant esthetics in the partially edentulous anterior mandible is high, however, remains hard to predict or objectively quantify., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Purpose: To evaluate patient satisfaction, oral health-related quality of life, and patients' preferences towards minimally invasive treatment options for graftless rehabilitation of complete edentulism by means of dental implants., Material and Methods: A MEDLINE search of literature in the English language up to the year 2013 was performed to summarise current evidence from the patient's perspective. The final selection included 37 studies reporting on minimally invasive implant treatment of 648 edentulous maxillae and 791 edentulous mandibles in 1328 patients, via a total of 5766 implants., Results: Patient satisfaction averaged 91% with flapless implant placement (range: 77 to 100%), 89% with short implants, 87% with narrow-diameter implants (range: 80 to 93%), 90% with a reduced number of implants (range: 77 to 100%), 94% with tilted implant placement (range: 58 to 100%), and 83% with zygomatic fixtures (range: 50 to 97%). Indirect comparison yielded patient preference towards tilted implant placement compared to a reduced number of implants (P = 0.036), as well as to zygomatic implants (P = 0.001)., Conclusions: While little evidence on patients' preferences towards minimally invasive treatment alternatives vs. bone augmentation surgery could be identified from within-study comparison, it may be concluded that patient satisfaction with graftless solutions for implant rehabilitation of completely edentulous jaws is generally high. Comparative effectiveness research is needed to substantiate their positive appeal to potential implant patients and possible reduction of the indication span for invasive bone graft surgery.

Purpose: Rehabilitation of the incomplete dentition by means of osseointegrated dental implants represents a highly predictable and widespread therapy; however, little is known about potential risk factors that may impair long-term implant success., Methods: From 2004 to 2012, a total of 13,147 implants were placed in 4,316 patients at the Academy for Oral Implantology in Vienna. The survival rates after 8 years of follow-up were computed using the Kaplan-Meier method, and the impact of patient- and implant-related risk factors was assessed., Results: Overall implant survival was 97% and was not associated with implant length (P=0.930), implant diameter (P=0.704), jaw location (P=0.545), implant position (P=0.450), local bone quality (P=0.398), previous bone augmentation surgery (P=0.617), or patient-related factors including osteoporosis (P=0.661), age (P=0.575), or diabetes mellitus (P=0.928). However, smoking increased the risk of implant failure by 3 folds (P<0.001) and a positive history of periodontal disease doubled the failure risk (P=0.001)., Conclusions: Summing up the long-term results of well over 10,000 implants at the Academy for Oral Implantology in Vienna it can be concluded that there is only a limited number of patients that do not qualify for implant therapy and may thus not benefit from improved quality of life associated with fixed implant-retained prostheses.

There is a lack of consensus guidelines for the decontamination of autogenous bone grafts after exposure to a nonsterile environment during graft contouring, intraoral bone harvesting, or when inadvertently dropped off the sterile field. Transplantation of contaminated bone may cause infectious complications or even augmentation failure. When selecting the antimicrobial agent of choice to treat harvested bone for transplantation purposes, focus should be placed on the safety of the agent towards bone and osteoprogenitor cells, maximum elimination of targeted pathogens that directly affect bone tissue, and a short exposure time. In systematically reviewing study results on the degree of bone graft contamination and the effects of decontamination methods, a protocol for decontamination of autogenous bone grafts is proposed. Among various decontamination agents investigated, 1% chlorhexidine proved highly effective (mean reduction of bacterial colony-forming units compared to saline solution: 99.97%). Minimum contact time required is 15 seconds and cell proliferation can be observed up to 30 seconds of exposure. The proposed decontamination protocol (1% chlorhexidine for 15 seconds) seems to represent a reasonable compromise in reference to sterility and cell viability. Comparative effectiveness research, however, is needed before clinical recommendations may be posed.

Objectives: Simultaneous implant placement in conjunction with lateral or transcrestal maxillary sinus floor augmentation gives the benefit of reduction in healing times and surgical interventions. Primary implant stability, however, may be significantly reduced in resorbed residual ridges. Aim of the present study was to investigate the impact of residual bone height, bone density, and implant diameter on primary stability of implants in the atrophic sinus floor., Material and Methods: A total of 66 NobelActive implants were inserted in the sinus floor of fresh human cadaver maxillae: 22 narrow (3.5 mm), 22 regular (4.3 mm), and 22 wide (5.0 mm) diameter implants in residual ridges of 2-6 mm height. Presurgical computed tomographic scans were acquired to assess bone height and density. Primary implant stability was evaluated by insertion torque values (ITV), Periotest values (PTV), and Osstell implant stability quotients (ISQ)., Results: Correlations within outcomes (ITV, PTV, ISQ) were highly significant (P < 0.001). Radiographic bone density was found to significantly impact all three outcome measures (P < 0.001), while no influence of residual bone height and implant diameter could be revealed by multifactorial analysis. Consistent results were seen in all subgroups (including residual ridges of 5-6 mm height)., Conclusions: Bone density seems to represent the major determinant of primary stability in maxillary sinus augmentation with simultaneous implant placement (as well as 5-6 mm short implants in the maxillary sinus floor). Preoperative bone density assessment may help to avoid stability-related complications in one-stage implant treatment of the atrophic posterior maxilla., (© 2012 John Wiley & Sons A/S.)

Purpose: To assess up-to-date expectations and preferences of patients seeking dental implants., Material and Methods: One hundred and fifty consecutive patients (66 male and 84 female interviewees) were asked to rank their concerns regarding implant therapy and answer a questionnaire on implant and bone graft surgery, cost and time considerations and second-opinion behaviour., Results: Treatment predictability and avoidance of removable dentures were ranked high priority (compared with time and cost efficiency or avoidance of bone grafts). Patients' estimation of the 10-year implant success rate was 84%, and 59% of patients expected implants to last for a lifetime. Total treatment time was estimated to be 4 months on average, and only 12% would tolerate increased risk of implant failure for the sake of shortening treatment duration. 61% of interviewees accepted autologous bone grafts (the majority favouring the retromolar area), while only 23% were willing to undergo bone harvesting from the hip. 43% opted for bone substitute material to avoid donor site morbidity. 67% would accept the additional costs associated with computed tomography, software-based treatment planning and guided implant placement to avoid bone graft surgery. Motivation for second-opinion seeking was high (46-62%), especially in young and male patients., Conclusion: Patient expectations on implant success and predictability are high compared with their reluctance towards treatment costs and duration. Acceptance of treatment morbidity is high among patients reporting low denture satisfaction; however, minimally invasive treatment alternatives are generally preferred., (© 2012 John Wiley & Sons A/S.)

Objectives: Autologous bone augmentation to rebuild compromised alveolar ridge contour prior to implant placement allows for favorable three-dimensional implant positioning to achieve optimum implant esthetics. The aim of the present study was to evaluate peri-implant soft tissue conditions around single-tooth implants following bone grafts in the esthetic zone of the maxilla., Materials and Methods: Sixty patients underwent autologous bone augmentation of deficient maxillary sites prior to placement of 85 implants in the esthetic zone. In case of multiple implants per patient, one implant was randomly selected. Objective evaluation of 60 single-tooth implants was performed using the Pink-Esthetic-Score (PES) and Papilla Index (PI) and supplemented by subjective patient evaluation, as well as clinical and radiologic examination., Results: Objective ratings of implant esthetics were satisfactory (median PES: 11, median PI: 2) and significantly correlated with high patient satisfaction (mean VAS score: 80%). Both esthetic indices demonstrated respectable levels of inter- as well as intra-observer agreement. Poor implant esthetics (low PES and PI ratings) were significantly associated with increased anatomic crown height, while no influence of horizontal implant-tooth distance could be found., Conclusions: The present investigation indicates that favorable esthetic results may be achieved in the augmented anterior maxilla. However, bony reconstruction of compromised alveolar ridges does not guarantee optimum implant esthetics., (© 2011 John Wiley & Sons A/S.)

Aim: To gain further insights and resolve conflicting results in the literature regarding prevalence, predominant location and morphologic variability of maxillary sinus septa., Material and Methods: Electronic and hand searching of English literature identified 33 investigations published from 1995 to 2011. Septa were defined as at least 2-4 mm in height., Results: Septa were present in 28.4% of 8923 sinuses investigated (95% confidence interval: 24.3-32.5%). Prevalence was significantly higher in atrophic sinuses compared with dentate maxillae (p < 0.001). Septa were located in premolar, molar and retromolar regions in 24.4%, 54.6% and 21.0% respectively. Orientation of septa was transverse in 87.6%, sagittal in 11.1% and horizontal in 1.3% of cases. Septa height measured 7.5 mm on average. Complete septa (dividing the sinus into two separate cavities) were found in only 0.3%. Other rare conditions included multiple septa in one sinus (4.2%) and bilateral septa (17.2%). Septa diagnosis using panoramic radiographs yielded incorrect results in 29% of cases., Conclusions: In view of their high overall prevalence and significant morphologic variability, 3D radiographic imaging prior to sinus floor augmentation may help to reduce complication rates in the presence of maxillary sinus septa., (© 2012 John Wiley & Sons A/S.)

Background: Little is known about maxillary sinus compliance, i.e., the intrinsic potential of the sinus membrane to resume its homeostatic status after the surgical trauma caused by sinus floor elevation. The aim of the present study is to investigate the effect of maxillary sinus floor augmentation on sinus membrane thickness., Methods: Within-patient comparison of computed tomographic scans before bone grafting versus 4 to 6 months after bone grafting was performed. Changes in membrane thickness were evaluated in 65 maxillary sinus floor augmentation procedures via a lateral approach in 35 patients without clinical signs of sinus pathology at any time., Results: Sinus membrane thickness differed significantly before (0.8 ± 1.2 mm) versus after (1.5 ± 1.3 mm) augmentation surgery (P <0.001), with a mean increase of 0.8 ± 1.6 mm (maximum: 4.4 mm). Only 28% of augmented sinuses did not show membrane thickening. In non-augmented control sinuses, there was no evidence of membrane thickness increase., Conclusions: The results indicate that the maxillary sinus membrane, even in healthy clinical conditions, undergoes morphologic modifications after sinus floor elevation, yet membrane reactions demonstrate significant variability. Future research on the effect of augmentation surgery on maxillary sinus physiology is recommended.

The aim of this systematic review was to evaluate the functionality of fixed and removable partial dentures as test interventions in relation to variations in the opposing dentition and their prosthetic restoration. The abstracts identified in the respective databases were screened independently by two investigators. RCTs and uncontrolled studies were considered, provided the patients were included consecutively and the confounding variables were adequately monitored. Seventeen papers were included. The study and publication quality was assessed using a "biometric quality" tool showing an overall poor quality. The reported outcomes, such as survival rates, were in each case obtained from a single study. Two possible trends could be deduced for the endpoint longevity: (a) the first trend in favor of removable partial dentures, compared to fixed partial dentures, with a fully edentulous opposing arch fitted with a removable prosthesis; (b) the second trend in favor of implant-supported partial dentures, compared to conventionally fixed partial dentures, with natural opposing dentition or with a removable partial denture in the opposing arch. No evidence could be generated as to whether, and if so how, variations in the opposing dentition have a bearing on the decision to fit a partially edentulous arch with a fixed or removable partial denture.

Aim: To test the null hypothesis of no difference in failure rates of short (minimum length: 7 mm) and longer dental implants (≥ 10 mm), a meta-analysis was performed on prospective observational trials., Materials and Methods: A systematic electronic and hand search was performed to identify eligible studies. Having additional data supplied by the authors, 54 publications were included (19,083 implants)., Results: In case of mandibular implants, the null hypothesis of no impact of reduced implant length on failure within the first year of prosthetic loading could not be rejected. A significant impact of implant length could be substantiated for short machined implants in the anterior [odds ratio (OR) 5.4] and posterior maxilla (OR 3.4), while short rough-surfaced implants demonstrated increased failure rates in the anterior maxillary sites. No influence of implant diameter and denture type on the failure rate of short implants could be revealed., Conclusion: In areas of reduced alveolar bone height the use of short dental implants may reduce the need for invasive bone augmentation procedures., (© 2011 John Wiley & Sons A/S.)

Objectives: Little is known about the level of information on implant dentistry in the public. A representative opinion poll on dental implants in the Austrian population was published in 2003 (Clinical Oral Implants Research 14:621-642). Seven years later, the poll was rerun to assess the up-to-date information level and evaluate recent progress and trends in patients' mindset on dental implants., Material and Methods: One thousand adults--representative for the Austrian population--were presented with a total of 19 questionnaire items regarding the level and the sources of information about dental implants as well as the subjective and objective need for patient information., Results: Compared with the survey of 2003, the subjective level of patient information about implant dentistry has significantly increased in the Austrian population. The patients' implant awareness rate was 79%. The objective level of general knowledge about dental implants was still all but satisfactory revealing unrealistic patient expectations. Three-quarters trusted their dentists for information about dental implants, while one-quarter turned to the media. The patients' wish for high-quality implant restorations was significantly higher than in 2003, yet the majority felt that only specialists should perform implant dentistry., Conclusions: This representative survey reveals that dentists are still the main source of patient information, but throws doubt on the quality of their public relations work. Dentists must improve communication strategies to provide their patients with comprehensible, legally tenable information on dental implants and bridge information gaps in the future., (© 2010 John Wiley & Sons A/S.)

Objectives: compared with widespread investigations on dental implant survival and biologic parameters, patient-based outcomes of implant dentistry have been neglected for years and are now becoming more popular. The aim of this representative opinion poll was to assess the up-to-date patients' mindset on dental implants and draw comparisons with the results published in 2003., Material and Methods: one thousand adults - representative for the Austrian population - were presented with a total of 16 questionnaire items regarding acceptance and subjectively perceived costs of dental implant treatment as well as patient satisfaction with implant-supported rehabilitation., Results: the implant acceptance rate was 56%, while 23% of the interviewees decidedly rejected implant treatment (same rate as in 2003), especially those over 50 years of age. Only 5% had themselves undergone implant treatment and 22% reported to know someone fitted with implants. The estimated costs of implant treatment were significantly higher than those in 2003, and three-quarters felt that the prize was too high and that the sick fund or social security agencies should bear them. Satisfaction scores were significantly higher among interviewees wearing implant-supported rehabilitations compared with those with conventional fixed or removable dentures., Conclusions: little has changed in patients' attitude toward dental implants compared with the representative opinion poll in 2003. Neither implant acceptance nor implant prevalence in the Austrian population demonstrated upward trends. Professional public relations efforts are indicated to drop resentments and increase patient acceptance of dental implants as a treatment modality.

Background and Study Aims: Endoscopic submucosal dissection (ESD) is a promising technique for the resection of early gastric neoplasia. There are only a few data from the Western world to date., Methods: Over a 7-year-period, 104 gastric lesions were treated with ESD in a European referral center, of which 91 were included in this study. A total of 66 lesions were early gastric cancer (EGC) and 25 were adenomas. Of the EGCs, 11 lesions (16.7 %) fulfilled the guideline criteria (EGC-GC) and 55 lesions (83.3 %) fulfilled the expanded resection criteria (EGC-EC) of the Japanese guidelines for the treatment of gastric cancer., Results: ESD was technically possible in 85 lesions (93.4 %). In six lesions ESD was not possible due to non-lifting. En bloc resection rates for all lesions, ECGs-GC, ECGs-EC, and adenomas were 87.1 %, 100 %, 88.2 %, and 79.2 %, respectively. R0 en bloc resection rates were 74.1 %, 90 %, 68.6 %, and 79.2 %, respectively. Complications were: one perforation during piecemeal endoscopic mucosal resection of a lesion in which ESD was judged to be impossible (1.2 %); three clinically relevant bleedings (3.5 %); one gastric ischemia (1.2 %); and four strictures (4.7 %). No mortality was observed. There were five recurrences after piecemeal resection (50 %) compared with only one after en bloc resection (1.5 %; P < 0.05). The rate of recurrence for EGCs was 5.6 %, and this were seen exclusively after piecemeal resection., Conclusions: Our data show that ESD is a feasible technique in Europe even in patients with EGC according to the extended criteria. Resection rates are promising and complication rates are acceptable. Results are worse compared with large studies from Japan but still excellent regarding the learning curve of the method. ESD should be offered as the treatment of choice for early gastric neoplasia especially when en bloc resection cannot be performed with other resection techniques., (© Georg Thieme Verlag KG Stuttgart · New York.)

Purpose: To evaluate a novel surgical technique for flapless transcrestal elevation of the maxillary sinus floor via surgical templates using gel pressure., Materials and Methods: Computed tomographic scans of fresh human cadaver maxillae and three-dimensional treatment planning software were used to design surgical templates. Access to the maxillary sinus was gained by guided transcrestal osteotomies to puncture the bony sinus floor. By injection of radiopaque gel, the maxillary sinus membrane was elevated to attain a postoperative bone height of 15 mm., Results: The gel-pressure technique was performed in 10 atrophic maxillary sites with a mean residual bone height of the alveolar crest of 4.7 +/- 1.6 mm. The sinus membrane was successfully elevated in all sites without causing iatrogenic perforation (mean elevation height, 10.6 +/- 1.6 mm)., Conclusions: The gel-pressure technique may provide a new option for minimally invasive transcrestal sinus surgery and may represent a safe method to increase bone volume in the atrophic posterior maxilla.

Objectives: Perforation of the Schneiderian membrane (maxillary sinus mucosa) is a common complication of maxillary sinus graft procedures. Membrane perforation increases the chance of postoperative sinusitis and endangers graft as well as implant survival. The aim of the present study was to explore the mechanical properties of the Schneiderian membrane., Material and Methods: Three test methods were performed on sinus specimen of 20 fresh human cadavers: one- and two-dimensional membrane elongation as far as perforation, as well as membrane detachment from the adherent bone., Results: Perforation of the Schneiderian membrane (mean thickness: 90 mum) occurred at a mean tension of 7.3 N/mm(2). The membrane could be stretched to 132.6% of its original size in one-dimensional elongation, and to 124.7% in two-dimensional elongation. Thicker membranes demonstrated significantly higher load limits (P<0.001). The mean modulus of elasticity accounted 0.058 GPa, the mean adhesion force between sinus membrane and bone surface was 0.05 N/mm., Conclusions: Respecting the mechanical properties of the Schneiderian membrane may help reducing the complication rates and thus patient morbidity in minimally invasive maxillary sinus floor elevation.

Objectives: Altered pulp sensitivity of anterior lower teeth is a frequent finding following chin bone harvesting. Persistent loss of tooth sensitivity has been reported in up to 20% of the patients. The aim of this study was to evaluate current recommendations for the location of the harvest zone with respect to the course of the mandibular incisive canal (MIC), the intrabony continuation of the mandibular canal mesial to the mental foramen., Material and Methods: On computed tomographic (CT) scans of 50 dentate mandibles, the MIC was located and its distance to the root apices, to the labial bony surface, and to the inferior margin of the mandible was assessed. The risk of nerve injury and the percentage of patients suitable for chin bone grafting were calculated., Results: Respecting current recommendations for chin bone grafting, the content of the MIC was endangered in 57% of the CTs. Therefore, new safety margins are suggested: the chin bone should be harvested at least 8 mm below the tooth apices with a maximum harvest depth of 4 mm., Conclusions: Applying the new safety recommendations and proper patient selection in chin bone harvesting could reduce the risk of altered postoperative tooth sensitivity due to injury of the mandibular incisive nerve.

Failure of nerve repair or poor functional outcome after reconstruction can be influenced by various causes. Besides improper microsurgical technique, fascicular malalignment and unphysiologic tension, we found in our clinical series that a subclinical nerve compression distal to the repair site can seriously impair regeneration. We concluded that the injured nerve, whether from trauma or microsurgical intervention, could be more susceptible to distal entrapment in the regenerative stage because of its disturbed microcirculation, swelling and the increase of regenerating axons followed by increased nerve volume. In two cases we found the regenerating nerve entrapped at pre-existing anatomical sites of narrowing resulting in impaired functional recovery. In both cases the surgical therapy was decompression of the distal entrapped nerve and this was followed by continued regeneration. Thorough clinical and electrophysiologic follow-up is necessary to detect such adverse compression effects and to distinguish between the various causes of failed regeneration. Under certain circumstances primary preventive decompression may be beneficial if performed at the time of nerve coaptation.

Brain-stem auditory evoked potentials (BAEPs) and the acoustic stapedius reflex (ASR) were recorded in 68 patients with definite, probable and possible multiple sclerosis (using the definitions of McAlpine). The high incidence of abnormal results, 68% and 60%, respectively, pointed to the diagnostic value of these two measures in detecting brain-stem dysfunction. Combination of the methods increased the diagnostic yield to 85%. Since in part the same brain-stem generator sites underlie BAEPs and the ASR, it was considered that a study of their correlation might serve to increase the reliability and validity of these techniques. There was 71% agreement overall between results from the two measures. Furthermore, 72% of the joint BAEP and ASR abnormalities corresponded in detection of the brain-stem lesion site. It was concluded that the combined approach may supply powerful, complementary information on brain-stem dysfunction, which may aid in establishing the diagnosis of multiple sclerosis.

A 43-year-old man developed severe global amnesia with uncinate fits and a single generalised convulsion 10 days after a febrile infection. CSF pleocytosis and serological findings indicated an acute Epstein-Barr virus encephalitis. All of the symptoms cleared within 2 weeks except for occasional generalised seizures. This seems to be the first observation of Epstein-Barr virus encephalitis presenting predominantly as transient global amnesia.

Symptoms such as tinnitus, hearing and taste disorders and facial palsy seldom occur in multiple sclerosis. Although ENT symptoms are few, vestibular and acoustic stapedius reflex tests combined with brainstem auditory evoked potentials (BAEPs) are available, and may give very useful evidence of the existence of MS. 52 patients with definite MS, and 13 patients with probable MS were examined (classified according to the McAlpine criteria). The vestibular and acoustic stapedius reflex tests were abnormal in 51%/61% and 61%/53% respectively of both groups. The corresponding figures for BAEP were 69% and 63%. The combination of the three tests on all patients showed at least one pathological finding.

103 patients with multiple sclerosis (MS) were investigated, of which 53% complained of micturition difficulties. Since these symptoms frequently are the main cause for social withdrawal of the multiple sclerosis patient, the investigation and therapy of micturition dysfunction should play a central role in the management of these patients.