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Purpose: The aim of this article is to systematically review the literature on prosthodontic maintenance requirements of maxillary implant overdentures with different prosthodontic designs. Materials and Methods: A standard approach of searching MEDLINE, PubMed, and Google Scholar databases as well as early online journal articles was followed. Hand-searching identified other relevant articles from the reference lists of the articles found. Selection criteria were details of prosthodontic maintenance related to different prosthodontic designs of maxillary implant overdentures, regardless of the dentition of the opposing arch or prosthesis. Results: From a total of 58 relevant studies identified, only 18 met the criteria. Several categories were used to document the prosthodontic maintenance of maxillary implant overdentures, usually with four or more splinted or unsplinted implants using different attachment systems. Aspects of patrix and matrix maintenance were primarily reported, although soft tissue complications were described frequently. Subjective information on relines and the rationale for minimizing overdenture fractures was found. Conclusions: Prosthodontic maintenance requirements of maxillary overdentures are a direct consequence of the attachment system, together with differing numbers and distributions of implants. The reviewed literature does not provide a clear controlled indication of prosthodontic maintenance requirements of maxillary overdentures for different prosthodontic designs and attachment systems. Future standardization of maxillary implant overdenture design is recommended, and universally accepted criteria for reporting maxillary implant overdenture maintenance should be implemented to establish accurate comparative data analysis. [ABSTRACT FROM AUTHOR]

Purpose: Resonance frequency analysis (RFA) is used to measure oral implant stability. There is controversy with regard to its accuracy in predicting both implant stability and osseointegration. This systematic review and meta-analysis determined the prognostic accuracy of RFA in predicting implant failure following immediate loading protocols. Materials and Methods: MEDLINE, EMBASE, the Cochrane Oral Health Group's Trials Register, the United Kingdom National Research Register, the Australian New Zealand Clinical Trials Registry, the Database of Abstracts of Reviews of Effectiveness, and the Conference Proceedings Citations Index were searched to select studies that used RFA in assessing implant stability prior to immediate loading. The sensitivity, specificity, and accuracy of RFA in the selected studies were evaluated using a random effects model. The summary receiver operating characteristic was constructed to summarize the overall test performance. Results: Fifteen studies with 2,236 immediately loaded implants were identified. The sensitivity of RFA in predicting failure of immediately loaded implants was 0.38 (95% confidence interval [CI]: 0.22 to 0.56), the specificity was 0.73 (95% CI: 0.71 to 0.75), and the diagnostic odds ratio was 2.10 (95% CI: 0.79 to 5.57). The area under the curve was 0.54, suggesting a poor predictive and discriminative ability. Conclusion: RFA measurement at the time of implant placement is not sufficiently accurate to determine implant stability and osseointegration during immediate loading protocols. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this research was to determine the long-term prosthodontic maintenance requirements of mandibular two-implant overdentures using different loading protocols and attachment systems. Materials and Methods: A total of 106 participants were allocated randomly to one of four different implant systems (Steri-Oss, Southern, Straumann, or Branemark). Three different loading protocols (2, 6, and 12 weeks) were used with six different ball abutment patrices and their respective matrices (Steri-Oss rubber, Straumann gold, Straumann titanium, Branemark gold, Southern plastic, and Southern gold/platinum). Prosthodontic maintenance events were documented prospectively from baseline until the 8-year recall according to predefined categories. Results: After 6 years, 90 participants attended recall and, thereafter, 68 participants were followed for 8 years. No significant differences were found between the number of prosthodontic maintenance events and the loading protocol used. Steri-Oss rubber matrices had the highest mean number of maintenance events at 32.2 ± 14.5 events, followed by the Branemark gold matrices at 28.8 ± 12.6 events. The Southern plastic matrices had a significantly lower mean number of maintenance events (8.7 ± 4.2) when compared with all other groups. Over a 6-year period, the matrices with the best longevity were Straumann gold at 3.9 ± 2.1 years. Straumann gold matrices also lasted significantly longer than all other matrices (P < .05). Southern gold/platinum, Branemark gold, and Southern plastic matrices all lasted significantly longer than the Straumann titanium and Steri-Oss matrices (P < .05). The mean time to reline for overdentures was 3.37 ± 2.06 years; remaking of overdentures peaked by year 7, with a mean time to remake of 5.81 ± 2.04 years. Conclusion: Early loading protocols do not influence long-term prosthodontic maintenance requirements of unsplinted mandibular two-implant overdentures. By contrast, attachment systems do influence prosthodontic maintenance, particularly with regard to the type of matrices used. Int J Prosthodont 2011;24:405-416. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to evaluate the mechanical properties of different attachment systems used for mandibular single-implant overdentures and to compare their wear/deformation features with clinical performance in patients after 1 year.Materials and Methods: Three attachment systems were evaluated: large 5.9-mm titanium nitride-coated ball attachments with plastic matrices, standard 2.25-mm uncoated titanium alloy ball attachments with Dalla Bona-type gold alloy matrices, and Locator attachments of titanium nitride-coated patrices and nylon matrices. The hardness and elastic modulus of the systems were determined using the nanoindentation technique. Twelve attachments from each system were used in 36 edentulous patients to support mandibular single-implant overdentures. After 1 year, 5 samples from each system were retrieved and evaluated for wear changes under a scanning electron microscope.Results: The titanium nitride-coated patrices, regardless of system, appeared unchanged and did not require any maintenance. Extensive wear was evident in the uncoated titanium alloy patrices and Dalla Bona-type gold alloy matrices, resulting in high maintenance (15 activations). Minimal wear was observed in the plastic matrices with minimal maintenance (2 replacements). The Locator nylon matrices showed extensive deformation and deterioration with a substantial need for maintenance (16 replacements). The performance of the patrices was related to hardness, while that of the matrices was related to the creep response.Conclusions: Large ball attachment systems of titanium nitride-coated patrices and plastic matrices reflect favorable wear behavior and clinical performance. These attachments are recommended for patients receiving mandibular single-implant overdentures. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to evaluate long-term marginal bone levels for two unsplinted implants supporting mandibular overdentures using conventional and early loading protocols with different implant surfaces and attachment systems. Materials and Methods: A cohort of 106 edentulous participants (mean age: 65 years) was treated with mandibular two-implant overdentures opposing complete maxillary dentures. Participants were randomly allocated into three loading protocol groups using four implant systems; single-stage surgery was performed for all participants, followed by an unsplinted prosthesis using six different attachment systems. Standardized intraoral radiographs taken at baseline (loading) and over 10 years appraised marginal bone levels mesially and distally from reference points under magnification. Three calibrated examiners repeated measurements, diminishing intra- and interobserver variability. Progressive attrition of participants occurred as a result of deaths, dropouts, and emigration. Seventy-nine participants (74.5%, mean age: 72 years) were available at the 10-year recall. Differences in bone loss among different loading protocols, implant surfaces, and attachment systems were tested using chi-square and one-way analysis of variance tests. Results: Minimal, time-dependent, long-term marginal bone loss occurred with all loading protocols. Annual marginal bone loss progressed at low levels after the first year with episodes of bone loss and gain. There was stability in marginal bone levels over the long term, with the majority of remodeling occurring during the first year of function. Roughened implant surfaces may be beneficial during the early remodeling period. The amount of marginal bone loss in the first year of loading differed significantly by loading protocol and implant surface, whereas attachment system had a minor influence. Differences were not reflected in the success rates calculated using standard criteria. The remaining participants at 10 years were classified as successful related to the criterion of marginal bone loss, irrespective of the determining criteria for success. Conclusions: Either a 2- , 6-, or 12-week loading protocol for mandibular two-implant overdentures is possible in the long term, irrespective of the attachment system used. Minimal marginal bone loss may be attributed primarily to mandibular basal bone remaining from long-term edentulism. Revision of the current implant success criteria to offer a stricter limit is desirable. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to investigate the retentive force of six different attachment systems used for mandibular single-implant overdentures, including two prototype large ball attachment designs. Materials and Methods: Two prototype ball attachments of larger dimensions (7.9 and 5.9 mm) and four commercially available ball and stud attachments of standard dimensions (2.25 and 4.0 mm) were evaluated on three identical test casts resembling an edentulous mandible with severe residual ridge resorption. Five samples from each attachment system (n = 30) were connected to three different implants (8.0-mm wide diameter, 3.75-mm regular diameter, and 4.0-mm regular diameter). An Instron testing machine with a computer software package was used to deliver a vertical dislodging force at a cross-head speed of 50 mm/min to each overdenture sample from the anterior direction. A total of 300 pull tests were conducted (50 per attachment system). The maximum load (retentive force) required to separate each overdenture from the supporting implant was then measured. Results: The highest retentive force (36.97 +/- 2.23 N) was achieved with the 7.9-mm prototype ball attachment design, followed in a decreasing order by the 5.9-mm prototype ball attachment design (32.06 +/- 2.59 N), the standard 2.25-mm ball attachment (17.32 +/- 3.68 N), Locator white (12.39 +/- 0.55 N), Locator pink (9.40 N +/- 0.74 N), and Locator blue (3.83 +/- 0.64 N). A statistically significant difference (P < .0001) was found between all attachments. Conclusions: Attachment systems of larger dimensions provided higher retentive forces for mandibular single-implant overdentures. Further in vitro and in vivo research is necessary to determine prosthodontic outcomes with these attachments in edentulous patients prior to their routine clinical use internationally. Int J Prosthodont 2010;23:160-166. [ABSTRACT FROM AUTHOR]

PURPOSE: The aim of this study was to review the published literature on in vitro articles investigating the retentive force or wear features of different attachment systems, specifically for mandibular two-implant overdentures using an unsplinted prosthodontic design. MATERIALS AND METHODS: An electronic search was performed through PubMed, Embase, and Medline databases using Boolean operators to combine the following key words: 'retention,' 'wear,' 'overdenture attachments,' 'attachment systems,' 'implant-retained overdentures,' and 'implant-supported overdentures.' The search was limited to articles written in English published up to October 2008. In addition, a hand search through articles and reference lists retrieved from the electronic search and peer-reviewed journals was also conducted. RESULTS: From a total of 193 articles, only 15 met the specified inclusion criteria for the review. These articles provided evidence that the majority of attachment systems for mandibular two-implant overdentures demonstrate a reduction in their retentive force under in vitro conditions. Wear was unquestionably implicated as the etiologic factor for the loss of retention; however, the specific mechanisms involved in the wear process have not been researched adequately. Findings from the literature have also implicated several factors that influence the retentive force of the attachment system and its wear features; compelling evidence on its precise role however, is still lacking. CONCLUSIONS: Further in vitro investigations of the factors involved in the retention and wear of attachment systems for mandibular two-implant overdentures are still needed. These factors must be investigated separately under well-controlled conditions to limit the influence of confounding variables on their outcome. [ABSTRACT FROM AUTHOR]

Purpose: A systematic review and meta-analysis of studies that specifically compared immediate to conventional loading of single implant crowns was conducted and the overall treatment effect was estimated. Materials and Methods: MEDLINE, the Cochrane Controlled Trials Register, and bibliographies of relevant primary and review articles were searched. Randomized and nonrandomized controlled studies that compared immediate with conventional loading of single implant crowns were selected according to strict criteria. From the 105 articles screened, five studies with 248 implants were analyzed. The meta-analysis was prepared in accordance with the Quality of Reporting of Meta-analyses (QUOROM) statement. Descriptive and outcome data were extracted using specially designed data extraction forms. The data were entered into MIX software for meta-analysis using a fixed effects model, relative risk, and 95% confidence interval (CI). Results: Immediate loading of single implant crowns was associated with a significantly higher risk of implant failure (relative risk: 5.07, 95% CI: 2.00 to 12.84, P < .001). Pooling of randomized controlled trials showed similar results, although the difference was not statistically significant. Immediate nonocclusal loading was also associated with worse outcomes when compared to conventional loading (relative risk: 4.76, 95% CI: 1.74 to 13.02, P = .002). Conclusions: This systematic review and meta-analysis shows that better outcomes are currently achieved using conventional loading of single implants with crowns, as opposed to immediately loaded ones, which are at a higher risk of failure. Further adequately powered clinical trials are needed. Caution with immediate loading of implants with crowns as a standard of care for single tooth replacement is recommended. Int J Prosthodont 2009;22:378-387. [ABSTRACT FROM AUTHOR]

Background: Alveolar bone changes following tooth extraction can compromise prosthodontic rehabilitation. Alveolar ridge preservation (ARP) has been proposed to limit these changes and improve prosthodontic and aesthetic outcomes when implants are used. This is an update of the Cochrane Review first published in 2015., Objectives: To assess the clinical effects of various materials and techniques for ARP after tooth extraction compared with extraction alone or other methods of ARP, or both, in patients requiring dental implant placement following healing of extraction sockets., Search Methods: Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 19 March 2021), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2021, Issue 2), MEDLINE Ovid (1946 to 19 March 2021), Embase Ovid (1980 to 19 March 2021), Latin American and Caribbean Health Science Information database (1982 to 19 March 2021), Web of Science Conference Proceedings (1990 to 19 March 2021), Scopus (1966 to 19 March 2021), ProQuest Dissertations and Theses (1861 to 19 March 2021), and OpenGrey (to 19 March 2021). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. A number of journals were also handsearched., Selection Criteria: We included all randomised controlled trials (RCTs) on the use of ARP techniques with at least six months of follow-up. Outcome measures were: changes in the bucco-lingual/palatal width of alveolar ridge, changes in the vertical height of the alveolar ridge, complications, the need for additional augmentation prior to implant placement, aesthetic outcomes, implant failure rates, peri-implant marginal bone level changes, changes in probing depths and clinical attachment levels at teeth adjacent to the extraction site, and complications of future prosthodontic rehabilitation., Data Collection and Analysis: We selected trials, extracted data, and assessed risk of bias in duplicate. Corresponding authors were contacted to obtain missing information. We estimated mean differences (MD) for continuous outcomes and risk ratios (RR) for dichotomous outcomes, with 95% confidence intervals (95% CI). We constructed 'Summary of findings' tables to present the main findings and assessed the certainty of the evidence using GRADE., Main Results: We included 16 RCTs conducted worldwide involving a total of 524 extraction sites in 426 adult participants. We assessed four trials as at overall high risk of bias and the remaining trials at unclear risk of bias. Nine new trials were included in this update with six new trials in the category of comparing ARP to extraction alone and three new trials in the category of comparing different grafting materials. ARP versus extraction: from the seven trials comparing xenografts with extraction alone, there is very low-certainty evidence of a reduction in loss of alveolar ridge width (MD -1.18 mm, 95% CI -1.82 to -0.54; P = 0.0003; 6 studies, 184 participants, 201 extraction sites), and height (MD -1.35 mm, 95% CI -2.00 to -0.70; P < 0.0001; 6 studies, 184 participants, 201 extraction sites) in favour of xenografts, but we found no evidence of a significant difference for the need for additional augmentation (RR 0.68, 95% CI 0.29 to 1.62; P = 0.39; 4 studies, 154 participants, 156 extraction sites; very low-certainty evidence) or in implant failure rate (RR 1.00, 95% CI 0.07 to 14.90; 2 studies, 70 participants/extraction sites; very low-certainty evidence). From the one trial comparing alloplasts versus extraction, there is very low-certainty evidence of a reduction in loss of alveolar ridge height (MD -3.73 mm; 95% CI -4.05 to -3.41; 1 study, 15 participants, 60 extraction sites) in favour of alloplasts. This single trial did not report any other outcomes. Different grafting materials for ARP: three trials (87 participants/extraction sites) compared allograft versus xenograft, two trials (37 participants, 55 extraction sites) compared alloplast versus xenograft, one trial (20 participants/extraction sites) compared alloplast with and without membrane, one trial (18 participants, 36 extraction sites) compared allograft with and without synthetic cell-binding peptide P-15, and one trial (30 participants/extraction sites) compared alloplast with different particle sizes. The evidence was of very low certainty for most comparisons and insufficient to determine whether there are clinically significant differences between different ARP techniques based on changes in alveolar ridge width and height, the need for additional augmentation prior to implant placement, or implant failure. We found no trials which evaluated parameters relating to clinical attachment levels, specific aesthetic or prosthodontic outcomes for any of the comparisons. No serious adverse events were reported with most trials indicating that the procedure was uneventful. Among the complications reported were delayed healing with partial exposure of the buccal plate at suture removal, postoperative pain and swelling, moderate glazing, redness and oedema, membrane exposure and partial loss of grafting material, and fibrous adhesions at the cervical part of previously preserved sockets, for the comparisons xenografts versus extraction, allografts versus xenografts, alloplasts versus xenografts, and alloplasts with and without membrane., Authors' Conclusions: ARP techniques may minimise the overall changes in residual ridge height and width six months after extraction but the evidence is very uncertain. There is lack of evidence of any differences in the need for additional augmentation at the time of implant placement, implant failure, aesthetic outcomes, or any other clinical parameters due to lack of information or long-term data. There is no evidence of any clinically significant difference between different grafting materials and barriers used for ARP. Further long-term RCTs that follow CONSORT guidelines (www.consort-statement.org) are necessary., (Copyright © 2021 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.)

Background: Implant overdentures are one of the most common treatment options used to rehabilitate edentulous patients. Attachment systems are used to anchor the overdentures to implants. The plethora of attachment systems available dictates a need for clinicians to understand their prosthodontic and patient-related outcomes., Objectives: To compare different attachment systems for maxillary and mandibular implant overdentures by assessing prosthodontic success, prosthodontic maintenance, patient preference, patient satisfaction/quality of life and costs., Search Methods: Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 24 January 2018); Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 12) in the Cochrane Library (searched 24 January 2018); MEDLINE Ovid (1946 to 24 January 2018); and Embase Ovid (1980 to 24 January 2018). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials on 24 January 2018. No restrictions were placed on the language or date of publication when searching the electronic databases., Selection Criteria: All randomised controlled trials (RCTs), including cross-over trials on maxillary or mandibular implant overdentures with different attachment systems with at least 1 year follow-up., Data Collection and Analysis: Four review authors extracted data independently and assessed risk of bias for each included trial. Several corresponding authors were subsequently contacted to obtain missing information. Fixed-effect meta-analysis was used to combine the outcomes with risk ratios (RR) for dichotomous outcomes and mean differences (MD) for continuous outcomes, with 95% confidence intervals (95% CI). We used the GRADE approach to assess the quality of evidence and create 'Summary of findings' tables., Main Results: We identified six RCTs with a total of 294 mandibular overdentures (including one cross-over trial). No trials on maxillary overdentures were eligible. Due to the poor reporting of the outcomes across the included trials, only limited analyses between mandibular overdenture attachment systems were possible.Comparing ball and bar attachments, upon pooling the data regarding short-term prosthodontic success, we identified substantial heterogeneity (I 2 = 97%) with inconsistency in the direction of effect, which was unexplained by clinical or methodological differences between the studies, and accordingly we did not perform meta-analyses for this outcome. Short-term re-treatment (repair of attachment system) was higher with ball attachments (RR 3.11, 95% CI 1.68 to 5.75; 130 participants; 2 studies; very low-quality evidence), and there was no difference between both attachment systems in short-term re-treatment (replacement of attachment system) (RR 1.18, 95% CI 0.38 to 3.71; 130 participants; 2 studies; very low-quality evidence). It is uncertain whether there is a difference in short-term prosthodontic success when ball attachments are compared with bar attachments.Comparing ball and magnet attachments, there was no difference between them in medium-term prosthodontic success (RR 0.84, 95% CI 0.64 to 1.10; 69 participants; 1 study; very low-quality evidence), or in medium-term re-treatment (repair of attachment system) (RR 1.75, 95% CI 0.65 to 4.72; 69 participants; 1 study; very low-quality evidence). However, after 5 years, prosthodontic maintenance costs were higher when magnet attachments were used (MD -247.37 EUR, 95% CI -346.32 to -148.42; 69 participants; 1 study; very low-quality evidence). It is uncertain whether there is a difference in medium-term prosthodontic success when ball attachments are compared with magnet attachments.One trial provided data for ball versus telescopic attachments and reported no difference in prosthodontic maintenance between the two systems in short-term patrix replacement (RR 6.00, 95% CI 0.86 to 41.96; 22 participants; 1 study; very low-quality evidence), matrix activation (RR 11.00, 95% CI 0.68 to 177.72; 22 participants; 1 study; very low-quality evidence), matrix replacement (RR 1.75, 95% CI 0.71 to 4.31; 22 participants; 1 study; very low-quality evidence), or in relining of the implant overdenture (RR 2.33, 95% CI 0.81 to 6.76; 22 participants; 1 study; very low-quality evidence). It is uncertain whether there is a difference in short-term prosthodontic maintenance when ball attachments are compared with telescopic attachments.In the only cross-over trial included, patient preference between different attachment systems was assessed after only 3 months and not for the entire trial period of 10 years., Authors' Conclusions: For mandibular overdentures, there is insufficient evidence to determine the relative effectiveness of different attachment systems on prosthodontic success, prosthodontic maintenance, patient satisfaction, patient preference or costs. In the short term, there is some evidence that is insufficient to show a difference and where there was no evidence was reported. It was not possible to determine any preferred attachment system for mandibular overdentures.For maxillary overdentures, there is no evidence (with no trials identified) to determine the relative effectiveness of different attachment systems on prosthodontic success, prosthodontic maintenance, patient satisfaction, patient preference or costs.Further RCTs on edentulous cohorts must pay attention to trial design specifically using the same number of implants of the same implant system, but with different attachment systems clearly identified in control and test groups. Trials should also determine the longevity of different attachment systems and patient preferences. Trials on the current array of computer-aided designed/computer-assisted manufactured (CAD/CAM) bar attachment systems are encouraged.

Objective: To determine implant survival and prosthodontic maintenance of implant-assisted mandibular removable partial dentures in a multicentre prospective study up to 10 years., Materials and Methods: Forty-eight participants with mandibular distal extension partial dentures were selected. A control group of 12 New Zealand participants had new conventional mandibular partial dentures made. Three test groups of 36 participants in New Zealand (n = 12), the Netherlands (n = 12) and Colombia (n = 12) had bilateral distal implants placed. Surgical and prosthodontic outcomes were documented with only healing caps placed (Stage 1) and with an attachment system (Stage 2)., Results: No implants failed after 3 years. Four late implant failures in three participants occurred in New Zealand (two unilateral implant failures after 5 and 8 years and two bilateral implant failures in the same participant after 6 and 10 years); two unilateral late implant failures occurred in the Netherlands and no late failures in Colombia. Implant survival rate was 92% by 10 years. Resonance frequency measurements were taken at surgery implant stability quotient (ISQ) 62.44 ± 7.46; range 40 - 79), baseline (ISQ 63.22 ± 6.17; range 50 - 74) and after 3 years (ISQ 66.38 ± 6.77; range 55 - 83). In New Zealand and Colombia, measured crestal bone levels were 2.03 ± 0.71 mm and 2.20 ± 0.81 mm, respectively, at baseline and 3 years. For Stage I, principal prosthodontic maintenance issues were loose healing caps among 10 New Zealand participants, four Colombian participants and one Netherlands participant. For Stage 2, matrix activation and overdenture puncture fractures resulted in 41 events (25 participants) in New Zealand over 10 years, whilst over 3 years, there were 14 events in nine Colombian participants and six events in five Netherlands participants., Conclusion: This clinical multicentre research complements previous case reports, case series, retrospective and prospective studies on the notion of implant-assisted removable partial dentures for partially edentulous patients. Late implant failures and increased prosthodontic maintenance when an attachment system is used identify the need for further research, including more robust statistical analyses., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Several clinical trials describe the effectiveness of xenogeneic collagen matrix (XCM) as an alternative option to surgical mucogingival procedures for the treatment of marginal tissue recession and augmentation of insufficient zones of keratinized tissue (KT). The aim of this systematic review and meta-analysis was to evaluate the clinical and patient-centred outcomes of XCM compared to other mucogingival procedures. Applying guidelines of the Preferred Reporting Items for Systematic Reviews and Meta analyses statement, randomized controlled trials were searched for in electronic databases and complemented by hand searching. The risk of bias was assessed using the Cochrane Collaboration's Risk of Bias tool and data were analysed using statistical software. A total of 645 studies were identified, of which, six trials were included with 487 mucogingival defects in 170 participants. Overall meta-analysis showed that connective tissue graft (CTG) in conjunction with the coronally advanced flap (CAF) had a significantly higher percentage of complete/mean root coverage and mean recession reduction than XCM. Insufficient evidence was found to determine any significant differences in width of KT between XCM and CTG. The XCM had a significantly higher mean root coverage, recession reduction and gain in KT compared to CAF alone. No significant differences in patient's aesthetic satisfaction were found between XCM and CTG, except for postoperative morbidity in favour of XCM. Operating time was significantly reduced with the use of XCM compared with CTG but not with CAF alone. There is no evidence to demonstrate the effectiveness of XCM in achieving greater root coverage, recession reduction and gain in KT compared to CTG plus CAF. Superior short-term results in treating root coverage compared with CAF alone are possible. There is limited evidence that XCM may improve aesthetic satisfaction, reduce postoperative morbidity and shorten the operating time. Further long-term randomized controlled trials are required to endorse the supposed advantages of XCM., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Purpose: This study aimed to evaluate the 10-year prosthodontic outcomes with splinted and unsplinted designs for maxillary overdentures on three implants opposing mandibular two-implant overdentures., Materials and Methods: Using two similar implant systems, 40 edentulous participants with existing mandibular two-implant overdentures were randomly allocated to two prosthodontic treatment groups (splinted design with bar units; unsplinted design with ball attachments). Participants had three narrow-diameter implants placed in their edentulous maxillae using a one-stage surgical procedure, and they were conventionally loaded with overdentures. Prosthodontic maintenance events were documented at 1-, 2-, 5-, 7-, and 10-year recalls., Results: Progressive attrition of the cohort resulted in 36 participants being seen for the 1-year recall, 31 participants for the 2-year recall, 30 participants for the 3-year recall, 28 participants for the 5-year recall, 26 participants for the 7-year recall, and 23 participants (nearly 60%) for the 10-year recall. Data showed no significant differences in prosthodontic maintenance or success associated with patrices, matrices, or other aspects of the overdentures using the different attachment systems and designs., Conclusion: Maxillary three-implant overdentures are a viable treatment option for edentulous patients wearing opposing mandibular two-implant overdentures. There were no differences in prosthodontic maintenance and success between the splinted (bar) and unsplinted (ball) designs.

Background: The surgical placement of four maxillary implants for overdentures may not be obligatory when opposing mandibular two-implant overdentures., Purpose: To determine 10-year surgical outcomes and implant success of three narrow diameter implants in edentulous maxillae with conventional loading., Materials and Methods: Forty participants with mandibular two-implant overdentures were randomly allocated for surgery for maxillary overdentures. Using osteotomes, three implants of similar systems were placed with a one-stage procedure and 12-week loading with splinted and unsplinted prosthodontic designs. Marginal bone and stability measurements were done at surgery, 12 weeks, 1-, 2-, 5-, 7-, 10 years., Results: One hundred seventeen implants were placed in 39 participants, with 35 being seen at 1 year; 29 at 2 years; 28 at 5 years; 26 at 7 years; and 23 (59%) at 10 years. Marginal bone loss was 1.35 mm between surgery and 12 weeks; 0.36 mm between 12 weeks and 1 year; 0.48 mm between 1 and 5 years; and 0.22 mm between 5 and 10 years. Implant stability quotients were 56.05, 57.54, 60.88, 58.80, 61.17 at surgery, 12 weeks, 1 year, 5 years, and 10 years. Four-field tables by implant showed success rates of 82% at 1 year; 69.2% at 2 years; 66.7% at 5 years; 61.5% at 7 years; 51.3% at 10 years. Data showed no differences between surgical technique, systems, or prosthodontic designs., Conclusions: Surgical placement with osteotomes of three narrow diameter implants for maxillary overdentures, opposing mandibular two-implant overdentures, is an acceptable approach, subject to strict patient selection. Implant success is independent of prosthodontic design., (© 2015 Wiley Periodicals, Inc.)

Background: Alveolar bone changes following tooth extraction can compromise prosthodontic rehabilitation. Alveolar ridge preservation (ARP) has been proposed to limit these changes and improve prosthodontic and aesthetic outcomes when implants are used., Objectives: To assess the clinical effects of various materials and techniques for ARP after tooth extraction compared with extraction alone or other methods of ARP, or both, in patients requiring dental implant placement following healing of extraction sockets., Search Methods: The following electronic databases were searched: the Cochrane Oral Health Group's Trials Register (to 22 July 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2014, Issue 6), MEDLINE via OVID (1946 to 22 July 2014), EMBASE via OVID (1980 to 22 July 2014), LILACS via BIREME (1982 to 22 July 2014), the Meta Register of Current Controlled Trials (to 22 July 2014), ClinicalTrials.gov (to 22 July 2014), the World Health Organization International Clinical Trials Registry Platform (to 22 July 2014), Web of Science Conference Proceedings (1990 to 22 July 2014), Scopus (1966 to 22 July 2014), ProQuest Dissertations and Theses (1861 to 22 July 2014) and OpenGrey (to 22 July 2014). A number of journals were also handsearched. Trial authors were contacted to identify unpublished randomised controlled trials. There were no restrictions regarding language and date of publication in the searches of the electronic databases., Selection Criteria: We included all randomised controlled trials (RCTs) on the use of alveolar ridge preservation techniques with at least six months of follow-up. Outcome measures were: changes in the bucco-lingual/palatal width of alveolar ridge, changes in the vertical height of the alveolar ridge, complications, the need for additional augmentation prior to implant placement, aesthetic outcomes, implant failure rates, peri-implant marginal bone level changes, changes in probing depths and clinical attachment levels at teeth adjacent to the extraction site, and complications of future prosthodontic rehabilitation., Data Collection and Analysis: Two review authors extracted data independently and assessed risk of bias for each included trial. Corresponding authors were contacted to obtain missing information. Results were combined using random-effects models with mean differences (MD) for continuous outcomes and risk ratios (RR) for dichotomous outcomes, with 95% confidence intervals (95% CI). We constructed 'Summary of findings' tables to present the main findings., Main Results: A total of 50 trials were potentially eligible for inclusion, of which 42 trials were excluded. We included eight RCTs with a total of 233 extraction sites in 184 participants. One trial was judged to be at unclear risk of bias and the remaining trials were at high risk of bias. From two trials comparing xenograft with extraction alone (70 participants, moderate quality evidence), there was some evidence of a reduction in loss of alveolar ridge height (MD -2.60 mm; 95% CI -3.43 to -1.76) and width (MD -1.97 mm; 95% CI -2.48 to -1.46). This was also found in one trial comparing allograft with extraction (24 participants, low quality evidence): ridge height (MD -2.20 mm; 95% CI -0.75 to -3.65) and width (MD - 1.40 mm; 95% CI 0.00 to -2.80) and height. From two RCTs comparing alloplast versus xenograft no evidence was found that either ridge preservation technique caused a smaller reduction in loss of ridge height (MD -0.35 mm; 95% CI -0.86 to 0.16) or width (MD -0.44 mm; 95% CI -0.90 to 0.02; two trials (55 participants); moderate quality evidence). There was insufficient evidence to determine whether there are clinically significant differences between different ARP techniques and extraction based on the need for additional augmentation prior to implant placement, complications, implant failure, or changes in peri-implant marginal bone levels and probing depths of neighbouring teeth. We found no trials which evaluated parameters relating to clinical attachment levels, specific aesthetic or prosthodontic outcomes., Authors' Conclusions: There is limited evidence that ARP techniques may minimise the overall changes in residual ridge height and width six months after extraction. There is also lack of evidence of any differences in implant failure, aesthetic outcomes or any other clinical parameters due to the lack of information or long-term data. There is no convincing evidence of any clinically significant difference between different grafting materials and barriers used for ARP. Further long term RCTs that follow CONSORT guidelines (www.consort-statement.org) are necessary.

Objectives: It is of imperative clinical significance to define a safe threshold for planned immediate implant restoration. The aim of this report was to evaluate the prognostic accuracy of resonance frequency analysis (RFA) measurements recorded at two different times (implant placement and 8-week post-implant placement) and to determine the optimal threshold value for predicting failure risk of immediately restored/loaded implants., Material and Methods: Twenty-eight 8- or 9-mm-diameter implants were placed in either a fresh molar extraction socket or a healed site. An electronic RFA device was used to record the implant stability quotients (ISQs) at implant placement surgery, 8 weeks and 1 year. Receiver operating characteristic (ROC) analysis was used to identify the optimal cut-off level. Sensitivity and specificity were also determined at the selected cut-off value., Results: The area under the ROC curve for RFA at 8 weeks was 0.93 with a significant P-value (P = 0.001). The optimum cut-off value for detecting implant stability was 60.5 ISQ measured at 8 weeks, with sensitivity and specificity of 95.2% and 71.4%, respectively., Conclusions: The implant stability measurements after 8 weeks showed a better accuracy in predicting implants that were at risk of failure than those taken at the time of implant placement., (© 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.)

Limited clinical research identifies prosthodontic perspectives of novel designs for zirconia implants supporting overdentures. Four pilot study participants were selected before a planned randomized clinical trial on zirconia implants supporting overdentures. Novel designs for maxillary four-implant overdentures (quadrilateral design) and mandibular three-implant overdentures (tripodal design) were used with 28 implants (maxilla, n = 16; mandible, n = 12). Four implants failed to achieve osseointegration prior to loading. At the 1-year follow-up appointment, all implants were surviving, the overdentures were in function, and there were no clinical signs of wear of the attachment system. A proof-of-principle for prosthodontic perspectives of a novel design using one-piece zirconia implants supporting maxillary and mandibular implant overdentures was achieved.

Background: In the replacement of missing teeth, a paradigm shift is currently observed with immediate implant placement and/or restoration, particularly in the aesthetic zone. In molar sites, however, anatomical, occlusal and biomechanical considerations remain deterrent factors influencing the outcome of this treatment paradigm. The aim of this report was to evaluate immediate placement and immediate restoration of strongly tapered wide-diameter implant in fresh mandibular molar extraction sockets., Methods: Twenty-four 8- or 9-mm diameter implants were placed in either a fresh molar extraction socket or a healed site. All the implants received provisional crowns within 48 h. The provisional crowns were replaced with full ceramic crowns after 8 weeks of implant placement., Results: The overall implant success rate after 1 year of service for the 24 implants in two treatment groups was 75%. Success rates were 83.3% and 66.7% for the delayed and immediate placement groups respectively, with no significant difference observed between the two groups (P = 0.35). Implant stability measurements identified the immediately placed implants to be more stable immediately after surgery than delayed placed implants. In contrast, the delayed placed implants were more stable after 8 week healing time., Conclusions: The rehabilitation of single missing mandibular molars by immediately placed and restored wide-diameter implants was associated with a relatively high failure rate., (© 2012 John Wiley & Sons A/S.)

Objective: To compare the levels of patient satisfaction with either conventional mandibular bilateral distal extension partial dentures or those assisted by bilateral distal implants., Materials and Methods: Forty-eight participants who were dissatisfied with their existing conventional mandibular distal extension dentures opposing complete maxillary dentures were selected for a multicentre prospective study in New Zealand, Colombia and the Netherlands. A control group of 12 participants in New Zealand received conventional mandibular partial dentures. Three test groups involving 36 participants in New Zealand (12), Colombia (12) and the Netherlands (12) received bilateral distal implants in the second molar regions. After conventional loading, the test group participants initially had healing caps placed on the distal implants providing support only, followed after approximately 6 months by ball abutments (retentive anchors) for support and retention. Patient outcomes were determined with questionnaires completed at specific stages of the study for up to 3 years., Results: Visual analogue scale, Likert and oral health impact questionnaires before and after treatment indicated improved results. There were significantly improved parameters of overall satisfaction, stability, chewing and appearance after 3 years (P < 0.05). There were also improvements on stability, chewing and overall satisfaction. Speech also improved, but not significantly. Ball abutments (retentive anchors) on the distal implants, as opposed to healing caps improved patient satisfaction for stability, chewing and overall satisfaction. Changing to ball abutments (retentive anchors) revealed significant improvement by participant response when evaluating parameters of stability, chewing and overall satisfaction (P < 0.05)., Conclusion: Mandibular implant-assisted removable partial dentures are a preferable treatment option for patients with complaints about their conventional distal extension partial dentures., (© 2011 John Wiley & Sons A/S.)

Objective: To use finite element analysis to investigate the influence of insertion torque on the stress distribution around an immediately placed oral implant., Method and Materials: Finite element software was used to model a mandibular molar extraction socket. The properties of surrounding cancellous bone and thickness of cortical bone were modified to give four 3D finite element models (I, II, III, and IV). A wide-diameter tapered oral implant was modeled and inserted into the socket. Final insertion torques of 32, 50, and 70 Ncm were applied, and the stress profile in each model was evaluated. The maximum von Mises stresses along the buccal cortical bone adjacent to the implant neck were statistically analyzed to compare the three torque values and four bone models., Results: At the level of the cortical bone, the greatest von Mises stress levels were generated in model IV and diminished as the bone quality increased. Significant increase in stress values at the crestal bone level was observed in all models after using 70 Ncm compared with 32 Ncm. The maximum von Mises stresses at the cancellous bone were higher in model I and reduced with lower level of bone quality (model IV)., Conclusion: The use of 70 Ncm or more insertion torque during placement of an immediately placed wide-diameter implant substantially increases stresses on the crestal bone. The development of a modified surgical protocol involving moderate insertion torque value (32 to 50 Ncm) may contribute to minimizing the risk of early implant failure in extraction sockets.

Background: Different attachment systems for mandibular two-implant overdentures could influence levels of patient satisfaction. Positive consensus of the majority of patients being satisfied does not preclude the possibility of dissatisfaction for some., Purpose: To evaluate patient satisfaction and dissatisfaction before and after 5 years of wearing mandibular two implant overdentures using different attachment systems ; to determine the prognostic relevance of pretreatment complete denture complaints to treatment outcomes., Materials and Methods: A total of 106 edentulous participants enrolled in a clinical trial completed a preliminary self-report inventory of their original complete denture complaints.New complete maxillary dentures and mandibular two-implant overdentures were provided to each participant using one of six different attachment systems. Patient satisfaction was determined at pretreatment; at baseline with mandibular two-implant overdenture insertion; and then annually for 5 years, using visual analogue and Likert-type scales., Results: Patient satisfaction with mandibular two-implant overdentures showed significant changes pre- to posttreatment(baseline) in all domains, but these were significant immediately and maintained without further significance for 5 years, other than pain with the overdenture. After 5 years, no significant differences were observed with all the attachment systems. Highly significant differences were found with some social and psychological aspects by the fifth year compared to baseline. Diagnostic and prognostic indicators from a pretreatment inventory identified 12 participants (13.5%) who were dissatisfied. These indicators revealed a maladaptive predisposition to mandibular two-implant overdentures., Conclusions: The provision of mandibular two-implant overdentures will, in the majority of patients, significantly enhance levels of patient satisfaction for 5 years, as compared to complete mandibular dentures, regardless of the attachment system. Careful evaluation of pretreatment complaints with conventional dentures can possibly identify patient dissatisfaction with mandibular two-implant overdentures [corrected]., (© 2010 Wiley Periodicals, Inc.)

Background: Patient-based outcomes with maxillary overdentures on a minimum number of implants, opposing mandibular 2-implant overdentures are not evident in the literature., Purpose: To evaluate patient's satisfaction with maxillary 3-implant overdentures, opposing mandibular 2-implant overdentures, using two different attachment systems over the first 2 years of service., Materials and Methods: Forty participants wearing mandibular 2-implant overdentures for 3 years were randomly allocated to one of two similar implant system groups to receive maxillary 3-implant overdentures. Twenty participants were allocated to splinted and unsplinted attachment system treatment groups for each system. Patient satisfaction with pre-treatment complete maxillary dentures, with maxillary 3-implant overdentures at baseline and annually for 2 years, was measured using visual analogue scale questionnaires and the oral health impact profiles. Palatal coverage of the maxillary overdentures was reduced at the first annual recall., Results: Data showed significant improvement in pain reduction, comfort, stability, and function variables of the visual analogue scale after treatment. Analysis by prosthodontic design using visual analogue scale showed no significant difference. The total oral health impact profile-14 scores after treatment for all participants, regardless of prosthodontic design, were significantly lower (more satisfied). The overall oral health impact profile-20E score at baseline was significantly higher (more satisfied) compared with pre-treatment conventional maxillary dentures. No significant changes were observed in the first or second years compared with baseline results. Twenty-two participants (84.6%) preferred reduced palatal coverage, regardless of prosthodontic design, after 1 year. Twenty participants (76.9%) still preferred reduced palatal coverage at the end of the second year., Conclusions: The provision of maxillary 3-implant overdentures to oppose mandibular 2-implant overdentures significantly improve levels of patient satisfaction compared with conventional maxillary dentures., (© 2011 Wiley Periodicals, Inc.)

Limited clinical research identifies prosthodontic maintenance requirements of mandibular overdentures using the Locator attachment system. Sixty-five edentulous participants received complete maxillary dentures opposing mandibular two-implant overdentures with either Locator nylon (n = 21), Southern plastic (n = 24), or Straumann gold (n = 20) matrices. Prosthodontic maintenance was recorded prospectively for 3 years using defined categories. Over the 3-year period, a mean 3.52 ± 4.8, 2.08 ± 1.9, and 5.5 ± 4.2 maintenance events occurred for Locator, Southern, and Straumann participants, respectively. Prosthodontic success rates of 90% in the Locator nylon group, 88% in the Southern plastic group, and 75% in the Straumann gold group were achieved. Int J Prosthodont 2011;24:328-331.

Objectives: To evaluate immediate placement and immediate restoration of a novel implant with a 12°-angled prosthodontic platform, in fresh extraction sockets of the aesthetic zone of the maxilla., Materials and Methods: Tapered, roughened surface implants of 4 mm (n=15) or 5 mm (n=13) diameter were placed in 27 participants (mean age: 47.1 years; range: 21-71 years) requiring an immediate replacement of single anterior maxillary teeth. Provisional screw-retained all-ceramic crowns were placed within 4 h following optical impressions. At 8 weeks (baseline), definitive screw-retained all-ceramic crowns were placed in occlusion., Results: Twenty-six of the 28 implants met the inclusion criteria at surgery. Marginal bone levels revealed bone gain between surgery and baseline, and between baseline and 1 year of 0.2 mm (SD 0.75) and 0.78 mm (SD 2.45). Mean mid-buccal mucosal margins showed gains of 0.2 mm (SD 0.44). Prosthodontic maintenance and the aesthetics of the screw-retained implant crowns were facilitated by the external hex 12°-angled prosthodontic platform on the novel implant design, re-orientating the access cavity to the palatal or occlusal surfaces. All-ceramic implant crowns showed a high success rate with low maintenance issues over 1 year., Conclusion: Tapered, roughened-surfaced implants with a novel 12°-angled prosthodontic platform immediately placed in fresh extraction sockets, immediately restored with provisional crowns and subsequent definitive crowns at 8 weeks were successful for 1 year., (© 2011 John Wiley & Sons A/S.)

Objectives: To determine surgical and prosthodontic outcomes of mandibular single-implant overdentures, opposing complete maxillary dentures, using a wide diameter implant and large ball attachment system compared with different regular diameter implants with standard attachment systems., Materials and Methods: Thirty-six edentulous participants (mean age 68 years, SD 9.2) were randomly assigned into three treatment groups (n=12). A single implant was placed in the mandibular midline of participants to support an overdenture using a 6-week loading protocol. The control group received Southern regular implants and standard ball attachments. One group received Southern 8-mm-wide implants and large ball attachments. Another group received Neoss regular implants and Locator attachments. Parametric and non-parametric tests of a statistical software package (SPSS) were used to determine between groups differences in marginal bone loss, implant stability, implant, and prosthodontic success (P<0.05)., Results: Implant success after 1 year was 75% for Southern regular implant (control) group; and 100% for the Southern wide and Neoss regular implant groups (P=0.038). Mean marginal bone loss at 1 year was 0.19 mm (SD 0.39) without significant differences observed. Implant stability quotient (ISQ) at baseline was significantly lower for the Southern regular (control) group than the other two groups (P=0.001; P=0.009). At 1 year, no significant difference in implant stability was observed (mean ISQ 74.6, SD 6.1). The change in implant stability from baseline to 1 year was significant for the control group (P=0.025). Prosthodontic success was comparable between the groups but the maintenance (41 events overall, mean 1.2) was greater for the Locator and the standard ball attachments., Conclusions: Mandibular single-implant overdentures are a successful treatment option for older edentulous adults with early loading protocol using implants of different diameters and with different attachment systems., (© 2010 John Wiley & Sons A/S.)

Objectives: To determine the primary stability of the Southern wide diameter (8 mm) implants, Neoss regular diameter (4 mm) implants, and Southern regular diameter (3.75 mm) implants placed in the midline of edentulous mandibles for single-implant overdentures. Variables related to host site and implant characteristics were investigated to determine their influence on the primary stability of the implants., Materials and Methods: A total of 36 implants were placed in the midline symphysis of the edentulous mandibles of 36 participants. Their primary stability was then measured using the magnetic Osstell mentor device. Analysis of variance (ANOVA) was used to compare the mean implant stability quotient (ISQ) scores with one-way ANOVA for multiple comparisons., Results: The highest measurement (ISQ) of primary stability was for the Southern 8 mm wide diameter implants (84.8, SD 9.8), followed by the Neoss 4 mm regular diameter (82.3, SD 4.8) implants and the Southern 3.75 mm regular diameter implants (75.3, SD 8.4), respectively. The Southern 3.75 mm regular diameter implants had a significantly lower mean ISQ value than the same system 8 mm wide diameter (P=0.004) and the Neoss 4 mm regular diameter implants (P=0.03). No significant differences were observed between the 8 mm and the 4 mm diameter implants (P>0.05)., Conclusions: Host-site variables such as age, gender, bone volume, and quality do not appear to influence the primary stability of the implants. No clear correlation was established between ISQ values and implant diameter.

Background: Mandibular overdentures are a successful treatment option for the edentulous patients with long-term predictable outcomes, using conventional loading protocols. Currently, both early and immediate loading protocols for mandibular implant overdentures are prevalent in the literature., Purpose: A systematic review and meta-analysis of the current published literature on comparative studies using conventional versus either early and/or immediate loading protocols for mandibular implant overdentures., Materials and Methods: The review was carried out in accordance with the QUOROM (Quality of Reporting of Meta-Analyses) guidelines. The PICO (Population, Intervention, Comparisons, Outcomes) format was used in conjunction with predefined inclusion criteria. A literature search of PubMed (1969-October 2008), EMBASE (1998-October 2008), the Cochrane Database of Systematic Reviews, and the Cochrane Controlled Trial Register was conducted. In addition, hand searching through refereed dental journals was also performed for the years 2000 to 2008. The meta-analysis was conducted by using the MIX software v.1.7 (Kitasato Clinical Research Center, Kanagawa, Japan)., Results: A total of 191 studies were identified through the electronic search. After full-text screening and cross-matching with the predefined inclusion criteria, only 10 studies with a minimum follow-up of 2 years were eligible for inclusion in this review. Of the 10 included studies, seven have compared the outcome of conventional versus early loading of implants supporting mandibular overdentures. The remaining three studies, on the other hand, compared the outcome of conventional versus immediate loading. The meta-analysis revealed no significant difference in the outcome between conventional and either early (p = .72) or immediate (p = .08) loading of implants supporting mandibular implant overdentures., Conclusions: Short-term outcomes of early or immediate loading protocols for mandibular implant overdentures achieved comparable success to conventional loading ones. No evidence was found of long-term studies to support or refute either early or immediate loading protocols for mandibular implant overdentures.

Background: Soldered or cast bars are used as a standard of care in attachment systems supporting maxillary and mandibular implant overdentures. When failures of these bars occur, currently there is a lack of evidence in relation to their specific etiology, location, or nature., Purpose: To investigate the failure process of a case series of six failed soldered bars, four intact soldered bars, and one intact cast milled bar, which had been supporting implant overdentures., Materials and Methods: A total of 11 different overdenture bars were removed from patients with different configuration of opposing arches. A failed bar (FB) group (n = 6) had failed soldered overdenture bars, which were recovered from patients following up to 2 years of wear before requiring prosthodontic maintenance and repair. An intact bar (IB) group (n = 5) had both soldered bars and a single cast milled bar, which had been worn by patients for 2 to 5 years prior to receiving other aspects of prosthodontic maintenance. All bars were examined using scanning electron microscopy to establish the possible mode of failure (FB) or to identify evidence of potential failure in the future (IB)., Results: Evidence of a progressive failure mode of corrosion fatigue and creep were observed on all the FB and IB usually around the solder areas and nonoxidizing gold cylinder. Fatigue and creep were also observed in all the IB. Where the level of corrosion was substantial, there was no evidence of wear from the matrices of the attachment system. Evidence of an instantaneous failure mode, ductile and brittle overload, was observed on the fracture surfaces of all the FB, within the solder and the nonoxidizing gold cylinders, at the solder/cylinder interface., Conclusion: Corrosion, followed by corrosion fatigue, appears to be a key factor in the onset of the failure process for overdenture bars in this case series of both maxillary and mandibular overdentures. Limited sample size and lack of standardization identify trends only but prevent broad interpretation of the findings.

Purpose: Mandibular two-implant overdentures opposing conventional complete maxillary dentures have been proposed as the standard for complete denture service. Monitoring marginal bone loss around implants is regarded as the most important criterion in determining the success of implants. The aim of this systematic literature review was to critically evaluate the literature on short- and long-term marginal bone loss associated with mandibular two-implant overdentures using different loading protocols., Materials and Methods: The MEDLINE, EMBASE, and PubMed (using medical subject headings) databases were searched using the restriction of articles in English only. Other articles were identified from the reference lists of the articles found, as well as from early online articles. Reviewed studies were those on two oral implants supporting mandibular overdentures with different loading protocols. Marginal bone loss was evaluated as well as the validity of using marginal bone loss measurements for determining the success of implants., Results: Twenty-five studies met the review criteria. Clinical studies involving conventional loading showed long-term results; however, early and immediate loading protocols were only in the short term. High success or survival rates of two implants supporting mandibular overdentures were reported, regardless of the loading protocol. A lack of standardization was revealed in the radiographic methods used for measuring marginal bone loss and the success criteria on which results were based. Long-term outcomes of the effect of different loading protocols on marginal bone loss were not found. Due to the wide methodologic variation among the included studies, it was difficult to compare data between studies or to determine long-term marginal bone loss patterns with this treatment. For conventional two-stage and one-stage loading protocols, the range of marginal bone loss seen in the first year was 0.2 to 0.7 mm and 0.0 to 2.0 mm, respectively. For early loading protocols, the range was 0.0 to 0.2 mm; immediate loading protocols saw a marginal bone loss of around 0.7 mm in the first year., Conclusions: Short-term findings indicate that so far, there is no detrimental effect on marginal bone levels with early and immediate loading protocols. However, to recommend these protocols in the long-term for two implants supporting mandibular overdentures may be premature.

Purpose: This systematic review and meta-analysis assessed the survival of immediately placed single implants in fresh molar extraction sites and immediately restored/loaded single molar implants in healed molar sites., Materials and Methods: A search of the main electronic databases, including the Cochrane Oral Health Group's Trials Register, was conducted up to November 1, 2008. The meta-analysis was prepared in accordance with the guidelines of the Academy of Osseointegration Workshop on the State of the Science on Implant Dentistry. The data were analyzed with statistical software., Results: For immediately placed molar implants, nine studies describing 1,013 implants were included to support a survival rate of 99.0%. There were no significant differences between immediate and delayed loading/restoration in molar sites (relative risk of 0.30, 95% confidence interval 0.05 to 1.61; P = .16). For immediate restoration/loading of single implants in healed molar sites, seven studies with 188 single implants were identified. In this case, the implant survival rate was 97.9%, with no difference between immediate and delayed loading (relative risk of 3.0, 95% confidence interval: 0.33 to 27.16; P = .33). Favorable marginal bone level changes in the immediate loading group were detected at 12 months (mean difference of -0.31, 95% confidence interval: -0.53 to -0.096; P = .005)., Conclusions: The protocols of immediate placement and immediate restoration/loading of single implants in mandibular molar regions showed encouraging results.

Bisphosphonates are used for the standard of care of patients with skeletal metastases and hypocalcemia of malignancy. Bisphosphonate-induced osteonecrosis (BION) is a serious complication. Clinically, BION presents as an area of exposed alveolar bone that occurs spontaneously or becomes evident following an invasive surgical procedure such as extraction of a tooth, periodontal surgery, apicoectomy, or oral implant placement. The mechanism by which bisphosphonates cause osteonecrosis is uncertain. There are no controlled trials to show a direct cause-effect relationship between bisphosphonates and osteonecrosis of the jaw. Oral bisphosphonate-induced necrosis is a rare clinical entity, less frequent, less aggressive, more predictable, and more responsive to treatment than IV forms of bisphosphonate-related osteonecrosis of the jaw. However, there have been reports of this complication with the less potent oral forms of bisphosphonates (0.007% to 0.01%). The morbidity of osteonecrosis of the jaw induced by IV bisphosphonates is significant, so prevention should receive prime importance. Patients should receive prophylactic dental examinations, and any necessary dental treatment before starting bisphosphonate therapy. Good communication among dentists, oral surgeons, physicians, and oncologists is of vital importance in providing care of these patients.

Purpose: A systematic review and meta-analysis of studies that specifically compared immediate to conventional loading of single implant crowns was conducted and the overall treatment effect was estimated., Materials and Methods: MEDLINE, the Cochrane Controlled Trials Register, and bibliographies of relevant primary and review articles were searched. Randomized and nonrandomized controlled studies that compared immediate with conventional loading of single implant crowns were selected according to strict criteria. From the 105 articles screened, five studies with 248 implants were analyzed. The meta-analysis was prepared in accordance with the Quality of Reporting of Meta-analyses (QUOROM) statement. Descriptive and outcome data were extracted using specially designed data extraction forms. The data were entered into MIX software for meta-analysis using a fixed effects model, relative risk, and 95% confidence interval (CI)., Results: Immediate loading of single implant crowns was associated with a significantly higher risk of implant failure (relative risk: 5.07, 95% CI: 2.00 to 12.84, P < .001). Pooling of randomized controlled trials showed similar results, although the difference was not statistically significant. Immediate nonocclusal loading was also associated with worse outcomes when compared to conventional loading (relative risk: 4.76, 95% CI: 1.74 to 13.02, P = .002)., Conclusions: This systematic review and meta-analysis shows that better outcomes are currently achieved using conventional loading of single implants with crowns, as opposed to immediately loaded ones, which are at a higher risk of failure. Further adequately powered clinical trials are needed. Caution with immediate loading of implants with crowns as a standard of care for single tooth replacement is recommended.

Objective: To compare systematically the survival and radiographic marginal bone level changes of two immediate implant protocols in the aesthetic region; immediate single implant restoration/loading in extraction sockets (the bimodal approach) compared with the same in healed sites., Material and Methods: A literature search of electronic databases, Cochrane Oral Health Group's Trials Register, National Research Register, conference proceedings and abstracts was performed without language restriction up to 1 August 2008. Hand searching included several dental journals and authors were contacted for missing information. Controlled trials that compared immediate restoration/loading of single implants placed in extraction sites with those placed in healed sites were selected. The meta-analysis was prepared according to the guidelines of the Quality of Reporting of Meta-analyses statement. The data were analysed using RevMan version 5.0 software. A fixed effects model was chosen with standardized mean differences for continuous data, and risk ratios for dichotomous data with 95% confidence intervals., Results: Ten studies with 629 implants were included. Immediate single implant restoration/loading in extraction sockets in the aesthetic zone was associated with significantly higher risk of implant failure (risk ratio of 3.62, 95% confidence interval 1.15-11.45, P=0.03). However, the bimodal approach showed favourable marginal bone changes after 1 year., Conclusion: The review and meta-analysis supported the potential advantages offered by this bimodal approach, but indicated a higher risk when compared with immediate restoration/loading in healed ridges. Further long-term, well-conducted, randomized-controlled studies are needed to confirm the validity of this treatment option.

In this paper the author proposes that at least some forms of sporadic ALS (amyotrophic lateral sclerosis) arise due to the effects of neurotoxic compounds synthesized by defective ependymal cells in the brain. These cells produce cerebrospinal fluid (CSF) that is laden with neurotoxic compounds that bring about motor neuron die-off. Evidence is garnered from various animal studies to demonstrate the toxicity of CSF taken from ALS patients and by virtue of the proposed mechanism (defective ependymal cells). In addition, a regimen created by the author is introduced; a regimen that has been used by four (4) sporadic ALS patients since 2005 resulting in what appears to be a slowing of disease progression. All four patients have significantly outlived best estimates of their survival tendered by their neurologists.

Objectives: To review the literature on mandibular single-implant overdentures (opposing complete maxillary dentures), and present surgical and prosthodontic perspectives of a novel approach for this treatment option., Material and Methods: An electronic search through the databases of Pubmed, Embase and Medline using the linked key words 'mandibular single implant overdentures' was performed. The search was limited to English language articles published up to August 2008. Hand searches through articles retrieved from the electronic search, peer-reviewed journals and recent conference proceedings were also conducted., Results: A limited number of reports were identified on mandibular single-implant overdentures (opposing maxillary complete dentures). They comprised of case-series reports, short-term prospective trials and current randomized-controlled clinical trials. Different loading protocols with different implant systems have been used, but always with regular diameter implants. Specific anatomical and vascular dangers of the mandibular midline symphysis are identified including a novel surgical approach using a currently available short, wide diameter tapered implant. In addition, the prosthodontic rationale for using a larger attachment system (incorporating a platform switch) for mandibular single-implant overdentures is described., Conclusion: The review reveals that there is a lack of published randomized clinical trials using mandibular single-implant overdentures, opposing maxillary complete dentures. Without the evidence from randomized clinical trials, routine use of this novel approach cannot be recommended, compared with using regular diameter implants and matching attachment systems.

Background: There is an absence of conclusive evidence for occlusal schemes in implant overdentures., Purpose: To investigate the consequences of two different occlusal schemes on levels of satisfaction for patients wearing implant overdentures., Materials and Methods: Within an existing randomized controlled clinical trial, a physiologic occlusal scheme was compared with a lingualized occlusal scheme for 18 selected participants all with implant overdentures. Nine participants had conventional maxillary complete dentures opposing mandibular 2-implant overdentures; a further nine participants had maxillary 3-implant overdentures opposing mandibular 2-implant overdentures. All participants recruited had been wearing their original prostheses for 3 years with a bilateral balance occlusal scheme. The participants' existing satisfaction levels, as a baseline, were determined using visual analogue scale questionnaires. They were followed by similar assessments of two further occlusal schemes using 2-month assessment periods. On completion of the study, the participants selected their preferred occlusal scheme and semiformal interviews were conducted to assess the rationale for their choices., Results: Baseline data showed all the participants had pre-existing high satisfaction levels. Thereafter, of those participants that received lingualized occlusion first, 55.6% reported that the physiologic occlusion was better than lingualized occlusion. For those participants who received the physiologic occlusion first, 85.7% reported that physiologic occlusion was better than lingualized occlusion. On completion of the study, 64.7% of the participants preferred the physiologic occlusion, 35.3% preferred the lingualized occlusion. However, when the two groups' satisfaction scores were modeled using the three main key indicator questions (general satisfaction, general ability to chew, or general function), there were no significant differences between them., Conclusions: Within the limitations of a small number of participants, the majority of them still indicated a preference for a physiologic occlusion for implant overdentures. Improved function was given as the main indicator for that preference. Having implant overdentures in one or both jaws is not a formative factor in patient's opinions on occlusal schemes.

The aim of this study was to evaluate the provision of removable prosthodontic services, including implant-supported overdentures, by dentists and denturists. A structured questionnaire was mailed to 474 randomly chosen dentists and 156 denturists registered to practise in New Zealand. Information was sought on the range of removable prosthodontic services provided (including implant-supported overdentures) and the professional fees charged for them. From 410 respondents, there was an overall response rate of 67.43%; 290 came from the dentists (males 78.6%, n = 228; females 21.48%, n = 62) and 120 from denturists (males 91.7%, n = 110; females 8.3%, n = 10). Most respondents were over 40 years of age, with one in three denturists (but only one in seven dentists) over 60 years of age. The extent of removable prosthodontic services varied. One-third of dentists referred complete denture patients and denturists referred a similar number of immediate denture cases. Denturists' complete denture, immediate denture and single reline prices were generally lower than those from dentists. Removable partial denture prices were similar. Implant-supported overdentures were recommended for edentulous patients by one-third of the dentists and three out of four denturists. Forty per cent of denturists (but only 10% of dentists) charged

Root overdentures and implant overdentures are two similar treatment options for the nearly-edentulous or edentulous mandible. The purpose of this literature review was to specifically compare their prosthodontic treatment philosophies and follow-up maintenance requirements. Critical comparison of these two prosthodontic treatment philosophies revealed that the foundation for overdentures which is provided by oral implants is more predictable than that provided by the roots of natural teeth. The two treatment modalities have both similarities and differences in their associated prosthodontic maintenance. The findings of this literature review suggest the future possibility that mandibular root overdentures may become obsolete as a treatment approach.

Background: Conventional implant protocols advocate a two-stage technique with a load-free, submerged healing period. Recent studies suggest that immediate restoration of single implants may be a viable treatment option., Purpose: The purpose of this study was to evaluate prosthodontic and aesthetic peri-implant mucosal outcomes of immediately restored, Southern single-tapered implants in the anterior maxilla after 1 year., Materials and Methods: Participants (mean age: 43.25 years; range: 23-71 years) satisfying specified inclusion criteria were randomly allocated to conventional two-stage restoration (control group; n=14) and immediate restoration groups (test group; n =14) in a randomized controlled clinical trial. Tapered, roughened-surface Southern implants were placed using a standardized technique, and implant level bone impressions were made. Provisional screw-retained crowns, out of occlusion, were placed at second-stage surgery after 26 weeks for the conventional restoration group, and within 4 hours of implant placement for the immediate restoration group. Both groups had definitive screw-retained metal-ceramic crowns placed in occlusion 8 weeks later. Peri-implant mucosal response and papilla index were recorded 4 weeks after definitive crown placement to allow for mucosal maturation and at 1 year. Prosthodontic and aesthetic outcomes were assessed using established criteria., Results: There were no significant differences within, or between, the control and test groups for age, gender, bone quality or quantity, implant stability measurements at surgery, or implant length. There were no significant differences in the implant success rate as determined by radiographic bone loss and stability tests after 1 year. There were no significant differences in prosthodontic maintenance, peri-implant mucosal response, and papilla index between the two groups over 1 year., Conclusions: Tapered, roughened-surface implants immediately restored with single provisional crowns at surgery and definitive crowns 8 weeks later were as prosthodontically and aesthetically successful as conventionally restored two-stage implants during the first year of service. Restoring single implants immediately with screw-retained crowns is an efficient procedure, but the short-term outcome is by no means superior to a conventional two-stage approach.

Chemo- and radio-resistant cancer cells within solid tumors undermine the effectiveness of these approaches to achieving oncolysis. These resistant cells and clusters of cells typically thrive at low oxygen tensions and are reliant on anaerobic metabolic pathways that churn out lactate. This hypoxic state is one that can be exploited and in this paper a novel method is advanced involving tumor cell infiltration by bifidobacterium species which should bring about prodigious lactate synthesis; concomitant blocking of its enzymatic degradation by urea as well as export (from the cell) by use of quercetin; depletion of ATP using exogenous thyroid; and compromised oxidative catabolism of free fatty acids and amino acids via oral intake of l-hydroxycitrate, melatonin and nontoxic NDGA. This "anaerobic pathway cocktail", it is hypothesized, will bring about a profound reduction in intracellular pH and a compromised state of cellular energetics sufficient to effect oncolysis.

The purpose of this literature review was to identify the etiological factors of failure of soldered bars in bar attachment systems for removable implant overdentures. A search of MEDLINE using the key words "bar attachment systems" was performed of English language peer-reviewed journals published between 1975 and 2005. Clinical studies of implant overdentures with prosthodontic maintenance complications of bar attachment systems were identified to establish the perceived etiology of failure. A further search of MEDLINE using the key words "solder joint" was also performed of the fixed prosthodontic literature to identify specific factors affecting the strength, fatigue resistance, and quality of gold solder joints used for bar attachment systems. The first search on bar attachment systems produced evidence of low failure rates of interabutment bars, but higher failure rates of bars where distal cantilever extensions were used. There were no explanations or descriptions of the nature of those failures in the clinical studies reviewed. The second search on fixed prosthodontic literature identified multiple factors that could potentially relate to the failed solder joints with bar attachments. Two potential sites of failure in bar attachments with distal cantilevers were identified, and a simple estimate of the tensile stresses at the solder joints was performed. The values found are comparable to the fatigue failure stresses reported in the searched literature.

Purpose: Surgical, prosthodontic, and esthetic outcomes of conventional and immediately loaded, single, tapered, roughened-surface Southern implants in the anterior maxilla that were restored with screw-retained crowns were compared over 1 year., Materials and Methods: Standardized surgical and prosthodontic procedures were followed and accepted criteria were used for assessment., Results: There were no significant differences within or between the control and test groups for age, gender, bone quality or quantity, implant stability measurements at surgery, or implant length., Conclusion: After 1 year, the implants that had been immediately loaded with single provisional crowns at surgery and definitive crowns 8 weeks later were as successful as conventionally loaded 2-stage implants.

Dental implants or precision attachments can be used to resolve the bilateral distal extension removable partial denture (RPD) dilemma. This report describes the fabrication of a mandibular implant-supported chromium-cobalt RPD with a combination of bilateral single molar implants and metal ceramic crowns using the principles of the channel-shoulder-pin system. The maxillary arch was restored with splinted metal crowns and a conventional RPD retained by extracoronal precision attachments.

Background: Maxillary implant overdentures opposing mandibular two-implant overdentures are an underused treatment option for edentulous patients. Fewer implants, simple surgery, and short healing periods may increase patients' acceptance of this treatment concept., Purpose: To determine implant success, after overdenture loading, of three narrow-diameter roughened-surface implants placed in edentulous maxillas, using a one-stage surgical procedure, a 12-week healing period, and opposing mandibular two-implant overdentures., Materials and Methods: Forty edentulous participants with mandibular two-implant overdentures were allocated to two groups with similar implant systems. Each group had three narrow-diameter roughened-surface implants placed into their edentulous maxillas in a one-stage surgical procedure. Standardized intraoral radiography and implant stability tests were performed sequentially at surgery, at 12 weeks (prior to loading), and at 64 weeks (after 1 year of loading with maxillary overdentures)., Results: One hundred seventeen implants were placed in 39 participants. After 1 year of loading, 15 implants had failed in 11 patients, 4 implants have been "put to sleep" in 3 patients, and 1 patient has died. Data on marginal bone loss and resonance frequency analysis showed no significant differences between the implant systems. The mean marginal bone loss was 1.30 mm (+/- 0.44 mm) from surgery to 12 weeks and 0.32 mm (+/- 0.48 mm) between 12 and 64 weeks with loading. The mean implant stability quotient and resonance frequency values showed a statistically significant improvement over time, at 56.05 (5,891 Hz), 57.54 (5,981 Hz), and 60.88 (6,167 Hz) at surgery, 12 weeks, and 64 weeks, respectively. The overall success rate for all implants combined was 81%, and the cumulative survival rate was 84.61%., Conclusion: In patients with mandibular two-implant overdentures, three narrow-diameter roughened-surface implants can be placed in the edentulous maxilla, using a one-stage surgical procedure, and can be loaded within 12 weeks with overdentures for 1 year.

If stem cell therapy is to be maximally effective, it is vital that progenitor (stem) cells get to the target tissue(s) and/or organ(s). Three methods of facilitating stem cell homing to target tissues are explored in this paper: (1) cobalt compounds such as cobalt phthalocyanines could be magnetically delivered to target tissue(s) and/or organ(s), and then subject to a brief pulsed magnetic field or ultrasound exposure suitable to induce mild hyperthermia with the result being the synthesis of cytokines that are chemoattractants to progenitor (stem) cells; (2) ferromagnetic nanobead particles could be tagged with antibodies specific to the target tissue(s) and/or organ(s) and infused into patients, followed by introduction of progenitor (stem) cells tagged with antibody-bound magnetic nanoparticles. This should result in passive attachment (stem cells to tagged tissue or organ); and (3) Reticulose, which stimulates the synthesis of the stem cell chemoattractant IL-8, could be magnetically guided to target tissue(s) and/or organ(s).