Endospanin Is a Candidate for Regulating Leptin Sensitivity

The hypothesis advanced is that endospanin, a highly conserved vesicle traffic protein in vertebrates, regulates leptin sensitivity in bone signaling. The effects of leptin on bones are well-studied but without consensus on whether the increases in leptin signaling stimulate bone gain or loss. The bone response may depend on leptin sensitivity, and endospanin is an established modulator of leptin sensitivity. An argument is advanced to develop zebrafish models for specific leptin signaling pathways. Zebrafish have well-developed molecular tools (e.g., CRISPR) and the advantage of non-destructive sampling of bones in the form of scales. Using these tools, experiments are described to substantiate the role of endospanin in zebrafish bone dynamics.

Adjunctive Effect of Systemic Antibiotics in Regenerative/Reconstructive Periodontal Surgery—A Systematic Review with Meta-Analysis

Background and Objective: Systemic antibiotics (AB) are often used in conjunction with regenerative/reconstructive periodontal surgery of intrabony defects and furcations; however, their potential benefits have not been systematically assessed. Materials and Methods: Data were retrieved from two recent systematic reviews (a total of 105 randomized clinical trials (RCTs) on clinical and radiographic outcomes in intrabony defects (ID) and molars with furcation involvement (FI) treated by surgical access with regenerative techniques. Pair-wise meta-analysis of RCTs with and without AB was performed. Meta-regressions from single-arm (subgroup) RCTs including study arms with or without adjunctive AB were also conducted. Results: No statistically significant benefits of systemic AB with regard to PPD, CAL and bone gain were detected in ID by pair-wise meta-analysis. Meta-regression revealed increased PPD reduction (−0.91 mm, 95% CI = −1.30; −0.51, p < 0.001), CAL gain (−0.92 mm, 95% CI = −1.32; −0.52, p < 0.001) and bone gain (−1.08 mm, 95% CI = −1.63; −0.53, p < 0.001) in ID but not in any of the outcomes in FI for arms treated with AB vs. study arms treated with no AB. No clear differences in adverse events were detected between AB and non-AB groups. Conclusion: There is only weak indirect evidence that AB may provide additional benefits in terms of clinical improvements in the regenerative/reconstructive periodontal surgery of intrabony defects and no evidence for a benefit in furcations. Until new data are gained and in the context of antibiotic stewardship, it may be questionable to justify the adjunctive use of systemic antibiotics.

Radiographic and Histomorphometric Evaluation of Biomaterials Used for Lateral Sinus Augmentation: A Systematic Review on the Effect of Residual Bone Height and Vertical Graft Size on New Bone Formation and Graft Shrinkage

The aim of the present systematic review was to investigate the effect of residual bone height (RBH) and vertical bone gain on new bone formation (NBF) and graft shrinkage after lateral sinus lifts using different biomaterials. Methods: An electronic search was conducted on three databases to identify randomized controlled trials (RCTs) published until January 2021 with at least one follow-up at 6 months and at least five patients treated, comparing biomaterials used for maxillary sinus augmentation with a lateral approach. Graft volumetric changes, RBH, vertical bone gain, implant failure, and post-operative complications were evaluated. The risk of bias was assessed using the Cochrane tool. Results: We used 4010 identified studies, of which 21 were RCTs. Overall, 412 patients and 533 sinuses were evaluated. Only three publications had an overall low risk of bias. After 6 months, xenograft (XG) showed the least volume reduction (7.30 ± 15.49%), while autogenous graft (AU) was the most reabsorbed (41.71 ± 12.63%). NBF appeared to not be directly correlated with RBH; on the contrary, the overall linear regression analysis showed that NBF significantly decreased by 1.6% for each mm of postoperative vertical graft gain. This finding suggests that the greater the augmentation, the lower the NBF. A similar tendency, with a regression coefficient even higher than the overall one, was also observed with alloplast (AP) and XG. Conclusions: The present results suggested that NBF was essentially independent of preoperative bone height. On the contrary, the smaller the volume was of the graft placed, the higher the amount of new bone formed, and the smaller the graft shrinkage was. Minimizing the augmentation volume might be beneficial to graft healing and stability especially when using AP and XG.

Implant survival after graftless sinus floor augmentation in highly atrophic maxillae: a randomized controlled trial in a split mouth study

Purpose The success rate of dental implants after graftless sinus augmentation versus conventional sinus augmentation surgery in atrophic maxillae in edentulous patients was investigated. Methods This randomized study was performed in ten edentulous patients with marked maxillary atrophy. On the graftless side, the sinus membrane was lifted by a resorbable membrane. The control side was augmented with a mixture of autografts and xenografts. Implant placement followed 6 months postoperatively. Outcomes were implant survival, success of prosthetic rehabilitation and stability of vertical bone gain. Results Ten patients were included. Postoperative radiology showed sufficient bone gain on both maxillary sides. Follow-up varied from 57 to 88 months. The conventional side showed significant (p = 0.041) more bone gain than the experimental side (respectively, 9.69 mm and 6.20 mm). A total of 59 implants were placed: 30 after conventional, 29 after graftless augmentation. One implant was lost on the conventional side and four on the experimental side. The implant survival was significantly higher on the conventional side (96.7% vs. 86.2%, p < 0.001, RR = 4.14). Prosthetic restoration was functionally successful in all cases. Conclusion Bone gain and implant survival were significantly lower in the non-grafted side versus the grafted side. Prosthetic rehabilitation was possible in all ten patients. The non-grafted technique may have some potential for clinical use, although it showed poorer results. Trial registration The Netherlands Trialregister. NTR NL3541 (NTR3696). Registered 20 January 2013, https://www.trialregister.nl/trial/3541.

The influence of laser-microgrooved implant and abutment surfaces on mean crestal bone levels and peri-implant soft tissue healing: a 3-year longitudinal randomized controlled clinical trial

Purpose The study aimed to compare clinical and radiographic parameters of peri-implant site of laser-microgrooved implants with either laser-microgrooved or regular machined prosthetic abutment post 3 years of early loading. Method Twenty edentulous sites of systemically and periodontally healthy individuals were allocated into two groups in this prospective, two-armed, randomized double-blinded clinical trial in 1:1 ratio, wherein each site received laser-microgrooved implants with either laser-microgrooved or machined prosthetic abutments. Outcome measures included full-mouth plaque (FMPS%) and bleeding score (FMBS%), site-specific plaque (SPS%) and bleeding score (SBS%), peri-implant sulcus depth (PISD mm), and mean crestal bone loss (MCBL mm) evaluated at baseline (6 weeks), 1 and 3 years post-early loading. Mean and standard deviation of all parameters were estimated, between groups and at different time points using independent and paired t-test, respectively, Normality was checked using Kolmogorov–Smirnov test and Shapiro–Wilk test, P value ≤ 0.05 was considered as statistically significant. Results Three-year follow-up of test group showed statistically significant reduction in SPS, SBS, PISD (P value ≤ 0.001). The MCBL reduced from 1.93 mm to 0.61 mm (P value ≤ 0.001); in other words, a bone gain of 0.15 mm was obtained in the test group. Conclusion Within the limitations of the present study, laser-microgrooved implants loaded with laser-microgrooved prosthetic abutments showed superior results clinically and radiographically when compared to loading with machined abutments.

The Use of Cortical Bone Wedges from the Mandibular Ramus “Wedge Technique” for 3-Dimensional Bone Augmentation of the Atrophic Ridges

Autogenous bone is still considered the gold standard in bone augmentation for implant insertion in atrophic ridges. However, augmentation of multiple edentulous atrophic segments usually necessitates the use of extraoral donor sites. This chapter introduces the Wedge Technique, as a new bone augmentation method that can augment multiple edentulous ridges with intraoral cortical bone grafts. Patients with moderate to severe ridge atrophy in different regions of the jaws were treated with the wedge technique (WT). Patients received a panoramic radiograph immediately after the surgery, and they were examined clinically and radiographically (periapical radiograph) every 2 weeks. At four months, CBCT was performed to evaluate the bone gain. Reentry was performed after 4 to 5 months to evaluate the new bone volume and quality and to insert implants. The follow-up period ranged from 30 to 120 months. The healing process was uneventful, with minimal morbidity. The success rate was 95%, the bone gain average was 3–6 mm vertically and 3–9 mm horizontally. The wedge technique can augment multiple segments of atrophic ridges with a small amount of autogenous graft. The achieved bone volume was satisfying, especially that the majority of the augmented areas were at posterior mandibular defects.

Horizontal Ridge Augmentation: A Comparison between Khoury and Urban Technique

Purpose. The objective of this systematic review was to evaluate and compare the clinical efficacy of horizontal alveolar ridge augmentation techniques described by Khoury and Urban. Methods. A systematic electronic search in the MEDLINE databases, SCOPUS, WOS, and the Cochrane Central Register of Controlled Trials (CENTRAL) as well as a manual search, were conducted independently by two reviewers up to July 2021. Results. Six studies met the pre-established inclusion criteria and were included in the descriptive analysis. Due to the heterogeneity found across the included studies, meta-analysis could not be performed. Horizontal bone gain was between 3.93 ± 0.9 mm and 5.02 ± 0.8 mm with the Khoury technique and between 3.9 ± 0.9 mm and 5.68 ± 1.42 mm with the Urban technique. Similar complication rates were reported in both groups: infection (7%), in the Khoury technique, and membrane exposure (3.2–13.6%), in the Urban technique, being the most frequent events. Conclusions. Both techniques were found to be effective, in terms of clinical bone gain, for horizontal alveolar ridge gain. Nevertheless, available literature is limited, and there is a lack of comparative studies to better evaluate the results.

Annually and Cumulative Radiographic Alveolar Bone Loss Rates using Digital Scanning Image for the Periodontal Disease Groups before and after Periodontal Treatment

The aim of the present study was to assess the cumulative radiographic alveolar bone loss (CRABL) and yearly radiographic periodontal attachment loss (YRABL) of periodontal disease groups over 5 years or more. A total of 53 subjects, who had taken two sets of full-mouth standardized paralleling radiographs with separated periods of 5 years or more in Kaohsiung Medical University Hospital during 1981-2001, were collected for the past 20 years. The radiographic alveolar bone levels at mesial and distal aspects of teeth were assessed by measuring the distance between cemento-enamel junction and alveolar bone crest using an electronic digimatic caliper (EDC) under a 3.5X magnified radiographs. The results revealed that 1) patients with a periodic recall (3-4 times/yr.) showed a significantly lower loss rate than patients without periodic recalls; 2) mean CRPAL was highest in the generalized aggressive periodontitis (GAgP) group (5.52±3.27mm), then the chronic periodontitis (CP) group (4.82±3.47mm), and the localized aggressive periodontitis (LAgP) group (4.47±3.47mm) followed, and lowest in the periodontal healthy (PH) group (1.05±0.59mm); 3) mean YRPAL was the highest in the LAgP group (0.26±0.25mm/yr.), then the GAgP group (0.20±0.13 mm/yr.), and the CP group (0.12±0.09 mm/yr.) followed, and lowest in the periodontal healthy group (0.07±0.06 mm/yr.). It was concluded that: 1) sites with more advanced alveolar bone loss are more likely to undergo further breakdown; 2) patients with a periodic recall showed a significantly lower alveolar bone loss rate and bone gain, irrespective disease groups; 3) mean CPBLs was highest in the GAgP group; mean YRABLs was highest in the LAgP.