Assessment of Surgical and Radiographic Parameters for Abutment Height Selection: A Prospective Study with 1-Year Follow-up.

PURPOSE: The "one-abutment, one-time" concept entails the placement of a definitive abutment at the time of implant placement, without removal during prosthesis manufacture, with the aim to promote a safer environment for the peri-implant tissues. Identifying surgical and radiographic parameters that can assist with the abutment height selection would facilitate the adoption of the one-abutment, one-time concept. Therefore, the aim of this study was to assess the role of surgical and radiographic parameters as predictive factors for abutment height selection in implant-retained single crowns. MATERIALS AND METHODS: This prospective study assessed the role of surgical and radiographic measurements in the implant survival and success rates and marginal bone loss in implant-retained single crowns. Implants were placed in both healed sites and extraction sockets, and the distances between the implant platform and alveolar bone crest, implant platform and gingival margin, and buccal gap (when present) were recorded using a straight periodontal probe. Digital radiographs were made at implant placement (T0), abutment height selection (Ta), and 1-year follow-up (Tf), and the distance between the implant platform and the alveolar bone crest (mm) was assessed. Linear regression models and Pearson correlation were used to assess the influence of primary and secondary outcomes on abutment height. RESULTS: A total of 130 implants were placed in 68 patients. The mean surgical distance between the bone crest and the implant platform was 1.71 ± 1.01 mm, and the mean distance from the gingival margin to the implant platform was 3.94 ± 1.90 mm, while at the abutment selection appointment, the mean transmucosal height was 3.58 ± 1.50 mm. A high linear correlation was found between the selected abutment height and two primary outcomes: the radiographic implant platform to alveolar bone crest distance at T0 (r2 = 0.66; P < .001) and the transmucosal height at Ta (r2 = 0.81; P < .001). CONCLUSION: Radiographic measurements of the distance between the implant platform and the alveolar bone crest at implant placement can serve as an important parameter to select the abutment height for definitive restorations.

Inherited bleeding disorders in oral procedures. Assessment of prophylactic and therapeutic protocols: a scoping review.

BACKGROUND: This scoping review aimed to map available evidence regarding minor/major oral procedures in patients with inherited bleeding disorders (IBDs). METHODS: Studies in medicine or dentistry that reported minor and major oral procedures in individuals presenting IBDs (e.g. haemophilia A or B, von Willebrand disease) were selected. Search and screening were performed in PubMed/Medline, Scopus, Web of Science and Cochrane Library by two independent researchers. RESULTS: Initial search yielded 4152 citations, of which 257 were included in the final analysis. Most of the evidence for prophylaxis use was derived from observational studies and the most-commonly reported prophylactic protocols were fresh frozen plasma and factor VIII concentrate. A considerable number of studies reported postoperative complications and hospitalizations. CONCLUSION: The present study identified that (1) there is room for new studies to assess the use of antifibrinolytic agents with no factor replacement; (2) to date, the use of factor replacement therapy is the most indicated approach when treating patients with IBDs with adjunct systemic or local antifibrinolytic agents to reduce post-operative complications; and (3) there is a critical need for high-quality evidence studies since much of the conclusions of the included studies are not supported by statistical analysis.

Assessment of stress/strain in dental implants and abutments of alternative materials compared to conventional titanium alloy-3D non-linear finite element analysis.

The aim of this study was to assess the stress/strain in dental implant/abutments with alternative materials, in implants with different microgeometry, through finite element analysis (FEA). Three-dimensional models were created to simulate the clinical situation of replacement of a maxillary central incisor with implants, in a type III bone, with a provisional single crown, loaded with 100 N in a perpendicular direction. The FEA parameters studied were: implant materials-titanium, porous titanium, titanium-zirconia, zirconia, reinforced fiberglass composite (RFC), and polyetheretherketone (PEEK); and abutment materials-titanium, zirconia, RFC, and PEEK; implant macrogeometry-tapered of trapezoidal threads (TTT) and cylindrical of triangular threads (CTT) (ø4.3 mm × 11 mm). Microstrain, von Mises, shear, and maximum and minimum principal stresses in the structures and in peri-implant bone were compared. There was increased stress and strain in peri-implant bone tissue caused by implants of materials with lower elastic modulus (mainly for PEEK and RFC). They also presented higher concentration of stresses in the implant itself (especially RFC). Zirconia implants led to lower stress and strains in peri-implant bone tissue. Less rigid abutments (RFC and PEEK) associated with titanium implants led to higher stress in the implant and in peri-implant bone tissue. The TTT macrogeometry showed a higher stress concentration in the implant and peri-implant bone tissue. The stress/strain in peri-implant bone tissue and implant structures were affected by the material used, where reduced values were caused by stiffer materials. Lower stress/strain values were obtained with cylindrical implants of triangular treads.

Industry sponsorship bias in clinical trials in implant dentistry: Systematic review and meta-regression.

AIM: Industry sponsorship might distort the conduct and findings of studies in a large range of medical disciplines. The objective of this study was to assess whether industry sponsorship bias is present in randomized controlled trials (RCTs) on dental implants. MATERIAL AND METHODS: Two databases were searched (MEDLINE; Web of Science) to identify RCTs published between 1996 and 2016 assessing different implant systems, components or techniques, such as implant-abutment connections, geometries, surfaces, loading protocols or regions of placement. Studies' sponsorship status was classified as unclear, non-sponsored or sponsored. Our outcome was marginal bone loss per year (MBL/year) of follow-up. Random-effects meta-analysis of MBL/year with subgroup analysis according to sponsorship status was performed. Moreover, multivariable stepwise-selection meta-regression was performed to assess whether sponsorship status, among other covariates, was associated with MBL/year. RESULTS: One hundred and two RCTs (4,775 patients, 8,806 implants) were included. Overall mean (95% confidence interval) MBL/year was 0.74 mm (95% CI 0.67/0.82). There was no significant difference in MBL/year among sponsorship categories; unclear: 0.64 (95% CI 0.37/0.91); non-sponsored: 0.65 (095% CI 0.55/0.75); and sponsored: 0.82 (95% CI 0.71/0.94). CONCLUSION: Meta-regression did not demonstrate a significant association of MBL/year with sponsorship status or other covariates was found. We did not detect significant sponsorship bias in RCTs on dental implants.