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In order to provide favorable conditions for bone regeneration, a lot of biomaterials have been developed and evaluated, worldwide. Composite biomaterials have gained notoriety, as they combine desirable properties of each isolated material. Thus, in this research, bone repair capacity of three developed formulations of ceramic scaffolds were evaluated histomorphometrically, after implantation. Scaffolds were based on wollastonite (W) and β -tricalcium phosphate ( β -TCP) composites in three different ratios (wt.%). Thirty Wistar rats were randomly assigned to three experimental groups: W-20 (20 W/80 β -TCP wt.%), W-60 (60 W/40 β -TCP wt.%), and W-80 (80 W/20 β -TCP wt.%), evaluated by optical microscopy at biological tests after 15 and 45 days of implantation. Throughout the study, the histological results evidenced that the scaffolds remained at the implantation site, were biocompatible and presented osteogenic potential. The percentage of neoformed mineralized tissue was more evident in the W-20 group (51%), at 45 days. The composite of the W-80 group showed more evident biodegradation than the biomaterials of the W-20 and W-60 groups. Thus, it is concluded that the scaffold containing 20 W/80 β -TCP (wt.%) promoted more evident bone formation, but all composites evaluated in this study showed notorious bioactivity and promising characteristics for clinical application., (© 2021 IOP Publishing Ltd.)

Context: Eroded dentin might present the opening of dentinal tubules, increasing permeability, and consequently dentinal hypersensitivity., Aims: This study evaluated the permeability of dentin surfaces exposed to different levels of erosion and methods of surface protection., Materials and Methods: Dentine samples (3 mm × 3 mm × 1 mm) were prepared from bovine incisors ( n = 90) and divided into three groups according to the method of controlling erosive challenge: Negative control, topical fluoride application, and glass ionomer sealant. Subsequently, they were randomly divided into three subgroups according to the exposure of simulated gastric acid solution (Demineralization - DES) (5% HCl, pH = 2.2), and remineralization (RE); negative control, 9 and 18 cycles DES-RE. The dentin permeability was measured by assessing the hydraulic conductance (μl/min.cmH 2 O.cm 2 ). Statistical analysis was performed by two-way ANOVA and Tukey's test., Results and Conclusions: Greater permeability was observed after 18 erosive cycles, followed by exposure to 9 cycles and negative control ( P < 0.0001). The application of glass ionomer sealant resulted in a major reduction of the hydraulic conductivity, regardless of the erosive challenge. Control groups and topical fluoride application showed similar results. In conclusion, the severity of erosive challenge contributed to the increase of dentin permeability. Besides, the glass ionomer sealant was the only protection agent that promoted significant effects in dentin permeability., Competing Interests: There are no conflicts of interest.

Background: Although increase of misfit has been reported when associating implant and abutment from different manufacturers, Procera® (Nobel Biocare™, Göteborg, Sweden) custom abutment has been universally used in clinical practice., Purpose: The purpose of this investigation was to compare the vertical gap of zirconia Procera abutment associated with implants from the same manufacturer (Nobel Biocare) and two other implant systems., Materials and Methods: Twenty-four zirconia Procera abutments were produced using computer-assisted design and manufacture (CAD/CAM) and paired with (1) eight MK Iii RP 4.1 × 10 mm implants (Nobel Biocare) - GNB group; (2) eight Try on, 4.1 × 10 mm implants (Sistema de Implantes, São Paulo, Brazil) - ES group; and (3) eight Master screw, 4.1 × 10 mm implants (Conexão Sistema de Prótese, São Paulo, Brazil) - EC group. A comparison of the vertical misfit at the implant-abutment interface was taken at six measuring sites on each sample using scanning electron microscopy with a magnification of 408×. One-way analysis of variance was used to test for differences, and Tukey's test was used for pairwise comparison of groups (α = 0.05)., Results: Significant differences relative to average misfit were found when Procera abutments were associated with other implant manufacturers. The ES group and EC group did not differ significantly, but both demonstrated significantly larger average misfit than the GNB group (p = .001). The average misfit was 5.7 µm ± 0.39, 9.53 µm ± 0.52 and 10.62 µm ± 2.16, respectively, for groups GNB, ES, and EC., Conclusion: The association of Procera zirconia abutment with other implant systems different from its manufacturer demonstrated significant alteration of vertical misfit at implant-abutment interface., (© 2010 Wiley Periodicals, Inc.)