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In order to ensure a correct occlusion and fit of restorations, the accuracy of entire arch is required. In these cases, the quality of the dental cast relies on the digitizing and machining processes provided by CAD-CAM systems. As geometric errors may be introduced during the step of scanning and manufacturing of casts, their accuracy is still questionable.The purpose of this study was to compare the accuracy of casts obtained using digital and conventional implant impressions. A maxillary model containing dentalimplants on the region of canine and pre-molar was used as master model. Dental casts (n=10) were fabricated through both conventional and digital implant impressions. The conventional casts (CC), stereolithographic casts (SC) and the master model (MM) were digitized and the accuracy was determined through a deviation analysis and linear measurements. Data were analyzed using Student t-test and ANOVA with p=0.05. SC showed higher deviation at vestibular (CC: 41 u00b1 28; SC: 117 u00b1 37 u03bcm) and lingual cusps (CC: 40 u00b1 19; SC: 80 u00b1 42 u03bcm) in comparison to CC. No statistically significant difference was found for linear measurements of conventional and digital casts. The entire-arch accuracy was comparable between casts. However, in located points, stereolithographic casts were less accurate in comparison with conventional casts.

Introduction: In order to overcome Clorhexidine 0,12% adverse effects, a mouthwash contaning Casearis sylvestris was developed. Objectives: The purpose of this study was to evaluate the influence of a mouthwash containing Casearia sylvestris on color alteration and surface roughness of teeth previously submitted to bleaching or in contact with acid drinks. Material and Methods: Thirty cylindrical bovine teeth samples were divided in 3 groups, according to the solution evaluated: A) distilled water, B) Chlorhexidine 0,12% and C) a mouthwash containing Casearia sylvestris. Each group was divided in subgroups, according to the categories (n=10): 1) No treatment (control group), 2) bleached teeth and 3) teeth immersed in an acid drink (pH 2,4). The bleaching procedure was performed with carbamide peroxide 16% during 6 hours by 8 days, totalizing 48 hours of immersion. Whereas the acid drink immersion was performed once in a day during 2 minutes each immersion, for 6 days. Afterward, the samples were immersed into a bowl containing the respective solutions by 2 minutes, three times per day, during 7 days. The color and surface roughness were evaluated before the first immersion on the solutions and after 7 days of immersion. In addition, a qualitative analysis was performed by scanning electron microscopy. Results: Data were statistically analyzed by two-way analysis of variance (ANOVA) and Tukey`s test. Teeth submitted to bleaching or immersed in acid drinks presented a higher color alteration in comparison to the control group. Clorhexidine 0,12% (B1-0.21u00b10.08, B2-0.84u00b10.08, B3-0.69u00b10.08) and the mouthwash containing Casearia sylvestris (C1-0.53u00b10.08,C2-0.71u00b10.08, C3-0.74u00b10.08) did not provide a statistically higher color alteration in comparison to the distilled water (A1-0.0u00b10.08; A2-0.72u00b10.08, A3-0.80u00b10.08). The surface roughness was not altered by the solutions and treatment provided. Conclusion: The mouthwash containing Casearis sylvestris can be safely used on teeth previously submitted to bleaching or immersed in acid drinks during the period evaluated in this study.

The dimensional change of buccal bone around dental implants may beaccompanied by cone-beam computed tomography (CBCT). The purpose of this study was to evaluate the accuracy of CBCT for the assessment of the buccal bone dimension surrounding dental implants.The search was performed in eight electronic databases until May 2016, and a search update was undertaken in September 2016. Studies which assessed the accuracy of CBCT in measuring bone dimension surrounding dental implants were evaluated. Individual risk of bias was determined by Quality Assessment Tool for Diagnostic Accuracy Studies-2 (QUADAS-2). The overall effect size was determined by means of the z-test and Q test was used to evaluate the homogeneity of effect sizes among studies. I2 was applied to determine the variance within studies. Three studies were considered eligible for this review. The mean difference [confidence interval] between CBCT and the reference standard was -0.71mm [-1.50;0.09mm] for bone level and -0.2 mm [-0.41;0.37mm] for bone thickness. The accuracy of CBCT to assess bonesurrounding implants was considered acceptable.

Cone-beam computed tomography (CBCT) has been widely used to evaluate peri-implant bone parameters in a tridimensional visualization. However, artifacts occur in the presence of metal objects and may affect the image quality of dental implants surroundings. The purpose of this study was to evaluate the accuracy of two cone-beam computed tomography (CBCT) devices for measurement of buccal-bone thickness surrounding dental implants. Dental implants (n=17) were installed in dry human skulls and scanned using two CBCT devices: G1 (85kVp, 7mA, 0.125mm voxel size) and G2 (70kVp, 6.3mA, 0.180mm voxel size). Buccal bone thickness was measured at points (A): apical of dental implant; (B): 5 mm above point A and (C): distance between top of implant to the bone surface. Values were compared with a high-precision computed tomography (210kV, 320u03bcA and 0.093mm voxel size) and statistically analyzed with a significance level of p=0.05.In point A, no statistical difference was found for bone thickness (G1:4.43u00b11.79; G2:4.20u00b11.73; CG:4.64u00b11.99). A statistically significant underestimation of values was found for points B (G1:1.35u00b10.91; G2:1.64u00b11.24; CG:3.79u00b11.61) and C (G1:1.39u00b11.12; G2:1.62u00b11.03; CG: 2.46u00b11.36). The CBCT devices presented similar accuracy for measurement of buccal-bone thickness surrounding dental implants.