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Objective: Evaluate the effect of staining and repeated firings on color, translucency and surface proprieties of CAD/CAM lithium disilicate (LD).Material and Methods: One hundred eighty LD discs were made (ISO 6872) and distributed in different groups (n = 20): control (CO)-no treatment; single-step characterization (SC)-crystallization and staining fired together; and double step characterization (DC)-crystallization and then staining. The samples were submitted to two, four, or six firings, resulting in nine groups: COII, COIV, COVI, SCII, SCIV, SCVI, DCII, DCIV, and DCVI. The color and translucency were measured by a reflectance spectrophotometer. Surface roughness (Ra) and Vickers nano-hardness were also measured. ANOVA and Tukey statistical tests were used (α = .05). Results:Only CO and DC demonstrated significant color alterations (ΔE 00 > 1.8). SC and DC did not show changes in translucency by the number of firings (P > .05); however, for CO (P = .02) these values increased. Nano-hardness was similar in all groups (P > .05). Ra values indicated differences due to the type of characterization (SC presented the highest values) and number of firings (CO and DC groups) (P < .01).Conclusion: SC promoted color, translucency, and roughness stability after repeated firings.Clinical Significance: The single characterization technic in CAD/CAM lithium disilicate presents good color, translucency, and hardness stability, which promote predictable results to monolithic restoration. K E Y W O R D Scolor, lithium disilicate, repeated firing, roughness, translucency

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<p><strong>AIMS: </strong>To evaluate influence of variables gender, diagnosis and severity of types of Temporomandibular Disorder (TMD) on the quality of life of the individual. <strong>METHODS: </strong>The sample consisted of one hundred one individuals seeking TMD treatment at the Faculdade de Odontologia/ Universidade Federal de Juiz de Fora. The TMD diagnosis was done through the RDC/TMD: Axis I (<em>Research Diagnostic Criteria/Temporomandibular Disorder)</em>. The severity of TMD was established by the Temporomandibular Index (TMI) and the impact on quality of life by the OHIP-14 (<em>Oral Health Impact Profile</em>). The data was tabulated and analyzed by the Mann-Whitney test, T student test and Spearman correlation analysis (α=0,05). <strong>RESULTS: </strong>Most patients had diagnosis of muscular disorder, followed by diagnoses of arthralgia and disk displacement, respectively. All patients had a negative impact on at least one question from OHIP-14.<strong><strong>CONCLUSIONS</strong>: </strong>Women presented worse quality of life when compared to men. The presence of muscular disorder was related to greater impact on quality of life (p&lt;0,05). The relationship between severity of TMD and quality of life in the muscle sub-index of TMI was observed in all domains of OHIP-14 (p&lt;0,05). In addition, there was positive correlation between TMI and the psychological incapacity.</p>

To evaluate the effect of different surface treatments on the marginal misfit and retentive strength between Y-TZP crowns and an epoxy resin. Forty (40) epoxy resin (G10) abutments (height: 5mm, conicity: 60, finish line: large chamfer) with equal dimensions were milled and included in polyurethane to simulate the periodontal ligament. Next, 40 Y-TZP crowns (thickness: 1mm) were milled (Cerec inLab) and randomly divided into four groups (n=10) according to the surface treatment: GS(glaze spray), GP(glaze powder/liquid), P(zirconia primer) and RS(tribochemical silica coating).The conditioned surfaces were cemented with dual self-adhesive cement, light cured and submitted to thermomechanical cycling (2x106, 100N, 4Hz, 5º/55ºC). Marginal misfit was analyzed by a stereomicroscope and SEM. Retentive strength test was performed (1mm/min) until crown debonding. Glaze layer thickness was also performed to GS and GP groups. Marginal misfit data were analyzed by Kruskal Wallis and Dunn tests; one-way ANOVA and Tukey (5%) analyzed the tensile strength data. The marginal misfit of the GS (48.6±19.9μm) and GP (65.4±42.5μm) were statistically lower than the RS (96±62.9μm) and P (156±113.3μm) (p=0.001).The retentive strength of the GP (470.5±104.1N) and GS (416.8±170.2N) were similar to the P (342.1±109.7N), but statistically higher than those of the RS (208.9±110N). The GS and GP glaze layer was 11.64μm and 9.73μm respectively. Thus, glaze application promoted lower marginal discrepancy and higher retentive strength values than conventional techniques.

This study evaluated the effect of different loading pistons, made of various materials and with different elastic moduli acting as antagonist material, on stress distribution and fatigue behavior of a CAD/CAM silica-based ceramic. Materials and methods: Discs of CAD/CAM made silica-based ceramic (N = 60) (VITA MARK II) were divided into six groups (n = 10 per group), according to the test method (M: Monotonic; F: Fatigue) and the antagonist piston material (T: Tungsten; S: Steel; G: Epoxy resin). FT, FS and FG combinations were submitted to mechanical cycling (2 × 10 cycles, 4 Hz, 45 N).The bending stress after fatigue were also valuated using Weibull analysis and the parameters (eta), (beta) and the mean time to failure (MTTF) were calculated. Fractographic analysis and Finite Element Analysis (FEA) were performed. Data were analyzed using ANOVA and Tukey's tests (alpha=0.05). Results: MG presented significantly less bending strength (MPa) (75.6) compared to MT (87.8) and MS (84.4) (p < 0.05).

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