Objective Evaluate the masking ability of bleach‐shade resin composites applied by multilayering techniques over colored substrates. Materials and methods Disc‐shaped specimens were fabricated from bleach‐shade resin composites using different multilayering techniques. Substrates were produced in opaque ceramic discs simulating colored substrates (A2, A3, A3.5, C2, C3, C4) and a bleached tooth (0M1). Color coordinates were obtained using a reflectance spectrophotometer. Color difference was calculated by CIEDE2000 using coordinates of 0 M1 ceramic as standard reference. Data were analyzed by one‐way ANOVA and Tukey's post‐hoc test (p ≤ 0.05). Masking ability interpretation was based on perceptibility and acceptability thresholds. Results All combinations presented ΔE00 above the acceptable threshold (ΔE00>1.8), ranging from 2.49 to 7.42, regardless of the restorative system, multilayering strategy or substrate color. Multilayering combinations placed over A2, A3 and A3.5 were moderately (1.8<ΔE00≤3.6) and clearly unacceptable (3.6<ΔE00≤5.4), combinations associated with C2, C3 and C4 were clearly unacceptable and, extremely unacceptable (ΔE00>5.4). Lower ΔE00 was observed for combinations with 0.5 mm extra white enamel layer (2.49), or 1.0 mm white dentin layer (2.69), over A2 and A3.5 substrates. Lightness difference showed the greatest contribution to ΔE00. Conclusions Bleach‐shade resin composite systems applied by the multilayering technique were not able to ensure effective masking ability. Clinical significance Bleach‐shade resin composites applied with different combinations of the multilayering technique were not effective in masking colored substrates. Alternative strategies, techniques and dental materials should be explored to obtain acceptable masking.

Ângela DALLA NORA (a) Andressa DALMOLIN (b) Larissa D'Olanda GINDRI (a) Carlos Heitor Cunha MOREIRA (a) Luana Severo ALVES (b) Júlio Eduardo do Amaral ZENKNER (a)

SUMMARY The aim of this study was to evaluate the masking ability of a combined application of opaquers and resin composite over discolored backgrounds: A3, A3.5, C2, C3, and C4. The groups were divided according to the opaquer brand, the number of opaquer coats (one or two), and the thickness of the resin composite layer (0.5 or 1.0 mm). The color measurements were made by a reflectance spectrophotometer (SP60, EX-Rite). The color difference between the opaquer + resin composite + background and a reference background was calculated using the CIEDE2000 formula. ANOVA and Tukey’s post hoc test (α=0.05) were used to analyze the ΔE00 mean values. A bivariate analysis was used to determine the association between dependent and independent variables. The masking ability was rated by the ΔE00 visual thresholds of acceptability and perceptibility (Excellent Match: ΔE00 ≤ 0.8; Acceptable Match: 0.8 &lt; ΔE00 ≤1.8; Moderately Unacceptable Mismatch: 1.8 &lt; ΔE00 ≤ 3.6; Clearly Unacceptable Mismatch: 3.6 &lt; ΔE00 ≤ 5.4; Extremely Unacceptable Mismatch: ΔE00 &gt; 5.4). The mean ΔE00 values ranged from 0.5 to 5.52. Masking ability was affected by the opaquer brand, thickness of the resin composite layer, and background shades. Most of the combinations that achieved either excellent or acceptable masking ability were obtained with combinations composed of one or two coats of opaquer and a 1.0-mm-thick resin composite layer for all backgrounds except C4. Acceptable results were also obtained for combinations with 0.5-mm-thick resin composite over C2, A3, and A3.5 backgrounds.

Introduction Longevity and clinical success of dental restorations can be influenced by many factors during the restorative procedures. Objective This study aimed to evaluate the influence of different placement techniques on color stability and surface roughness of two resin composites. Material and method The groups of specimens (n=10) were divided according to resin composite (FiltekTM Z250 XT and FiltekTM Z350 XT) and placement technique: Mylar strip, spatula, dry brush, modeling liquid, and surface sealant. Color stability and surface roughness were accessed using a spectrophotometer (CIELab color space) and a rugosimeter (standard cutoff of 0.8 mm), respectively, after water storage. Subsequently, the specimens were immersed in coffee for 48 h and final color was measured. The data were analyzed using ANOVA and the Tukey’s post hoc test (α=5%) and the correlation between surface roughness (Ra) and color change (∆Eab) was assessed using the Pearson’s correlation coefficient. Result The different placement techniques influenced Ra and ∆Eab on both resin composites. The groups treated with surface sealant showed greater difference in ∆Eab for both resin composites. The FiltekTM Z250 XT resin showed greater color stability compared with the FiltekTM Z350 XT resin regardless of the placement technique used. Ra of each placement technique was similar among the resin composites except for the FiltekTM Z350 XT modeling liquid group, which presented lower Ra values compared with those of FiltekTM Z250 XT. A correlation between Ra and staining was identified (p=0.268). Conclusion Color stability and Ra are influenced by different placement techniques.

O câncer surge quando uma célula sofre uma instabilidade genética, causando mutações no seu DNA, e passam a se proliferar de forma descontrolada e desordenada, podendo invadir tecidos e órgãos distantes, gerando as metástases. O câncer de próstata é a neoplasia mais comum em homens acima de 40 anos, tendo entre os principais fatores de risco idade avançada, histórico familiar, fatores ambientais, sedentarismo e alimentação rica em gorduras e pobre em fibras e verduras. Uma das principais formas de tratamento, a radioterapia, usa radiação ionizante de forma controlada, procurando uma entrega de dose direcionada às células doentes, afetando o mínimo possível as células sadias em torno do tumor. O objetivo desta revisão foi avaliar a associação entre radioterapia e câncer de próstata, bem como os avanços usando a radioterapia. Os dados para esta revisão foram obtidos através de buscas nas bases de dados Pubmed de artigos publicados nos últimos 10 anos usando os descritores câncer, próstata, tratamentos, radioterapia, novas terapias de radioterapia, evolução em tratamentos de próstata. Houve um grande avanço tecnológico nas terapias com radioterapia, onde a principal delas é a IMRT, pois sua modulação de dose protege de forma mais eficiente os órgãos de risco, como bexiga, reto e pelve. Estudos com códigos de Monte Carlo também apontam o uso de nanopartículas de ouro radiotivas como tratamento promissor para o câncer de próstata.