Color stability of sealed composite resin restorative materials after ultraviolet artificial aging and immersion in staining solutions.

STATEMENT OF PROBLEM: The color alteration of resin-based materials is one of the most common reasons to replace esthetic dental restorations. PURPOSE: This study assessed the influence of surface sealant (Biscover) on the color stability of nanofilled (Supreme XT) and microhybrid (Vit-l-escence and Opallis) composite resins after artificial aging. MATERIAL AND METHODS: One hundred disc-shaped (6 × 1.5 mm) specimens were made for each composite resin. After 24 hours, all specimens were polished and sealant was applied to 50 specimens of each material. Baseline color was measured according to the CIE L*a*b* system using a reflection spectrophotometer. Ten specimens of each group were aged for 252 h in an ultraviolet (UV)-accelerated aging chamber or immersed for 4 weeks in cola soft drink, orange juice, red wine staining solutions or distilled water as control. Color difference (ΔE) after aging was calculated based on the color coordinates before (baseline) and after aging/staining treatment. Data were analyzed with 2-way ANOVA and Fisher's test (α=.05). RESULTS: The results showed significant changes in color after artificial aging in all the groups (P<.05). Independent of the material studied, red wine resulted in the highest level of discoloration. Intermediate values were found for orange juice, UV accelerated aging, and the cola soft drink. The lowest values of ΔE were found for specimens stored in distilled water. CONCLUSIONS: All composite resins showed some color alteration after the aging methods. The surface sealant did not alter the color stability of the tested materials.

Efeitos in vivo da profilaxia do esmalte dental na penetraçäo de selantes de fóssulas e fissuras: estudo microscópico / In vivo effects of surface enamel cleansing on preparation of pits and fissures sealants: microscopic study

Com a microscopia óptica comum sob açäo da luz polarizada foi verificado a penetraçäo in vivo de dois selantes de fóssulas e fissuras no esmalte dental humano, após à aplicaçäo ou näo de profilaxia dental. Dessa forma, foi constatado que a profilaxia com pedra-pomes e água possibilitou maior penetraçäo do selante do que as superfícies tratadas com o ácido cítrico e as que näo receberam qualquer profilaxia. Comprovou-se também que o selante Delton apresentou maior penetraçäo no esmalte dental do que o selante Prisma-Shield