The aim of this in vitro study was to evaluate the effect of different mouthwashes on superficial roughness and Knoop hardness of two resin composites. Eighty specimens (6 mm Ø and 2 mm height) were prepared and divided into eight experimental groups (n = 10) according to the resin composites (4 Seasons and Esthet X), and storage solutions (G1 - Distilled water; G2 - Colgate Plax Overnight; G3 - Colgate Plax Alcohol Free; and G4 - Colgate Plax Whitening). The initial hardness and roughness readings (T1) were measured and then the specimens were stored in 2 mL of mouthwash for 12 h (T2) and 24 h (T3). The data were analyzed with repeat-measures two-way ANOVA and Tukey's test (α = 5%). Regardless of the type of solution and time of exposure, there was no statistical difference for roughness between the resins (p = 0.44). G4 and G8 presented higher roughness means than G1, G3, G5 and G7, after 12 and 24 hours of immersion. For Knoop microhardness analysis, there was a significant reduction for all groups after 12 hours and 24 hours. We conclude that the mouthwashes containing hydrogen peroxide and/or alcohol decrease the microhardness of the resins tested; however, the mouthwash containing hydrogen peroxide had a higher deleterious effect on roughness.

AIM: This study aimed to evaluate the enamel microhardness, surface roughness, and chemical composition after microabrasion technique, followed by polishing and different immersion times in artificial saliva. MATERIALS AND METHODS: Ninety enamel blocks (25 mm2) from bovine incisors were divided into two groups (G1 and G2), and then subdivided in five subgroups (n = 9) according to their microabrasion treatment and polishing with a diamond paste: 35% phosphoric acid and pumice (H3PO4+Pum) and polishing; just H3PO4+Pum; 6.6% hydrochloric acid and silica (HCl+Sil) and polishing; just HCl+Sil; and control (no treatment). For G1, roughness and microhardness analyses were performed before (L1) and after (L2) microabrasion. After 15 (L3) and 30 (L4) days of immersion in artificial saliva, microhardness analysis was also performed. After (L4) analysis, the specimens were subjected to SEM analysis. G2 was used for the chemical analysis using energy dispersion testing (EDS). The data was subjected to statistical analysis (α = 5%). For roughness, L2 presented higher values than L1, except for the polished groups. For microhardness, L2 presented higher values than L1, except for unpolished groups. The L3 and L4 did not differ and were higher than L1. RESULTS: No changes were observed in the phosphorus concentrations of the microabrasioned enamel. However, the specimens treated with HCl+Sil were observed as having decreased calcium and increased chlorine and silica on the EDS test. CONCLUSION: Microabrasion followed by polishing and immersion in artificial saliva for 15 days is enough to increase the microhardness of microabrasioned enamel surfaces, although the microabrasion procedure can alter the mineral content of the enamel.

All products increased enamel roughness, and the effectiveness of the polishing systems was dependent upon the abrasive used.

No abstract

Na família, aquilo que os une está num plano imensamente superior a tudo aquilo que os possa afastar. Muito acima das discórdias, das zangas, dos amuos, dos diferentes pontos de vista. Podem as ondas enfurecidas de um mar de inverno salpicar as estrelas? Alguém ligou aquelas vidas com um nó, e a vida de um é a vida dos outros. E o sorriso de um é a alegria dos outros. E a dor de um é a dor dos outros. E a conquista de um é a vitória dos outros.