ABSTRACT
AIM : To evaluate the influence of finishing and polishing techniques on the surface roughness of two composite resins (CRs) subjected to bleaching procedure. METHODS : Forty-eight CR specimens were divided into six groups (n=8). For G1 to G3, a microhybrid CR (Opallis; FGM) was used, and G4 to G6, received a nanohybrid CR (Brilliant NewLine; Coltène/Whaledent). All specimens were subjected to bleaching procedure with 35% hydrogen peroxide (two 45-min applications, with a 5-day interval). The surface roughness of all specimens was evaluated before and after the bleaching and/or finishing/polishing (Ra parameter) by a roughness meter. After bleaching, the groups were subjected to finishing and polishing procedures: G2 and G5 - felt discs + diamond pastes; and G3 and G6 - silicon rubber tips. The control groups (G1 and G4) had no finishing or polishing treatment after bleaching. Data were analyzed by ANOVA and Tukey's post-test, and t test for paired samples (a=0.05). RESULTS : bleaching treatment increased Ra values for the nanohybrid CR specimens, but both finishing/polishing techniques were able to reduce these values; for the microhybrid specimens, only finishing/polishing with silicon rubber tips decreased the roughness values. CONCLUSIONS : For both microhybrid and nanohybrid CRs, the silicon rubber tips were effective to reduce the surface roughness after bleaching procedure...
Subject(s)
Anti-Infective Agents, Local/therapeutic use , Composite Resins , Tooth Bleaching/adverse effects , Silicone Elastomers/therapeutic use , Hydrogen Peroxide/therapeutic use , Dental Polishing/adverse effectsABSTRACT
Avaliou-se o efeito de agentes clareadores de uso caseiro na microdureza de resinas compostas (RC) microhíbrida e nanohíbrida. Foram confeccionados 30 corpos-de-prova (cp), divididos em seis grupos (n=5). Os grupos G1 a G3 utilizaram RC microhíbrida (Opallis), e os grupos G4 a G6, RC nanohíbrida (BrilliantNewLine). Os agentes clareadores utilizados foram: peróxido de hidrogênio 6% (PH) (White Class Cálcio) e peróxido de carbamida 16% (PC) (Whiteness Perfect). Após a confecção dos cp, o clareamento foi realizado: G1 e G4: grupo controle sem agente clareador, G2 e G5: PH - 28 dias, G3 e G6: PC - 28 dias, de acordo com as recomendações dos fabricantes. Em seguida, o teste de microdureza foi realizado. Os dados obtidos foram analisados por ANOVA e Tukey (5%). Os resultados de microdureza (HV) e desvio-padrão foram: G1-26,56 ± 3,9, G2-25,98 ± 3,3 e G3-24,94 ± 4,4; G4-27,24 ± 3,3; G5-32,02 ± 6,4 e 37,72 G6- ± 8,1. O único grupo que apresentou diferenças significativas para os outros foi o G6 (p <0,05), mas não diferiu significativamente em relação ao G5 (p = 0,0058). Concluiu-se que o uso de agentes clareadores de uso caseiro não afetou negativamente a microdureza das resinas compostas testadas.
It was evaluated the effects of home bleaching agents on microhardness of microhybrid and nanohybrid composite resins. 30-of-body were made and divided into 6 groups (n=5). The groups G1 to G3 used a microhybrid CR (Opallis), while groups G4 to G6 used a nanohybrid CR (BrilliantNewLine). The bleaching agents used were: 6% hydrogen peroxide (PH) (White Class Cálcio) and 16% carbamide peroxide (PC) (Whiteness Perfect). After the specimens were prepared, the bleaching was realized as follows: G1 and G4: control group without bleaching agent, G2 and G5: PH - 28 days, G3 and G6: PC - 28 days, in accordance with the manufacturer's recommendations. After it, the microhardness test was performed. The data were statistically analyzed by ANOVA and Tukey's tests (5%). The results of microhardness (HV) and standard deviation of each group were: G1- 26.56±3.9; G2- 25.98±3.3; G3- 24.94±4.4; G4- 27.24±3.3; G5- 32.02±6.4 and G6- 37.72±8.1. The only group that showed significant differences to the anothers was the G6 (p<0.05), but did not differ significantly in relation to G5 (p=0.0058). It was concluded that the use of home bleaching agents didn't affect negatively the microhardness of the composite resins tested.