RESUMO
Coloured compounds (anthocyanins) in açaí can stain resin-modified glass-ionomer cement (RMGIC) due to its low staining resistance. AIM: The aim of this study was to assess whether açaí compromises the surface colour and roughness of RMGIC in vitro. MATERIALS AND METHOD: Disc-shaped specimens (2 mm thick, 8 mm in diameter) of Vitremer™ (3M ESPE, St Paul, MN, USA) were prepared according to the manufacturer 's instructions. The mixture was inserted into a silicone mouldplaced between two mylar strips, and light cured. Specimens were randomly divided into three groups (n=25) according to the solutions to be used for chemical degradation: artificial saliva (control), açaí sorbet and açaí juice. A spectrophotometer CM-2600d/2500d (Konica Minolta, Tokyo, Japan) was used to analyse the colour (CIELa*b* scale). Surface roughness (Ra, mm) was measuredusing theprofilometer Surfcorder SE 1700 (Kosaka Corp, Tokyo, Japan). The specimens were subjected to three daily soaks (6 ml, 15 minutes) for 14 days at 37°C. They were washed in distilled water and placed in fresh saliva (30 minutes in the interval). After the third soak in a day, they were stored in fresh saliva overnight. Outcomes were analysed at baseline (L*, a*, b*, Ra) and after degradation (L'*, a'*, b'*, Ra'). RESULTS: The pH values of saliva, sorbet, and juice were 7.0, 3.8, and 4.9, respectively. ΔE* values were 6.6 for saliva, 6.9 for sorbet and 7.8 for juice. There was a significant ΔE* difference between saliva (p=0.005) and juice (p=0.002), and between juice and sorbet (p=0.019), but none between saliva and sorbet (p=0.401). There was no significant Δb* difference between the solutions. No difference between juice and sorbet was observed for Δa*, but they were significantly different from saliva (p<0.001). Brightness (L*) changed significantly. Juice showed the highest ΔE* (7.8) and ΔL* (7.7). No significant change was observed for roughness and there was no difference between the solutions for ARa. CONCLUSIONS: Açaí and saliva led to unacceptable staining, but no significant roughness changes in the resin-modified glass-ionomer cement.
As antocianinas presentes no açaí podem manchar o cimento de ionomero de vidro modificado por resina (CIVMR) devido a baixa resistencia ao manchamento do material. OBJETIVO: O objetivo desse estudo foi avaliar se o açaí compromete a cor e a rugosidade de superficie de um CIVMR in vitro. MATERIAIS E MÉTODOS: Amostras (2 mm de espessura, 8 mm de diámetro) de Vitremer™ (3M ESPE, St Paul, MN, USA) foram preparadas de acordo com as instrugoes do fabricante. O materialfoi espatulado, inserido em um molde de silicone colocado entre duas tiras de poliestireno e fotopolimerizado. Após, as amostras foram randomizadas e alocadas em tres grupos (n=25) de acordo com as solugoes usadas para a degradagao química: saliva artificial (controle) e sorbet de açaí e suco de açaí. Utilizou-se o espectrofotometro CM-2600d/2500d (Konica Minolta, Tokyo, Japan) para a análise da cor (escala CIELa*b*) e o rugosímetro Surfcorder SE 1700 (Kosaka Corp, Tokyo, Japan) para a rugosidade de superficie (Ra, mm). As amostras foram submetidas a tres imersoes diárias (6 ml, 15 minutos) em cada solugao por 14 dias a 37°C, tendo sido lavadas em água destilada e mantidas em saliva fresca (30 minutos) nos intervalos. Após a terceira imersao no dia, as amostras foram mantidas em saliva renovada até o dia seguinte. As variáveis foram analisadas antes (L*, a*, b*, Ra) e depois da degradagao química (L'*, a'*, b'*, Ra'). RESULTADOS: Os valores de pH da saliva, sorbet e suco foram, respectivamente 7,0, 3,8 e 4,9. Houve diferenga significante para ΔE* entre saliva (p=0.005) e suco (p=0.002) e entre suco e sorbet (p=0.019), mas nao entre saliva e sorbet (p=0.401). Nao foi observada diferenga significante para Δb* entre as solugoes. Nao houve diferenga significante para Δa* entre suco e sorbet, mas eles foram significativamente diferentes da saliva (p<0.001). A luminosidade (L*) mostrou alteragao significante. O suco mostrou os maiores valores de ΔE* (7,8) e ΔL* (7,7)". Nao houve mudanga significante para a rugosidade e nao foi observada diferenga significante entre as solugoes para ARa (p>0.05). CONCLUSÃO: O açaí e a saliva causaram manchamento inaceitável do glaze do CIVMR e insignificante alteragao da rugosidade.
