Efeito da aplicação de solução à base de CPP-ACP na microdureza da interface formada entre a resina composta e a dentina desmineralizada

Abstract

The use of bioactive agents, such as casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), has been proposed as a promising alternative to optimize the adhesive interface in demineralized dentin (DD). This study evaluated the effect of a CPP-ACP-based solution on the microhardness of the interface between DD and composite resin (CR) restoration. Twelve sound human third molars were used and distributed into four groups: sound dentin (SD), SD treated with CPP-ACP, demineralized dentin (DD), and DD treated with CPP-ACP. Demineralization was induced by pH cycling for 14 days, and the dentin pretreatment consisted of applying a CPP-ACP solution (5% w/v) for 60 seconds. A universal adhesive system was then applied using the self-etch protocol, followed by CR placement. For the Knoop microhardness test, 24 resin-dentin slices from each group were analyzed at different depths: underlying dentin, 30, 70, and 100 μm. Data were subjected to Kruskal-Wallis analysis (p<0.05). There was no interaction between the evaluated factors (dentin treatment × dentin type) at any depth; however, in all depths, the microhardness of the DD groups was significantly lower than that of the SD groups. Only at 30 μm depth did the groups that received CPP-ACP pretreatment show a statistically significant reduction in microhardness compared to the untreated groups (p=0.002). It is concluded that the application of the CPP-ACP solution as a pretreatment did not provide an advantage over the traditional protocol using the universal adhesive system.