Influência do pré-aquecimento e modo de aplicação de diferentes tipos de resinas compostas utilizadas para reforço radicular em raízes enfraquecidas

Abstract

The aims of this study were: 1- to evaluate the influence of different composite resins (CR) (conventional- C or bulk- BF) and pre-treatment (heated or not) used for root reinforcement (RR) in the adhesion of glass fiber post (GFP) to the root canal (RC) through the tests of bond strength (BS), microhardness vickers (VHN) and gap formation (GAP); 2- evaluate the influence of the application mode (passive-PA and sonic-SA) of different types of CR (C or BF) used for RR in the adhesion of GFP to the root canal through the tests of BS, VHN and GAP. In experiment 1, 72 roots of uniradicular teeth were selected, after endodontic treatment, were prepared for RR and divided into 6 groups (n = 12): Positive control group ([PCG] - RC without enlargement), Negative control group ([NCG] - RC extended without RR) and in the remaining 4 groups, RC were extended to receive RR, according to the type of CR (C or BF) and pre-treatment (heated or not). After RR and GFP cementation, six slices of each root were obtained which were submitted to BS, VHN and GAP analysis and the data obtained for each material were submitted to two-way ANOVA (experimental group vs root region) and Tukey (α = 0.05). It was observed that the groups of RR regardless of the type of CR and treatment showed superior results of BS to the group NCG and GAP values similar to PCG, and that the heating of CR significantly increased the values of VHN. In the experiment, 2 roots of 72 uniradicular teeth after endodontic treatment were prepared for RR and divided into 6 groups (n = 12): PCG- RC without enlargement, NCG- RC enlarged without RR, and in the other groups, the RC were enlarged to receipt of RR, according to the type of RC (C or BF) and application mode (passive or sonic). After RR and cementation, six were obtained from each root which were submitted to BS, VHN and GAP analysis and the data obtained were submitted to two-way ANOVA (experimental group vs root region) and Tukey (α = 0.05 ). It was observed that the sonic application group obtained higher BS and lower GAP values at the adhesive interface, however the application mode did not significantly influence the VHN values. It is concluded that the previous heating and the sonic application of composite resins, can be alternative auxiliary techniques in the root reinforcement of excessively enlarged root canals.