Análise da microinfiltração em dentina hígida em restaurações de resina composta de um produto biotecnológico: gel de bromelina

Abstract

The development of restorative materials as well as the knowledge of caries disease has enabled more preservation of the tooth structure and the introduction of new products to remove the carious tissue. In this context, the aim of this study was to investigate in vitro the influence of 1% bromelain-based gel (Ananas cosmosus) on microleakage of restorative materials, idealized to remove the carious tissue. For this study, 30 healthy human third molars were used. Standardized Class V cavity preparations were performed on the buccal and lingual faces. The samples were divided into six groups: GI - sound dentin (positive control) + Adper Easy One® 3M (ESPE) + Z 350 3M (ESPE); GII - sound dentin (positive control) + acid etching + Adper Single Bond® 3M (ESPE) + Z350 3M (ESPE); GIII - 1% Bromelain Gel + acid etching + Adper Easy One® 3M + Z350; GIV - 1% Bromelain Gel + Adper Single Bond® 3M (ESPE) + Z 350 3M (ESPE); GV - Papacárie® + acid etching + Adper Easy One® 3M (ESPE) + Z350 3M (ESPE); GVI- Papacárie® + Adper Single Bond® 3M (ESPE) + Z 350 3M (ESPE). All the adhesive systems were used in accordance with the manufacturer s instructions. After storing the samples in an oven for 24 hours, they were immersed into 50% silver nitrate for 2 hours and then immersed in a pure developer solution for 16 hours under fluorescent light. The teeth were immersed in a physiological solution for a further 24 hours. Afterwards, they were submitted to a thermal cycling test at temperatures from 5° to 55°C, totaling 500 cycles. The teeth were washed under running water and the layers of enamel and Araldite were removed with No 15 scalpel blade. They were then fixed to a small metal plate, using hot glue, with the purpose of stabilizing them for later sectioning. Next the teeth were sectioned using a diamond disk under water cooling, first in the mesio-distal direction and then in the buccal-lingual direction passing through the center of the restoration. Microleakage was assessed according to the degree of leakage of the tracer and classified by the scoring criteria from 0-4. The data were submitted to the Kappa index in order to define reliability and reproducibility of the research, and the values were submitted to the non-parametric Kruskal-Wallis test at a level of significance of 5%. The results showed that there was no significant difference on the cervical surface in the Experimental Groups and that the occlusal surface of Group IV showed less microleakage. It may be concluded that the methods for chemical-mechanical removal did not influence microleakage of the restorative procedures. Descriptors: Ananas cosmosus, carboxymethylcellulose gel, Papacárie ®, microleakage.