Eficiência de agentes naturais de biomodificação dentinária utilizados como pré-tratamento dentinário na adesão intrarradicular de pino de fibra de vidro

Abstract

Glass fiber posts are indicated to increase retention of restorations on weakened teeth. Its advantage over other retentive materials is due to its modulus of elasticity being similar to root dentin, however the loss of retention is the predominant failure mode in this type of restoration. Dentin biomodification corresponds to a biomimetic strategy to improve the mechanical properties of dentin and to reduce the rates of biodegradation through the formation of crosslinkings of collagen. The objective was to evaluate the effects of agents crosslinkings as a pretreatment in glass fiber post cementation. The solutions were prepared and the groups were divided according to the biomodification agents: proanthocyanidin from grape seed (PAC), Cardol and Cardanol (extracted from cashew nut shell liquid) and negative control (no pre treatment). The solutions were applied before the adhesive system on 20 roots of unirradicular (n = 5) extracted teeth and then the glass fiber post were cemented with RelyX ARC (3M) resin cement. Slices for the push-out test were cut and tested after 24h or 6 months of storage in distilled water. The underlying dentin was analyzed by micro-Raman spectroscopy to evaluate the formation of collagen crosslinking. Three slices were also separated and the degree of in situ conversion (GC) of the adhesive was analyzed by the reduction of the 1639 cm-1 peak by Micro-Raman spectroscopy. The results were analyzed with ANOVA and Tukey test (p <0,05). The Cardol group (15.0 ± 0.9 MPa) presented better bond strength in the push-out test after 6 months of storage, however in 24h there was no statistically significant difference (p> 0.05) between the groups. The peak formation of 1117cm-1 and 1235cm-1 crosslinked peaks was verified in all experimental groups at 6 months. The GC showed no statistical difference between the groups. Therefore, the biomodifying agents are shown to be promising to be used intra-channel in glass fiber post cementation.