Avaliação da eficácia dos métodos de desinfecção de pinos de fibra de vidro e sua influência na resistência de união

Abstract

The purpose of this study was to evaluate which disinfection method was more effective on the decontamination of fiberglass posts, and to observe if these methods influence on the bond strength between the post to the root canal. Sixty-four fiberglass posts were used, being 32 serrated type, and 32 smooth type. They were submersed in solution containing 5mL of E. faecalis suspension during one hour. Then, were divided in 8 groups (n=8), being 4 groups composed by posts serrated type, and 4 groups composed by posts smooth type, each group remained for 5 minutes in its respective disinfection agents (Chlorhexidine 2%, phosphoric acid 35%, and alcohol 70%), with the exception of the control groups. Afterwards, the number of colony forming units per milliliter (UFC/mL) of E. faecalis was determined. Then, the posts were cemented in 64 bovine roots. Passed 7 days of cementation, the roots were sectioned perpendicular to the long axis, and the specimens were submitted to the adhesive resistance test (push-out). Anova 2 factors and Tukey post test were used as statistical method to analysis of the results obtained. The UFC/mL analysis did not present any growing/development of E. faecalis colonies at the experimental groups. The evaluation of bond strength, considering the post type, presented significant statistical difference (p<0,05) only on control and alcohol groups, in which the smooth type post showed greater results. There was not any significant statistical difference (p<0,05) on the group of serrated posts. The antimicrobial substances tested were effective at the elimination of E. faecalis colonies. Alcohol 70% presented greater bond strength results when compared to the others tested substances and control groups.