Resumo

CAMPOS, Gabriel Rocha; CARDOSO, Rielson José Alves  e  SILVA, Marcelo Cavenaghi Pereira da. Analysis of the force required to remove resin cement from roots prepared with different chemicals. RGO, Rev. gaúch. odontol. (Online) [online]. 2011, vol.59, n.1, pp. 95-102. ISSN 1981-8637.

OBJECTIVE: This study assessed in vitro how the chemicals used in the preparation of root canals affected the force required to remove the resin cement Rely-X (3M, Sumaré, Brazil) from bovine root dentin. METHODS: The crowns of 72 bovine teeth were sectioned and the roots were standardized. The specimens were then placed in resin blocks and treated for 10 minutes with sodium hypochlorite at 0.5%, 1%, 2.5% or 5.25% or chlorhexidine gel at 2%. The control group was treated with distilled water. Next, the specimens were soaked in 17% EDTA for 3 minutes. The surfaces of two specimens from each group were assessed by electron scanning microscopy. The tested specimens were then treated with 37% phosphoric acid for 15 minutes, adhesive system Single-Bond (3M, Sumaré, Brazil) and the resin cement Rely-X (3M, Sumaré, Brazil) was applied over it. RESULTS: The results in Kgf were: GChlorhex (2.26); GNaOCl-0.5% (7.92); GNaOCl-1% (9.70); GNaOCl-2.5% (9.05); GNaOCl-5.25% (8.91); GA (0.61). CONCLUSION: Sodium hypochlorite in the tested concentrations increased the adhesion of the resin cement to the dentin significantly when compared with water and 2% chlorhexidine. Electron scanning microscopy showed that the structure of the root dentin treated with sodium hypochlorite presented widened dentinal tubules, less intertubular dentin and depression areas, all of which were not observed in the roots treated with water and 2% chlorhexidine gel.

Palavras-chave : Resin cements; Dentin; Endodontics.