The importance of final rinse after disinfection of gutta-percha and Resilon cones.

OBJECTIVES: The aim of this study was to evaluate the morphologic alterations on the surface of gutta-percha and Resilon cones exposed to disinfectant solutions. STUDY DESIGN: Fifty-six gutta-percha and Resilon cones were used. Seven groups were analyzed: G1: control; G2, G3, and G4: 5.25% NaOCl, 2% CHX, and MTAD, respectively, without final rinse; G5, G6, and G7: the same solutions with final rinse. Then the samples were analyzed by means of scanning electron microscopy and energy dispersive spectroscopy. RESULTS: Regarding the use of NaOCl without rinse, there was chloride crystal formation in all samples. When the cones were rinsed, the crystals were removed. When 2% chlorhexidine was used, no change was observed. MTAD without rinse showed the presence of a precipitate in gutta-percha cones. When the cones were rinsed, it was eliminated. CONCLUSIONS: The final rinse is essential, especially when NaOCl and MTAD are used in the cones' disinfection process.