Effect of disinfectant solutions on the surface free energy and wettability of filling material.

INTRODUCTION Gutta-percha (GP) and Resilon (Res) cones are usually disinfected by the use of solutions such as sodium hypochlorite (NaOCl) and chlorhexidine (CHX). The aims of this study were to evaluate the surface free energy of GP and Res cones after disinfection procedures and to investigate the wettability of endodontic sealers in contact with these surfaces. METHODS GP and Res flat smooth surfaces were prepared. Thirty-six samples of each material were used. The samples were divided into 6 groups as follows: Control group GP, immersed in Milli-Q water (MQW); CHX group GP, immersed in 2% CHX solution and then washed with MQW; NaOCl group GP, immersed in 5.25% NaOCl and then washed with MQW; Control group Res, immersed in MQW; CHX group Res, immersed in 2% CHX solution and then washed with MQW; and NaOCl group Res, immersed in 5.25% NaOCl and then washed with MQW. Samples were analyzed first with a goniometer to measure the contact angle between the test surfaces and 3 solutions (water, ethylene glycol, and diiodomethane) to determine the surface free energy. Then the contact angle between surfaces and each one of the sealers tested, AH Plus and Real Seal SE, was measured. Data were statistically analyzed. RESULTS The results showed that when disinfectant solutions were used, the surface free energy was greater. When evaluating the interaction between materials and sealers, the use of CHX presented lower values of contact angle, followed by NaOCl. CONCLUSIONS It was concluded that the solutions used in decontamination increase the surface free energy, promoting high interaction between GP/Res and sealers.