RESUMO
INTRODUCTION: In 1890, Breuer applied an electrical field concept to root canals in an attempt at sterilization. Recently, Balson and Dovgan have renewed interest in the use of electricity to aid in canal disinfection. The purpose of this investigation is to determine if the use of the apex locator or apex locator in conjunction with low speed handpiece causes a previously unreported electrophoretic effect. MATERIALS: Forty low-fat, dried sirloin steak cubes separated into four groups of 10 and immersed in 5.25% sodium hypochlorite for two minutes while connected to 1) an apex locator with no batteries, 2) one with batteries, or an apex locator and low speed handpiece set at either 3) zero or 4) 800 rotations per minute. Samples were dried and percentage of weight loss was calculated. ANOVA and Tukey Multicomparison tests were performed for statistical significance of α ≤ 0.05. RESULTS: ANOVA test and Tukey Multicomparison tests showed that there was a significant difference (α ≤ 0.05) between the groups. They revealed statistically significant differences between 800 rotations per minute and all other groups. This study showed that there were no significant differences between an apex locator with no batteries, one used with batteries and one used in conjunction with the low speed handpiece at zero rotations per minute. However, it was shown that there was significantly more tissue dissolution with an apex locator with low speed handpiece at 800 rotations per minute compared to the first three groups. CONCLUSION: These results did not support the original hypothesis that the apex locator with or without the low speed handpiece has an electrophoretic effect. However, the results do support the use of sodium hypochlorite agitation for increased tissue dissolution.