Torsional strength of gates glidden drills exposed to clinical conditions

Gates Glidden drills are exposed to a variety of conditions during clinical usage. These usually include canal preparation, endodontic irrigants, and sterilization procedures. All sizes 1 to 6 (n = 5/size) were tested and the torsional fracture strength determined. There were four groups (n = 30/group): group A, control; group B, sterilized 10 times; group C, exposed to 5.25% NaOCl during testing; and group D, sterilized 10 times and exposed to NaOCl during testing. Data were analyzed by ANOVA. Tukey-Kramer intervals at the 0.05 significance level were calculated. No significant differences were noted as a result of simulated clinical conditions. The larger diameter instruments had significantly higher torsional fracture strength.