ABSTRACT
CONTEXT: The aim was to evaluate the cutting efficiency of different diamond burs after successive cuts and repeated sterilization in an autoclave. The morphology and grit sizes were analyzed and correlated to cutting efficiency. MATERIALS AND METHODS: Ten medium-grit diamond burs of five different manufacturers were investigated (KG, KG Sorensen; TH, Tri-Hawk; KM, Komet; HC, Heico; and FD, Frank Dental). Changes in the cutting efficiency of diamond burs on composite resin blocks were measured after five repeated cuts and after five sterilization cycles. Grit sizes were analyzed by scanning electron microscopy (SEM) and correlated to cutting efficiency. The data were statistically analyzed using 3-way ANOVA and Tukey's test (α = 0.05). RESULTS: Significant differences were observed for diamond burs (P < 0.0001) and condition (P < 0.0001). FD presented the lowest mean cut time (21.88s), followed by KM (36.08s). TH (40.18s), HC (41.65s), and KG (42.23s) had the highest cut times. The number of cuts was not statistically significant. New burs had a significantly shorter cutting time (33.38s) when compared with the ones after sterilization cycles (39.55s). A moderate to strong positive correlation was found between diamond size and cutting time (Pearson's coefficient of 0.77). CONCLUSION: All diamond burs demonstrated lower cutting efficiency after repeated autoclaving. Cutting efficiency did not decrease as the number of cuts increased.
