Evaluation of high-speed handpiece cutting efficiency according to bur eccentricity: An in vitro study

This study aimed to evaluate the correlation between the cutting efficiency and bur eccentricity of high-speed handpieces. The prepared lithium disilicate samples were digitized using a 3D model scanner (reference model, RM) (n = 45), and the lithium disilicate samples were cut using three high-speed handpieces. To evaluate the cutting efficiency, the cut lithium disilicate sample was digitized (cutting model, CM), and the RM and CM were superimposed using a 3D analysis software. Bur eccentricity of the high-speed handpieces was measured using dedicated equipment. Statistical analyses were performed using an analysis software. The statistical differences in pairwise comparisons (α = 0.05) were analyzed using the Kruskal-Wallis and post hoc tests. The S-max M600 obtained a cutting efficiency of 6.13 mm³. TG-98 and TRAUS ATN-400 showed similar efficiencies of 2.914 and 3.05 mm³, respectively. There was a significant difference in the cutting efficiency of the S-max M600 compared with TG-98 and TRAUSATN-400 (p < 0.001). S-max M600 had an eccentricity of 3.507 μm. TG-98 and TRAUS ATN-400 had eccentricities of 5.99 and 7.767 μm, respectively. There were statistically significant differences in the eccentricity among all the high-speed handpieces (p < 0.001).