Evaluation of High-speed Handpiece Cutting Performance According to Bur Eccentricity: In-vitro Test

Objectives: The purpose of this study was to evaluate the cutting performance of high-speed handpieces using dental area according to bur eccentricity.
Methods: We used the three industrial high-speed handpieces (S-max M600, TG-98, TRAUS ATN-400) for comparing the cutting performance according to bur eccentricity. For this experiment, the fifteen lithium disilicate blocks of IPS e.max ware cut with 12 mm × 6 mm × 8 mm. A self-fabricated jig was used for the experiment under the same conditions which were set cutting load of 0.9 Nm and cutting time of 15 sec. In order to compare the cutting amount, fifteen samples were scanned using E1 model scanner of 3 shape. Bur eccentricity tester was used to measure the eccentricity of the High-speed handpieces. The experiment parameters that the 0.3 MPa of pressure, 400,000 rpm, 6 mm of bur insertion length ware set. For statistical analysis of cutting amount and eccentricity, we used the Kruskal-Wallis test (α=0.5) and the significance level was set at P <0.001.
Results: The S-max M600 had average cutting amount of 6.132 mm³, and TG-98 and TRAUS ATN-400 showed the 2.019 mm³ and 1.733 mm³, respectively. The cutting amount of S-max M600 had significance difference with TG-98 and TRAUS ATN-400, while TG-98 and TRAUS ATN-400 showed no significant difference in cutting amount. The results of the eccentricity showed that the S-MAX M600 had 3.507μm and TG-98 had 5.99μm, TRAUS ATN-400 had 7.767μm. Respectively. Bur eccentricity between all High-handpieces was statistically significant each other.
Conclusions: The cutting amount and eccentricity of high-speed handpiece was opposite to each other. Bur eccentricity showed the lowest value at S-max M600 and increased in the order of TG-98 and TRAUS ATN-400. Unlike the result of eccentricity, S-max M600 has the highest cutting amount and TG-98 and TRAUS ATN-400 had lower cutting amount than S-max M600.