Optimum Design of the Air-turbine for the High-speed Dental Air-turbine Handpiece Using Design of Experiment

High-pressure air enters the air-turbine of the dental handpiece and strikes the blades to drive the impeller. The air-turbine has impeller and the air tube is connected to the air-turbine housing. The flowfield of the air-turbine were investigated for the optimum air-turbine design using ANSYS CFX. The objective of the research was to find an optimum design variables for the air-turbine to increase the torque. Design of Experiments (DOE) was used for the optimization design of the air-turbine. The airflow inside the air turbine was analyzed by changing the impeller blade number and angle and the gap as the design variables. The computational results showed influential design variables for the optimization to improve the performance of the air-turbine. The optimum values of the design were observed using Analysis of Variance (ANOVA). The optimum design variables were when the blade angle and number and the gap were 90 degree, 7 and 0.13 mm, respectively. The dental handpiece with the optimum air-turbine was manufactured for the performance analysis. The performance results of the existing advanced handpieces were compared by the high quality accuracy, reliability and flexibility. The designed dental air-turbine handpiece was compatible with advanced handpieces.