Comparison between slow-speed handpiece and ultrasonic instrument in retropreparation of root-end in apicectomy / 实用口腔医学杂志

Objective:To evaluate the effect of retrograde preparation by using slow-speed handpiece or by ultrasonic tips.Methods:Forty-eight extracted premolars were inspected with Scanning Electron Microscope for the minimum dentine thickness recorded after preparation of root-end cavities by low-speed handpiece and ultrasonic instrument respectively.Results:By using slow-speed handpiece,the minimum dentine thickness recorded after the preparation of root-end cavities was 0.15 mm;whereas that was 0.82 mm and 0.76 mm by ultrasonic instrument with S12 9D and S12 9 respectively(handpiece vs ultrosonic instrument,P