Pei Dan-Dan, Meng Yu-Chen, Fayed Ahmed S, You Yu-Fei, Wu Zi-Xiao, Lu Yi
Associate Professor, Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, PR China.
Postgraduate Resident, Department of Prosthodontics, College of Stomatology, Xi'an Jiaotong University, Xi'an, PR China.
J Prosthet Dent. 2021 Jan;125(1):111-116. doi: 10.1016/j.prosdent.2019.11.001. Epub 2020 Feb 7.
Tooth preparations for ceramic crowns require precision and accuracy, which may be influenced by the choice of dental handpiece. However, comparisons of the accuracy of tooth preparations made with traditional air-turbine handpieces and electric handpieces are lacking.
The purpose of this in vitro study was to evaluate operator preferences and tooth preparation performance by using electric and air-turbine handpieces with self-reported preferences, sound levels, surface roughness, and the fit of the crown produced.
Twenty dentists were asked to use the air-turbine or the electric handpiece. Feedback on the noise, weight, feel of grip, flexibility, and tooth preparation in general was scored according to a visual analog scale (VAS). Additionally, the dentists were asked to complete a questionnaire on their handpiece preference. The noise of the 2 handpieces was measured by using a precision sound level meter. The surface roughness of 10 teeth was measured by using a profilometer. The other 18 teeth were prepared to measure the marginal and internal fit of ceramic crowns by the replica technique. The VAS scores of operator preferences were analyzed with the Wilcoxon signed ranks test. Decibel levels were analyzed with the Mann-Whitney U test. The McNemar test was used to compare the ratio of preferred handpiece. The surface roughness and marginal and internal fit were analyzed with the independent t test to determine significant differences (all α=.05).
The electric handpiece was heavier, had a poorer grip feel, was less flexible (P<.001), produced lower noise and better feeling of the tooth preparation in general (P<.001), and was preferred in the finishing stage for its greater smoothness (P<.05). The noise produced by the electric handpiece was lower during both idling and tooth preparation at 15-cm, 30-cm, and 45-cm distances (P<.01). The electric handpiece produced surface roughness values (Sa) similar to those of the air-turbine handpiece (P>.05). No significant differences were noted for the marginal and internal crown fit between the air-turbine handpiece and electric handpiece groups (P>.05).
Despite its heavier weight, poorer grip feel, and less flexibility, the electric handpiece emitted lower noise, produced better feeling of the tooth preparation in general, and was preferred in the finishing step of tooth preparation for its greater smoothness than the air-turbine handpiece. The surface roughness of the prepared teeth and the crown fit between the tooth and ceramic crown were not affected by the air-turbine or electric handpiece.
用于制作陶瓷冠的牙齿预备需要精确性和准确性，而这可能会受到牙科手机选择的影响。然而，对于使用传统涡轮手机和电动手机进行牙齿预备的准确性比较尚缺乏相关研究。
本体外研究的目的是通过使用电动手机和涡轮手机，并结合自我报告的偏好、噪音水平、表面粗糙度以及所制作牙冠的适合性，来评估操作者的偏好和牙齿预备性能。
邀请20名牙医分别使用涡轮手机或电动手机。根据视觉模拟量表（VAS）对关于噪音、重量、握持手感、灵活性以及总体牙齿预备情况的反馈进行评分。此外，要求牙医完成一份关于其手机偏好的问卷。使用精密声级计测量两种手机的噪音。使用轮廓仪测量10颗牙齿的表面粗糙度。使用复制技术对另外18颗牙齿进行预备，以测量陶瓷冠的边缘适合性和内部适合性。采用Wilcoxon符号秩检验分析操作者偏好的VAS评分。采用Mann-Whitney U检验分析分贝水平。采用McNemar检验比较偏好手机的比例。采用独立t检验分析表面粗糙度以及边缘和内部适合性，以确定显著差异（所有α = 0.05）。
电动手机较重，握持手感较差，灵活性较低（P < 0.001），产生的噪音较低，总体牙齿预备感觉较好（P < 0.001），并且因其在修整阶段更光滑而更受青睐（P < 0.05）。在15厘米、30厘米和45厘米距离处，电动手机在空转和牙齿预备期间产生的噪音均较低（P < 0.01）。电动手机产生的表面粗糙度值（Sa）与涡轮手机相似（P > 0.05）。涡轮手机组和电动手机组之间在牙冠边缘适合性和内部适合性方面未观察到显著差异（P > 0.05）。
尽管电动手机重量较重，握持手感较差且灵活性较低，但与涡轮手机相比，它发出的噪音更低，总体牙齿预备感觉更好，并且在牙齿预备的修整步骤中因其更光滑而更受青睐。预备牙齿的表面粗糙度以及牙齿与陶瓷冠之间的冠适合性不受涡轮手机或电动手机的影响。
