Zhang Lei, Ji Ping, Fu Xinhai, Song Xiaolei
Dept. of Prosthodontics, College of Stomatology, Shandong University, Shandong Provincial Key Laboratory of Oral Biomedicine, Jinan 250012, China.
Hua Xi Kou Qiang Yi Xue Za Zhi. 2011 Aug;29(4):361-4.
The residual dentin thickness of first premolars were measured by anatomical methods before and after post preparation, the data from which can help clinicians to choose proper sizes of peeso drill.
30 first maxillary premolars and 30 first mandibular premolars were collected. Walls of 4 mm short of the apex were respectively measured before and after post preparation with peeso drills number 1-3.
The measurement results of all indexes assumed a normal distribution. For two-canal first maxillary premolars and single-canal first mandibular premolars, the average residual mesial and distal thickness of root walls 4 mm short of the apex were less than 1 mm after post preparation by number 3 peeso drill. The buccal root had nonsignificant differences (P>0.05). The palatine root and the first mandibular premolars had significant differences (P<0.05). For single-canal first maxillary premolars, the average residual mesial and distal thickness were less than 1 mm after post preparation by number 2 peeso drill. The distal wall had significant differences (P<0.05).
In post preparation, for the buccal root of two-canal maxillary premolars, the maximum size of peeso drill was number 3, and for the palatine root and first mandibular premolars, the size was number 2, and for single-canal maxillary first premolars, the size was number 1.
通过解剖学方法测量第一前磨牙桩道预备前后的剩余牙本质厚度，所得数据有助于临床医生选择合适尺寸的梨形钻。
收集30颗上颌第一前磨牙和30颗下颌第一前磨牙。分别用1-3号梨形钻测量桩道预备前后根尖上方4mm处的牙壁厚度。
所有指标的测量结果呈正态分布。对于双根管上颌第一前磨牙和单根管下颌第一前磨牙，用3号梨形钻进行桩道预备后，根尖上方4mm处根壁近中及远中平均剩余厚度小于1mm。颊根差异无统计学意义（P>0.05）。腭根和下颌第一前磨牙差异有统计学意义（P<0.05）。对于单根管上颌第一前磨牙，用2号梨形钻进行桩道预备后，平均剩余近中及远中厚度小于1mm。远中壁差异有统计学意义（P<0.05）。
在桩道预备中，对于双根管上颌前磨牙的颊根，梨形钻最大尺寸为3号；对于腭根和下颌第一前磨牙，尺寸为2号；对于单根管上颌第一前磨牙，尺寸为1号。
