不同投照角度数字化X线片检测上颌第一前磨牙根管状况的体外研究

Study on the muticanals detective rate in the first premolar with different angle digital X-ray figures

目的探讨不同投照角度数字化X线片对上颌第一前磨牙非单根管检出率的影响,从而选出最佳投照角度。方法收集从2006年10月至2007年10月中国医科大学口腔医学院口腔外科拔除的上颌第一前磨牙共计62颗灌制成标准牙列模型。分别采取正位、近中倾斜10°和20°角、远中倾斜10°和20°角5个角度进行投照,采集数码X线片并存入电脑,阅片后评定出非单根管牙的牙片。以横断离体牙手术显微镜下记录根管数为金标准,进行不同投照角度与金标准的根管检出一致性分析,从而确定最佳投照角度。结果上颌第一前磨牙近倾10°投照时非单根管牙检出率与显微镜下结果的一致性有统计学意义。结论上颌第一前磨牙近倾10°投照,有利于发现非单根管牙。

Objective To study the muticanals detective rate of the maxillary first premolar with different angle digital X-ray figures, and screen out the best projection angle. Methods A total of 62 maxillary first premolar tooth pulled out at the School of Stomatology, China Medical University were collected from October 2006 to October 2007. They were then fixed in dent models. The first premolar dent models were projected with orthotopic, mesioclination 10° , 20° , distalclination 10°, 20°. The digital X-ray films were collected and stored into computer and were read by two dentist and muticanals tooth were evaluated. The number of roots intersected from the ex vivo teeth in the eyesight of the operating microscope were recorded and it was regarded as the gold standard. SPSS11.5 software was used to analyse the consistency of muticanals detective rate between each of five different projection angle digital X-ray figures and the gold standard in the first premolar,and the diagnostic tests were conducted to screen out the best projection angle. Results On maxillary first premolar the consistency of muticanals detective rate had statistical significance compared with the gold standard （P 〈 0.01）when the mesioclination 10° projection was deployed. Conclusions Mesioclination 10° projection for maxillary first premolar is recommanded for detecting muticanals tooth.