关键词: 根管, 数字化X线片, 偏位投照

Abstract:

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.

Key words: root canal；digital X-ray；dyssynmetry projection