两种根尖片诊断牙根吸收的比较

目的探讨数字化根尖片和普通根尖片在评价牙齿长度和牙根吸收方面的差异。方法选取20颗离体上颌恒中切牙，磨除根尖部约0．5mm，以模拟牙根吸收。分别从6个投照角度拍摄普通根尖片和数字化根尖片。配对秩和检验比较数字化根尖片和普通根尖片反映牙齿长度和牙根吸收的差异。结果在同一种X线投照角度下，数字化根尖片与普通根尖片牙齿长度影像误差的差异有统计学意义（P〈0．05），牙根吸收影像误差的差异无统计学意义（P〉0．05）。结论数字化根尖片上牙齿影像长度比普通根尖片更接近牙齿的实际长度。数字化根尖片与普通根尖片在牙根吸收的测量诊断上差异无统计学意义。

The reliability of digital periapical films in diagnosis of root resorption

Objective To investigate the difference between digital periapical film and conventional film in the evaluation of tooth length and root resorption. Methods A standard for root resorption in vitro was developed based on 20 extracted upper central incisors. Digital periapical films and conventional periapical films were taken before and after the process of simulating root resorption at six different projection angles respectively. The tooth length and root resorpiton were measured on these films. The results were analyzed by paired-samples rank sum test. Results Significant difference on tooth length measurement was found between two types of films on the same projection angle. No significant difference on the length of root resorption calculated on digital and conventional films was found. Conclusions The accuracy of the digital periapical film was greater than that of conventional periapical films. The conventional periapical film can still be used in the evaluation of root resorption.