Katz A, Kaffe I, Littner M, Tagger M, Tamse A
Department of Endodontology, Tel Aviv University, Israel.
J Endod. 1990 May;16(5):211-3. doi: 10.1016/S0099-2399(06)81671-7.
National and international standards require that gutta-percha cones be sufficiently radiopaque to be distinguished from natural structures such as dentin and to permit evaluation of the density of the root canal filling. Discs, 1-mm thick, made from 15 commercial and experimental brands of gutta-percha cones, were tested for their compliance with the requirements. The radiopacity of 1-mm thick root dentin slabs was similarly measured with a photo-densitometer. All radiographs were made on D-speed occlusal film and replicated on E-speed film. The mean radiopacity of the gutta-percha discs on D-speed film was 7.26 mm of aluminum equivalent and 7.53 mm on E-speed film, greatly exceeding the minimal requirement of 3 mm. The difference in the values obtained with the two film types was not significant, suggesting that E-speed films may be used for the test. Dentin slabs were uniform in their radiopacity, equivalent to 1 mm of aluminum, confirming previous findings. In view of complaints of insufficient clinical performance, the present minimal requirement for radiopacity of gutta-percha cones seems too low.
国家和国际标准要求牙胶尖具有足够的射线不透性，以便与牙本质等天然结构区分开来，并允许评估根管充填的密度。对由15种商业和实验品牌牙胶尖制成的1毫米厚的圆盘进行了是否符合要求的测试。用光电密度计同样测量了1毫米厚的牙根牙本质板的射线不透性。所有X光片均在D速咬合片上拍摄，并在E速片上复制。牙胶圆盘在D速片上的平均射线不透性相当于7.26毫米铝，在E速片上为7.53毫米，大大超过了3毫米的最低要求。两种胶片类型获得的值的差异不显著，这表明E速片可用于该测试。牙本质板的射线不透性均匀，相当于1毫米铝，证实了先前的研究结果。鉴于对临床性能不足的投诉，目前牙胶尖射线不透性的最低要求似乎过低。
