Sealers' radiopacity influence on radiographic interpretation of root canal fillings

Objective: To evaluate the effects of sealers' radiopacity in the detection of simulated root canal filling voids. Methods: A total of 80 extracted maxillary straight-rooted canines had its single root canals prepared equally with the classic technique before being divided into five groups. In half of the specimens a radiolucent nylon monofilament string (Ø 0,25 mm) was positioned inside the tooth and along the root canal wall to simulate a filling void. The root canals of each group were obturated using gutta-percha lateral condensation and one of the tested sealers (AH Plus®, Endométhasone®, Sealer 26® and Acroseal®) previously distinguished by different radiopacities. A non-radiopaque sealer served as negative control group. Each tooth and respective periapical E-speed film were strictly positioned in a maxillary phantom socket and exposed to X-rays using the paralleling technique. After conventional processing, the resulting images were interpreted for voids by two radiologists and two endodontists. The agreement of observers was determined by Cohen's Kappa statistic method and the differences in sensitivity, specificity, positive predictive value, negative predictive value and accuracy of diagnosis between groups were assessed using the McNemar significance probability test at 95% confidence level. Results: There were no significant differences in sensitivity and negative predictive values between groups. Root canal fillings performed with AH plus, Endométhasone and Acroseal showed higher levels of specificity, positive predictive value and accuracy when compared to Sealer 26 and control group (r>0.05).

Conclusion: Under the conditions of this ex vivo study, the radiopacity of sealers had influenced the radiographic detection of root canal filling voids.