Evaluate four different ways in diagnosing tooth cracks

Abstract

Introduction The aim of this study was to evaluate four different ways in diagnosing tooth cracks, which may provide certain theoretical bases for early diagnosis of cracks. Methods 123 freshly extracted human teeth were collected in the Stomatology Hospital of Guangzhou Medical University, Guangzhou, China. Three observers examined the cracks of the crowns with naked eye, microscope, methylene blue dye, and methylene blue dye with magnification microscopic examination methods independently. Two criteria (crack lines appeared in enamel and dentin) were used to diagnose teeth cracks, and statistical analysis was performed using the SPSS and MedCalc statistical software. Kendall's W was conducted to assess the agreement among the three observers in each detection method. Sensitivity, specificity, positive predictive value, negative predictive value, and the area under the curve (AUC) drawn in terms of sensitivity and (1-specificity) were calculated to evaluate the diagnostic value of four different methods. Results 3 teeth were excluded because of the visual fatigue of the observer, and there were 120 teeth left. The method of methylene blue plus microscope had the lowest value of Kendall's W in criterion 1 and 2. The overall AUC values were more than 0.7 in both the microscopic and methylene blue plus microscopic method according to criterion 1 and 2, and in the method of naked-eye according to criterion 2. The pairwise comparison between A, B and C had statistical difference in the method of naked-eye, microscope and methylene blue plus microscope in criterion 2 ( P < 0.05). Conclusions Detecting tooth crack with the method of methylene blue plus microscope have a higher consistency among different experienced endodontists. Microscope and methylene blue dye with magnification microscopic examination were effective methods to diagnosis tooth crack. More cracks can be detected by experienced endodontists, and the difference persisted even with the use of microscopes or methylene blue dye.