Evaluation of the effectiveness of manual and rotary techniques in the desobturation and reinstrumentation of root canal

Introduction and Objective: This study aimed to evaluate the ability of desobturation and reinstrumentation of root canal with manual and rotary techniques. Material and methods: Sixty single-rooted incisors were selected, prepared with ProTaper® rotary system and obturated with gutta-percha and AH Plus®, using the lateral condensation technique. The teeth were restored with Cimpat® and were kept for 90 days at 37°C and 100% humidity. After this period, the teeth were divided into three groups according to the technique of desobturation and reinstrumentation. In group A, D1, D2 and D3 instruments of ProTaper® system for desobturation were used associated with F4 instrument of the same system for reinstrumentation. In group B, K type manuals instruments were employed in the desobturation and reinstrumentation. The teeth of group C (control) were not treated. After the desobturation and reinstrumentation steps of groups A and B, the teeth were radiographed at mesiodistal and labial-lingual incidences. The images were evaluated by three examiners previously trained and calibrated. Results and Conclusion: The data were statistically analyzed and showed no significant differences in the amount of the remaining filling material tested by both techniques, except from the medium third, at mesiodistal direction, in which the rotary technique was more effective. There was no difference in the cleaning of the canal walls after the desobturation and reinstrumentation. The apical third showed the largest amount of remaining material, regardless of the technique used.