Comparação entre instrumentação rotatória e manual em biopulpectomias de molares decíduos: um ensaio clínico aleatório duplo-cego de 9 meses

Abstract

Purposes: To compare, through clinical and radiographic analyzes, the instrumentation time and the efficacy of rotary and hand instrumentation; the quality of obturation and final restoration in the biomechanical preparation of root canals of primary mandibular molars during the biopulpectomy procedure; and the resorption speed of root filling material in comparison with rizolisis. Method: After the approval of the Institutional Review Board, an interventional, quantitative, and longitudinal study was performed with 40 children with mean age of 7.6 years old, through the biopulpectomy treatment and the clinical and radiographic follow-up during 3, 6 and 9 months. The teeth were randomly divided into the hand (biopulpectomy with Kerr hand files) and rotary (biopulpectomy with Hyflex EDM® rotary files) groups, and treated by the conventional obturation and restoration techniques in a single session. Clinical success was considered in the absence of pain, sensitivity to percussion, abscess/fistula and pathological mobility. Radiographic success was considered when the teeth presented lack of interradicular radiolucent area and periapical lesion, as well as sound periodontal ligament and proper length of obturation. The evaluation of restoration followed the United States Public Health Service (USPHS) criteria. Data were statistically assessed using the Statistical Package for the Social Sciences (SPSS), version 20.0, through descriptive and inferential (Pearson´s chi-squared and Mann-Whitney) tests and generalized estimating equations (GEE), at 5% of significance. Results: Instrumentation time was significantly increased in the hand group than rotary one (20.24 and 11.30 minutes, respectivelly; p= 0.001). There was no statistically significant difference between the groups concerning the clinical and radiographic success over the 9 months of follow-up. Irrespective of the group, there was a statistically significant correlation between the retention of restorations and the presence of periapical lesion, in which the teeth with failure of restorations presented more periapical lesions at 3, 6 and 9 months. Conclusion: Both instrumentation techniques were effective, with no differences between the clinical and radiographic success rates and the obturation quality, althoug rotary instrumentation has allowed the execution of the treatment in a shorter clinical time. The root filling material resorbed in the same speed of the rizolisis during the nine months of follow-up Besides, the retention of restoration was as much important as the root canal instrumentation with regards to the treatment prognosis.