Comparação de sistemas rotatórios e manuais na instrumentação dos canais mésio-vestibular e disto-vestibular de segundos molares decíduos superiores: análise por microtomografia computadorizada

Abstract

Introduction: Maintaining primary teeth in functional condition until their natural shedding is essential for proper oral development in children. Pulpectomy is a widely recommended treatment option in cases of irreversible pulp damage resulting from extensive carious lesions or dental trauma. However, the complex anatomy of the root canals of primary teeth, especially the upper second molars, poses a significant clinical challenge during the endodontic instrumentation phase. Objectives: To compare the effects of different endodontic instrumentation systems—rotary and manual—on the mesio-buccal and disto-buccal canals of artificial upper deciduous second molars, using computed microtomography analysis. Methodology: Thirty-six artificial teeth were used, divided into three experimental groups (n=12), according to the system employed: Sequence Baby File NiTi (BF), ProDesign Logic 2 (LOGIC), and K-type manual files (MANUAL). After determining the working length, the specimens were instrumented following the manufacturers’ recommendations and subjected to computed microtomography before and after biomechanical preparation. Changes in root canal volume in the cervical, middle, and apical thirds were evaluated, as well as the loss of dentin wall thickness. The data were subjected to statistical analysis, considering a significance level of 5%. Results: the results demonstrated that all systems caused changes in the internal anatomy of the root canals, with differences in the pattern of volumetric increase and dentin wear among the groups. The BF and MANUAL systems exhibited greater volumetric changes in specific regions of the canals, while the LOGIC system demonstrated more homogeneous and conservative behavior. Regardless of the system used, greater wear was observed in the apical third of the mesio-buccal canal, indicating greater structural vulnerability in this region. Conclusion: All systems evaluated are capable of performing biomechanical preparation of root canals in deciduous teeth; however, significant differences exist regarding the preservation of remaining dentin structure, reinforcing the need for careful selection.