RESUMO
OBJECTIVE: This study evaluates whether endodontic cavity access into molars influences the chemomechanical preparation of curved root canals. MATERIALS AND METHODS: Twenty mesiobuccal canals of maxillary molars were randomly divided into two experimental groups (n = 10), according to the type of endodontic access analyzed (conventional and minimally invasive). The preparations were made by a single operator, and the canals, after access, were prepared with Logic system (0.25, 0.04 taper) along the working length. Samples were scanned before and after canal preparation (SMX-90CT Plus (Shimadzu® microtomograph operated with 70 kV, 100 uA, FOV (XY) 13.3 mm, FOV (Z) 7.0 mm, and voxel size 0.013 mm/Pix)) to match canal volumes. Images were analyzed to evaluate surface areas, transport, and centralization at 3 mm from the canal entrance and 3 mm from the apex (OnDemand3DTM Dental software). Student's t test with a significance level of 5% was used for the statistical analysis. RESULTS: Regardless of the position of the analyzed canals, there was no difference in the prepared area regarding the transport and centralization of the endodontic instrument between the two types of cavity accesses performed. CONCLUSIONS: The conventional and minimally invasive access did not influence the action of the 0.25 and 0.04 taper instrument during the curved root canal preparation. CLINICAL RELEVANCE: The type of endodontic access did not influence the action of the rotary instrument during the curved root canal preparation.