Analysis of preparation time, wear, transportation and centering ability of Flexofile and Prodesign® M manual instruments in curved root canals preparation

OBJECTIVE: This in vitro study aimed to evaluate preparation time, wear, transportation, and centering ability of two manual instruments, namely Flexofile and Prodesign® M, in curved root canal preparation.METHODS: Forty mesiobuccal and mesiolingual canals of the first or second lower molars were used, with standard length, degree, and radius of curvature among all samples. The canals were randomly divided into two experimental groups (n=20) according to the preparation instrument analyzed. The preparations were performed by a single operator. The preparation time was controlled, and the values obtained were analyzed. To verify the wear, transportation, and centering ability of the instruments, tomography images were taken before and after instrumentation. The analysis was performed using axial sections previously identified at 2 mm below the tooth apex with the aid of the OnDemand3DTM Dental program. For statistical analysis, Student’s t-test was used, with a significance level of 5%.RESULTS: The time required to prepare root canals was lesser using Prodesign® M instruments than using Flexofile instruments. Regarding tooth wear, no statistical difference was observed. However, Flexofile instruments had a low centralization capacity in root canal preparation, and there is a trend of transport in the mesial direction of the root canal.CONCLUSION: Although no statistical difference was observed between the two instruments, the Prodesign® M instruments had a better cantering ability in the preparation. As well as, the time required to prepare the root canals was inferior when Prodesign® M was used.