Shaping ability of rotary or reciprocating systems for oval root canal preparation: a micro-computed tomography study

Abstract

Objectives: To evaluate the shaping ability and cleaning after oval root canal preparation using one or more instruments in reciprocating or rotary motion. Materials and methods: Oval-shaped mandibular incisors were selected, based on the radiographic diameter (2 ≤ diameter ratio ≤ 4), and assigned according to root canal preparation (n = 18): single-file (Reciproc R40); two reciprocating files (Unicone size 20 and 40,.06 taper) or Mtwo rotary files until a size 40,.06 taper instrument. Root canal preparations were performed using an open root canal model. Scanning was performed before and after preparation using SkyScan 1176 with a voxel size of 17.42 μm. Volume, percentage of debris, and percentage of uninstrumented surface were analyzed in the entire root canal and in each root canal third. Data were compared using ANOVA and Tukey or Kruskal-Wallis and Dunn tests (α = 5%). Results: The initial volume were similar among the groups (p >.05). Unicone preparation was associated with higher debris, increase in root canal volume and uninstrumented surface in entire root canal and in the middle third (P