Topography of four different endodontic rotary systems, before and after being used for the 12th time

Abstract

Root canal preparation may damage NiTi instruments resulting in wear and deformation. The aim of this study was to make a comparative evaluation of the surface topography of the cervical third of four different rotary systems, before and after being used twelve times, in 1.440 resin blocks with simulated root canals with standardized 45° curvatures, and analyzed by atomic force microscopy AFM. The blocks were divided into four groups and prepared according to the manufacturers recommendations: Group 1--K3®; Group 2--Protaper Universal®; Group 3--Twisted Files® and Group 4--Biorace®. After each preparation, the instruments were washed and autoclaved. A total of 240 instruments were selected, being 30 new instruments and 30 after having been used for the 12th time, from each group. These instruments were analyzed by AFM and for quantitative evaluation, the mean RMS (Root mean square) values of the cervical third of the specimens from the four groups were used. The result showed that all the rotary files used for the 12th time suffered wear with change in the topography of the cervical region of the active portion of the file (ANOVA p < 0.01). Classifying the specimens in increasing order, from the least to the greatest wear suffered, Group 3 (2.8993 nm) presented the least wear, followed by Group 4 (12.2520 nm), Group 1 (36.0043 nm) and lastly, Group 2 (59.8750 nm) with the largest amount of cervical surface wear.

Effect of irrigation on surface roughness and fatigue resistance of controlled memory wire nickel‐titanium instruments

“…, Yamazaki‐Arasaki et al . ). Thus, it is unreliable to determine the surface irregularities of solution‐immersed files caused by irrigation.…”

Topographic and Chemical Analysis of Reciprocating and Rotary Instruments Surface after Continuous Use

“…The microcavities after use may be associated with loss of Ni and Ti atoms (22). The chemical composition and geometry of NiTi alloys has a binary intermetallic and equiatomic bonding force between Ni and Ti (22), which may be changed by a thermodynamic process, or/and when submitted to certain stress, as root canal preparation (23).…”

Noncontact three-dimensional evaluation of surface alterations and wear in NiTi endodontic instruments

“…The safe clinical use of the "single use" Reciproc and WaveOne instruments for shaping multi-rooted teeth has been discussed. According to Yamazaki-Arasaki et al, 30 the single use of reciprocating instruments can actually refer to the use in three or four root canals of the same molar or of the same patient. Nevertheless, it was previously reported that although both instruments can be used in 3-4 root canals, the canals can be complex and tortuous, increasing fatigue.…”