Shaping ability of rotatory or reciprocating instruments in curved canals: a micro-computed tomographic study

Abstract

This study aimed to compare apical transportation, centering ratio, and working time during root canal preparation with Wizard Navigator (WN), WaveOne (WO), or ProTaper Universal (PT) and to describe deformation and fracture of these instruments. Thirty-six mesiobuccal roots from maxillary molars were micro-computed tomography (micro-CT) scanned and then sorted into three groups (n = 12): Wizard Navigator (WN), WaveOne (WO), and ProTaper Universal (PT). The root canals were prepared using WN, WO, or PT; the time of each canal preparation was timed; and the specimens were micro-CT re-scanned. The instruments were submitted to scanning electron microscopy (SEM) before and after their use. The data on canal transportation at 1, 2, 3, 4 and 5 mm and preparation time were analyzed by the Kruskal-Wallis test, followed by the Mann-Whitney U test. The centering ratio was analyzed by ANOVA, followed by Tukey's test. Both instrument deformation and fracture were described. Apical transportation was similar among groups at 1, 2, 3 and 4 mm. The WO group showed higher canal transportation at 5mm than the other groups (p = 0.03). There was no significant difference in centering ratio among the groups. Preparation time in the WO group was significantly lower than in the other groups (p = 0.004). Small differences were observed in the surface area of all instruments. The WN, WO, and PT groups had a similar centering ratio without procedural errors or significant structural changes. At 5 mm from the apex, the WO group showed the largest canal transportation toward the furcation and root canal preparation was faster than in the WN and PT groups.

Comparative analysis of mechanical properties of differently tapered nickeltitanium endodontic rotary instruments

“…Consequently, Group 0.04 better maintained the original canal shape in comparison to Group 0.06, most probably because of its flexibility, as shown in this study. This finding is consistent with several studies showing that an instrument with a larger taper generates larger values of transportation 49,50) .…”

Root canal preparation using micro-computed tomography analysis: a literature review

“…1,2,3,4,5 Since 2012, new protocols for biomechanical root canal preparation have been developed using nickeltitanium (NiTi) instruments, whose flexibility and resistance to torsion allow their use in a continuous rotating movement; these in turn reduce the working time, operator fatigue, and the risk of operative accidents. 6,7,8,9,10,11,12,13,14,15 NiTi instruments have been developed with various geometric conformations, 8 with the most significant design difference being the taper with conicity ranging from 2% to 12%, compared to the standard 2% taper of stainless steel instruments established by ANSI/ADA in 1976 and updated in 1982. 8 NiTi rotary instruments were first commercialized in the 1990s, and since then about 700 studies have been published in journals indexed in PubMed before June 2010.…”

Centering ability, canal transportation and surface modifications of ProTaper F2 and F3 used in continuous rotation and reciprocating motion in curved root canals

“…The concept of a single-file technique using PT F2 was introduced by Yared (2008). After that, other studies have evaluated the same protocol showing favorable results with respect to centering ability of the reciprocant cinematic 28,29,30 . In the present study, F3 instrument was used in Group III, providing greater apical final enlargement when compared to the other studies 11,26,31 .…”