Dentinal Microcrack Formation after Root Canal Instrumentation by XP-Endo Shaper and ProTaper Universal: A Microcomputed Tomography Evaluation

Abstract

Aim. To evaluate dentinal microcrack formation on root canals instrumented, continuously in the body temperature, with XPendo shaper (XPES) and ProTaper Universal (PTU), by means of microcomputed tomographic (micro-CT) analysis. Methodology. Nineteen mesial roots with two separate canals (Vertucci Type IV) of extracted mandibular molars were used in this study. e root canals (N � 38) were divided into 2 groups. Group 1 (n � 19): all MB canals were instrumented with XPES. Group 2 (n � 19): all ML canals were instrumented with PTU. All roots were scanned with micro-CT before and after instrumentation. Two precalibrated examiners evaluated the cross-sectional images of each sample with DataViewer program. e dentinal microcracks (complete and incomplete) were counted in each third of the root for the preinstrumentation and the postinstrumentation images. Wilcoxin signed-rank and Mann-Whitney U tests were used for statistical analysis at a significance level of P < 0.05. Results. e number of microcracks increased significantly (P < 0.05) after instrumentation with XPES in the middle and cervical thirds. e number of microcracks increased significantly (P < 0.05) after instrumentation with PTU in the cervical third only. ere was no significant difference between the groups in the cervical and apical thirds. In the middle third, the XPES induced more incomplete microcracks than PTU (P < 0.05). Conclusion. Within the limitations of this study, there was no significant difference in the dentinal microcrack formation between XPES and PTU in the apical and cervical thirds of the root. However, XPES instrumentation induced more incomplete microcracks than PTU in the middle third of human roots.

Micro‐computed tomographic assessment of dentinal microcrack formation in straight and curved root canals in extracted teeth prepared with hand, rotary and reciprocating instruments

“…Although micro-CT is a reliable, highly accurate and non-destructive experimental imaging method (De-Deus et al 2014), recently, several micro-CT studies (Ceyhanli et al 2016, Aksoy et al 2019, Alkahtany & Al-Madi 2020 have reported that root canal preparation produced microcracks in mandibular molars. These findings increased the suspicion that root canal curvature may be one of the factors related to the creation of dentinal defects (de Oliveira et al 2017b).…”

“…2016, Aksoy et al . 2019, Alkahtany & Al‐Madi 2020) have reported that root canal preparation produced microcracks in mandibular molars. These findings increased the suspicion that root canal curvature may be one of the factors related to the creation of dentinal defects (de Oliveira et al .…”

“…Despite these advantages, even in studies that have used micro-CT analysis, the percentage of microcracks created by nickel-titanium instruments in curved roots has ranged from 0% (De-Deus et al 2014, Migu ens-Vila et al 2021 to 38% (Ceyhanli et al 2016, Aksoy et al 2019, Alkahtany & Al-Madi 2020, increasing the suspicion that root canal curvature may be one of the factors related to the development of dentinal microcracks.…”

“…2016, Aksoy et al . 2019, Alkahtany & Al‐Madi 2020), increasing the suspicion that root canal curvature may be one of the factors related to the development of dentinal microcracks.…”

Influence of obturating techniques on root dentin crack propagation: A micro-computed tomography assessment

“…The degree of microcrack formation may depend on the number of files used, taper, pitch, cross-section design, flexibility, and other metallurgical features of the instruments. [ 13 14 15 ] Obturation techniques used in endodontics force the root filling materials into the root canal. These forces may result in microcracks or craze lines, which may develop into VRFs.…”