Comparative analysis of apical root crack propagation after root canal preparation at different instrumentation lengths using protaper universal, protaper next and protaper gold rotary files: An In vitro study

Abstract

Aim:To compare the incidence of apical root crack formation after root canal preparation at different instrumentation lengths using ProTaper Universal (PTU), ProTaper Next (PTN) and ProTaper Gold (PTG) file systems.Subjects and Methods:Eighty-four mandibular first premolars with single and straight root canal were mounted in resin block after simulating periodontal ligaments. 1–2 mm of root apex was exposed followed by sectioning of 1 mm of root tip for better stereomicroscopic visualization. While the Control group was left unprepared, experimental groups were instrumented up to root canal length (RCL) and (RCL-1 mm) respectively using PTU, PTN and PTG. After staining the root apex with 1% methylene blue dye, stereomicroscopic images were obtained for evaluating apical root cracks. The data were analyzed using Chi-square, phi and Cramer test. The significance level was set at P < 0.05.Results:Significantly less dentinal defects were seen between PTG and PTU while there was no significant difference between PTU-PTN and PTN-PTG. Furthermore, samples instrumented up to RCL-1 mm showed lesser cracks as compared with samples instrumented up to RCL.Conclusion:PTG produced least number of cracks followed by PTN and PTU. Furthermore, instrumenting short of RCL reduced the crack formation risk.

Comparative Evaluation of the Incidence of Dentin Microcracks Following Biomechanical Preparation Using Four Different Nickel-Titanium Rotary File Systems: An In Vitro Study

“…In all the experimental groups, the apical section presented more cracks than the middle sections. This is in line with what Karatas et al [ 7 ], Nishad and Shivamurthy [ 19 ], and Chole et al [ 20 ] found in their studies. The root canal systems vary greatly in their cross-sectional anatomy, and root fracture susceptibility may be influenced by the canal morphology.…”

Oval Root Canals Prepared With Two Different Endodontic Rotary Files: An In Vitro Study Comparing the Incidence of Dental Defects

“…In all of the experimental groups, the apical section had more cracks than the middle and coronal sections. This is in line with what Karatas et al [ 14 ], Nishad and Shivamurthy [ 15 ], and Chole et al [ 16 ] found in their studies. Stress from repeated instrumentation and the inability of the thin, fragile dentin in the apical area to handle the mechanical stress caused by direct contact with the instrument tip may lead to cracks.…”

A critical analysis of research methods and experimental models to study dentinal microcracks

“…Taken together, the inconsistency among the clinical incidence of VRFs, the reported incidence of dentinal microcracks in laboratorial studies, the position of the cracks starting mostly from the outside surface of the root instead of the root canal walls (Figure 6a), and the large discrepancy of laboratory‐based results pointed out that the destructive sectioning method was inappropriate to study the influence of endodontic procedures on dentinal crack formation. Although it seems logical that such a limited methodological approach (sectioning method) to study dentinal defects in extracted/stored teeth should not be accepted by scientific journals, articles using this method are still being published (Bürklein et al, 2018; Cassimiro et al, 2018; Das et al, 2018; Fráter et al, 2020; Guha et al, 2020; Haridas et al, 2020; Jacob et al, 2019; Khoshbin et al, 2018; Kumar et al, 2020; Lin & Ghani, 2021; Nishad & Shivamurthy, 2018; de Oliveira et al, 2017a).…”