Effect of Reciproc blue, XP‐endo shaper, and WaveOne gold instruments on dentinal microcrack formation: A micro‐computed tomographic evaluation

Abstract

The purpose of this study was to evaluate and compare the effect of Reciproc Blue (RPCB), XP‐endo Shaper (XPS), and WaveOne Gold (WOG) single‐files on dentinal microcrack formation using micro‐computed tomography (micro‐CT). Twenty‐four mesial roots (24 mesio‐buccal and 24 mesio‐lingual canals) of mandibular molar teeth were prepared using RPCB, XPS, and WOG files (n = 8/each group). The samples were scanned with micro‐CT in the pre‐ and post‐preparation. Then, before preparation and after preparation cross‐sectional images of the teeth were evaluated to detect the presence of microcracks. For each group, the number of microcracks was calculated as a percentage rate. The data were statistically analyzed using McNemar at 5% significance level (p < .05). Dentinal microcracks were observed in 25.99% (2,103 of 7,813), 31.99% (2,482 of 7,758), and 36.66% (2,836 of 7,731) of cross‐sectional images of the XPS, WOG, and RPCB groups, respectively. In all the groups, all the dentinal microcracks seen in the post‐treatment cross‐sectional images were present in the corresponding pre‐treatment images. Within the limitations of this study, the XPS, WOG, and RPCB files did not cause new dentinal microcrack formation or propagation of existing dentinal microcracks.

Influence of voxel size on dentinal microcrack detection by micro-CT after root canal preparation

“…The highest number of slices in images at 5 μm may have contributed to better capacity to detect the thinner continuity of microcracks, since micro-CT high-resolution scans were recommended to provide more accurate analysis of microstructures. 30 On the other hand, considering that statistical significance is dependent on the sample size 35 and that each cross-sectional image was used for statistical qualitative tests, 9,12,14 the larger number of slices observed at the higher resolution (5 µm) may have contributed to the statistical significance observed in the analyses before and after preparation with HEDM performed at 5 um.…”

“…11 Owing to contrasting information in the literature, there is still no consensus on whether root canal preparation using continuous or reciprocating motion induces the formation of microcracks. 4,9,12,13,14 High precision tools are required to detect microcracks, such as micro-computed tomography (micro-CT), which allows the defect to be located with great precision. 9 Microcracks can be evaluated for endodontic instrumentation at different resolutions, using scanning voxel sizes of 10 μm, 14 14 μm, 15,16 17.42 to 21 μm, 9,12,17 and 30 μm.…”

“…4,9,12,13,14 High precision tools are required to detect microcracks, such as micro-computed tomography (micro-CT), which allows the defect to be located with great precision. 9 Microcracks can be evaluated for endodontic instrumentation at different resolutions, using scanning voxel sizes of 10 μm, 14 14 μm, 15,16 17.42 to 21 μm, 9,12,17 and 30 μm. 13,18 Although most studies using micro-CT have not observed any correlation between root canal preparation with NiTi files and microcrack formation, 14,15,16,17,18 some studies have correlated the presence of microcracks with root canal preparation using rotary NiTi files.…”

“…9 Microcracks can be evaluated for endodontic instrumentation at different resolutions, using scanning voxel sizes of 10 μm, 14 14 μm, 15,16 17.42 to 21 μm, 9,12,17 and 30 μm. 13,18 Although most studies using micro-CT have not observed any correlation between root canal preparation with NiTi files and microcrack formation, 14,15,16,17,18 some studies have correlated the presence of microcracks with root canal preparation using rotary NiTi files. 12,13 ProDesign Logic -PDL (Easy Equipamentos Odontológicos, Belo Horizonte, Brazil) are Ni-Ti files with control memory (CM).…”

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

“…Currently, our digital search revealed 27 confirmatory studies using micro‐CT imaging technology to evaluate the frequency of dentinal microcracks after root canal preparation in extracted/stored teeth published in peer‐reviewed journals from research groups worldwide (Table 2). Eighteen of them found no new dentinal microcracks (Arumugam & Yew, 2021; Bayram et al, 2017a, 2017b; Belladonna et al, 2021; Cassimiro et al, 2017; De‐Deus et al, 2014, 2015, 2016, 2017c; Martins et al, 2021; Miguéns‐Vila et al, 2021; de Oliveira et al, 2017a, 2017b; Rödig et al, 2019; Stringheta et al, 2019; Ugur Aydin et al, 2019; Vieira et al, 2020; Zuolo et al, 2017), whilst nine studies reported the development of new defects after canal preparation (Aggarwal et al, 2021; Aksoy et al, 2019; Alkahtany & Al‐Madi, 2020; Çakici et al, 2019; Ceyhanli et al, 2016; Jain et al, 2018; Jamleh et al, 2021; Mandava et al, 2018; Tsenova‐Ilieva et al, 2019).…”