Systematic Reviews
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Stomatol. May 20, 2015; 4(2): 108-114
Published online May 20, 2015. doi: 10.5321/wjs.v4.i2.108
Effects of different root canal preparation methods on root fracture resistance: A systematic review of the literature
Xiao-Guang Li, Qing Wang
Xiao-Guang Li, Qing Wang, Laboratory of Oral Biomedicine, School of Stomatology, Shandong University, Jinan 250000, Shandong Province, China
Author contributions: Li XG and Wang Q contributed equally to this work; Li XG and Wang Q designed the research; Li XG performed the research, analyzed the data and wrote the paper; Wang Q modified the paper.
Conflict-of-interest: The authors deny any conflicts of interest related to this study.
Data sharing: Technical appendix and dataset available from the corresponding author at Participants gave informed consent for data sharing.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Qing Wang, Professor, Laboratory of Oral Biomedicine, School of Stomatology, Shandong University, 44-1 West Wenhua Road, Lixia District, Jinan 250000, Shandong Province, China.
Telephone: +86-531-88382623
Received: November 16, 2014
Peer-review started: November 16, 2014
First decision: January 8, 2015
Revised: January 25, 2015
Accepted: February 10, 2015
Article in press: February 12, 2015
Published online: May 20, 2015

AIM: To study the root fracture resistance after root canal preparation with Ni-Ti rotary instruments and stainless hand instruments by means of meta-analysis.

METHODS: Literature was researched in CNKI and CBMDisc, PubMed, CALIS, Proquest, Web of Science and 11 kinds of Chinese or English dentistry journals. Retrieval time on Internet was in all years and hand retrieval time was from January 2013 to October 2013. The literatures were selected through reading abstracts and full texts by two reviewers independently and Revman 5 software was used to analysize the literature.

RESULTS: Six articles met the inclusion criteria. According to Meta-analysis of tooth root bending properties, total standardized mean difference (SMD) was 0.63 (95%CI: -0.24-1.50, P > 0.05). That indicated there was no statistically significant between the two groups. Subgroup analysis was carried out. SMD were 2.22 (95%CI: 0.23-4.20, P < 0.05) and -0.61 (95%CI: -1.05- -0.17, P < 0.05) when the premolar teeth with a single canal or the mesiobuccal roots of molars were used as the materials for tests to compare the effects of different root canal preparation methods on root fracture resistance. That only indicated that there were statistically significant in two subgroups.

CONCLUSION: In vitro experiments, the effects on the fracture resistance of root had no statistical difference with Ni-Ti rotary instruments and stainless steel hand instruments in root canal preparation.

Keywords: Root canal therapy, Root canal preparation, Root fracture, Meta-analysis

Core tip: There were different opinions on the effect of root fracture resistance using nickel-titanium rotary instrument. The present study carried out Meta-analysis on the references related to the influences on root fracture resistance of two different root canal preparation methods. The result can provide evidence for clinical therapy.The present study confirms that the effects of root canal preparation by Ni-Ti rotary instruments or manual stainless steel instruments on root fracture resistance are not statistically significant. These two preparation methods are both safe and effective if dentin is not excessively cut under normal chewing conditions.