The influence of ProTaper and WaveOne on apically extruded debris: A systematic review and meta-analysis

BACKGROUND: Apically extruded debris produced during root canal preparation can induce postoperative inflammation and subsequent failure of root canal treatment. Therefore, debris production must be reduced to improve the outcome of root canal treatment. AIM: This study aimed to provide a theoretical basis for the improvement of root canal treatment by comparing the difference in the amount of apically extruded debris produced during the root canal preparation of extracted human teeth with ProTaper Universal (PTU), ProTaper Next (PTN), and WaveOne (WO). MATERIALS AND METHODS: On March 30, 2017, three researchers searched five electronic databases (PubMed/Medline, Cochrane, Science Direct Online, Embase, and Web of Science) with no time limitations. Only articles written in English were retrieved, and 150 articles were obtained. Then, the three researchers independently selected articles in accordance with previously established inclusion and exclusion criteria, and inconsistent results were discussed. Data were analyzed through meta-analysis for standardized mean difference (SMD). RESULTS: Eight studies met the inclusion criteria and were subjected to qualitative analysis. Four articles showed that PTU produced higher amounts of apical debris than WO; two articles showed that PTU produced lower amounts of apical debris than WO; and three articles showed that PTN produced lower amounts of apical debris than WO. Moreover, one article demonstrated that PTU produced higher amounts of apical debris than PTN. A meta-analysis showed that PTU and WO did not produce significantly different amounts of apically extruded debris: SMD = −0.26, Z = 0.50 (P > 0.05). PTU produced lower amounts of apically extruded debris than WO: SMD = −4.98, Z = 2.79 (P < 0.05). However, results were significantly heterogeneous among all the included studies (I(2)= 97%). No significant difference was found between PTU and WO in the amounts of apically extruded debris: SMD = 0.47, Z = 1.06 (P > 0.05). CONCLUSION: Currently available evidence shows that PTN can produce lower amounts of apical debris than WO (P < 0.05). Moreover, the amounts of apically extruded debris produced by PTU and WO are not significantly different (P > 0.05). Nevertheless, given the limited number of studies reviewed, a definitive conclusion cannot be reached.