Is lentulospiral the best option for root canal filling of endodontically treated primary teeth? A systematic review and meta-analysis.

Purpose: To evaluate the quality of root canal filling of primary teeth using lentulospiral in comparison with other instruments.

Methods: Electronic databases (PubMed/MEDLINE, Scopus, TRIP, LILACS, and CENTRAL Cochrane) were searched up to Jan 2021. Clinical trials that compared the quality of root canal filling of endodontically treated primary teeth using lentulospiral with other instruments were included. Two reviewers independently selected the studies, extracted data, and assessed the risk of bias. Two outcomes were considered: inadequate root canal filling (under or overfilling) and presence of voids. Conventional meta-analyses were performed using a fixed-effects model. Statistical analyses were performed using RevMan5.3 at a significance level of 5%.

Results: Of the 68 potentially relevant studies, eight were selected for full-text analysis, and three were included in the systematic review. The use of syringes resulted in a lower risk of presence of voids in the root canal filling compared to the use of lentulospiral (RR: 0.62 95% CI 0.45; 0.85). However, there was no difference between lentulospiral and bi-directional spiral (RR:1.17 95% CI: 0.90; 1.51). There was no significant difference between lentulospiral and syringes (RR: 1.37 95% CI 1.00; 1.87) considering the length of the root canal filling. The use of bi-directional spiral had a higher risk of inadequate root canal filling compared to the use of lentulospiral (RR: 1.75 95% CI: 1.12; 2.74). Two studies were at "high", and one study at "unclear" risk of bias in the key domains.

Conclusions: There is insufficient scientific evidence showing the superiority of using lentulospiral for the root canal filling in endodontically treated primary teeth. Due to the limited level of evidence, professionals may opt to choose the instrument based on their preferences.