Randomized controlled trial on the effectiveness of absorbable collagen sponge after extraction of impacted mandibular third molar: Split-mouth design

Background: The purpose of this study was to compare the effectiveness of absorbable collagen sponge insertion in tooth extraction sites for socket healing of the impacted mandibular third molar. Methods: Thirty-six patients with bilateral mandibular impacted third molars based on Pell-Gregory and Winter classification were included in this study. This study was a randomized clinical trial utilizing a split-mouth design with one side assigned as collagen sponge insertion and the other side assigned as the control. Post-operative clinical complications, periodontal integrities, and radiographic outcomes were assessed at 1, 2, and 14-weeks post operatively. Results: Five patients were excluded during the follow-up period due to loss of follow-up. The study was conducted on 31 patients in total. The mean VAS score of collagen sponge insertion side at 1 week post operation was 1.42 ± 1.26, which was significantly lower than the control side (P < 0.05). The mean probing depth of collagen sponge insertion side at 2-week post operation was 5.55 ± 2.28 mm, which was significantly lower than the control side (7.13 ± 1.86; P < 0.05). Other various measurements including radiographic outcomes showed no significant group differences. Conclusions: Placement of collagen sponge after extraction of mandibular impacted third molar reduced early stage post-operative complications and enhanced initial healing of soft tissues and periodontal defects. Trial registration: This study was retrospectively registered at the WHO ICTRP platform and Clinical Research Information Service, KCT0003363. Registered 21 Sep 2018.