Effects of photobiomodulation therapy on implant stability and postoperative recovery: a systematic review and meta-analysis

The purpose of this study was to systemically analyse the effects of photobiomodulation therapy (PBMT) on implant stability and postoperative recovery. Electronic searches on MEDLINE (PubMed), Cochrane Library, EMBASE, and Web of Science were completed independently by two researchers in February 2021, and a manual search was performed for the references of the included articles. The primary outcome was implant stability. The secondary outcome was postoperative recovery, including postoperative pain, recovery of peri-implant hard tissue (marginal bone loss and bone mineral density), facial swelling, and peri-implant clinical parameters. Twenty studies were finally obtained (17 randomised controlled, and 3 controlled clinical studies). Meta-analysis revealed that PBMT increased implant stability at 10 days after insertion (MD 2.27, 95% CI: 0.40 to 4.13, P = 0.020), and reduced marginal bone loss at 6 months after insertion (MD -0.16, 95% CI: -0.23 to -0.08, P < 0.001). However, no significant improvements were noted in implant stability two weeks (P = 0.070), three weeks (P = 0.090), six weeks (P = 0.050), and 12 weeks (P = 0.080) after insertion. Qualitative analysis suggested that PBMT could not alleviate postoperative pain, increase bone mineral density, or improve peri-implant clinical parameters. It was effective only in reducing facial swelling. This study suggests that the effects of PBMT on implant stability and postoperative recovery may be limited.