The Effect of Antimicrobial Photodynamic Therapy on the Healing of the Post-Extraction Socket of the Mandibular Third Molar: A Randomized Clinical Study

<b>Objectives</b>: We aimed to evaluate the efficacy of antimicrobial photodynamic therapy (aPDT) in promoting wound healing after the surgical removal of inferior third molars. <b>Methods</b>: Patients in need of unilateral mandibular third molar extraction were randomly assigned to either a test or control group before surgery. During the test, a photoactive substance activated with laser light (20 mW, 660 nm) was applied to the post-extraction site for 60 s before suturing to promote healing and disinfection. The control group did not receive any laser applications after tooth removal. The probing pocket depth (PPD), bleeding on probing (BOP), plaque index (PI), gingival recession (REC), and levels of clinical attachment loss (CAL) before surgery (T0), 14 days after surgery (T1), and after 3 months after surgery (T2) were evaluated for the adjacent second molar. Post-operative swelling, pain (VAS index), the number of painkillers taken, alveolar probing, and Landry's healing index were recorded at T1. <b>Results</b>: Sixty-five patients, aged between 14 and 39 years, were assigned randomly to test (n = 32) or control (n = 33) groups. Five dropouts occurred. Post-operative swelling and the VAS index were significantly lower in the test group compared to the control (<i>p</i> = 0.002 and <i>p</i> = 0.04, respectively). All periodontal indexes except recession significantly worsened at T1 in both groups. After three months, a significant improvement for PPD, CAL, and PI was recorded in the test group compared to the control (<i>p</i> = 0.001). <b>Conclusions</b>: According to the results of this study, the use of aPDT seems to have a beneficial effect on post-operative swelling and pain, as well as the plaque index, in the short-term follow-up.