Adjunctive Nd Laser Therapy and Zinc L-Carnosine in the Surgical Treatment of Infrabony Defects: A Prospective Randomized Clinical Trial

Introduction
Severe infrabony periodontal defects represent a major therapeutic challenge because persistent bacterial contamination and inflammation may compromise periodontal regeneration and long-term tooth retention. Adjunctive approaches aimed at improving surgical decontamination and postoperative wound healing may enhance clinical outcomes. This prospective randomized clinical trial evaluated the effectiveness of open flap debridement combined with Nd laser therapy with or without adjunctive zinc L-carnosine in the treatment of severe infrabony defects.

Methods
A prospective randomized clinical trial was conducted at the Department of Dentistry, University of Bari. Twelve patients presenting severe infrabony periodontal defects requiring periodontal surgery were randomly allocated into two groups (n = 6). Group A underwent open flap debridement with Nd laser decontamination 25 Hz, 3.5 W, 180 mJ/pulse. Group B received the same protocol followed by application of zinc L-carnosine cream into the periodontal pocket using a sterile syringe. Probing depth, clinical attachment level, bleeding on probing, plaque index, postoperative pain, and wound healing, were assessed at baseline and follow-up.

Results
All patients completed the study without postoperative complications. Both groups showed significant improvements in probing depth, clinical attachment level, bleeding on probing, and plaque index. Compared with the Nd-only laser group, patients receiving adjunctive zinc L-carnosine demonstrated improved soft-tissure healing, lower postoperative pain, and greater reduction in inflammatory signs. No adverse events related to laser therapy or zinc L-carnosine application were observed.

Conclusions
Within the limitations of this prospective randomized clinical trial, Nd laser-assisted periodontal surgery achieved favorable clinical outcomes in severe infrabony defects. Adjunctive zinc L-carnosine further improve wound healing and postoperative comfort, supporting its potential as a local adjunct in regenerative periodontal therapy. Larger randomized controlled trials with longer follow-up are required to confirm these findings.