Antimicrobial Efficacy of NaOCl and PDT in Primary Root Canal Treatment (PDT-NaOCl)

This is an in vivo randomized clinical study designed to evaluate the antimicrobial effect of root canal disinfection protocols during primary root canal treatment. The study focuses on the reduction of viable intracanal bacteria following irrigation with sodium hypochlorite, with or without adjunctive photodynamic therapy. Eligible participants requiring primary root canal treatment will be enrolled and randomly allocated to one of the study groups according to the approved protocol. Under rubber dam isolation, root canal treatment will be performed using standard endodontic procedures. Intracanal microbiological samples will be collected using sterile paper points before and after the assigned disinfection protocol. The collected samples will be processed for culture-based microbiological analysis, and bacterial reduction will be assessed by comparing viable bacterial counts before and after the intervention. Photodynamic therapy will be used as an adjunctive disinfection method in the relevant study group. This technique involves the use of a photosensitizing agent followed by activation with light of an appropriate wavelength to produce an antimicrobial effect. Sodium hypochlorite irrigation will be used as the standard chemical disinfection method. For ethical and clinical safety reasons, all participants will receive completion of treatment according to accepted endodontic standards. Postoperative pain will be recorded after treatment using a visual analogue scale. The study is intended to determine whether adding photodynamic therapy to sodium hypochlorite improves intracanal bacterial reduction compared with sodium hypochlorite irrigation alone during primary root canal treatment.