Photodynamic therapy for endodontic treatment of primary teeth: A randomized controlled clinical trial

This study aimed to evaluate the reduction in bacterial load following conventional endodontic treatment with and without antimicrobial photodynamic therapy (a-PDT) in primary teeth.

Thirty primary anterior teeth with a diagnosis of pulp necrosis were selected. Patients were randomly allocated to two groups as follows: Group I, patients undergoing conventional root canal therapy (n = 15) and Group II, patients undergoing conventional root canal therapy combined with antimicrobial PDT (n = 15). For PDT, methylene blue, at a concentration of 0.005 %, was used as the photosensitizing agent, which was applied to the interior of the canal with a sterile paper cone for 3 min, followed by the administration of laser light for 40 s (wavelength: 660 nm, energy density: 4 J/cm², power: 100 mW), delivered in direct contact at the entrance to the root canal. Two microbiological samples of the intra-canal content were taken (one before and one immediately after treatment in both groups) using paper cones. Clinical follow-up involved the investigation of fistulas and mobility and was performed 1- and 3 months after treatment. Data were statistically analyzed.

The reduction in bacterial load was 93 % in Group I and 99 % in Group II, with no statistically significant difference.

Conventional treatment combined with antimicrobial PDT with parameters used in this study proved effective but presented equal efficacious capability to conventional endodontic treatment alone.

The use of PDT has been studied in endodontic treatment protocols in permanent teeth. However, clinical trials in deciduous teeth are necessary for establishing the effectiveness and parameters of this application. The present study analyzes the results of PDT in the endodontic treatment of deciduous teeth.