Comparative Analysis of Intra-canal Photodynamic Therapy With Different Photosensitizers on Periapical Healing

Root canal therapy seeks to eradicate root canal infections and prevent their recurrence. Given the intricate nature of the root canal system and biofilm formations, achieving complete disinfection with current techniques is challenging. Nevertheless, it has been noted that residual microorganisms within the root canal contribute significantly to either the healing or the development of apical periodontitis. Various methods, such as sonic and ultrasonic activation, laser application, and PDT (Photodynamic Therapy), have been proposed in literature to enhance root canal disinfection.

Several in vivo and in vitro studies have demonstrated a significant reduction in bacterial load following PDT adjunct to root canal therapy. However, long-term in vivo outcomes of PDT as a complement to root canal disinfection remain scarce. From an endodontic perspective, many photosensitizers have not undergone clinical evaluation. This study seeks to assess the impact of PDT using different photosensitizers on in vivo lesion healing.

First of all, teeth that met the inclusion criteria were planned to be randomly divided into 4 groups. However, in this case, gender and tooth numbers would not be distributed equally among the groups. Therefore, a stratified randomization method was employed to ensure balanced distribution of participants across the four study groups based on gender (male, female) and tooth type (anterior, premolar). To ensure an unbiased distribution of teeth across four treatment groups (Curcumin, Methylene Blue, Erythrosine B, and Control) a randomization process was implemented using Excel VBA (Visual Basic for Applications) by a third party not involved in the study intervention.

Vitality tests yielded negative results for all teeth. The treatments were administered consistently by the same operator to ensure uniformity. However, due to irregular attendance at follow-up appointments by six patients and one instance of tooth extraction, the study ultimately involved 70 teeth, as elaborated in. , Study Design Participants were randomized into four groups. Periapical radiographs of the teeth were captured using a dental X-ray unit (Satalect X-Mind, France) set at 250 kV, 4 mA, and 0.12 seconds of irradiation time, employing a parallel technique guided by a cone indicator. For teeth with indistinct lesion sizes on periapical radiographs, three-dimensional images were acquired using cone beam computed tomography (CBCT) (Planmeca, Helsinki, Finland) with settings of 90 kVp, 12 mA, 14 seconds, and a 16x5 imaging field.

Following rubber dam isolation, access cavities were prepared using a diamond bur. The working length was determined using a 15 K-file (Dentsply Maillefer, Ballaigues, Switzerland) coupled with an apex locator (Root ZX, Morita, Japan), ensuring a 0.5 mm short of the "00" point. Radiographic confirmation of the working length was obtained.