Comparative Evaluation of Different Modes of Laser Assisted Endodontics in Primary Teeth: An In vitro Study.

Introduction: The presence of bacteria in root canals has been considered to be responsible for endodontic treatment failure, even in case of primary teeth. The use of lasers can be a valuable addition in removing bacterial load in areas where traditional methods may fail to succeed. Methods like direct laser irradiation of canals, Laser Activated Irrigation (LAI) with sodium hypochlorite (NaOCl) and Photodynamic Therapy (PDT) seem to be a promising alternative for disinfection.

Aim: This study was designed to compare the efficacy of latest advancements in disinfection techniques using diode laser namely direct laser irradiation, photodynamic therapy and laser activated irrigation using sodium hypochlorite.

Materials And Methods: Sixty freshly extracted primary teeth either single or multi-rooted teeth with two third of their root length intact were collected. Instrumentation was completed to size 30 H-file. Teeth were randomly divided into Group 1- Direct Laser- irradiation, Group 2 - Photodynamic therapy; Group 3- Laser activated irrigation with 2.5% NaOCl. The tooth specimens were inoculated with . The bacterial colonies were counted preoperatively. Laser irradiation was performed for all groups in accordance to the groups each tooth belonged to. Postoperatively the bacterial colonies were counted. One-way Analysis was applied to compare bacterial count at baseline and post-test between three groups. Tukey's post-hoc test was applied for pairwise comparison between groups. Paired t-test was applied to compare the mean baseline bacterial count with post-test mean bacterial count.

Results: The results obtained with all the three groups postoperatively were highly significant (p-value<0.001). Statistically significant difference between results of Group 1 and Group 2 and also between Group 1 and Group 3 was found (p-value≤ 0.001). However, no statistical difference between Group 2 and Group 3 was found (p-value- 0.96).

Conclusion: Disinfection strategies using diode laser by techniques gives promising results. Techniques like laser activated irrigation and photoactivated disinfection are better than direct laser irradiation in eliminating .