Radiographic and Clinical Outcomes of Laser-Enhanced Disinfection in Endodontic Therapy

<b>Background and Objectives</b>: Periapical healing and bone regeneration are key indicators of endodontic success. This study evaluated the effectiveness of laser-assisted disinfection compared to conventional chemical irrigation in promoting periapical healing across various bone densities (D1-D5), using cone-beam computed tomography (CBCT) over multiple follow-up intervals. <b>Materials and Methods</b>: A total of 120 patients with radiographically confirmed periapical lesions were enrolled and allocated into two groups: an experimental group (<i>n</i> = 60, chemical irrigation + Er,Cr:YSGG laser disinfection) and a control group (<i>n</i> = 60, chemical irrigation only). CBCT scans were obtained at 6 months, 1 year, 2 years, and 2.5 years post-treatment to assess lesion size and CBCT-PAI scores. Lesions were classified radiographically as either <i>well-defined radiolucent lesions</i> or <i>undefined</i> periapical radiolucencies. Paired <i>t</i>-tests and ANOVA were used for statistical comparisons. <b>Results</b>: The experimental group demonstrated significantly greater reductions in lesion size and improvements in CBCT-PAI scores at all time points. Healing was especially enhanced in low-density bone (D4-D5). Complete healing rates were higher in the laser group for <i>well-defined radiolucent</i> (89.5% vs. 68.4%) and <i>undefined lesions</i> (81.8% vs. 59.1%). Post hoc power analysis confirmed statistical reliability (Cohen's d = 3.48; power > 0.99). <b>Conclusions</b>: Laser-assisted endodontic disinfection significantly accelerates periapical healing and promotes bone regeneration, particularly in low-density bone. CBCT imaging supports its clinical superiority over conventional irrigation methods.