摘要： Background/purpose: It is still challengeable to treat periodontal pockets refractory to mechanical debridement. This study is to evaluate the potential of indocyanine green (ICG)-diode laser-based photothermal therapy (PTT) for solving this dilemma. Methods: Bone marrow-derived mesenchymal stem cells (BMSCs) and periodontal ligament cells (PDLCs) were incubated with phosphate-buffered saline, chlorhexidine, or ICG, non-irradiated or irradiated with 810-nm diode lasers, and the cell viability was evaluated. Patients with teeth refractory to mechanical periodontal debridement on different quadrants were recruited. At baseline (T0), all examined teeth received scaling and root planing, and those on the test quadrant (PTT group) received ICG-diode laser treatment. The outcome was evaluated using clinical parameters and cytokines in the gingival crevicular fluids at 4e6 weeks (T1) and 6 months (T2). Results: In ICG-treated cultures, the viability of BMSCs and PDLCs was recovered on day 4, and laser irradiation inhibited the metabolic activities of BMSCs. 22 patients with 30 control teeth and 35 PTT-treated teeth were examined. All examined teeth showed modest reductions in probing pocket depth (PPD), clinical attachment loss (CAL), bleeding upon probing (BOP), and plaque score at T1 and T2 and significant reductions in IL-1b and MMP-8 at T2. Compared with controls, BOP was reduced more prominently, IL-1b and MMP-8 were significantly lower, and reductions in PPD and CAL were slightly greater in the PTT group at T1 (0.05e0.19 mm). Conclusion: ICG-diode laser-based PTT is compatible to periodontium and assists in faster resolution of gingival inflammation in periodontal pockets refractory to mechanical debridement.