Role of antimicrobial photodynamic therapy ( <scp>aPDT</scp> ) and systemic resveratrol on immediate implant placement in type 2 diabetic rats

This study investigated the synergistic effects of resveratrol and antimicrobial photodynamic therapy (aPDT) on peri-implant bone repair in a type 2 diabetes model. Forty-eight rats were allocated into four groups: normoglycemic, normoglycemic + resveratrol, type 2 diabetes (T2D), and T2D + resveratrol. Diabetes was induced using a cafeteria diet and streptozotocin (35 mg/kg). Resveratrol (100 mg/kg) was administered systemically beginning 7 days later. After 14 days, maxillary molars were extracted, and surgical drilling was performed. Half of the animals in each group received aPDT (methylene blue and 660 nm diode laser) before immediate implant placement. Animals were euthanized 28 days post-surgery for biomechanical, RT-PCR, and confocal microscopy analyses. Resveratrol improved glycemic control and body weight. In T2D animals, aPDT significantly enhanced implant removal torque. Gene expression analyses revealed downregulation of bone resorption markers and upregulation of bone mineralization genes in T2D and T2D + resveratrol groups treated with aPDT. Confocal microscopy demonstrated increased mineral apposition rates in animals treated with resveratrol and/or aPDT. These findings suggest that the combination of systemic resveratrol and local aPDT enhances peri-implant bone healing under diabetic conditions, highlighting a potential therapeutic approach to improve implant osseointegration in compromised metabolic states.