Salicylic Acid Polymers in Periodontal Tissue Healing

Salicylic acid (SA) has therapeutic potential based on its anti-inflammatory and antimicrobial properties. A limitation of SA treatment is its short half-life in vivo that can be overcome by the sustained release by incorporation into a polymer backbone resulting in biodegradable salicylic acid-based poly(anhydride-esters) (SAPAE). In addition to slow release for up to 1 month, SAPAE is simple to produce and is an effective low-cost alternative to biologic factors. These properties are useful in promoting bone regeneration, particularly under situations where inflammation is enhanced by systemic conditions such as diabetes. In a rat critical size defect model, SAPAE application with bone grafting material significantly increased bone fill as assessed by micro-computed tomography (CT) and histomorphometry. While there was accelerated bone formation in the normoglycemic group, there was both accelerated and increased bone formation in diabetic rats. The increased bone formation in the diabetic group was tied to a decrease in inflammation during the period of bone formation, an increase in the number of osteoblasts, and a reduction of osteoclasts. The results suggest that SAPAE polymer can be used to accelerate and enhance bone formation in the treatment of periodontal and other craniofacial osseous defects and may be useful for the treatment of peri-implantitis, particularly in diabetic conditions.