Effects of PPAR ? activation on bone repair and dental implant osseointegration: An experimental study

Peroxisome proliferator-activated receptor gamma (PPAR-γ) is a nuclear transcription factor involved in multiple metabolic pathways and plays an important role in obesity and associated diseases. Recent studies have suggested that PPAR agonists, commonly used in the treatment of cardiovascular diseases and type 2 diabetes, may also influence bone cell function and fracture risk. Therefore, understanding the effects of PPAR-γ activation on bone metabolism may have relevant implications for bone repair and dental implant therapy. The aim of this study was to evaluate the effects of PPAR-γ activation on bone repair and the osseointegration of dental implants. Forty-two Wistar rats were fed a standard rodent diet and provided water ad libitum. The PPAR-γ agonist was administered through the diet for four weeks, and the animals were allocated into two experimental groups: Control Group (SC) and PPAR-γ Group (SC-γ). Subsequently, the animals underwent surgical procedures for dental implant placement and the creation of bone defects in the right and left tibiae, respectively. After 7, 15, and 45 days, the animals were euthanized, and the tibiae were collected for histological processing, descriptive histological analysis, and histomorphometric evaluation. Regarding the bone defects, descriptive histological analysis demonstrated a slight delay in bone repair in the SC group compared with the SC-γ group at all evaluated periods. Histomorphometric analysis revealed significant differences between the groups in newly formed bone at 7 days (P = 0.0374) and 15 days (P = 0.0134), as well as in mature bone at 15 days (P = 0.0009). At 45 days, no statistically significant differences were observed for either newly formed or mature bone. In the tibiae containing dental implants, both groups showed similar cellular events and patterns of bone maturation in the implant thread areas. In conclusion, PPAR-γ activation accelerated tissue apposition and bone repair at 7 and 15 days in the treated group. However, descriptive histological analysis indicated differences in the cellular characteristics observed during the repair process. Regarding dental implants, no differences between the groups were observed in the descriptive histological analysis at any of the evaluated periods.