Histopathological investigation of the effects of caffeine administered systemically at different doses on experimentally induced bone defects

This study aims to investigate the effects of systemically administered caffeine at different doses and tricalcium silicate-based NeoPutty® on the healing of apical periodontitis in an experimental model, evaluating their potential contributions to this process. A total of 72 male Sprague Dawley rats were divided into six groups: control (n=12), caffeine control dose-1 (n=12), caffeine control dose-2 (n=12), biomaterial without caffeine (n=12), caffeine biomaterial dose-1 (n=12), and caffeine biomaterial dose-2 (n=12). At the beginning of the study, a defect was created in the right tibia, and in groups receiving biomaterial, the defect area was filled with tricalcium silicate-based NeoPutty®. The caffeine solution was prepared by dissolving the appropriate dose (3 mg/100 g and 10 mg/100 g) in pure water according to the experimental groups to ensure homogeneity and was administered once daily via gavage for 30 days. At the end of the 30-day period, the rats were sacrificed, and samples were collected for histopathological analysis. Histopathological evaluation included new bone formation, osteoblastic activity, inflammation, and fibrosis. Statistical analysis was performed using the SPSS software package (IBM SPSS Version 22.0).The control group exhibited the highest osteoblastic activity and bone formation, whereas these parameters were at the lowest levels in the caffeine biomaterial dose-2 group. The fibrotic tissue ratio and inflammation were higher in caffeine-treated groups, with the lowest inflammation observed in the control group and the highest in the caffeine biomaterial dose-2 group. No statistically significant differences were observed among the other groups. High-dose caffeine increased inflammation and fibrotic tissue formation, while NeoPutty® helped to counteract these effects. Low-dose caffeine exhibited a neutral effect on bone healing. Based on the findings of this study, the use of NeoPutty® in root canal treatment for patients with apical periodontitis who consume high doses of caffeine may positively impact healing. Keywords: Apical periodontitis, caffeine, bioceramic, NeoPutty®, osteoblast activity, new bone formation, histopathology, inflammation, fibrosis.