Odontoblasts' and Pulpal Cells' Apoptosis with Experimentally Periodontitis and Diabetes

Objectives: The aim of this study was to evaluate the apoptotic behaviors of pulpal and odontoblast cells in the presence or absence of experimentally induced diseases; diabetes and periodontitis. Methods: Thirty-six adult male Sprague Dawley rats were used in this study. Experimental periodontitis was created by placing silk ligature around cervices of first mandibular molars. Experimental diabetes was induced by intraperitoneal injection of the diabetogenic agent streptozotocin (STZ). Following the induction of the both experimental diseases, the animals were divided into four groups; 1- healthy group (H, n=10), 2- diabetic group (D, n=8), 3- periodontitis group (P, n=11), 4- diabetic and periodontitis group (DP, n=7). At seventh week of the experiment, the animals were sacrificed. The two halves of each mandible were dissected removing all soft tissues, demineralized, and embedded in paraffin. Apoptotic cells were determined by immunohistochemical method and frequency of the apoptotic cells was evaluated by apoptotic index score. Results: In H, D, P and DP groups, the mean apoptotic index scores were 1.80±0.79, 1.75±1.04, 2.00±0.71 and 1.89±1.01 for pulpal cells, and 2.00±0.82, 1.63±0.92, 3.11±0.60 and 2.00±1.12 for odontoblast cells, respectively. There was no significant difference among groups for pulpal tissue (p>0.05). However, significantly higher apoptosis in group P was detected when compared to others for odontoblast cells (p<0.05). Conclusions: The results of this study showed that experimental periodontitis alone provoked apoptosis in odontoblast cells, whereas experimental diabetes together with periodontitis did not cause to any additional effect on it.