Histological, Histochemical and Immunohistochemical Evaluation of the Role of Bone Marrow-Derived Mesenchymal Stem Cells on the Structure of Periodontal Tissues in Carbimazole-Treated Albino Rats

Objective: To elucidate the role of bone marrow-mesenchymal stem cells (BM-MSCs) on the structure of periodontal tissues in carbimazole (antithyroid drug) treated rats at different durations.

Design: 28 albino rats were divided into: Group I: received distilled water. Group II: received therapeutic dose of carbimazole. Group III: received carbimazole then single injection of BM-MSCs by the end of 3^rd week. Group IV: received carbimazole and single injection of BM-MSCs at the beginning of the experiment. Specimens were examined by light microscope. New collagen and β-catenin-immunoreactivity area% were assessed histomorphometrically, and statistically using ANOVA test.

Results: Histological examination revealed normal periodontal tissues structure in Groups I & IV. Group II showed disorganized periodontal ligament fibers and different stainability of cementum and alveolar bone. Group III illustrated dense periodontal ligament fibers, normal stainability of cementum and most of alveolar bone. Masson's trichrome results of Groups I & IV illustrated large areas of new collagen in periodontal ligament, old collagen in cementum and intermingled old and new collagen in alveolar bone. Group II showed old collagen. Group III revealed only new collagen. β-catenin-immunoreactivity was strong in Groups I & IV, negative in Group II and moderate in Group III. Statistically, Group III showed highest mean of new collagen area% followed by Groups I, IV and II respectively. Highest mean of β-catenin-immunoreactivity area% was for Group I followed by Groups IV, III and II respectively.

Conclusions: Carbimazole has damaging effects and BM-MSCs are capable to mend these destructive outcomes in time dependent manner.