Journal of Dental Hygiene Science (치위생과학회지), Vol.15(3) : 295~300, 2015
Journal of Dental Hygiene Science (치위생과학회지)
Odontoclasts and osteoclasts resorb tooth root and alveolar bone, respectively. Many studies have focused on osteoclast formation in periodontitis, but effect of periodontitis on odontoclast formation is not clearly clarified. In this study, we observed formation of odontoclasts as well as osteoclasts in rats with ligature-induced periodontitis. To induce periodontitis, ligatures were placed around the first molars in left mandibles of rats. Rats were sacrificed at days 1, 3, and 10 after ligation. After tartrate resistant acid phosphatase (TRAP) staining in mandible section, the number of TRAP-positive odontoclasts and osteoclasts were histologically counted along the root and the alveolar bone surfaces of tooth, respectively. Odontoclasts increased until day 10 in mesial and furcation root surface, but did not increase in distal root surface. When compared odontoclast formation to osteoclast formation in mesial surface, osteoclasts peaked at day 3, and then decreased gradually, whereas odontoclasts were continuously increased until day 10. The number of odontoclasts was lower than that of osteoclasts before and after periodontitis induction. These indicate that periodontitis increased formation of odontoclasts as well as osteoclasts, but odontoclast formation occurs slower and weaker than that of osteoclasts.