Pathological examination of experimentally induced periodontal polyp in mice

The mechanism in the formation of periodontal polyp has been established in several histological studies but details on cell differentiation and/or proliferation have not been elucidated. In the present study, we established a convenient and possible experimental system using ddY mice. Briefly, pentobarbital sodium (Somnopentyl) was injected into the abdominal cavity of the mouse followed by access cavity preparation on maxillary first molar using low speed ½ round bur (Merufa Inc), exposing the pulp and then allowed to perforate the floor of the pulp chamber. Observation was done over time until 6 months using micro CT (m_CT) image photography. Results with transmission image using m_CT showed the expansion in the width of the periodontal ligament in the furcation area. The lesion was excised as one mass and examined histopathologically. The granulation tissue was covered with stratified squamous epithelium. The present experimental technique has been confirmed to be effective in analyzing the formation of periodontal polyp induced by mechanical perforation.