Pathological Examination of Experimentally Induced Periodontal Polyp in Mice

Abstract

: 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.

Migration and Differentiation of GFP-transplanted Bone Marrow-derived Cells into Experimentally Induced Periodontal Polyp in Mice

“…Experimental perforation of floor of the dental pulp in mice caused a slight initial suppurative inflammation leading to granulation tissue growth due to gradual chronic inflammation. Similar results were observed from previous experiment 1 .…”

“…These problems tend to be more when treating deciduous teeth in clinical pediatric dentistry. The consequence of a large perforation is chronic inflammatory hyperplasia 1 . Granulation tissue grows in the periodontal ligament from the perforated dentin causing periodontal polyp, which may also grow into the pulp cavity.…”

“…In this study, the method of Osuga et al 10 was implemented and the mechanism by which cellular components of the granulation tissue to induce chronic inflammation at the furcation in GFP mouse was carried out 1 . Observation with micro CT (m_CT) 11 , 12 , histopathology and immunohistochemistry were followed through over specific periods of time.…”

Regeneration of Dentin Using Stem Cells Present in the Pulp

“…Kaneko et al also reported the differentiation of BMDCs into cell components of periodontal tissue [14]. In our study, the method suggested by Osuga et al [22] was used for the formation of granulation tissue through chronic inflammation in the dental pulp of GFP bone marrow transplanted mice [16]. Observations by micro-computed tomography (m-CT) [23,24], histopathology, and immunohistochemistry were followed over time.…”

“…When the tooth crown is destroyed by caries, the pulp cavity is perforated. High proliferative activity of the pulpal tissue results in chronic inflammatory hyperplasia [16]. Granulation tissue grows from the pulp and forms periodontal polyps that can grow from inside the pulp cavity to outside the pulp.…”