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 theexpansion 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

Chapter 1 : Root Canal Treatment and the Role of Filling Materials

Endodontics includes diagnosis and treatment as well as management of pulpal and periapical diseases. Treatment aims to reduce inflammation of the periapical tissues, to dissolve remaining organic material, and to counteract coronal microleakage in the root canal through the use of medication and mechanical instruments. Finally, irrigated root canals should be obturated with filling material and sealer to prevent reinfection.Editor, Toshiyuki KawakamiLanguage Editor, David M Carlsonviii, 232 p. ill. (some col.

Chapter 13 : Clinico-Pathological Healing of Periapical Tissues in Aged Patients by Root Canal Filling using Calcium Hydroxide: Case resentation

Two root canal filling materials, Calvital and Vitapex (Neo Dental Chemical Products Co., Ltd., Tokyo, Japan), were used to treat six teeth in a 78-year-old man and one tooth in an 82-year-old woman, respectively. Both of these filling materials were paste, consisting chiefly of calcium hydroxide and iodoform. One year later these teeth, along with surrounding alveolar bone, were examined histopathologically following the patients’ deaths. Of the six teeth treated with Calvital, four were instrumented prior to root canal obturation and two were not. The teeth that were instrumented prior to obturation showed good healing, while those that were not showed poor healing. The tooth treated with Vitapex was instrumented prior to obturation and showed good periapical healing and osteoid closure of the apical foramen. This finding suggests that canal instrumentation followed by obturation with Vitapex can allow favorable healing even in aged patients.Editor, Toshiyuki KawakamiLanguage Editor, David M Carlsonviii, 232 p. ill. (some col.