The colonizing of periodontopathic bacteria and the transition of inflammation with dental calculus formation periodontal rat model.

2004 Fiscal Year Final Research Report Summary

• Project/Area Number: 14571976
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Periodontal dentistry
• Research Institution: Tohoku University
• Principal Investigator: ENDO Hideaki Tohoku University, Graduate School of Dentistry, Assistant Professor, 大学院・歯学研究科, 助手 (80168830)
• Co-Investigator(Kenkyū-buntansha): SHIMAUCHI Hidetoshi Tohoku University, Graduate School of Dentistry, Professor, 大学院・歯学研究斜, 教授 (70187425) ; SHINODA Hisashi Tohoku University, Graduate School of Dentistry, Professor, 大学院・歯学研究科, 教授 (80014025)
• Project Period (FY): 2002 – 2004
• Keywords: experimental periodontitis / calculus formation / Porphyromonas gingivalis

Research Abstract

Rats were inoculated 2 weeks (three times per week) with Porphyromonas gingivalis (P.g.) that is thought as the periodontopathic bacteia, after dental calculus had been formed. Before inoculation, the specific pathogen were reduced with sulfamethoxazole/trimethoprim and were eliminated oral pathogenic bacteria. After the medicament of anti-bacterial drugs, P.g. was inoculated. The dental calculus formation food by the prescriptions of Bringer et al (1971) was given to rats for 4 weeks. Rats were divided into 4 groups, 1 group was negative control (bacteria was not inoculated), 3 remaining groups were changed breed periods. P.g. was cultivated on supplemented blood agar (Colombia CNA based with 5.0μg/ml hemin, 0.5μg/ml menadione and 5% defibrinated sheep's blood). For experiments, bacteria were grown on supplemented blood agar at 37℃ in an anaerobic chamber under an atmosphere of 10% carbon dioxide, 10% hydrogen and 80% nitrogen. The rats were inoculated live P.g.suspension in 5% carboxymethyl-cellulose in PBS solutions. The bacteria were inoculated directly in the oral cavity of rats. It was estimated the adhesion of calculus with the method of Bringer et al(1971), and evaluated the absorption degree of an alveolar bone defects. Although the adhesion of the calculus is adhering a lot on the side of the lower jaw as a result, the settlement of the P.g.bacteria was in a decrease trend gradually. Also, the adhesion degree of the calculus was in a big trend, without being related to low, in the case that the absorption degree of the alveolar bone inoculated the P.g.bacteria.