The comprehensive studies for establishment of a system to prevent periodontitis in adolescent students

为建立青少年学生牙周炎预防体系，本课题进行了为期3年（2001-2003）的调查，获得以下结果：本研究项目的流行病学研究显示，青少年学生牙周状况随年龄增长而恶化。这可能是由于在学校牙齿健康检查中对牙周炎高危部位的筛查有助于这些学生随后的牙周状况改善。结果表明，牙龈假单胞菌、连翘假单胞菌、直链假单胞菌、放线菌和中间假单胞菌可作为青少年学生牙周炎发病的危险标志物。检测这些特异性牙周病原体和测定抗这些细菌的IgG抗体滴度可能对牙周炎学生的筛查方法有用。在日本，IL-1受体拮抗剂基因串联重复序列（VNTR）多态性和维生素D受体(VDR)/FcRIIIb基因型组合与广泛性EOP相关。此外，FcγRIIb基因多态性与慢性牙周炎易感性相关。40-kDa外膜蛋白（40k-OMP）和200-kDa抗原蛋白中的免疫反应结构域（IVTVPENGK）被认为在牙周炎成分疫苗中具有潜在的应用价值。此外，40k-OMP可能可用作预防牙周炎的鼻用疫苗。另一方面，新构建的针对130-kDa血凝素结构域的抗体可能有助于开发针对牙周炎的被动免疫。研究了放线菌的毒力因子（胞毒膨胀毒素和荚膜多糖）及其对放线菌感染的保护机制。对青少年学生进行学校口腔健康检查，收集牙周状况资料。

To establish a system to prevent periodontitis in adolescent students, we investigated for 3 years (2001-2003) in this research project, and the following results were obtained.1. Epidemiological studies in this research project demonstrated that periodontal conditions worsened with increased age in adolescent students.2. It was possible that the screening for students with high risk sites of periodontitis in school dental health examination contributed to the subsequent improvement of periodontal conditions in those students.3. It was clarified that P.gingivalis, B.forsythus, C.rectus, A.actinomycetemcomitans and P.intermedia might be able to be use as risk markers for onset of periodontitis in adolescent students.4. Both of detection of these specific periodontal pathogens and measuring IgG antibody titer against these bacteria might be useful for screening method for students with periodontitis.5. In Japanese, tandem repeat (VNTR) polymorphisms in IL-1 receptor antagonist gene and vitamin D receptor (VDR)/FcRIIIb genotype combination were associated with generalized EOP. Further, FcγRIIb gene polymorphisms associated with susceptibility of chronic periodontitis.6. The immunoreactive domain (IVTVPENGK) in 40-kDa outer membrane protein (40k-OMP) and 200-kDa antigenic protein from P.gingivalis were thought to have a potential use in a component vaccine against periodontitis. Further, 40k-OMP might be useful as a nasal vaccine for prevention of periodontitis. On the other hand, a newly constructed antibody against 130-kDa hemagglutinin domain may prove to be useful for development of passive immunization against periodontitis.7. The virulence factors (cytolethal distending toxin and capsular polysaccharide) from A.actinomycetemcomitans and a protection mechanism against infection of A.actinomycetemcomitans were clarified.8. The school dental health examination was performed in adolescent students, and the data on periodontal condition was accumulated.