総義歯装着者の歯周病性細菌による口腔内のコロニー形成について

Colonisation of the oral cavity by periodontopathic bacteria in complete denture wearers.

抄録

目的:

本研究の目的は、高齢者の上下総義歯装着者を対象に歯周病菌のコロニー形成とコロニー形成部位を検討することである。また、口腔衛生レベルと歯周病菌によるコロニー形成との関連についても検討した。

OBJECTIVE: The purpose of this study was to investigate colonisation by periodontopathic bacteria and the sites of colonisation in elderly upper and lower complete denture wearers. We also investigated the relationship between level of oral hygiene and colonisation by periodontopathic bacteria.

材料および方法:

無歯顎者40名と有歯顎者37名のボランティアが本研究に参加した。全唾液からサンプルを採取し、Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythiaおよびFusobacterium nucleatumのレベルをPCR Invader技術により測定した。口腔粘膜および義歯表面におけるこれらの菌種の検出は，PCR法により行った．統計解析にはFisherの正確検定を用いた．また，クラスター解析により，各サンプリングエリアにおける歯周病菌叢の傾向を検討した．

MATERIALS AND METHODS: Forty edentulous and 37 dentate volunteers participated in this study. Samples were collected from whole saliva, and levels of Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia and Fusobacterium nucleatum were determined by PCR Invader technology. Detection of these species on oral mucosal and denture surfaces was performed by PCR. Fisher's exact test was used for the statistical analysis. Cluster analysis was employed to investigate trends in the periodontopathic bacteria flora in each sampling area.

結果:

唾液中の歯周病菌検出率は，A. actinomycetemcomitansとF. nucleatumを除き，無歯顎の方が有歯顎より低かった（p＜0.01）．また，F. nucleatumの検出率は，すべての部位で最も高かった．P. gingivalisのDNA定量と唾液中のCandida属菌数には正の相関が認められた．試験菌のクラスター分析では，2つのクラスターが確認された．舌苔の有無は調査したすべての歯周病菌の検出率と関連し，義歯プラークの有無はT. denticolaとF. nucleatumの検出率と関連した．

RESULTS: Detection rates of periodontopathic bacteria in whole saliva were lower under edentulous conditions than under dentulous conditions, except for A. actinomycetemcomitans and F. nucleatum (p < 0.01). Detection rate of F. nucleatum was the highest in all areas. A positive correlation was observed between DNA quantification of P. gingivalis and number of Candida species in saliva. Cluster analysis of the test species identified two clusters. Tongue-coating status was associated with the detection rate of all periodontopathic bacteria investigated, and denture plaque status was associated with the detection rate of T. denticola and F. nucleatum.

結論:

無歯顎状態における歯周病菌の存在と，粘膜や義歯表面の口腔衛生状態が T. denticola や F. nucleatum のコロニー形成に影響することが示唆された．

CONCLUSION: Results indicate the presence of periodontopathic bacteria under edentulous conditions and that the status of oral hygiene of the mucosal or denture surfaces affects colonisation by T. denticola and F. nucleatum.