アブストラクト（9巻4号：神奈川歯学）

神奈川歯学

Japanese

Title　： 小窩裂溝部における齲蝕の進行とStreptococcus mutansおよびLactobacilliの分離比率
Subtitle　： 原著
Authors　： 蛭間哲雄, 長田保
Authors（kana）　：
Organization　： 神奈川歯科大学保存学教室
Journal　： 神奈川歯学
Volume　： 9
Number　： 4
Page　： 168-195
Year/Month　： 1975 / 3
Article　： 原著
Publisher　： 神奈川歯科大学学会
Abstract　： 「抄録」Streptococcus mutansは, Fitzgeraldら (1960) の無菌動物を使用した研究で, 齲蝕細菌として注目されるようになった. その後, 本菌の疫学および生化学的研究が各国で行われ, 現在では本菌が齲蝕の最も重要な原因菌であることが決定的となった. 一方lactobacilli原因菌説も, 過去約70年間数多くの研究により各国で強く支持されてきた. 1960年頃を境として, 齲蝕と関連したlactobacilliの研究報告は以前と比較して少なくなったが, 最近の報告でも本菌は齲窩から高率に検出されており, 齲蝕細菌としての意義については未解決に近い状態である. 著者は以上の見地から, ヒトの齲蝕過程における病巣中のS.mutansとlactobacilliの動態を先ず明らかにすることが必要と考え, 以下の実験を行った. 年齢20～25歳の男女につき, 大臼歯咬合面小窩裂溝部が臨床的に健全歯(C0群), 初期齲蝕あるいはその疑いが濃厚な歯 (C1群), 明らかな齲蝕でその病変が象牙質に及ぶ歯 (C2群) の3群に分けて選出し, 該当部位の歯垢および病変組織からS.mutansおよびlactobacilliを選択培地で定量的に培養し, 両菌の量的検出比を追究した. 併せて, 充填物辺縁から両菌の検索と分離菌の代表株について生物学的諸性状検査を行ない, 次の結論を得た. 1. S.mutansは, 検出率でC0群では92.9%, C1群では100%, C2群では100%であり, 齲蝕の全例から検出された. 対菌数分離比率ではC0群が27.9%, C1群が18.9%, C2群が15.0%であり, 齲蝕が進行するとともに本菌の分離比率は低くなった. C0群とC2群との両群の差は有意である. 対レンサ球菌分離比率もC0群では62.8%, C1群では50.7%およびC2群では46.7%で同じ傾向が認められた. 2. lactobacilliの検出率はC0群では0%, C1群では50%, C2群では84.6%を示し, 齲蝕が進行するとともに大差で高くなった. 対総菌数分離比率は, S.mutansとは逆にC0群では0%, C1群では7.0%およびC2群では22.4%で, 検出率と同様に齲蝕が進行すると比率は高くなり, その差はそれぞれ有意であった. 3. 対レンサ球菌分離比率は, 各群間で著明な差は認められなかった. またS.salivariusの検出率は非常に低かった. 4. 充填物辺縁からのS.mutansとlactobacilli両菌の検出は, S.mutansの対総菌数分離比率では, インレー群で7.4%, アマルガム群で11.3%, lactobacilliではインレー群で15.3%, アマルガム群で11.1%で, 両菌ともC0群との差は有意であった. 5. S.mutansとlactobacilliの発育に及ぼす培地pHの影響を追究し, 酸性側で特に発育度の相違が著明に認められた. pH7.0の発育度を100とすると, 供試菌の平均発育度は, S.mutansではpH5.0で2.1%, pH4.5で0%であったが, lactobacilliではpH5.0で44.3%, pH4.5で17.9%であった.
Practice　： 歯科学
Keywords　：

English

Title　： Prevalence of S.mutans and Lactobacilli in relation to the caries progress in pits and fissures
Subtitle　：
Authors　： Tetsuo Hiruma, Tamotsu Osada
Authors（kana）　：
Organization　： Department of Conservative Dentistry Kanagawa Dental College
Journal　： Kanagawa Shigaku
Volume　： 9
Number　： 4
Page　： 168-195
Year/Month　： 1975 / 3
Article　： Original article
Publisher　： Kanagawa Odontological Society
Abstract　： Samples of plaque and carious lesion from clinically sound enamel (C0 group), initial enamel caries (C1 group) and slight dentinal caries (C2 group) in pits and fissures of molar were examined for the prevalence of S.mutans and lactobacilli. The three groups of adults, 20-25 yr. of ages, were selected for study. Material was collected with sharp explorers from the occlusal pits and fissures of each group, and was quantitatively cultured on the selective media. The representative strains of isolets were identified by the biochemical characteristics. Plaque samples from the edge of dental fillings were also examined for the same purpose. The results are summarized as follows : 1. The isolation frequency of S.mutans from the three groups was 92.9% in C0 group, 100% in C1 group and 100% in C2 group. The prevalence of S.mutans in relation to the total number of cultivable bacteria was 27.9% in C0 group, 18.9% in C1 group and 15.0% in C2 group. It was observed that the prevalence of S.mutans decreased when samples were obtained from advanced carious lesion, and the difference of prevalence between C0 group arid C2 group was statistically significant. The prevalence of S.mutans to the total streptococci was 62.8% in C0 group, 50.7% in C1 group and 4.67% in C2 group. The same tendency as the above-mentioned was shown in the result. 2. The isolation frequency of lactobacilli from the three groups was 0% in C0 group, 50.0% in C1 group and 84.6% in C2 group. The prevalence of lactobacilli in relation to the total number of cultivable bacteria was 0% in C0 group, 7.0% in C1 group and 22.4% in C2 group. In contrast with S.mutans, the isolation frequency and the prevalence of lactobacilli increased obviously when samples were obtained from advanced carious lesion. The differences between C0 group and C1 group, C1 group and C2 group, C0 group and C2 group were statistically significant respectively. 3. Little difference was observed between the three groups in the prevalence of total streptococci in relation to the total number of cultivable bacteria. Streptococcus salivarius was present in quite low number in samples. 4. The prevalence of S.mutans in plaque samples from the edge of dental fillings was 7.5% in inlay group, 11.3% in amalgam group, and lactobacilli was 15.3% in inlay group, 11.1% in amalgam group. The differences of prevalence between C0 group and both inlay and amalgam group were statistically significant respectively. 5. The effect of pH in the medium on the growth of S.mutans and lactobacilli was also studied, and it was observed that the growth of both species were much different in acid environment. When the growth rate in pH 7.0 mearsured by optical density, is expressed as 100%, the mean growth rate of S.mutans was 2.1% in pH 5.0, 0% in pH 4.5 and the mean growth rate of lactobacilli was 44.3% in pH 5.0, 17.9% in pH 4.5.
Practice　： Dentistry
Keywords　：