Firestone A R, Feagin F F, Heaven T J, Sheetz J, Denys F
Department of Restorative Dentistry, School of Dentistry, University of Alabama at Birmingham 35294.
J Dent Res. 1993 Aug;72(8):1180-3. doi: 10.1177/00220345930720080301.
Root sections were inoculated with one of two strains of Actinomyces viscosus or a strain of Streptococcus sobrinus and then incubated for 9 days in Trypticase soy broth (TSB) containing 0.25% glucose or TSB supplemented with 0.25% sucrose (TSB+S). Lesion progression was measured from microradiographs. One section from each group was examined with a transmission electron microscope. Lesion progression was associated with a fall in the pH of the medium. However, lesion progression was not correlated with the mean 48-hour pH of the medium. In both TSB and TSB + S, lesion progression with A. viscosus was significantly greater than in the S. sobrinus group. However, the mean 48-hour pH value in TSB + S was lower than that in the S. sobrinus group. Plaque formation in TSB was, subjectively, least in the S. sobrinus group. Examination of transmission electron micrographs revealed bacteria penetrating the surfaces of the sections and extending into the lesion in the A. viscosus groups but not in the S. sobrinus group. This in vitro bacterial plaque model of root caries may be suitable for investigations of the bacterial etiology of root-surface caries and the virulence factors associated with pathogenicity.
将根段接种两种粘性放线菌菌株之一或一种远缘链球菌菌株，然后在含有0.25%葡萄糖的胰蛋白酶大豆肉汤（TSB）或补充有0.25%蔗糖的TSB（TSB+S）中培养9天。通过显微放射照片测量病变进展。每组取一个切片用透射电子显微镜检查。病变进展与培养基pH值下降有关。然而，病变进展与培养基平均48小时pH值无关。在TSB和TSB+S中，粘性放线菌引起的病变进展均显著大于远缘链球菌组。然而，TSB+S中的平均48小时pH值低于远缘链球菌组。主观上，远缘链球菌组在TSB中形成的菌斑最少。透射电子显微镜照片检查显示，在粘性放线菌组中细菌穿透切片表面并延伸至病变部位，而远缘链球菌组则未出现这种情况。这种根龋的体外细菌菌斑模型可能适用于研究根面龋的细菌病因及与致病性相关的毒力因子。
