MICROBIAL INTERACTION IN DENTAL PLAQUE

牙菌斑中高水平的变形链球菌与牙病有关 龋齿，而高水平的血链球菌与非致龋性有关 斑块。这些生物体的数量与它们的数量成反比 已注意到从斑块样本中提取的。建议的因素是 负责这种关系的包括对牙齿的选择性粘连 或预先存在的菌斑表面，产生抑菌产物 通过一个或两个物种，以及由环境促进的选择 PH、pO2和养分利用率等条件。在工作中 拟议研究的假设是变形链球菌之间的相互作用 和血链球菌以及环境因素决定了其组成。 从而确定牙菌斑的健康或疾病状态 齿面。此外，据推测，相对重要性 对于光滑和有裂痕的牙齿表面，选择系数的大小将有所不同。 这些假设将通过连续流动培养来解决，因为 以这种方式生长的细菌在生理上与细菌更相似。 在体内生长的它们的生长速度、酶谱和代谢 活动。细菌生长参数和相互作用将是 以连续流动系统为特征，并与所获得的结果进行比较 来自静态文化。然后将对系统进行修改，以研究 斑块中的初始细菌附着和细菌间黏附 队形。变形链球菌和血链球菌培养的流出物将溢出 羟基磷灰石和釉质光滑和裂开的表面以及由此产生的 斑块的特征将是。环境条件将是 单独改变以研究它们对这一过程的影响。通过研究 斑块细菌与环境之间的基本相互作用， 控制和可能选择保护性正常菌群的因素可以 更好地理解，并有可能在开发中实现 基于生物的治疗方案。

High levels of S. mutans in dental plaque are associated with dental caries, while high levels of S. sanguis are associated with noncariogenic plaque. An inverse relationship between the number of these organisms recovered from plaque samples has been noted. Factors suggested to be responsible for this relationship include selective adhesion to the tooth or preexisting plaque surface, production of bacterial inhibitory products by one or both species, as well as selection promoted by environmental conditions such as pH, pO2, and nutrient availability. The working hypothesis for the proposed studies is that interactions between S. mutans and S. sanguis as well as environmental factors determine the composition of dental plaque and thus determine the state of health or disease on the tooth surface. Additionally, it is postulated that the relative importance of selective factors will differ for smooth and fissured tooth surfaces. These hypotheses will be addressed using continuous flow cultures because bacteria grown in this manner are physiologically more similar to bacteria grown in vivo in terms of their growth rates, enzyme profiles and metabolic activity. Bacterial growth parameters and interactions will be characterized in a continuous flow system and compared to results obtained from static cultures. The system will then be modified to study the initial bacterial attachment and interbacterial adhesion involved in plaque formation. Effluents of S. mutans and S. sanguis cultures will flow over hydroxyapatite and enamel smooth and fissured surfaces and the resulting plaque will be characterized. Environmental conditions will be individually altered to study their effects on this process. By studying the basic interactions between plaque bacteria and their environment, factors which control and possibly select for a protective normal flora can be better understood, and potentially implemented in the development of biologically based therapeutic regimens.