Alkali production in human dental plaque and saliva as predictor of caries risk

描述(申请人提供)：龋病在所有年龄组中仍然是一种发病率很高的流行疾病。体外研究和间接临床观察表明，口腔细菌的酶分解精氨酸和尿素产生的氨可以减缓菌斑酸化，并可能抑制龋齿。本研究的目的是在临床水平上探讨精氨酸脱亚胺酶(AD)和尿素酶活性与龋病的关系。我们假设无龋者斑块和/或唾液中的AD和尿素酶活性显著高于有龋齿的受试者。牙菌斑和唾液样本中的AD和尿素酶活性将被检测，这些样本来自无龋齿受试者、有龋齿经历的受试者和至少有4颗牙齿有活动性龋齿的受试者。特定目标(SA)1将确定斑块和唾液AD之间的关联的大小和方向，以及人体受试者中尿素酶活性水平与龋齿的关联。SA 2将研究AD和尿素酶活性水平与口腔样本中选定的主要产酸和产碱细菌种类的数量之间的关系。SA 3将调查AD和尿素酶活性水平的预测因素。SA 1将通过病例对照研究达到，SA 2将使用受试者的子样本(最高10人，最低10人，中等斑块AD和尿素酶水平10人)达到。SA3将通过收集患者的年龄、性别、种族、牙科病史、牙菌斑和口腔护理频率的信息，并调查这些解释因素与AD和斑块和唾液中尿素酶活动水平的关系来满足SA3的要求。如果本研究的结果支持AD和/或尿素酶活性水平与成人龋齿之间的联系，所获得的知识将用于在赠款期末设计一项前瞻性队列研究，该研究将确定这种联系是否是因果关系。如果AD和尿素酶活性水平被证明可以单独或与其他危险因素一起预测成人的龋病风险，那么我们将把这种关系应用于开发新的方法，以早期识别有风险的个人，以发展龋齿和防龋策略。 公共卫生相关性：拟议的研究将有助于开发新的龋病风险评估和预防方法，同时更好地了解影响龋病风险的未知因素。

DESCRIPTION (provided by applicant): Caries continues to be a prevalent disease with high incidence among all age groups. Ammonia production from the hydrolysis of arginine and urea by enzymes of oral bacteria moderates plaque acidification and may inhibit dental caries, as suggested by in vitro studies and indirect clinical observations. The objective of this study is to examine the relationship of arginine deiminase (AD) and urease activities with dental caries status at the clinical level. We hypothesize that AD and urease activities in plaque and/or saliva of caries free subjects is significantly higher than in caries active subjects. AD and urease activities will be measured in dental plaque and saliva samples from caries free subjects, caries experienced subjects, and subjects with at least 4 teeth with active caries. Specific Aim (SA) 1 will determine the magnitude and the direction of the association between plaque and saliva AD and urease activity levels with dental caries in human subjects. SA 2 will examine the relationship between AD and urease activity levels with the numbers of selected major acid-producing and alkali-producing bacterial species in the oral samples. SA 3 will investigate the predictors of AD and urease activity levels. SA 1 will be met through a case-control study and SA 2 will be met using a sub-sample of the subjects (10 with the highest, 10 with the lowest, and 10 with medium plaque AD and urease levels). SA3 will be met by gathering information on patient's age, gender, race, dental history, plaque, and frequency of oral care, and investigating the relationship of these explanatory factors to AD and urease activity levels in plaque and saliva. If the results of the present study support an association between AD and/or urease activity levels with dental caries in adults, the knowledge obtained will be applied to the design of a prospective cohort study at the end of the grant period, which will determine whether this association is a cause-and-effect one. If AD and urease activity levels are shown to be predictive of caries risk in adults, either alone or in combination with other risk factors, we will then apply this relationship to the development of novel approaches for early identification of individuals at risk to develop caries and for caries prevention strategies. PUBLIC HEALTH RELEVANCE: The proposed study will contribute to the development of novel methods for caries risk assessment and prevention, while providing a better understanding of unknown factors affecting caries risk.