Optical Assessment of Caries Lesion Structure and Activity

描述（由申请人提供）：本研究的总体目标是发展近红外（NIR）成像方法，用于检测和诊断早期龋齿（蛀牙）。需要新的、更复杂的诊断工具来检测和表征早期发展阶段的龋齿病变。如果在空化之前足够早地发现龋齿病变，那么可以通过氟治疗、抗菌治疗、饮食改变或低强度激光照射等非手术手段将其阻止/再矿化。仅仅检测龋齿是不够的，还需要评估龋齿活动性并确定是否需要化学干预的方法。先前的体外和体内研究已经证明，光学相干断层扫描可以用于对表面下病变结构进行无损成像，并测量高度矿化的表面区域的厚度。其他研究表明，脱水速率可以与病变活动相关，并且可以使用光学方法测量脱水速率。这一提议的核心假设是，由于龋齿引起的活动性病变、迟发性病变和发育缺陷之间存在结构差异，这些差异可以通过近红外波长的光学成像方法非破坏性地解决。由于釉质的质地和颜色相似，迟发性病变和发育性缺陷很容易被误认为是活动性早期龋病。停止病变和轻度发育缺陷通常具有坚硬的外层或表面区域，其矿物质含量高于病变体，从而降低病变的渗透性。本课题的总体目标将通过以下几个具体目标来实现：(1)验证光学方法可用于评估牙冠状面和牙根表面病变活动的假设；(2)验证近红外成像方法可用于区分牙冠状面龋齿病变与发育缺陷引起的牙釉质低矿化的假设。如果这些研究和未来的临床试验取得成功，这种新的成像技术很可能被用于检测和监测早期的蛀牙病变，而不使用电离辐射，从而实现保守的非手术干预和保护健康的组织结构。

DESCRIPTION (provided by applicant): The overall objective of this proposed research is to develop near-infrared (NIR) imaging methods for the detection and diagnosis of early dental caries (dental decay). New, more sophisticated diagnostic tools are needed for the detection and characterization of caries lesions in the early stages of development. If carious lesions are detected early enough, before cavitation, then they can be arrested/remineralized by non-surgical means through fluoride therapy, anti-bacterial therapy, dietary changes, or by low intensity laser irradiation. It is not sufficient to simply detect caries lesions, methods are needd to assess the activity of the lesion and determine if chemical intervention is needed. Previous in vitro and in vivo studies have demonstrated that optical coherence tomography can be used to nondestructively image the subsurface lesion structure and measure the thickness of the highly mineralized surface zone. Other studies have demonstrated that the rate of dehydration can be correlated with the lesion activity and that rate can be measured using optical methods. The central hypothesis underlying this proposal is that there are structural differences between active lesions due to caries, arrested lesions and developmental defects, and these differences can be resolved nondestructively using optical imaging methods at NIR wavelengths. Arrested lesions and developmental defects of enamel can be easily mistaken for active early caries lesions due to similar texture and color. Arrested lesions and mild developmental defects typically have a hard outer layer or surface zone of higher mineral content than the body of the lesion which reduces the lesion permeability. The overall objectives of this proposal will be achieved through the following specific aims: (1) To test the hypothesis that optical methods can be used to assess lesion activity on tooth coronal and root surfaces, (2) To test the hypothesis that NIR imaging methods can be used to differentiate caries lesions on tooth coronal surfaces from enamel hypomineralization due to developmental defects. It is likely that if these studies and future clinical trials are a success, this novel imaging technology will be employed for the detection and monitoring of early carious lesions without the use of ionizing radiation, thereby enabling conservative non-surgical intervention and the preservation of healthy tissue structure. PUBLIC HEALTH RELEVANCE: Dental caries is one of the most prevalent chronic diseases of people worldwide (NIH). If an active dental caries is detected early enough, it can be arrested or reversed by non-surgical means through fluoride therapy, anti-bacterial therapy, dietary changes, or by low intensity laser irradiation. By utilizing optical imaging technology for accurat diagnosis of lesion activity, we can avoid unnecessary treatment and allow more frequent monitoring of dental caries without ionizing radiation.