Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California.
J Biophotonics. 2018 Nov;11(11):e201800113. doi: 10.1002/jbio.201800113. Epub 2018 Jul 13.
The identification of root caries and calculus on tooth roots is of increasing importance with our aging population. Exposed root surfaces are often impacted by erosion, abrasion, calculus and staining which can make the identification and management of caries challenging. Identification of dental calculus on root surfaces and verification of its removal is also important for patient education and to decrease susceptibility to caries and periodontal disease. The objective of this study was to determine how the contrast of root caries lesions and dental calculus varies with wavelength in the visible to near-infrared. The contrast of suspected root caries lesions and dental calculus on 30 extracted teeth was measured using cross-polarization reflectance measurements at wavelengths from 400 to 2350 nm. Significantly higher (P < 0.05) lesion contrast was measured at wavelengths greater than 1460 nm. Stains interfered significantly at wavelengths less than 850 nm yielding non-diagnostic contrast for root caries lesions. We postulate that the high absorption of water at longer wavelengths reduced the light scattering from the surrounding and underlying normal dentin, thus increasing the lesion contrast. This study indicates that wavelengths beyond 1400 nm are advantageous for imaging calculus and caries lesions on root surfaces due to the high contrast and lack of interference from stain.
随着人口老龄化，对牙根龋和牙石的识别变得越来越重要。暴露的牙根表面经常受到侵蚀、磨损、牙石和染色的影响，这使得龋病的识别和管理具有挑战性。识别牙根表面的牙石并验证其去除情况，对于患者教育和降低龋病和牙周病的易感性也很重要。本研究旨在确定在可见到近红外范围内，根龋病变和牙石的对比度随波长如何变化。使用从 400 到 2350nm 的波长的交叉偏振反射测量法，对 30 颗离体牙上疑似根龋病变和牙石的对比度进行了测量。在大于 1460nm 的波长下，病变对比度显著更高（P<0.05）。在小于 850nm 的波长下，染色物会产生显著干扰，从而导致根龋病变的对比度无法诊断。我们推测，较长波长下的水高吸收率减少了周围和下方正常牙本质的光散射，从而增加了病变的对比度。本研究表明，由于高对比度和不受染色干扰，1400nm 以上的波长有利于对牙根表面的牙石和龋病进行成像。
