Ng Chung, Simon Jacob C, Fried Daniel, Darling Cynthia L
University of California, San Francisco, San Francisco, CA 94143-0758.
Proc SPIE Int Soc Opt Eng. 2018 Jan-Feb;10473. doi: 10.1117/12.2296030. Epub 2018 Feb 8.
Most new lesions are found in the pits and fissures of the occlusal surface. Radiographs have extremely low sensitivity for early occlusal decay and by the time the lesion is severe enough on a radiograph it typically has penetrated well into the dentin and surgical intervention is required. The occlusal surfaces are heavily stained and visual and tactile methods for their detection also have poor sensitivity and specificity. Previous studies at wavelengths beyond 1300-nm have demonstrated that stains are not visible and demineralization on the occlusal surfaces can be viewed without interference from stains. New extended range InGaAs near-IR cameras allow access to wavelengths beyond 1700-nm. The objective of this study was to determine how the contrast of occlusal lesions varies with wavelength from the visible to 2350-nm. The lesion contrast was measured in 55 extracted teeth with suspected occlusal lesions using reflectance measurements from 400-2350-nm using Si and InGaAs imaging arrays. The highest lesion contrast in reflectance was measured at wavelengths greater than 1700-nm. Stains interfered significantly at wavelengths shorter than 1150-nm. This study indicates that the optimum wavelengths for reflectance imaging decay in the occlusal surfaces are greater than 1700-nm.
大多数新病变位于咬合面的窝沟处。X线片对早期咬合面龋的敏感性极低，当病变在X线片上严重到一定程度时，通常已深入牙本质，需要手术干预。咬合面严重染色，通过视觉和触觉方法检测其病变的敏感性和特异性也很差。以往在波长超过1300nm的研究表明，污渍不可见，咬合面的脱矿可以在不受污渍干扰的情况下观察到。新型扩展范围的铟镓砷近红外相机可捕捉超过1700nm的波长。本研究的目的是确定咬合面病变的对比度如何随波长从可见光到2350nm变化。使用硅和铟镓砷成像阵列，在400-2350nm范围内进行反射率测量，对55颗怀疑有咬合面病变的离体牙测量病变对比度。反射率中病变对比度最高值在波长大于1700nm处测得。在波长小于1150nm时，污渍有显著干扰。本研究表明，用于反射率成像检测咬合面龋的最佳波长大于1700nm。
