Nakamura Shino, Ando Masahiro, Hamaguchi Hiro-O, Yamamoto Matsuo
Department of Periodontology, Showa University School of Dentistry, 2-1-1, Kitasenzoku, Ohta-ku, Tokyo, 145-8515, Japan.
Lasers Med Sci. 2017 Nov;32(8):1857-1863. doi: 10.1007/s10103-017-2291-x. Epub 2017 Jul 25.
The aim of this study is to evaluate the existence of residual calculus on root surfaces by determining the fluorescence/Raman intensity ratio. Thirty-two extracted human teeth, partially covered with calculus on the root surface, were evaluated by using a portable Raman spectrophotometer, and a 785-nm, 100-mW laser was applied for fluorescence/Raman excitation. The collected spectra were normalized to the hydroxyapatite Raman band intensity at 960 cm. Raman spectra were recorded from the same point after changing the focal distance of the laser and the target radiating angle. In seven teeth, the condition of calculus, cementum, and dentin were evaluated. In 25 teeth, we determined the fluorescence/Raman intensity ratio following three strokes of debridement. Raman spectra collected from the dentin, cementum, and calculus were different. After normalization, spectra values were constant. The fluorescence/Raman intensity ratio of calculus region showed significant differences compared to the cementum and dentin (p < 0.05). The fluorescence/Raman intensity ratio decreased with calculus debridement. For this analysis, the delta value was defined as the difference between the values before and after three strokes, with the final 2 delta values close to zero, indicating a gradual asymptotic curve and the change in intensity ratio approximating that of individual constants. Fluorescence/Raman intensity ratio was effectively used to cancel the angle- and distance-dependent fluctuations of fluorescence collection efficiency during measurement. Changes in the fluorescence/Raman intensity ratio near zero suggested that cementum or dentin was exposed, and calculus removed.
本研究的目的是通过测定荧光/拉曼强度比来评估牙根表面残留牙石的存在情况。使用便携式拉曼光谱仪对32颗牙根表面部分覆盖有牙石的拔除人类牙齿进行评估，并应用785nm、100mW的激光进行荧光/拉曼激发。采集的光谱以960cm处羟基磷灰石拉曼带强度进行归一化。在改变激光焦距和目标辐射角度后，从同一点记录拉曼光谱。对7颗牙齿的牙石、牙骨质和牙本质状况进行了评估。在25颗牙齿中，在进行三次清创术后测定荧光/拉曼强度比。从牙本质、牙骨质和牙石采集的拉曼光谱不同。归一化后，光谱值恒定。牙石区域的荧光/拉曼强度比与牙骨质和牙本质相比有显著差异（p<0.05）。荧光/拉曼强度比随着牙石清创而降低。对于该分析，差值定义为三次清创前后的值之差，最后两个差值接近零，表明为逐渐渐近曲线，强度比的变化近似于各个常数的变化。荧光/拉曼强度比有效地用于消除测量过程中荧光收集效率的角度和距离依赖性波动。荧光/拉曼强度比接近零的变化表明牙骨质或牙本质暴露，牙石被清除。
