龋影响牙本质折射系数变化的体外研究

doi:10.13701/j.cnki.kqyxyj.2018.08.011

口腔医学研究 ›› 2018, Vol. 34 ›› Issue (8): 841-845.DOI: 10.13701/j.cnki.kqyxyj.2018.08.011

龋影响牙本质折射系数变化的体外研究

丁江峰^1*, 高青枫², 陆敏华²

1. 深圳市南山区人民医院(深圳大学第六附属医院)口腔科广东深圳 518060;
2. 深圳大学医学院生物医学工程系广东深圳 518060

收稿日期:2018-02-19 出版日期:2018-08-28 发布日期:2018-08-23
通讯作者: 丁江峰,E-mail:tintindjf@126.com
作者简介:丁江峰(1980~ ),男,湖北人,硕士,副主任医师,主要从事牙体牙髓病学研究工作。
基金资助:
广东省医学科研基金(编号:A2015606);深圳市科创委科研基金(编号:JCYJ20150402152130179)

Evaluation on Refractive Index of Caries-affected Dentin: An In Vitro Study

DING Jiang-feng^1*, GAO Qing-feng², LU Min-hua²

1. Shenzhen Nanshan People's Hospital (The 6th Affiliated Hospital of Shenzhen University), Shenzhen 518060, China;
2. The School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen 518060, China

Received:2018-02-19 Online:2018-08-28 Published:2018-08-23

摘要/Abstract

摘要： 目的:利用光学相干断层成像技术(OCT)分析龋影响牙本质折射系数变化。方法:选取4颗无龋坏和15颗颌面牙本质龋下颌第三磨牙。垂直牙冠长轴制备厚度为300~500 μm的10个无龋和15个龋影响牙本质切片,分别纳入对照和研究组。使用micro-CT和自建OCT扫描切片并重建其三维数字模型。应用基于改良canny边界提取技术的光程通路法分析无龋和龋影响牙本质切片折射系数;通过对比牙本质切片和参考体(K₂HPO₄液)的X线灰度值,计算龋影响牙本质矿化密度。结果:由参考中心点到釉牙本质界,无龋牙本质折射系数先增大而后减小,均值为1.578;龋影响牙本质折射系数无明显变化,均值为1.507,两者间存在显著差异(P<0.001)。龋影响牙本质折射系数和矿化密度间存在显著正相关趋势(P<0.001)。结论:龋引起牙本质折射系数发生改变。矿化密度是导致牙本质折射系数下降的重要因素。

关键词: 光学相干断层成像, 牙本质厚度, 折射系数, 龋影响牙本质

Abstract: Objective: To analyze the variation of refractive index (RI) of caries-affected dentin by using OCT. Methods: Nineteen extracted third molars were selected, and four of which were caries free and other fifteen had occlusal dentin caries. The dentin slices with thickness ranging from 300 to 500μm were prepared perpendicular to long axis of the tooth crown for all teeth. Ten slices from caries free teeth were chosen as the control group. Fifteen slices were chosen as the study group. All dentin slices were scanned by micro-CT and a self-built OCT system (Dental 1.0, demo), and reconstructed to be three-dimensional digital slices. The RI of the caries-free and caries-affected dentin slices were calculated by optical path length-matching method basing on an improved canny edge detection algorithm. The mineral density (MD) of the caries-affected dentin slices was evaluated by comparing the grayscale difference between the slice and the calibration phantom using K₂HPO₄ liquids. Results: ith an increase of the distance from the reference center to enamel-dentin junction (EDJ), the RI of caries-free dentin increased firstly and then decrease, while that of caries-affected dentin is less affected. The mean value of RI of the caries-free dentin was 1.578, which was significantly higher than that of the caries-affected dentin (P<0.001). A good linear correlation was found between the RI and MD (Pearson's r=0.78) in the caries-affected dentin (P<0.001). Conclusion: Caries would lead to variation of refractive index of dentin. The mineral density was an important factor causing the decrease of dentin refractive index.

Key words: Optical coherence tomography, Dentin remaining thickness, Refractive index, Caries-affected dentin

丁江峰, 高青枫, 陆敏华. 龋影响牙本质折射系数变化的体外研究[J]. 口腔医学研究, 2018, 34(8): 841-845.

DING Jiang-feng, GAO Qing-feng, LU Min-hua. Evaluation on Refractive Index of Caries-affected Dentin: An In Vitro Study[J]. Journal of Oral Science Research, 2018, 34(8): 841-845.

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龋影响牙本质折射系数变化的体外研究

Evaluation on Refractive Index of Caries-affected Dentin: An In Vitro Study

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