Department of Cariology, Endodontology and Periodontology, University of Leipzig, Liebig Str. 12, Haus 1, 04103 Leipzig, Germany.
J Dent. 2017 Jul;62:31-35. doi: 10.1016/j.jdent.2017.05.005. Epub 2017 May 4.
This study evaluated (1) the detection and assessment of non-cavitated occlusal carious lesions by spectral domain optical coherence tomography (SD-OCT) and (2) the impact of varying angle of incidence (AI) of probe light and refractive index matching (RIM).
Nine extracted human molars with 18 occlusal lesions (ICDAS code 2) were visually selected. 18 regions of interest (ROI) were imaged with SD-OCT under varying AI (0°, ±5°, ±10°, ±15°) and with/without application of glycerine at 0°. X-ray micro computed tomography (μCT) was used as a validation standard. μCT and OCT signals were categorized according to the lesion extent: 1-sound, 2-lesion limited to half of enamel, 3-lesion limited to enamel, 4-lesion into dentin. Agreement between both methods was assessed. Intra- and inter-examiner reproducibility analyses were conducted.
Cohen's kappa coefficient (κ), Spearman's rho correlation (r) and Wilcoxon test (α=0.05).
Slight to moderate agreement (κ=0.153) between μCT and OCT was obtained at an AI of 0° (Wilcoxon: p=0.02). With variation of Al a substantial agreement (κ=0.607) was observed (p=0.74). Spearman's correlation between both methods was 0.428 at 0°, 0.75 with varying AI and 0.573 with glycerine. Kappa values for intra-and inter-examiner analysis ranged between 0.81 and 0.88 and between 0.25 and 0.73, respectively.
Variation of AI improves the detectability of non-cavitated occlusal carious lesions. RIM can enhance signal-to-noise ratio.
OCT could provide additional diagnostic information in single and longitudinal assessments of occlusal carious lesions.
本研究评估了（1）光谱域光相干断层扫描（SD-OCT）对非龋性窝沟病变的检测和评估，以及（2）探针光入射角（AI）和折射率匹配（RIM）变化的影响。
从 9 颗离体磨牙中选择了 18 颗窝沟龋（ICDAS 编码 2）。在不同 AI（0°、±5°、±10°、±15°）下，SD-OCT 对 18 个感兴趣区域（ROI）进行成像，并在 0°时应用/不应用甘油。X 射线微计算机断层扫描（μCT）被用作验证标准。根据病变范围对 μCT 和 OCT 信号进行分类：1-完好，2-病变局限于釉质一半，3-病变局限于釉质，4-病变进入牙本质。评估两种方法之间的一致性。进行了内部和外部检查者重现性分析。
Cohen's kappa 系数（κ）、Spearman's rho 相关系数（r）和 Wilcoxon 检验（α=0.05）。
在 AI 为 0°时，μCT 和 OCT 之间获得了轻微到中度的一致性（κ=0.153）（Wilcoxon：p=0.02）。随着 AI 的变化，观察到高度一致（κ=0.607）（p=0.74）。两种方法之间的 Spearman 相关性在 0°时为 0.428，在变化 AI 时为 0.75，在使用甘油时为 0.573。内部和外部检查者分析的 κ 值范围分别为 0.81 至 0.88 和 0.25 至 0.73。
AI 的变化可提高非龋性窝沟病变的检测能力。RIM 可以提高信噪比。
OCT 可以在窝沟龋的单次和纵向评估中提供额外的诊断信息。
