Abdalla Rowida, Omar Amr, Eid Kareem
Division of Restorative Dentistry, Department of Oral Health Practice, D632A UK Chandler Hospital, University of Kentucky, Lexington, KY, 40536-0297, USA.
Health Radiation Research Department, National Center for Radiation Research and Technology (NCRRT), Atomic Energy Authority, Cairo, Egypt.
Radiat Environ Biophys. 2018 Aug;57(3):293-299. doi: 10.1007/s00411-018-0749-2. Epub 2018 Jun 14.
The purpose of this study was to evaluate the ability of radiographic densitometry in detecting the early demineralization of human enamel and cementum in irradiated and non-irradiated teeth. Sixty extracted teeth were divided into two groups: irradiated group and non-irradiated group. After irradiation, the groups were subjected to demineralization-remineralization (PH) cycling. Radiographic densitometric measurements (gray values) of a selected area of interest in the enamel and in the cementum of each tooth were performed at baseline and after PH cycling. After PH cycling, there was a significant reduction in gray values for both groups. The difference between "baseline" and "after PH cycling" values represents the reduction in the mineral content of the hard tissue, i.e., the demineralization. Results show that the demineralization of irradiated tooth enamel and cementum was significantly higher compared to that of non-irradiated tissues as determined by gray-level values. It is concluded that densitometric measurements by means of digital radiographs allow for the detection of demineralization of enamel and cementum, and can be used successfully for diagnosis of the early carious lesions in patients who received head and neck radiotherapy. This will allow implementation of remineralizing therapy and avoid the risk of progression of radiation caries. Furthermore, it is concluded that gamma irradiation with typical therapeutic doses for head and neck carcinoma is a direct cause of demineralization of tooth enamel and cementum.
本研究的目的是评估射线密度测定法检测受照射和未受照射牙齿中人类牙釉质和牙骨质早期脱矿的能力。60颗拔除的牙齿被分为两组：照射组和未照射组。照射后，两组进行脱矿-再矿化（pH）循环。在基线和pH循环后，对每颗牙齿的牙釉质和牙骨质中选定的感兴趣区域进行射线密度测量（灰度值）。pH循环后，两组的灰度值均显著降低。“基线”值与“pH循环后”值之间的差异代表硬组织矿物质含量的降低，即脱矿。结果表明，通过灰度值测定，受照射牙齿的牙釉质和牙骨质脱矿程度明显高于未受照射组织。得出结论，通过数字射线照片进行密度测量可以检测牙釉质和牙骨质的脱矿情况，并可成功用于诊断接受头颈部放疗患者的早期龋损。这将有助于实施再矿化治疗并避免放射性龋齿进展的风险。此外，得出结论，头颈部癌典型治疗剂量的伽马射线照射是牙釉质和牙骨质脱矿的直接原因。
