Hegde Nishmitha N, Gatti Priya, Balan Usha, Ravinanthanan Manikandan, Vittal Chaithra Lakshmi, Hegde Mithra N
Departments of Conservative Dentistry and Endodontics, AB Shetty Memorial Institute of Dental Sciences, Nitte (Deemed to be University), Mangalore, Karnataka, India.
Department of Cell and Molecular Biology, University of California, Berkeley.
J Conserv Dent Endod. 2025 Jul;28(7):626-631. doi: 10.4103/JCDE.JCDE_237_25. Epub 2025 Jul 2.
Radiation therapy, which is frequently used to treat head-and-neck cancers, significantly alters the characteristics of dentin, making it more vulnerable to radiation caries.
To analyse the effect of radiation on microhardness and morphology of dentin.
After obtaining the Institutional ethical clearance (Nu/CEC/BRNS-01/2015), 40 freshly extracted molar teeth were obtained from the Department of Oral and Maxillofacial Surgery at the A. B. Shetty Memorial Institute of Dental Sciences, Mangalore. The teeth were disinfected and cleaned as per Occupational Safety and Health Administration regulations. The tooth samples were stored in distilled water at 4°C-8°C for further use. The roots of the tooth were removed and bisected longitudinally in mesiodistal direction using carborundum disc and a micromotor. The dentin's microhardness and Scanning Electron Microscopy (SEM) were examined before and after radiation.
Following radiation, the microhardness of the superficial, intermediate, and deep dentin significantly decreased ( < 0.001). Dentin tubule loss following radiation was revealed by the SEM analysis.
The radiation treatment decreases the microhardness of the dentin. 70 Gy radiation is damaging to dental tissues and can cause radiation caries. Damage to collagen fibrils causes changes in dentin, which significantly lowers the hardness and stability of dentin and lowers the microhardness of superficial, intermediate, and deep dentin. The SEM analysis showed the total destruction of tubule morphology postradiation.
放射治疗常用于治疗头颈癌,会显著改变牙本质的特性,使其更易患放射性龋齿。
分析辐射对牙本质显微硬度和形态的影响。
获得机构伦理批准(Nu/CEC/BRNS - 01/2015)后,从芒格洛尔A. B. 谢蒂纪念牙科学院口腔颌面外科获取40颗新鲜拔除的磨牙。按照职业安全与健康管理局的规定对牙齿进行消毒和清洁。将牙齿样本储存在4°C - 8°C的蒸馏水中以备进一步使用。去除牙根,使用碳化硅盘和微型电机沿近远中方向纵向将牙齿对半切开。在辐射前后检查牙本质的显微硬度和扫描电子显微镜(SEM)。
辐射后,表层、中层和深层牙本质的显微硬度显著降低(<0.001)。SEM分析显示辐射后牙本质小管缺失。
放射治疗会降低牙本质的显微硬度。70 Gy的辐射对牙齿组织有损害,可导致放射性龋齿。胶原纤维的损伤会引起牙本质变化,显著降低牙本质的硬度和稳定性,降低表层、中层和深层牙本质的显微硬度。SEM分析显示辐射后小管形态完全破坏。