Montoya C, Arango-Santander S, Peláez-Vargas A, Arola D, Ossa E A
Materials Engineering Research Group, School of Engineering, Universidad Eafit, Medellín, Colombia.
Faculty of Dentistry, Universidad Cooperativa de Colombia, Envigado, Colombia.
Arch Oral Biol. 2015 Dec;60(12):1811-20. doi: 10.1016/j.archoralbio.2015.10.002. Epub 2015 Oct 9.
Understanding the effects of biological aging on human tissues has been a topic of extensive research. With the increase in healthy seniors and quality of life that topic is becoming increasingly important. In this investigation the effects of aging on the microstructure, chemical composition and hardness of human coronal dentin was studied from a comparison of teeth within "young" and "old" age groups.
The microstructure of dentin within three regions (i.e., inner, middle and outer) was analyzed using electron and optical microscopy. The mineral-to-collagen ratio in these three regions was estimated using Raman spectroscopy and the hardness was evaluated using microindentation.
Results showed that there were significant differences in tubule density, tubule diameter and peritubular cuff diameter with depth. Although there was no difference in tubule density and diameter of the tubules between the age groups, there was a significant difference in the occlusion ratio. A significant increase in hardness between young and old patients was found for middle and outer dentin. An increase in mineral-to-collagen ratio from inner to outer dentin was also found for both groups. In old patients, an increase in mineral content was found in outer coronal dentin as a consequence of tubule occlusion.
An increase in occlusion ratio, hardness, and mineral content was found in the dentin of adult patients with age. This increase is most evident in the outer coronal dentin.
了解生物衰老对人体组织的影响一直是广泛研究的课题。随着健康老年人数量的增加和生活质量的提高，这一课题变得越来越重要。在本研究中，通过比较“年轻”和“老年”年龄组的牙齿，研究了衰老对人牙冠部牙本质的微观结构、化学成分和硬度的影响。
使用电子显微镜和光学显微镜分析三个区域（即内层、中层和外层）牙本质的微观结构。使用拉曼光谱法估计这三个区域的矿物质与胶原蛋白的比例，并使用微压痕法评估硬度。
结果表明，牙本质小管密度、小管直径和管周套袖直径随深度存在显著差异。虽然年龄组之间牙本质小管密度和直径没有差异，但闭塞率存在显著差异。发现年轻患者和老年患者的中层和外层牙本质硬度有显著增加。两组从内层到外层牙本质的矿物质与胶原蛋白比例也都有所增加。在老年患者中，由于牙本质小管闭塞，牙冠外层牙本质的矿物质含量增加。
发现成年患者的牙本质中闭塞率、硬度和矿物质含量随年龄增加。这种增加在牙冠外层牙本质中最为明显。
