Waidyasekera Kanchana, Nikaido Toru, Weerasinghe Dinesh, Watanabe Akihiko, Ichinose Shizuko, Tay Franklin, Tagami Junji
Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate school, Tokyo Medical and Dental University, Tokyo, Japan.
J Med Dent Sci. 2010 Mar;57(1):17-23.
Chronic endemic dental fluorosis is a malformation of teeth caused by excessive ingestion of fluoride during period of tooth development. Apatite crystallites and collagen fibrils determine the caries susceptibility related properties of dentine. Information relating the effect of dental fluorosis with dentine crystallite and collagen structure is currently unavailable. This study examined structural aberrations of apatite crystallites and collagen fibrils in human fluorosed dentine.
Superficial dentine of thirty six normal (Thylstrup-Fejerskov index - 0) and thirty six severely fluorosed (Thylstrup-Fejerskov index - 7 to 9) extracted human molars from individuals living in an area which is endemic for dental fluorosis were morphologically analyzed using transmission electron microscopy with selected area electron diffraction and dynamic force microscopy.
A statistically significant enlargement in the size of crystallites was found in fluorosed dentine (p<0.05). These crystallites were not homogenously arranged. Selected area electron diffraction revealed a lower density of crystallites in fluorosed dentine. Randomly distributed collagen fibrils showed a less complex lay out in contrast to normal dentine tissue.
Ultrastructure aberrations of the dentine explain the caries susceptibility of the tissue and suggest the necessity of special approach in dental caries treatment for patients with chronic severe endemic dental fluorosis.
慢性地方性氟斑牙是牙齿发育期间摄入过量氟化物导致的牙齿畸形。磷灰石微晶和胶原纤维决定了牙本质与龋齿易感性相关的特性。目前尚缺乏有关氟斑牙对牙本质微晶和胶原结构影响的信息。本研究检测了人类氟斑牙本质中磷灰石微晶和胶原纤维的结构畸变。
使用透射电子显微镜结合选区电子衍射和动态力显微镜，对来自氟斑牙流行地区的36颗正常（蒂尔斯楚普-费耶斯科夫指数-0）和36颗重度氟斑牙（蒂尔斯楚普-费耶斯科夫指数-7至9）的拔除人类磨牙的表层牙本质进行形态学分析。
在氟斑牙本质中发现微晶尺寸有统计学意义的增大（p<0.05）。这些微晶排列不均匀。选区电子衍射显示氟斑牙本质中微晶密度较低。与正常牙本质组织相比，随机分布的胶原纤维排列布局较简单。
牙本质的超微结构畸变解释了该组织的龋齿易感性，并表明对于慢性重度地方性氟斑牙患者，在龋齿治疗中需要采取特殊方法。
