Chowdhary N, Subba Reddy V V
Department of Pedodontics and Preventive Dentistry, HKE's S. Nijalingappa Institute of Dental Sciences and Research, Gulbarga, India.
J Indian Soc Pedod Prev Dent. 2010 Jul-Sep;28(3):167-72. doi: 10.4103/0970-4388.73793.
Dentin is the fundamental substrate of restorative dentistry and its properties and characteristics are key determinants of nearly all restorative, preventive and disease processes of the teeth. The intrinsic permeability of dentin is responsible for permitting bacterial or chemical substances to diffuse across the dentin and irritate the pulpal and periradicular tissues. Improved understanding of the dentin structure and nature will have important consequences for today's dental procedures. The aims of the study were to observe the direction of dentinal tubules, interglobular dentin, incremental lines of dentin and the dead tracts.
A total of 30 teeth (15 primary and 15 permanent molars), unrestored, noncarious, hypoplastic extracted molars were used. Longitudinal ground sections of teeth were obtained using hard tissue microtome.
Examination of ground sections of the primary teeth dentin showed "s"-shaped curvature in four (26.7%) specimens and a straight course of dentinal tubules in 11 (73.3%) specimens out of 15 teeth examined whereas in permanent teeth, all 15 (100%) specimens showed an "s"-shaped curvature. These results are statistically highly significant (P < 0.001).
Dentinal tubules followed an "s"-shaped course in all the 15 (100%) permanent molars and in four (26.7%) primary molars. There was no significant difference in the occurrence of interglobular dentin of primary and permanent molars. But, they were at angles in the primary teeth.
牙本质是修复牙科的基本基质，其性质和特征是几乎所有牙齿修复、预防和疾病过程的关键决定因素。牙本质的固有渗透性使得细菌或化学物质能够扩散穿过牙本质并刺激牙髓和根尖周组织。对牙本质结构和性质的深入了解将对当今的牙科手术产生重要影响。本研究的目的是观察牙本质小管的方向、球间牙本质、牙本质生长线和死区。
共使用30颗未修复、无龋、发育不全的拔除磨牙（15颗乳牙和15颗恒牙）。使用硬组织切片机获得牙齿的纵向磨片。
在检查的15颗乳牙中，4颗（26.7%）标本的牙本质磨片显示牙本质小管呈“s”形弯曲，11颗（73.3%）标本的牙本质小管呈直线状；而在恒牙中，所有15颗（100%）标本均显示牙本质小管呈“s”形弯曲。这些结果具有高度统计学意义（P < 0.001）。
在所有15颗（100%）恒牙和4颗（26.7%）乳牙磨牙中，牙本质小管呈“s”形。乳牙和恒牙磨牙中球间牙本质的发生率没有显著差异。但是，它们在乳牙中的角度不同。
