Murray P E, Matthews J B, Sloan A J, Smith A J
Oral Biology, School of Dentistry, The University of Birmingham, St. Chad's Queensway, B4 6NN, Birmingham, UK.
Arch Oral Biol. 2002 Oct;47(10):709-15. doi: 10.1016/s0003-9969(02)00055-9.
Pulp cell function and viability is important for maintaining tooth vitality throughout life. However, the effects of ageing on pulpal cell populations and pulp tissue remodelling are still unclear. The aim here was to quantify age-related cell-density changes in the pulp of rat incisor teeth, using histomorphometric analysis and ANOVA. Mandibular (n=35) and maxillary (n=34) incisors were carefully extracted from 20 Wistar rats aged between 1 and 18 months, fixed and processed for light microscopy. Cell counts were performed in mature and immature regions at both labial and lingual aspects of all teeth. Odontoblast and subodontoblast cell densities were reported per mm of pulp-dentine border and core fibroblast density per mm2 pulp tissue. Irrespective of age, odontoblast and subodontoblast densities were lower in the immature than the mature regions of both maxillary and mandibular incisors (P<0.001). However, in both regions odontoblast and subodontoblast densities decreased significantly with increasing age (P<0.0001). The age-related reduction in odontoblasts was significantly greater in mature than immature regions (P<0.02) but not influenced by other variables. In contrast, the age-related reduction in subodontoblasts was significantly different between mandibular and maxillary teeth (P=0.012) but not influenced by site. Unlike odontoblasts and subodontoblasts, core fibroblasts showed small but significant increases with increasing age (P<0.0001). These age-related reductions in the density of odontoblasts and subodontoblasts may partly explain the slower rate of secondary dentine secretion and decreased pulp repair activity associated with ageing.
牙髓细胞的功能和活力对于维持牙齿一生的生命力至关重要。然而，衰老对牙髓细胞群体和牙髓组织重塑的影响仍不清楚。本研究的目的是使用组织形态计量学分析和方差分析来量化大鼠切牙牙髓中与年龄相关的细胞密度变化。从20只年龄在1至18个月之间的Wistar大鼠中小心提取下颌切牙（n = 35）和上颌切牙（n = 34），固定并进行光镜处理。对所有牙齿唇面和舌面的成熟和未成熟区域进行细胞计数。报告每毫米牙髓-牙本质界的成牙本质细胞和成牙本质细胞下层细胞密度以及每平方毫米牙髓组织的核心成纤维细胞密度。无论年龄如何，上颌和下颌切牙未成熟区域的成牙本质细胞和成牙本质细胞下层密度均低于成熟区域（P < 0.001）。然而，在这两个区域，成牙本质细胞和成牙本质细胞下层密度均随年龄增长而显著降低（P < 0.0001）。成熟区域成牙本质细胞与年龄相关的减少显著大于未成熟区域（P < 0.02），但不受其他变量影响。相比之下，下颌和上颌牙齿成牙本质细胞下层与年龄相关的减少存在显著差异（P = 0.012），但不受部位影响。与成牙本质细胞和成牙本质细胞下层不同，核心成纤维细胞随年龄增长呈现小幅度但显著的增加（P < 0.0001）。成牙本质细胞和成牙本质细胞下层密度与年龄相关的这些减少可能部分解释了与衰老相关的继发性牙本质分泌速率减慢和牙髓修复活性降低的原因。
