Grevstad H J, Selvig K A
Scand J Dent Res. 1985 Aug;93(4):289-303. doi: 10.1111/j.1600-0722.1985.tb01972.x.
The morphology of the continuously erupting rabbit incisor differs characteristically from that of the rodent incisor and is incompletely known. In this study, permanent incisors from fetal New Zealand white rabbits aged 26-30 days in utero were processed for transmission electron microscopy. Examination of longitudinal and cross-sections revealed that disintegration of the epithelial sheath on root analog surfaces was followed by cementogenesis. The first layer of cementum matrix was seen on the mesial aspect and consisted of a finely granular ground substance and a few embedded collagen fibrils which extended to the cementodentinal junction. Within the period 27-30 days in utero, acellular cementum was formed on all root-analog surfaces and, in addition, formed a fine coating over the enamel. Although the initially formed cementum layer contained fewer collagen fibrils than subsequent layers, a layer of so-called intermediate cementum was not observed.
持续萌出的兔切牙形态与啮齿动物切牙形态有显著差异，且尚未完全明确。在本研究中，对子宫内26 - 30日龄的新西兰白兔胎儿的恒切牙进行透射电子显微镜处理。纵切面和横切面检查显示，牙根类似物表面的上皮鞘解体后发生牙骨质生成。在近中面可见牙骨质基质的第一层，由细颗粒状基质和一些延伸至牙骨质牙本质界的嵌入胶原纤维组成。在子宫内27 - 30日龄期间，无细胞牙骨质在所有牙根类似物表面形成，此外，还在釉质上形成一层薄涂层。尽管最初形成的牙骨质层所含胶原纤维比后续层少，但未观察到所谓的中间牙骨质层。
