The initial attachment of cemental fibrils to the root dentin surface in acellular and cellular cementogenesis in rat molars

To elucidate the initial attachment mechanism of cemental fibrils to the ro ot dentin surface in acellular and cellular cementogenesis, developing rat molars were observed by light microscopy and scanning electron microscopy c ombined with NaOH maceration. The NaOH maceration was used to observe detai ls of the positional association of cemental and dentinal fibrils during ce mentogenesis. An initial hematoxylin stained, cementum layer began to form on the root dentin surface with the first dentin mineralization in both ace llular and cellular cementogenesis. The initial attachment of cemental fibr ils to the dentin surface also began at this point. At the initial attachme nt the intermingling of cemental and dentinal fibrils occurred only in plac es. With advanced cementogenesis the initial cementum layer became the fibr il-poor cemento-dentinal junction. This suggests that cemental fibrils atta ch on the initial cementum layer, and not directly on dentinal fibrils, so that the layer results in the fibril-poor cemento-dentinal junction. The pr esent study suggests that an intervening adhesive is necessary for the ceme nto-dentinal attachment at any stage of cementogenesis in rat molars.