The fibrous structure of the cemento-dentinal junction in human molars shown by scanning electron microscopy combined with NaOH-maceration

The cemento-dentinal junction was studied in acellular and cellular cementu m of human mandibular third molars by scanning electron microscopy combined with NaOH-maceration. Scanning electron microscopy with NaOH-maceration wa s applied to observe the fibrous structure in detail through long sections of the cemento-dentinal junction. In macerated specimens, the cemento-denti nal junction was a fibril-poor groove. Some cemental fibrils or fibril bund les penetrated the groove and appeared to intermingle with dentinal fibrils . Prolonged maceration caused detachment of the cemento-dentinal junction i rrespective of fibril intermingling allowing observation of the inner cemen tum surface facing the root dentin. Observations suggested that the fibril intermingling was point-like and present only in places at the cemento-dent inal junction. It was established that NaOH-maceration removes interfibrill ar substances effectively in connective tissues and does no damage to the c ollagen fibril structure and architecture. This study showed the 3-dimensio nal fibrous structure of the cemento-dentinal junction in human mandibular third molars, and suggested that interfibrillar adhesive substances are mor e important than the fibril intermingling for the cemento-dentinal attachme nt.