Presence and role of noncollagenous proteins in dentin: Dentin siaolproten, bone sialoprotein and osteopontin

Abstract

Dentin, as a specific hard tooth tissue is very rich in organic materials, representing approximately 20% of its weight and 33% of its volume. The basic organic component of dentin is collagen. However, the noncollagenous organic content of dentin has not been sufficiently studied. Dentin and its complex ultrastructure, molecular content and biochemical process, playing the main role in dentinogenesis, still haven’t been fully explained, which presents a real scientific challenge. Protein separation was done with sodium dodecil sulfate poliacrilamid gel electrophoresis (SDS PAGE) technique in which polipeptides are separated by the differences in their molecular masses.Electrophoretic analysis of proteins is very important in basic research of proteins family which are organic constituents of the dentin tissue. Research results revealed significant presence of dentin sialoprotein, bone sialo protein and osteopontin in analized samples of dentin. Dentin sialoptotein (DSP) is one of the specific proteins in dentin, and its produced by secretory activity of mature odontoblasts. It also represents a reliable phenotype marker of odontoblasts. The fact that dentin sialoprotein is specific for dentin and cannot be found in any other tissue implicate sits unique, critical and key-roll in dentinogenesis. Bone sialoprotein (BSP) and osteopontin, revealed in this research, are not specific for dentin. They are produced both by odontoblasts and osteoblasts. Bone sialoprotein may have a function in the initiation of the crystal hydroxiapatite growth in mineralized tissues. Osteopontin and alkaline phosphatase could be the markers of the odontoblast differentiation. Upon analyzing the characteristics of the presented nonspecific proteins, the necessity of their presence during the process of dentinogenesis can be stated as a conclusion to this research.