Sequence of protein expression of bone sialoprotein and osteopontin at the developing interface between repair cementum and dentin in human deciduous teeth

Abstract

Experimental periodontal regeneration studies have revealed the weak binding of repair cementum to the root surface, whereas attachment of cementum to dentin preconditioned by odontoclasts appears to be superior. The aim of this study has been, therefore, to analyze the structural and partial biochemical nature of the interface that develops between resorbed dentin and repair cementum by using human deciduous teeth as a model. Aldehyde-fixed and decalcified tooth samples were embedded in acrylic or epoxy resins and sectioned for light and transmission electron microscopy. Antibodies against bone sialoprotein (BSP) and osteopontin (OPN), two noncollagenous proteins accumulating at hard tissue interfaces in bone and teeth, were used for protein A-gold immunocytochemistry. Light microscopy revealed a gradually increasing staining intensity of the external dentin matrix starting after the withdrawal of the odontoclast. Labeling for both BSP and OPN was first detected among the exposed collagen fibrils and in the intratubular dentin matrix when odontoclasts had withdrawn but mesenchymal cells were present. Subsequently, collagen fibrils of the repair cementum were deposited concomitantly with the appearance of labeling for BSP and OPN over the intratubular, intertubular, and peritubular dentin matrix. Labeled mineralization foci indicated the advancing mineralization front, and the collagenous repair matrix became integrated in an electron-dense organic material that showed labeling for BSP and OPN. Thus, no distinct planar interfacial matrix layer lies between the resorbed dentin and the repair cementum. The results suggest that odontoclasts precondition the dentin matrix such that the repair cementum becomes firmly attached.

Ultrasound Stimulation Induces PGE2 Synthesis Promoting Cementoblastic Differentiation Through EP2/EP4 Receptor Pathway

“…In addition, Inubushi et al (2008) reported that US promoted early cementoblastic differentiation of immature human cementoblasts. Cementoblasts share many characteristics with osteoblasts, including similar molecular properties and the ability to promote mineralization (Matias et al 2003;Bosshardt et al 2005). Because the effects of USinduced PGE 2 in cementoblasts metabolism have not yet been raised as the subject of investigation, we thus accessed the available information about the effects of US stimulation on osteoblasts' metabolism.…”

Immunohistochemical analysis of periodontal reattachment on denuded root dentin after periodontal surgery

“…There have been two opinions for the etching effects. First, the etching removes a smear layer and exposes the dentinal matrix fibers, resulting in that the fibers of regenerated cementum can be easily interwoven with those of dentin, to reinforce the cemento-dentinal attachment (6,8). Second, some electron-dense substances, which inhibit the cemento-dentinal adhesion, remain on the dentin defect, but are removed by etching (6,17,21).…”

Expression and processing of small integrin-binding ligand N-linked glycoproteins in mouse odontoblastic cells

“…OPN is a secreted adhesive glycoprotein expressed in both mineralized and non-mineralized tissues (20). In mineralized tissues, this gene expression is relatively abundant in bone (13) but also found in dentin (9,(21)(22). Defective OPN gene in mice increases mineral content and crystallinity (23).…”

“…Also, these proteins contain an Arg-Gly-Asp (RGD) motif that mediates cell attachment/signaling via interaction with cell surface integrins and post-translational modification of phosphorylation and glycosylation. These SIBLING genes are highly expressed in mineralizing tissues related to tooth and bone development and mineralization (9)(10)(11)(12)(13)(14)(15)(16)(17).…”