A comparison of fibronectin and laminin binding to undemineralized and demineralized tooth root surfaces

Abstract

To determine the effect of altering the nature of the surface of the roots of teeth upon selective attachment of specific cell types, we have studied the binding of fibronectin (FN) and laminin (LN) to both undemineralized and demineralized root surfaces using a modified direct ELISA. Discs of dentine with the cementum removed were prepared from porcine premolar roots and incubated with various concentrations of FN or LN. The amount of attachment protein that binds to the dentine surface was determined using specific antibodies. It was found that FN binding was two‐fold greater on demineralized compared to undemineralized root surfaces. Healing the demineralized discs increased FN binding, whereas bacterial collagenase treatment essentially abolished binding, suggesting that FN binding occurred to exposed collagen fibres. In contrast, FN binding on undemineralized discs was unaffected by heat or collagenase treatment. Pronase treatment eliminated FN binding to demineralized and to undemineralized discs, whereas 4M guanidine hydrochloride extraction increased binding lo undemineralized discs, indicating that a non‐collagenous protein on Ihe undemineralized surface may bind to FN, Studies with LN showed a two‐fold greater binding of LN to undemineralized compared to the demineralized roots. These results indicate that surface treatment of exposed roots may be used to promote the adhesion of specific attachment proteins and thereby promote selective attachment of cells to tooth root surfaces.