TENSILE PROPERTIES OF RESIN-INFILTRATED DEMINERALIZED HUMAN DENTIN

The ability of adhesive resins to restore the physical properties of d emineralized dentin has not been well-documented. The unfilled resins that are used for adhesion have relatively low moduli of elasticity an d limited ability to increase dentin stiffness, although they may incr ease the ultimate tensile strength of dentin. This study tested the hy pothesis that resin infiltration of demineralized dentin can restore i ts tensile properties to those of mineralized dentin. Small (ca. 0.5 m m thick x 0.5 mm wide) specimens of demineralized human dentin were in filtrated with one of five different dentin bonding resins over many h ours, to determine how these resins altered the tensile properties of dentin. Tensile stress and strain were measured in these and control ( mineralized and demineralized) specimens until their ultimate failure. The results indicate that some adhesive resins, after infiltrating de mineralized dentin, can restore and even exceed the ultimate tensile s trength of mineralized dentin. These resins increased the modulus of e lasticity of resin-infiltrated dentin to values equal to or greater th an those of the resins but far below those of mineralized dentin. Alth ough the conditions in this experiment were far removed from the manuf acturer's recommendations or clinical practice, the results support th e potential of resin infiltration for reinforcing dentin.