ESR Study of the Spin-labeled Poly(methyl methacrylate) Adsorbed on the Human Tooth and Hydroxyapatite

The motion and the configurational behavior of the poly(methyl methacrylate) adsorbed on the surfaces of human tooth substances (dentin, enamel, and hydroxyapatite crystal) from a solution were clarified by using the electron-spin-resonance technique. The polymer molecules were more strictly bound by the surfaces of enamel and hydroxyapatite than the dentin. On both enamel and hydroxyapatite, the adsorbed molecules behaved in the same manner in their motion and configuration. However, the segments directly bound by each tooth substance had a much higher degree of motional freedom than those by the silica surface. These results were discussed in relation to the interaction between the polymer and the tooth, and in relation to the clinical adhesive aspects.