Studies on dental self-curing resins. XV. Application of nitrene to reactive adhesive with a tooth.

Effectiveness of p-azidobenzoyloxyethyl methacrylate on the adhesion of a tooth was studied. This methacrylate, dissolved in suitable monomer solvents such as 2-hydroxyethyl methacrylate, was painted on ivory- or acid-etched enamel and the surface was irradiated by ultraviolet light. Photolysis of the azide produced a nitrene which was reactive with polypeptides in the tooth. As the treated surface must have affinity with methyl methacrylate (MMA) and pol(methyl methacrylate) (PMMA), it was joined with a PMMA bar by the self-curing resin. The adhesive strength was 100 kg/cm2 with ivory or 65 kg/cm2 with enamel. Graft copolymerization of methyl methacrylate onto collagen may take place by the nitrene prepared in situ by photolysis of the azide. Subject to satisfactory biologic evaluation, this coupler may be useful in the development of adhesive dental filling materials and fissure sealants.