Evaluation of MMA-4-META-TBB resin as a dental adhesive material

A new adhesive resin containing a reactive monomer, 4-methacryloxyethyl trimellitate anhydride (4-META) was prepared, and its application to hard tooth tissues and metals was studied. Scanning electron microscopy showed that the average length of 4-META resin tags in enamel and dentin was 22 mu and 40 mu respectively. The tensile adhesive strength between 4-META resin and enamel was about 130 kg/cm2 after etching with 65% phosphoric acid. Its bond strength to dentin treated with a cleaning solution of 10% citric acid and 3% ferric chloride was about 190 kg/cm2. In precious alloys heated at 500 degrees C for 5-10 minutes, a bond strength of more than 100 kg/cm2 was obtained. The precious alloys containing Au, Ag, Pt and Cu should be selected especially for dental restorations. In polished non-precious alloys, the bond strength was greater than 100 kg/cm2. If non-precious alloys were oxidized with HNO3, the bond strength increased to 150-200 kg/cm2. The results suggest that the nickel-chromium alloy used in fixed prosthodontics must be treated chemically before adhesion with 4-META resin, but cobalt-chromium alloy used in removable partial dentures bonds well with 4-META resin without chemical treatment. In conclusion, MMA-4-META-TBB resin seems to be a promising adhesive material in dentistry.