Effect of sulfonamides and 4-MET on adhesion to tooth substrates.

Adhesion of a composite to tooth substrates was studied. The bonding liner was a mixture: camphorquinone, 0.5%; one of four sulfonamides (A, B, C, and D), 0.5%; 4-methacryloxyethyl trimellitate (4-MET), 0, 2, and 5%; in triethyleneglycol dimethacrylate (TEGDMA). The best tensile bond strength to bovine dentin treated with 0.3 M EDTA 2 Na-0.2 M EDTA FeNa (EDTA 3-2) was 7.5 MPa. The bond strength to bovine dentin decreased with the addition of 4-MET. The bond strength to bovine enamel treated with 65% phosphoric acid (H3PO4) was 12.0 MPa. The tensile bond strength to bovine enamel treated with EDTA 3-2 was lower than that to enamel treated with 10% citric acid-3% ferric chloride (10-3) and with H3PO4. The polymerization of these liners was characterized by differential scanning calorimetry (DSC). The photocurable bonding liner studied was adequate for clinical studies.