methacryloyl-tyrosineamide and hydroxyethyl-methacrylate

Seven types of amide monomers, methacryloyl tyrosine amide (MTYA), p-methacryloxybenzamide (p-MBA), p-methacryloxybutoxybenzamide (p-MBBA), o-methacryloxybutoxybenzamide (o-MBBA), p-methacryloxybutoxy phenylpropionamide (p-MBPPA), 3,5-dimethacryloxybenzamide (3,5-DMBA), and 3,5-di (methacryloxybutoxy)benzamide (3,5-DMBBA), were prepared for use as bonding agents. The monomers were dissolved in HEMA. Bovine enamel was etched with 40% phosphoric acid, and bovine dentin was etched with 10% citric acid before being primed with MTYA.G.H. The tensile bond strengths between bovine enamel or dentin and experimental adhesives were measured after one day immersion in water at 37 degrees C. HEMA was used as a control adhesive. When bonding to etched enamel, the bond strengths of composite resins with o-MBBA and 3,5-DMBA were significantly higher than those with HEMA. The bond strengths of composites with MTYA, p-MBA, p-MBBA, 3,5-DMBBA and p-MBPPA were almost the same as those with HEMA. When bonding to dentin, the bond strengths of composite resin with MTYA and p-MBBA were significantly higher than those with HEMA.

Topics: Acid Etching, Dental; Adhesiveness; Amides; Analysis of Variance; Benzamides; Composite Resins; Dental Bonding; Dental Cements; Dental Enamel; Dentin; Methacrylates; Molecular Structure; Phenylpropionates; Tensile Strength; Tyrosine

New dentin etchants AC (ammonium citrate) were examined. The pH of the AC solution was 7.3-7.4, and the concentration of the solutions varied from 5% to 30%. The etching of a 10% AC solution was the most effective in improving the adhesion between the composite resin and dentin among the AC solutions employed when MTYA.G.H was used as a dentin primer. The smear layer was removed and the tubules were not generally opened with AC etching. The bond strengths to dentin etched with 10% AC were comparable with those to dentin etched with neutralized 0.5 M EDTA or EDTA 3.2. The bond strengths increased with primers MTYA.H and MTYA.G.H, in that order.

Topics: Acid Etching, Dental; Animals; Cattle; Citrates; Citric Acid; Composite Resins; Dental Bonding; Dentin; Edetic Acid; Glutaral; Methacrylates; Tyrosine

In this study the efficacy of the primer on adhesion of MMA (TBB-O) resin to dentin was investigated. The primer consists of two parts. One is 6% MTYA and 70% HEMA aqueous solution, and the other is 2% glutaraldehyde aqueous solution. As an etching agents, 10% citric acid-3% FeCl3 (10-3), 40% phosphoric acid, 10% citric acid, and 0.5 M EDTA were used. After etching, the two parts of the primer were mixed well and applied on the etched surface. Then MMA (TBB-O) resin or p-MBA/MMA (TBB-O) resin was applied on the treated surface. The tensile bond strengths after storage in 37 degrees C water were measured. It revealed that the primer treatment increased the bond strength despite the kind of etching agents. Though the thickness of the resin reinforced dentin was the same as that of demineralized dentin, it was not proportional to the bond strength. Then the durability of the adhesion to dentin treated with primer was examined by the thermal cycling tests. After 2000 thermocycles between 5 degrees C and 55 degrees C, the decrease in the bond strength was very small.

Topics: Acid Etching, Dental; Acrylic Resins; Adhesives; Animals; Boron Compounds; Cattle; Dental Bonding; Dentin; Methacrylates; Methylmethacrylate; Methylmethacrylates; Tensile Strength; Tyrosine