Study On Preparation And Properties Of Visible Light Cured Dental Adhesive

In recent years, visible light cured adhesive is being widely employed in restorative dentistry. Because of this kind of adhesive can be used to act as a barrier against microleakage, sealing the interface between the teeth and the filling and holding them together through some forms of surface attachment that may be mechanical, chemical or a combination of both methods. So the clinical success of fixed restorative composite resin and against secondary caries is heavily dependent on the visible light adhesive with good performance. But the durable problem and strength problem of adhesive have not been altogether resolved because of peculiarities of the oral circumstances and teeth texture. The goal of this subject is to develop a kind of visible light cured adhesive which has excellent adhesive strength and water-resistant property.In this thesis, the experiments included two parts: firstly, the matrix resin of visible light cured adhesive and composite resin were synthesized and characterized; secondly, adhesive system was prepared and tested.Firstly, four matrix resins were synthesized. The maleic anhydride modified epoxy methylacrylate was synthesized from the reaction of the maleic anhydride, the epoxy resin and the methacrylic acid by direct esterification. The polyurethane methylacrylate was synthesized from tolylene 2,4-diisocyanate, hydroxyethyl methacrylate and polyethylene glycol-400, and then altogether mixed with the maleic anhydride modified epoxy methacrylate. One isocyanate modified epoxy methylacrylate was prepared with hexamethylene diisocyanate and epoxy methylacrylate. The other one was synthesized from diphenylmethane diisocyanate and epoxy methylacrylate. Secondly, visible light cured adhesive and composite resin were made through adding active diluent, photoinitiator, coupling agent and filling material etc. into the matrix resin. The effects of the different matrix resins and each component on properties of adhesive system were investigated also. Finally, the best formulation of adhesive was obtained through orthogonal experiment.The experimental results about the four matrix resins indicated that the adhesive system would obtain the best performance when the diphenylmethane diisocyanate modified epoxy methylacrylate was used to act as the matrix resin in the four matrix resins. When the mass ratio of the matrix resin and the active diluent was 3:2 and the content of photoinitiator and coupling agent was 0.4% and 0.5% respectively, the shearing strength of adhesive achieved 8.64MPa and 12.18MPa for the glass and the tooth respectively. When the mass ratio of the matrix resin and active diluent was 3:2, the content of photoinitiator was 0.3%, the content of filling material was 30%, the compressive strength and cured depth of composite resin achieved 240MPa and 4.14mm respectively.