Development of Non-Shrinkage Composite Resins : Expansible Monomers for Radical Polymerization

In this study, two kinds of expansible monomersisophorone and trimethyl hexamethylene diisocyanate containing bicyclic ortho ester structuressynthesized, and various expansible composite resins，dilute monomers （triethylene glycol dimethacrylate and two）mixtures (isophorone diisocyanate or trimethyl hexamethylene diisocyanate：hydroxyethyl methaerylate=2：1) ratio和trial microspherical filler with improved surface (75wt%) were prepared. The physicalproperties of various expansible composite resins被examined，and the following results were obtained.1. In cases of two radical catalysts，ter -butyl peroxy maleic acid N，N-dihydroxy ethyl-p-toluidine b1 -cyclohexyl-5-ethyl barbituric acid-4-acryloxy ethyl trimelliticacid system (BMA catalyst) and benzoyl peroxide-N，N-dihydroxy ethyl-p-toluidine 1-benzyl-5-phenyl barbituric acid 4-acryloxy ethyl trimellitic acidanhydride system (BPO catalyst)，setting time of expansible composite resins were tended to behind time and to decrease compressivetensile strength in proportion to increase additive volume (more than 20wt%) of expansiblemonomer respectively. Therefore，their composite resins had not been become practicable.2. In case of BMA catalyst，composite resins with two expansible monomers (range from 5 to 20wt %) were tended to hind timeand to decrease compressive and tensile strength. However, in case of BPO catalyst, and to decrease compressive and tensile strength. However, in case of BPO catalysttheir composite resins had been same setting time and maximum values of compressive and tensilestrength of composite resins with expansible monomers(5或10 wt%) respectively.In the future，这是必需的，new kinds and additive volume of expansible monomers，catalysts and accelerator are investigatedin order that expansible composite resins become practicable。

In this study, two kinds of expansible monomers, isophorone and trimethyl hexamethylene diisocyanate containing bicyclic ortho ester structures were synthesized, and various expansible composite resins, which had each expansible monomer/dilute monomers (triethylene glycol dimethacrylate and two mixtures (isophorone diisocyanate or trimethyl hexamethylene diisocyanate : hydroxyethyl methaerylate=2 : 1) ratio and trial microspherical filler with improved surface (75wt%) were prepared. The physical properties of various expansible composite resins were examined, and the following results were obtained.1. In cases of two radical catalysts, tert-butyl peroxy maleic acid・N, N-dihydroxy ethyl-p-toluidine F1-cyclohexyl-5-ethyl barbituric acid-4-acryloxy ethyl trimellitic acid system (BMA catalyst) and benzoyl peroxide-N, N-dihydroxy ethyl-p-toluidine・1-benzyl-5-phenyl barbituric acid・4-acryloxy ethyl trimellitic acid anhydride system (BPO catalyst), setting time of expansible composite resins were tended to behind time and to decrease compressive and tensile strength in proportion to increase additive volume (more than 20wt%) of expansible monomer respectively. Therefore, their composite resins had not been become practicable.2. In case of BMA catalyst, composite resins with two expansible monomers (range from 5 to 20 wt%) were tended to behind time and to decrease compressive and tensile strength. However, in case of BPO catalyst, their composite resins had been same setting time and maximum values of compressive and tensile strength of composite resins with expansible monomers (5 or 10 wt%) respectively.In the future, it is necessary that new kinds and additive volume of expansible monomers, catalysts and accelerator are investigated, in order that expansible composite resins become practicable.