title: Novel, multi-purpose, PMMA-type adhesive resin with newly synthesized microcapsule of radical polymerization initiators.
abstract: The behavior of microencapsulated polymerization initiators in dental adhesives is unknown. This study investigated the effects of new microencapsulated initiators in novel, multi-purpose, PMMA-type adhesive resin on the bonding performance and polymerization reactivity. Microencapsulated BPO and 1,3,5-trimethylbarbituric acid (TMBA) with PEMA as a shell polymer were quantitatively synthesized at 97-98% yield with 30-54 microm diameter. Adhesive-MC (comprising the synthesized microcapsules) and Adhesive-BR (comprising bare BPO and bare TMBA) were prepared and stored at 5 degrees C, 23 degrees C, and 40 degrees C for two months. MMA monomer was used as a solvent for the microcapsules. At the starting period, there were no significant differences between Adhesive-MC and Adhesive-BR in shear bond strength to enamel or dentin treated with or without surface treatment agent (p<0.05); moreover, their curing times (tc=304 seconds) were almost the same. After two months' storage at 40 degrees C, Adhesive-BR degraded in bond strength and showed markedly delayed polymerization reactivity as storage period progressed. In direct contrast, it was found that Adhesive-MC still retained its capabilities for adhesion to gold alloy and initiation of radical polymerization (p<0.05).
authors.affiliation: Department of Research and Development, Shofu Inc., 11 Kamitakamatsu-cho, Fukuine, Higashiyama-ku, Kyoto 605-0983, Japan.
authors.forename: Kiyomi
authors.initials: K
authors.lastname: Fuchigami
authors.forename: Kunio
authors.initials: K
authors.lastname: Ikemura
authors.forename: Kensuke
authors.initials: K
authors.lastname: Ichizawa
mesh_terms: D001463:Barbiturates / Q000737:chemistry; D001585:Benzoyl Peroxide / Q000737:chemistry; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure; D003764:Dental Materials / Q000737:chemistry; D003804:Dentin / Q000648:ultrastructure; D004339:Drug Compounding; D004356:Drug Storage; D006801:Humans; D008422:Materials Testing; D020366:Methylmethacrylate / Q000737:chemistry; D008768:Methylmethacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D011108:Polymers / Q000737:chemistry; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D012997:Solvents / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors
chemical_list: D001463:Barbiturates; D003764:Dental Materials; D008768:Methylmethacrylates; D011108:Polymers; D019279:Resin Cements; D012997:Solvents; D020366:Methylmethacrylate; C009931:poly(ethylmethacrylate); D019904:Polymethyl Methacrylate; D001585:Benzoyl Peroxide; C032232:barbituric acid