title: Effects of aging on repair of resin-modified glass-ionomer cements.
abstract: The effects of aging on the repair bond strengths of resin-modified glass-ionomer cements after different methods of surface conditioning were studied. Surface conditioning methods included the following: maleic acid; maleic acid with resin application; polyacrylic acid; polyacrylic acid with resin application. Shear bond testing between the aged and new material was carried out with an Instron Universal testing machine. Surface conditioning with maleic acid and resin application gave the highest repair bond strengths at 3 and 6 months. There was, however, no statistically significant difference in bond strengths between the different treatment groups after both 3 and 6 months storage. Intergroup comparisons revealed no significant difference in failure modes after both storage periods. For all treatment groups, no significant difference in repair bond strengths was noted between storage after 1 week, 3 and 6 months. There appears to be a general decrease in repair bond strengths for all treatment groups after 3 months storage. The clinical repair of resin-modified glass-ionomer cements after this period of time is therefore not recommended.
authors.affiliation: Faculty of Dentistry, National University of Singapore, Singapore. rsdyapuj@nus.edu.sg
authors.forename: A U
authors.initials: AU
authors.lastname: Yap
authors.forename: K W
authors.initials: KW
authors.lastname: Lye
authors.forename: C W
authors.initials: CW
authors.lastname: Sau
mesh_terms: D000134:Acid Etching, Dental; D000180:Acrylic Resins; D000704:Analysis of Variance; D020770:Compomers / Q000737:chemistry*; D001840:Dental Bonding; D003793:Dental Restoration, Permanent; D004356:Drug Storage; D005899:Glass Ionomer Cements / Q000737:chemistry*; D008298:Maleates; D008422:Materials Testing; D011108:Polymers / Q000737:chemistry; D012117:Resins, Synthetic / Q000737:chemistry*; D018709:Statistics, Nonparametric; D013499:Surface Properties; D013997:Time Factors
chemical_list: D000180:Acrylic Resins; D020770:Compomers; C079765:Fuji II LC cement; D005899:Glass Ionomer Cements; D008298:Maleates; D011108:Polymers; D012117:Resins, Synthetic; C006903:carbopol 940; C030272:maleic acid