Class I gap-formation in highly-viscous glass-ionomer restorations: Delayed vs immediate polishing

Masao Irie, Yukinori Maruo, Goro Nishgawa, Kazuomi Suzuki, David C. Watts

    Research output: Contribution to journalArticlepeer-review


    This in vitro study evaluated the effects of delayed versus immediate polishing to permit maturation of interfacial gap-formation around highly viscous conventional glass-ionomer cement (HV-GIC) in Class I restorations, together with determining the associated mechanical properties. Cavity preparations were made on the occlusal surfaces of premolars. Three HV-GICs (Fuji IX GP, Glaslonomer FX-II and Ketac Molar) and one conventional glass-ionomer cement (C-GIC, Fuji II, as a control) were studied, with specimen subgroups (n=10) for each property measured. After polishing, either immediately (six minutes) after setting or after 24 hours storage, the restored teeth were sectioned in a mesiodistal direction through the center of the model Class I restorations. The presence or absence of interfacial-gaps was measured at 1000x magnification at 14 points (each 0.5-mm apart) along the cavity restoration interface (n=10; total points measured per group = 140). Marginal gaps were similarly measured in Teflon molds as swelling data, together with shear-bond-strength to enamel and dentin, flexural strength and moduli. For three HV-GICs and one C-GIC, significant differences (p
    Original languageEnglish
    Pages (from-to)196-202
    Number of pages6
    JournalOperative Dentistry
    Issue number2
    Publication statusPublished - Mar 2008


    • classification: Dental Cavity Preparation
    • ultrastructure: Dental Enamel
    • methods: Dental Polishing
    • classification: Dental Restoration, Permanent
    • ultrastructure: Dentin
    • Elasticity
    • chemistry: Glass Ionomer Cements
    • Humans
    • Marginal Adaptation (Dentistry)
    • Materials Testing
    • Pliability
    • Shear Strength
    • Stress, Mechanical
    • Surface Properties
    • Time Factors
    • Viscosity
    • chemistry: Water


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