title: Minimizing dentinal fluid flow associated with gap formation.
abstract: The relationship between gap formation and outward fluid flow and procedures to minimize both phenomena were investigated in extracted human premolars restored in vitro with MOD composite restorations. We hypothesized that either glass-ionomer cement (GIC) liners or low-shrinkage composite could reduce fluid flow related to gap formation. Two groups restored with bonding agents with either high- or low-shrinkage resin composites, and 2 groups restored by either conventional or light-cured GIC liner plus resin composite were compared (8 teeth/group). Fluid flow was measured with an automated apparatus. Baseline fluid flow was low and unchanged after bonding, but increased sharply (though transiently) after teeth were lined with GIC. Outward flow was significantly greater with conventional than with light-cured GIC. Inward fluid flow occurred during light-curing, followed by extensive, prolonged outward flow after curing. Low-shrinkage composite or GIC liners reduced gap formation and limited outward fluid flow. GIC liners promoted outward fluid flow during their setting reactions.
authors.affiliation: Department of Restorative Dentistry, School of Dental Science, The University of Melbourne, 720 Swanston Street, Melbourne, Victoria 3010, Australia.
authors.forename: D N
authors.initials: DN
authors.lastname: Ratih
authors.forename: J E A
authors.initials: JE
authors.lastname: Palamara
authors.forename: H H
authors.initials: HH
authors.lastname: Messer
mesh_terms: D000704:Analysis of Variance; D001641:Bicuspid; D003188:Composite Resins / Q000009:adverse effects* / Q000737:chemistry; D003736:Dental Cavity Lining; D003763:Dental Leakage / Q000209:etiology / Q000517:prevention & control*; D018772:Dental Marginal Adaptation; D003793:Dental Restoration, Permanent / Q000009:adverse effects*; D003799:Dental Stress Analysis; D019234:Dentinal Fluid / Q000502:physiology*; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D008855:Microscopy, Electron, Scanning; D044367:Phase Transition; D012212:Rheology; D018709:Statistics, Nonparametric
chemical_list: D003188:Composite Resins; D005899:Glass Ionomer Cements