An in vitro model for assessment of fluoride uptake from glass-ionomer cements by dentin and its effect on acid resistance.
This investigation presents an experimental model for studying interactions of glass-ionomer cements (GICs) with bovine dentin slabs. Fluoride incorporation was studied with five serial abrasion biopsies, each being approximately 10 microns thick. The time of interaction was a very important parameter, indicating continuous fluoride release from the GIC and diffusion into dentin over a 30-day period. Expressed in mass per volume (mg F/cm3), the fluoride incorporation reached 12.0 mg at the first and 2.5 mg at the fifth layer, several times greater than the baseline of 0.27 mg/cm3 in bovine dentin. A subsequent test of acid resistance in a lactic acid buffer (pH 4.0), followed by microradiography of lesions, showed a characteristic 40-microns-wide acid-resistant zone on surfaces exposed to the GICs. In contrast, the untreated control surfaces had lesions demineralized evenly from the surface to the intact tissue, without the higher-density zone at the surface of the lesion. The model seems promising for screening fluoride incorporation into dentin from fluoride-releasing dental materials.
Tsanidis
V
V
Department of Pediatric Dentistry, University of Alabama School of Dentistry, Birmingham 35294.
Koulourides
T
T
D000818:Animals; D002417:Cattle; D003692:Delayed-Action Preparations; D003804:Dentin / Q000378:metabolism*; D003806:Dentin Permeability; D005460:Fluorides, Topical / Q000008:administration & dosage / Q000378:metabolism*; D005899:Glass Ionomer Cements / Q000494:pharmacology*; D008852:Microradiography; D017001:Tooth Demineralization / Q000517:prevention & control*
D003692:Delayed-Action Preparations; D005460:Fluorides, Topical; D005899:Glass Ionomer Cements