Artificial caries around restorations in roots.

An artificial caries technique was used to produce caries-like lesions in the cavity walls adjacent to microfilled resin restorations with and without dentin bonding agent, and glass-ionomer cement restorations, in the roots of extracted teeth. The lesions had histological characteristics similar to those of natural lesions and to those of the lesions produced by other experimental methods. The zonal pattern of the lesions was examined by means of polarized light microscopy and microradiography, and the depth of the lesions was measured for assessment of the microleakage around the restorations. Three cavity cleaning regimes-water spray alone, 50% citric acid, and a proprietary cleaner-were compared in conjunction with the three restorative methods. Cavity cleaning with the citric acid or the proprietary cleaner, and the use of a fluoride-releasing restorative material, acted to reduce the depths of the lesions. Glass-ionomer cement restorations in cavities cleaned with citric acid showed lesions significantly shallower than those treated with other restorations. The glass-ionomer cement was soluble in the acidic environment but promoted the precipitation of minerals in the lesions. The use of a dentin bonding agent did not affect the depth of demineralization around the microfilled resin restorations.