[Experimental caries lesions under composite resins]

42 extracted teeth on two sites received a small (2 mm2) surface restoration with a Bowen composite onto the healthy etched enamel without any cavity preparation; afterwards we tried to induce artificial caries by storing the teeth in lactic acid in hydroxyethyl-cellulose-solution. A certain number of teeth was kept in an alkaline buffer solution once a week. All teeth exhibited demineralisation in dentin, though the resin remained perfect in place-even if great areas of dentin had disappeared. The alkaline buffer-solution did not prevent, but only led to a protracted demineralisation, also in the enamel. There seem to be hazardous regions (e.g. fissures, cervical regions), where caries under Bowen-material fillings easily can arise.