Several recent studies have demonstrated the success of the ART (atraumatic restorative treatment) technique under field conditions in developing countries. The ART technique involves removal of caries using only hand instruments, and placing a glass ionomer cement (GIC) restoration. To estimate the longevity of Fuji II GIC ART restorations placed in permanent teeth by dental nurse students under field conditions in rural Cambodia. Clinical field trial. One high school in rural Cambodia. 53 subjects between the ages of 12 and 17 who had dental caries were selected to participate. Subjects were randomly assigned to a dental nurse student for cavity preparation and placement of ART restorations (without cavity conditioning). 92.1% of the carious lesions required class I or class V restorations, and 85.4% were in the lower molars. 89 teeth were filled. At 1 and 3 years 86.4% and 79.5% of restorations were still present. Restorations were assessed by one dentist according to standard criteria. 76.3% of the restorations were judged to be successful at 1 year, and 57.9% at 3 years. Factors which may have affected the success rates included: the material used, technical factors, failure to condition the cavity prior to restoration, and inexperience of the operators. The results suggest that ART restorations in permanent teeth using Fuji II GIC are only moderately successful after 3 years. Better results could be expected by using a dentine conditioner in conjunction with one of the newer stronger glass ionomer cements.