Different ways of service provision frequently lead to different services being provided. In the School Dental Service (SDS) in Western Australia, all 5-15-yr-olds are eligible for care free of charge and most avail themselves of the service. The parents of some children choose to use private dentists (typically copaying about 50% of the cost) and their children do not attend the SDS. This study aimed to compare the dental status of 12-yr-olds who attended private dentists with that of matched children enrolled in the SDS. Non-enrolled 12-yr-olds in Perth (F- 0.8 mg/l) were identified and asked to provide background information and participate in clinical examinations. Each non-enrolled participant was matched with a classmate of the same sex. Of 184 non-enrolled children, 100 actually participated. Data on caries experience (DMFT and DMFS), fissure sealants and gingival health (CPITN) were collected by clinical examination. Analyses used Wilcoxon's signed rank, categorical and t-tests and simple linear regression. Caries prevalence was lower in non-enrolled children (0.31) than in enrolled (0.47). Caries experience was also lower in non-enrolled children (mean DMFT 0.71 vs. 0.95, ns). Enrolled children had more FT than non-enrolled (Wilcoxon, P = 0.059) but the mean number of DT in each group was 0.14. Enrolled children had somewhat fewer fissure sealants than non-enrolled children but in enrolled children there was an apparent (P = 0.056) inverse relationship between number of fissure sealants and DMFT scores; this was not the case in the non-enrolled group, suggesting better targeting of fissure sealants in the SDS.(ABSTRACT TRUNCATED AT 250 WORDS)