The contribution of health services to improvements in health is contentious. The main aim of the present study was to assess the relative contribution that dental services may have made to the changes in dental caries (decayed, missing or filled permanent teeth) level of 12-year-old children in some industrialized countries in the 1970s and early 1980s. A secondary aim was an analysis of the association of the changes in caries levels with broad socioeconomic factors. In this study aggregate (ecological) data from 18 industrialized countries were analyzed at a national level. Data were obtained from published papers and official publications and included 3 kinds of variables: caries, presence of dental service and broad socioeconomic factors (including fluoridated toothpastes). Dental services explained 3% of the variation in changes in 12-year-old caries levels in the 1970s and early 1980s period whereas broad socioeconomic factors (including or excluding fluoridated toothpastes) explained 65%. The findings suggest that dental services were relatively unimportant in explaining the differences in changes in 12 year-old caries levels in the 1970s and early 1980s in the 18 countries. The view that fluoride in toothpaste was the only important cause of the declines in decayed, missing or filled permanent teeth in industrialized countries was questioned. A possible important contribution of the dental services to the declines was a change in the diagnostic and treatment criteria of caries.