The characteristics and service utilization of 2,071 high and 2,337 moderate users of Alberta's dental plan from 1978-79 to 1990-91 are reported. High users are those who used the plan for 14 consecutive years; moderate users are those who used the plan in seven of the 14 years. Both groups were over 74 years of age in 1991-92. Compared to high users, moderate users lived in less urbanized regions, visited denturists more often and received far more complete dentures and fewer partial dentures. As a percentage of their total annual plan expenditures, moderate users spent less on diagnostic, preventive, periodontal and restorative services and much more on removable prosthodontic and denturists' services. However, during the study period, the moderate users increased their annual relative expenditures for diagnostic, preventive and, especially, periodontal services, and decreased them for prosthodontic services. With respect to specific preventive and periodontal services, the percentage of total annual expenditures for dental prophylaxis, topical fluoride applications, periodontal scaling, gingival curettage, and combinations of these, was much higher for the high user group. Despite these differences favoring the high user group, during the 14 year period, the moderate user group considerably increased its relative expenditures for dental prophylaxis, topical fluoride and periodontal scaling services. While the observed differences in service expenditures between high and moderate users were anticipated, the shift over time to using more preventive and periodontal services by both groups was an encouraging harbinger of the "new elderly" dental patients.