This study investigated whether difficulty in covering dental expenses, measured in Australian dollars, is associated with the utilization of dental services among adults in Australia, considering potential sociodemographic confounders. Additionally, it examined whether dental anxiety and satisfaction with dental care providers act as mediators and whether they modify the link between affordability and dental service use. We analyzed longitudinal data from the Australian National Study of Adult Oral Health collected in 2004–06 and 2017–18. Associations between financial difficulty and frequency of dental visits were estimated using Poisson regression and path analysis. To explore potential effect modification, analyses were stratified according to levels of dental anxiety and satisfaction with dental professionals. The sample comprised 1,698 Australian adults. Individuals reporting trouble paying dental bills had a 20% higher prevalence of infrequent dental visits. Higher prevalence ratios were observed among those experiencing dental anxiety (PR = 1.14) and those dissatisfied with their dental providers (PR = 1.17), indicating that both factors modify the relationship between financial barriers and dental service utilization. Adults with dental anxiety or low satisfaction with dental professionals are particularly likely to reduce dental visits when confronted with financial difficulties. These associations highlight modifying factors in dental care use but do not establish causality.