Importance: Little is known about the spatial accessibility to dental clinics across the US.
Objective: To map the spatial accessibility of dental clinics nationally and to examine the characteristics of counties and US Census block groups with dental care shortage areas.
Design, setting, and participants: Cross-sectional study of US dental clinics in 2023 using data from the IQVIA national practitioners' database, which includes 205 762 active dentists. Data were analyzed from November 2023 to April 2024.
Exposures: Socioeconomic characteristics of block groups and counties including rurality, area deprivation, racial and ethnic segregation, and uninsured population.
Main outcomes and measures: Enhanced 2-step floating catchment area method with a 30-minute drive time impedance was used to calculate the accessibility score to dental clinics at the block group level. The outcomes were dental clinic shortage areas and inequality in access to dental clinics.
Results: Nearly 1.7 million people in the US (0.5%) lacked access to dental clinics within a 30-minute drive. This included 0.9 million male (52.2%), 1.2 million White (71.0%), 52 636 Black (3.0%), and 176 885 Hispanic (10.2%) individuals. Approximately 24.7 million people (7.5%) lived in dental care shortage areas (defined as <1 dentist per 5000 population). There was a significant difference in spatial accessibility scores between rural and urban areas, with 1 dentist for every 3850 people in rural areas and 1 dentist for every 1470 people in urban areas. Additionally, there were 387 counties with significant disparities in access to dental clinics. Rural block groups (23.9 percentage points [pp]; 95% CI, 23.6-24.3), block groups with higher levels of Black (1.5 pp; 95% CI, 1.3-1.7) and Hispanic (4.5 pp; 95% CI, 4.3-4.8) segregation, and block groups with the highest levels of area deprivation (5.5 pp; 95% CI, 5.1-5.9) were more likely to experience dental care shortages compared with urban block groups and those with lower levels of segregation and area deprivation. Moreover, rural counties (11.3 pp; 95% CI, 8.9-13.7), counties with a high uninsured population (3.0 pp; 95% CI, 1.5-4.4), and counties with high levels of deprivation (5.8 pp; 95% CI, 2.1-9.5) were more likely to have inequality in access to dental clinics.
Conclusions and relevance: In this cross-sectional study of US dental clinics, there was geographic shortage and maldistribution of the dental workforce. These findings can support dental workforce planning efforts at the federal and state levels to encourage dentists to practice in underserved areas to reduce disparities in access to dental care.