ImportanceChildren with special health care needs (CSHCN) are recognized to be at increased risk of developing dental caries (decay). Evidence is mixed regarding the association of preventive oral health care delivered by pediatric primary care clinicians with caries experience among CSHCN.ObjectiveTo investigate caries experience, including untreated decay, among Medicaid-enrolled preschoolers with or without special health care needs.Design, Setting, and ParticipantsThis cross-sectional study used baseline data from the Pediatric Providers Against Cavities in Children’s Teeth study, a cluster-randomized hybrid effectiveness-implementation trial conducted among 1022 Medicaid-enrolled preschoolers aged 3 to 6 years attending well-child visits at 18 participating community pediatric primary care practices in northeast Ohio. Baseline data were collected from November 1, 2017, to August 31, 2019, with statistical analyses conducted from April to August 2022.ExposuresPresence of special health care needs, as assessed by applying the Pediatric Medical Complexity Algorithm to International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes, was abstracted from electronic medical records. CSHCN were defined as having either noncomplex chronic disease (presence of only 1 nonprogressive chronic condition, or multiple nonprogressive chronic conditions in a single body system) or complex chronic disease (presence of any progressive chronic condition, malignant neoplasm, or significant chronic conditions involving multiple body systems).Main Outcomes and MeasuresUntreated dental decay and caries experience as assessed through clinical dental examinations using International Caries Detection and Assessment System criteria.ResultsA total of 1022 children aged 3 to 6 years from 18 practices were enrolled in the study. The mean (SD) age of the study population was 4.3 (1.1) years, 554 (54.2%) were boys, and of 988 with data on race and ethnicity, 451 (45.6%) were Black. Of these, 301 of 1019 (29.5%) had a likely special health care need (225 with noncomplex chronic conditions and 76 with complex chronic conditions). The most frequent chronic conditions included asthma (n = 209) and mental or behavioral health disorders (n = 146), including attention-deficit/hyperactivity disorder, autism, and developmental delays. Overall, 296 children (29.0%) had untreated decay, and 378 (37.0%) had caries experience (decayed and filled teeth). Accounting for sociodemographic characteristics, CSHCN had 34% reduced odds of untreated decay (adjusted odds ratio [AOR], 0.66 [95% CI, 0.48-0.92]) compared with those with without chronic disease. In addition, caries experience was lower among CSHCN (AOR, 0.79 [95% CI, 0.60-1.04]).Conclusions and RelevanceIn this cross-sectional study of Medicaid-enrolled children who attended well-child visits as preschoolers, untreated dental decay was lower among CSHCN compared with those without chronic conditions. This study suggests that CSHCN may have had better access to the various types of dental care facilitated in medical settings.