BackgroundThis study was aimed to investigate the prevalence of dental anxiety in a population of patients with Borderline Intellectual Functioning (BIF) and patients with mild and moderate intellectual disability (ID), and how dental anxiety correlated with their age and gender.MethodsThe sample was made of 700 patients, 287 females and 413 males, 6-to-47 years old, either with borderline intellectual functioning or mild/moderate intellectual disabilities. All patients were administered the Dental Anxiety Scale to assess their level of dental anxiety.ResultsModerate Anxiety was the most prevalent dental anxiety category for patients with intellectual borderline functioning (15.56 %) and mild intellectual disabilities(18.79 %), while Severe Anxiety was the most prevalent category for patients with moderate intellectual disabilities(21 %). Overall, a statistically significant difference (p < 0.001) between the three groups (BIF, Mild-ID and Moderate-ID) was found. Also, the correlation analysis between participants’ age and dental anxiety was statistically significant (p < 0.001); indeed, dental anxiety turned out to decrease with the increasing of the age. Moreover, the analysis between gender and dental anxiety was found to be significant as well (p < 0.001), where higher prevalence of dental anxiety was found in females.ConclusionsTo our knowledge, this is the first study on dental anxiety carried out in the field of intellectual disability. Results show that the higher the level of intellectual disability – and consequently the lower the cognitive functioning – the higher the percentage and the severity of dental anxiety.