Patient knowledge and misconceptions about imaging exams and X-rays: the need for clearer guidance in dental care.

Objective: To assess patients' knowledge and possible misconceptions regarding imaging exams and their association to ionizing radiation.

Methods: Patients who sought dental care at the Federal University of Santa Maria Dental School (Brazil) were invited to enroll in the study. Patients filled out a questionnaire that covered demographic information, knowledge regarding imaging exams, X-rays, dental radiographs, and information sources (internet or dentist/physician). Data analysis was performed using descriptive statistics and chi-square test.

Results: Two hundred thirty-five participants were enrolled (mean age 44 ± 15 years), of whom 60% were female and 68% had at least 8 years of formal education. Most participants (74.5%) reported knowing what X-rays are. When questioned if the following exams used X-rays, the majority said radiographs used X-rays (91.5%), but mistakes were revealed for tomography (51.7%), mammography (59.4%), and magnetic resonance imaging (MRI) (40.2%). Gender, educational level, and reported knowledge about X-rays were not associated with correct answers (P > 0.05). Younger patients answered more accurately that ultrasound (P = 0.009) and MRI (P = 0.025) do not use X-rays, and older patients correctly associated mammography with X-rays (P < 0.001). Patients whose information source was the internet tended to incorrectly state that mammography (P = 0.007) and tomography (P = 0.063) did not use X-rays.

Conclusion: Patients often fail to differentiate the imaging exams that use X-rays, despite reporting that they understand what X-rays are. Dentists should be aware of the misconceptions patients may encounter when using the internet as a source of information and provide clearer guidance about acquisition and purpose of imaging exams, with emphasis on radiation protection.