6th German Oral Health Study (DMS • 6): fieldwork, data collection, and quality assurance.

The article focuses on the methodology, fieldwork, data collection, and quality assurance of the 6th German Oral Health Study (DMS • 6), a nationally representative oral epidemiologic survey conducted in Germany from 2021 to 2023. The study assessed oral health status, behavior, and dental care across seven age groups using clinical examinations and social science surveys, incorporating both cross-sectional and, for the first time, longitudinal components by reexamining participants from the previous DMS V study. Data collection was carried out by the field institute Cerner Enviza (now Oracle Life Sciences) at temporary study centers, employing standardized protocols and a two-part social science survey (paper and pencil interview and computer-assisted personal interview). A comprehensive multi-stage quality assurance system—including pretesting, pilot studies, training, calibration, reliability testing, and monitoring—was implemented to ensure high data validity and minimize bias, with a non-response survey indicating no systematic differences between participants and non-participants.