Background: It has been suggested that dental caries should be regarded as a chronic disease as many individuals repeatedly develop new caries lesions. How this is perceived by caries active patients is unclear. The aim of this study was to measure patient-reported attitudes and negative experiences related to caries and dental treatment. Methods: A questionnaire was mailed to 134 caries active (CA) and 40 caries inactive (CI) adult patients treated at a Swedish public dental service clinic. The questionnaire included items regarding patient-reported oral health; attitudes towards caries and efforts to prevent them; and negative experiences related to caries and dental treatment. Questionnaire data were supplemented with data on caries and caries prophylaxis from patients' dental records. Exploratory factor analysis was conducted on items related to patients' perceptions of problems to see whether scales could be created. Experiences, perceptions and dental records of CA and CI patients were compared. Results: The overall response rate was 69%. Dental records confirmed that CA patients had significantly more decayed teeth per year and a longer period of caries-active time than CI patients. Factor analysis resulted in 3 distinct scales measuring problems related to caries; 1) caries-related information; 2) negative experiences; and 3) negative treatment/staff attitudes. A fourth scale measuring perceived problems related to caries was also created. The CA group reported significantly more problems related to caries and dental treatment, received significantly more caries-related information, and reported significantly more negative treatment experiences compared to CI patients. Conclusions: Caries prophylaxis methods need to be improved in order to better meet the needs of caries active patients and to create a more positive experience with dental care.