Dental caries and associated factors in 7-, 12- and 15-year-old schoolchildren in the canton of Basel-Landschaft, Switzerland: Changes in caries experience from 1992 to 2021.

BACKGROUND: Epidemiological surveys in schoolchildren are used to assess the current status of oral health.

AIM: To investigate the changes in caries experience among schoolchildren in the canton of Basel-Landschaft, Switzerland, over a period of three decades. Secondary objectives were to evaluate the impact of various personal and demographic factors such as age group, place of residence or dental hygiene awareness on caries prevalence as well as the history of orthodontic treatment in the year 2021.

DESIGN: A random sampling of school classes from first, sixth and ninth grades, that is schoolchildren aged 7, 12 and 15 years, was performed. Children's dmft and DMFT scores were determined according to the WHO methodology while information on oral hygiene habits and dental prophylaxis awareness was collected by means of a questionnaire directed to the legal guardians of the children. Individual logistic regressions were performed to identify possible influencing factors for caries.

RESULTS: A total of 1357 schoolchildren could be included in the study. In the year 2021, the youngest age group had an average of 0.68 primary teeth that needed treatment, whereas the 12- and 15-year-olds each had approximately 0.3 permanent teeth requiring treatment. While these numbers remained constant over the examination period of three decades, most of the other caries indices improved. Younger children (p = .001) and children with a migrant background (p < .001) were found to be risk groups. Orthodontic treatment was more frequent in females, schoolchildren of Swiss nationality and children attending higher secondary schools at ninth grade.

CONCLUSION: This study demonstrated that even in a country with a low prevalence of caries experience, untreated carious lesions remain a problem as their prevalence remained unchanged over the examination period of three decades.