OBJECTIVE: To investigate whether low daily doses of fluoridated milk, as an adjunct to oral hygiene routines with fluoridated toothpaste, can prevent caries development in enamel and dentine in adolescents.

MATERIAL AND METHODS: Adolescents (mean age 13 years) at three dental clinics in Sweden were enrolled to a randomised clinical trial (RCT) including baseline and 2-year follow-up examinations. The intervention group consumed milk supplemented with fluoride (0.75-1.0 mg) daily, while the control group consumed milk with water. Caries lesion development was assessed visually in line with the international caries detection and assessment system (ICDAS), except for proximal surfaces of premolars and molars which were assessed using a radiological classification system. Outcome measures were decayed, missing and filled surfaces (DMFS) increment, caries lesion arrest and progression.

RESULTS: Eighty seven participants in the intervention group and 72 in the control group completed the study. The intervention reduced the incidence of DMFS increment for enamel lesions, but not for dentine lesions. The degree of caries lesion arrest in outer enamel was higher in the intervention group compared to the control group, whereas caries lesion progression was lower in the intervention group.

CONCLUSION: Fluoride exerts an effect on caries lesions in the outer enamel, and fluoridated milk thus can be beneficial to adolescents with such lesions.

TRIAL REGISTRATION: Clinicaltrials.gov registration number NCT06684405.