The Risk of Enamel Fluorosis and Caries Among Norwegian Children : Implications for Norway and the United States

ABSTRACT BackgroundThe authors investigated the associations between enamel fluorosis, caries and early fluoride use among Norwegian children who received fluoride supplementation under a protocol similar to the current U.S. protocol.MethodsTwo examiners whose techniques were calibrated examined randomly selected middle-school–aged children living in Bergen, Norway—where the water supply contains less than 0.10 milligrams of fluoride per liter—for both enamel fluorosis and caries by using the Fluorosis Risk Index and modified National Institute of Dental and Craniofacial Research criteria. The authors ascertained past fluoride exposure via a follow-up questionnaire mailed to parents.ResultsThe questionnaire had an 88 percent response rate and 87 percent reliability. Adjusted analyses revealed a strong association between regular supplementation (given in the form of lozenges) and mild to moderate enamel fluorosis (odds ratio [OR], 6.85; P < .05), as well as fluorosis of lesser severity (OR, 3.07; P < .05). No children who had exclusively used only a pea-sized amount of toothpaste (0.1 percent fluoride) had mild to moderate fluorosis. The authors found a 40 percent reduction in caries risk associated with early use of pea-sized amounts of fluoridated toothpaste and a 46 percent reduction associated with regular use of fluoride supplement lozenges.ConclusionsThese findings suggest that both risk of fluorosis development and caries-preventive benefit are associated with regular use of fluoride supplements, and caries prevention was associated with early use of a pea-sized amount of toothpaste.Clinical ImplicationsThese findings underscore the need for clinicians to consider thoroughly—and discuss with a child's parent or guardian—both the benefit and the potential risk of fluorosis development associated with preventive fluoride agents before introducing them. Clinicians also should emphasize the proper use of such agents.