Dental restorative materials and the prevalence of eczema, allergic rhino-conjunctivitis, and asthma in schoolchildren. Dental amalgam and allergy in schoolchildren.
OBJECTIVE--To study the association between allergic diseases (eczema, allergic rhino-conjunctivitis, and asthma) and different types of dental restorative materials (amalgam, composite, and glass ionomer) in Swedish schoolchildren. DESIGN--Cross-sectional survey with a questionnaire asking for symptoms of allergic disease during the previous year. This information was combined with current dental status (number and type of filled tooth surfaces). SETTING--Primary care and a school in the centre of a middle-sized Swedish town (approx. 80,000 inhabitants). PARTICIPANTS--348 pupils of both sexes 13-15 years old. OUTCOME MEASURES--The occurrence of allergic disease in pupils with and without dental fillings of different types. The mean number and type of filled tooth surfaces in diseased and healthy pupils. RESULTS--44% of the pupils had no amalgam fillings. This group of children reported significantly more often asthmatic symptoms than the group with amalgam (P = 0.02). The asthmatic children had a lower mean number of amalgam surfaces than the other pupils (P = 0.002) and also a lower mean number of filled tooth surfaces of all types. CONCLUSION--The results of this study do not support the theory that amalgam fillings increase the prevalence of allergic diseases or allergic reactivity as such in schoolchildren. Neither do composite and glass ionomer seem to cause such complications.