Children with insulin-dependent diabetes mellitus have a lower salivary flow rate, pH and buffer capacity, but a higher glucose content and peroxidase, IgA, magnesium and calcium concentration, in comparison with healthy children. Nevertheless the incidence of caries is lower than normal in diabetic children with good metabolic control. Periodontal disease usually starts at puberty as mild gingivitis with bleeding and gingival recession, and it may develop into severe periodontitis, especially in children with poor control of diabetes. Microangiopathy, impaired immune response, different bacterial microflora and collagen metabolism are involved in the pathogenesis of diabetic periodontal disease. The gingival flora is mostly composed of Gram-negative, anaerobic bacteria, while collagen has a lower solubility and is atrophic and inadequate to support the occlusion forces. For these reasons, prevention of periodontitis is important in diabetic children; they should receive oral hygiene instruction and visit a dentist at least twice a year.

Our results lead to the conclusion that Alt spore concentration is significantly higher at ground level in the presence of vegetation, even when the spore concentration is very low (<10 spores/m(3)). These results further suggest that the individual's exposure to Alt, especially in the case of children, is underestimated by samples taken at roof-top level by FVC.