METHODS: A total of 15 subjects, aged 4 to 10 years, with at least one cavity on a primary tooth, were recruited for this study. Urine samples were collected at baseline, first 24 h (F1) and second 24 h (F2) after SDF treatment for analysis of silver and fluoride content. Hair samples were also collected at baseline and at 7, 14, 30, 60, 75, and 90 days after SDF treatment to analyze silver content.
RESULTS: Participants with under or over-collection of urine, or failure to provide urine collection were excluded for fluoride analysis. As a result, eight subjects' urine samples were eligible for fluoride analysis. Significant correlations were observed between baseline urinary fluoride levels and F1/F2 levels. Pairwise comparisons from Friedman's test showed significant differences between baseline and F1 fluoride levels. For silver analysis, 15 subjects were studied. F1 urinary silver levels were higher than baseline and F2 levels. Subsequent to SDF treatment, hair silver levels displayed fluctuations around the baseline. None of the participants reported adverse effects, and all caries teeth ceased progression within 30 days.
CONCLUSIONS: The urinary fluoride levels after SDF treatment, although higher, were not clinically significant. Urinary and hair silver levels were negligible. Therefore, SDF appears safe to be used among children.
RESEARCH DESIGN AND METHOD: Data were obtained from the published biomedical literature as well as abstracts and posters presented at scientific meetings. Using MEDLINE, EMBASE and BIOSIS databases (to July 2007), epidemiological studies were identified using the search terms: 'human', 'vitamin D', 'vitamin D deficiency', 'vitamin D inadequacy', 'vitamin D insufficiency' and 'hypovitaminosis D', 'osteomalacia' and 'osteoporosis'. Additional references were also identified from the bibliographies of published articles.
RESULTS: The prevalence of vitamin D inadequacy in studies of postmenopausal women (ambulatory or with osteoporosis or related musculoskeletal disorders) in Eastern Asia ranged from 0 to 92%, depending on the cut-off level of serum 25-hydroxycholecalciferol [25(OH)D] that was applied (range < or =6-35 ng/mL [< or = 15-87 nmol/L]). One large international study found that 71% of postmenopausal women with osteoporosis in Eastern Asia had vitamin D inadequacy, defined as serum levels of 25(OH)D < 30 ng/mL (75 nmol/L). Prevalence rates using this cut-off level were 47% in Thailand, 49% in Malaysia, 90% in Japan and 92% in South Korea. High prevalences of vitamin D inadequacy were evident in two studies using a lower 25(OH)D level cut-off value of < 12 ng/mL (30 nmol/L) - 21% in China and 57% in South Korea. Dietary deficiency and inadequate exposure or reactivity to sunlight (due to lifestyle choices, cultural customs and/or aging) were identified as important risk factors for vitamin D inadequacy.
CONCLUSIONS: Non-uniform, epidemiological studies indicate a high prevalence of vitamin D inadequacy in postmenopausal women in Eastern Asia. Recommended remedial approaches are education campaigns and broad-based provision of vitamin D supplementation.