Analysis of human enamel surface composition using SEM-EDX

Objective: The composition of dental enamel, in particular its mineral content, is an important factor to withstand an erosive attack. A correlation of mineral content and substance loss after an acid impact should be evaluated. Method: Therefore, we extracted 53 caries free teeth (4±4 [mean±SD]) from nine body donors (4 females, 5 males, 81.0±12.0 years). Enamel samples were cut from the buccal surfaces and subdivided in mesio-buccal (scanning electron microscope equipped with an electron dispersive x-ray spectroscope analysis [SEM-EDX]) and disto-buccal (erosive attack) samples. The disto-buccal samples were eroded with 0.3 % citric acid (pH 4) in vitro for 8 days. Daily, the enamel mass was measured using a laboratory microgram balance. Moreover, the fluoride, calcium and phosphate mineral content of mesio-buccal samplesx surface were analyzed using SEM-EDX. Results: All enamel samples showed a loss of mass. The remaining dental enamel mass of the basic value was in mean 88.0 %±3.0 % after 8 days of erosive attack. The percent of weight was 1.2±0.5 % for fluoride, 26.5±0.6 % for calcium and 12.0±3.0 % for phosphate. There was no correlation of dental enamel loss and fluoride, calcium or phosphate content. Conclusion: These findings suggest a low range of enamel mineral content and a similar response in loss of mass by an acid attack in vitro.