Different compositions of silicate-based bioactive glasses of the system SiO2-CaO-P2O5 (45S, 58S, and 77S) were evaluated for teeth remineralization effect on the etched human dental enamel in simulate human oral environment. Enamel samples were subjected to demineralization in citric acid solution, then treated with different bioactive glass pastes, and finally soaked in simulated oral fluid (SOF) for 7 days before evaluation. The results indicated that enamel surface formed a homogenous and dense mineralized layer with the treatment of 45S and 58S samples. The average thickness was 4 and 2.5 mu m, respectively. But 77S treatment showed a loose and uneven remineralized layer. Although the surface roughness decreased with the increase of silicon content, mechanical strength of enamel samples became less gradually. Taken together, 45S paste had the best remineralization ability, best mechanical strength, and satisfactory surface roughness. These results also indicated that the level of silicon content of bioactive glasses played a key role in dental enamel remineralization.