The influence of SrO and CaO in silicate and phosphate bioactive glasses on human gingival fibroblasts

In this paper, we investigate the effect of substituting SrO for CaO in silicate and phosphate bioactive glasses on the human gingival fibroblast activity. In both materials the presence of SrO led to the formation of a CaP layer with partial Sr substitution for Ca. The layer at the surface of the silicate glass consisted of HAP whereas at the phosphate glasses it was close to the DCPD compn. In silicate glasses, SrO gave a faster initial dissoln. and a thinner reaction layer probably allowing for a continuous ion release into the soln. In phosphate glasses, SrO decreased the dissoln. process and gave a more strongly bonded reaction layer. Overall, the SrO-contg. silicate glass led to a slight enhancement in the activity of the gingival fibroblasts cells when compared to the SrO-free ref. glass, S53P4. The cell activity decreased up to 3 days of culturing for all phosphate glasses contg. SrO. Whereas culturing together with the SrO-free phosphate glass led to complete cell death at 7 days. The glasses contg. SrO showed rapid cell proliferation and growth between 7 and 14 days, reaching similar activity than glass S53P4. The addn. of SrO in both silicate and phosphate glasses was assumed beneficial for proliferation and growth of human gingival fibroblasts due to Sr incorporation in the reaction layer at the glass surface and released in the cell culture medium.