Bioactivity and biocompatibility of two fluoride containing bioactive glasses for dental applications

Bioactive glasses (BAG) form, in contrast to formerly used implant materials, a stable bond with tissues, especially bone, when implanted. Nowadays BAGs are often mixed with a cement/composite that hardens in situ to broaden its applications in dentistry or orthopedics. The bioactivity and biocompatibility of possible BAG candidates for BAG-cement/composite development were evaluated.

Two fluoride containing BAGs were tested: a Na⁺-containing (45S5F), based on the first commercial BAG, and a Na⁺-free BAG (CF9), with a higher Ca²⁺ and PO₄^3- content. BAGs were tested on their bioactivity upon immersion in SBF for 7days by evaluating the surface changes by FT-IR, SEM, EDS and PO₄^3- and Ca²⁺ uptake and/or release from SBF. Moreover, the biocompatibility of the BAGs was investigated with a direct contact cell viability study with HFF cells and a cell adhesion study with MG-63 cells.

The Na⁺-free BAG, CF9, showed the highest potential to bioactivate cements because of its high Ca²⁺-release and apatite (Ap) formation, as evidenced by SEM pictures and corresponding EDX patterns. FT-IR confirmed the formation of an Ap layer. Moreover CF9 had a higher biocompatibility than 45S5F.

For the bioactivation of GICs/composites in order to enhance bonding and remineralization of surrounding tissues, fluoride containing BAG may have advantages over other BAGs as a more stable fluorapatite can be formed. CF9 may be an excellent candidate therefore.