Bone is a highly specialized connective tissue with distinct capability to remodel and regenerate. When the defect exceeds 2-2.5 times the diameter of affected bone, the capability to repair the large damage tissue is exceeded.  Large bone defects can be repaired with bone grafting procedures using biomaterials as graft. 
Biological grafts have its own limitations and they are also expensive, require strict handling protocols, and the sterilization process deteriorates the tissue properties. These drawbacks have encouraged the use and development of alternative synthetic grafts.?? 
The challenge of synthetic grafts is to promote osteoinduction and osteoconduction, with adequate mechanical properties and degradation time. One of the synthetic biomaterials widely used as bone grafts are bioactive and biodegradable glasses (BGs), discovered by Larry Hench in 1969, being the first material to form a chemical bond with bone, giving rise to a stable and active implant in the healthy restoration of damaged bone tissue?.  
Since the first composition, 45S5 BG, the research in the field had been intensive and BGs demonstrated to be outstanding biomaterials due to their desirable characteristics such as high bioactivity, osteogenic stimulation, angiogenic effect, ability to bond to soft tissues, high biocompatibility, and antibacterial activity induced by their ion release capability. It is estimated since FDA approval, 45S5 Bioglass® was implanted in around 1.5 million patients to repair bone and dental defects between 1985 to 2016. 
Bioglasses bioactivity is responsible to promote the bond to bone through the formation of a hydroxyl-cabonate apatite (HCAp) layer which mimics the mineral phase of bone. The use of these materials as grafts stimulates the regeneration of bone defects and their effect is intrinsically linked to characteristics such as chemical composition and morphology of these biomaterials. The processing influences these characteristics, and the conventional routes for obtaining bioglasses basically consist of fusion and sol-gel processing. Through fusion the melt is cooled down, usually from a temperature of 1450°C and quenching is the main process to obtain particles between 0.8 - 3.5 mm. By sol-gel processing, a chemical synthesis technique, it is possible to obtain a well-ordered mesoporous structure with pore size between 4.0 - 10 nm. 
The aim of the work is to evaluate the chemical reactivity of four different bioactive glasses, BG 45S5 and S53P4 from melted derived process and BG 58S and yours mesoporous structure, MBG 58S, through thesol-gel technique. In order to evaluate the developed materials properties, samples were characterized by physicochemical properties measurement by SEM, FRX and N2 adsorption/desorption analysis for the MBG powder. The chemical reactivity was evaluated by SEM, EDX, FRX, FTIR and Ca/P analysis after being immersed in simulated body fluid (SBF) solution for 8, 24 and 72h. All compositions will be also evaluated regarding biological properties through cytotoxicity evaluation and the result of four compositions and two districting process route provid an extensive bioactive glasses analysis. 
This work is part of health national research and is supported by CNPq, CAPES to contribute with Brazil’s Unified Health System.