Destructive and non-destructive behavior of nickel oxide doped bioactive glass and glass-ceramic

Nickel oxide substituted bioactive glasses (45S5) have been prepared by melting and annealing techniques. The doping of Ni2+ ion from 0 to 1.65 mol% of NiO was done to replace Si4+ ion and yield a charge balanced (CB) bioactive glass. The Ni2+ ion would enter into [SiO4] 4-network as [NiO4] 2-tetrahedra due similar charge/size ratio, but depending upon oxygen environment, it may act as modifier also in octahedral coordination in the glass. Polycrystalline bioactive glass-ceramics were prepared through controlled heat treatment. The glass and glass-ceramic structure was evaluated using FTIR and XRD techniques. The crystalline phases in bioactive glass-ceramics were identified using X-ray difractometry. The SEM micrographs of the samples after chemical treatment with simulated body fluid (SBF) for definite time of 15 days had shown the formation of hydroxyl carbonate apatite (HCP) layer on their surface which indicated that NiO had no opposite effect on the overall bioactivity. The destructive tests like microhardness, compressive, flexural strengths, and the non-destructive tests of elastic moduli were carried out. Both the results indicated that substitution of nickel oxide by silica in 45S5 bioactive glass and glass-ceramic influenced the structure and enhanced its density, compressive, flexural strength, micro hardness, and elastic properties.