Al-free glasses of general composition 0.340SiO2:0.300ZnO:(0.250-a-b)CaO:aSrO:bMgO:0.050Na2O:0.060P2O5
(a, b=0.000 or 0.125) were synthesized by melt quenching and their ability to form glass-ionomer cements
was evaluated using poly(acrylic acid) andwater.We evaluated the influence of the poly(acrylic acid)molecular
weight and glass particle size in the cementmechanical performance.Higher compressive strength (25±5 MPa)
and higher compressive elasticmodulus (492±17 MPa) were achieved with a poly(acrylic acid) of 50 kDa and
glass particle sizes between 63 and 125 μm. Cements prepared with glass formulation a=0.125 and b=0.000
were analyzed after immersion in simulated body fluid; they presented a surface morphology consistent with
a calcium phosphate coating and a Ca/P ratio of 1.55 (similar to calcium-deficient hydroxyapatite). Addition of
starch to the cement formulation induced partial degradability after 8 weeks of immersion in phosphate buffer
saline containing α-amylase. Micro-computed tomography analysis revealed that the inclusion of starch increased
the cement porosity from 35% to 42%. We were able to produce partially degradable Al-free
glass-ionomer bone cements with mechanical performance, bioactivity and biodegradability suitable to be applied
on non-load bearing sites and with the appropriate physical characteristics for osteointegration upon partial
degradation. Zn release studies (concentrations between 413 μM and 887 μM) evidenced the necessity to
tune the cement formulations to reduce the Zn concentration in the surrounding environment.