(a) Compressive strength of bioactive ceramic scaffolds compiled from literature studies, and grouped based on their structures. Purple: isotropic scaffolds; green: anisotropic scaffolds; pink: peroidic scaffolds;[46, 47, 48, 49, 61, 63, 65, 78, 79, 80] (b) Influence of porosity on the compressive strength of bioactive ceramic scaffolds The black dotted line indicates a linear fitting by Rossi model[72], while red and blue dotted lines indicates the upper and lower theoretical strength predicted by Gibson and Ashby model.[75]