Novel inorganic-organic hybrid resins [IOHRs] containing mixture of alkoxides of calcium/magnesium/zinc with polymerizable dimethacrylate groups were synthesised using a simple single-pot modified sol-gel method. Objective of the present study is to investigate the impact of calcium content over bioactivity, polymerization shrinkage, and physico mechanical properties of bioactive IOHR containing mixture of alkoxides of calcium/magnesium/zinc having polymerizable methacrylate groups, along with various fillers they can be used as a dental restorative material. Various formulations with varying concentration of inorganic content were used during the synthesis. The concentration of inorganic content was optimised as 0.1% by weight of with respect to the silane.  This optimised formulation based photocured composite [CMZ2] showed better DTS (35-40 MPa), FS (65-70 MPa), VHN (140-146 kg/mm 2 ), possess low shrinkage, non-cytotoxic in nature, bioactive with good cell adhesion and cell proliferation properties. CMZ2 was found to be a potential novel dental composite.