Inorganic-organic hybrid resins revolutionarize the biomedical field by virtue of its versatility. In this work, bioactive inorganic-organic hybrid resins containing mixture of alkoxides of calcium/magnesium/zinc with polymerizable tetramethacrylate groups was synthesized using 1,3-bis methacryloxy 2-(trimethoxy silyl propoxy) propane as the precursor. We optimised the processing parameters by investigating the influence of pH of the medium used for the hydrolysis of silane on molecular weight of the resultant resin obtained. Physico-mechanical properties including polymerisation shrinkage of photocured composites prepared from novel inorganic-organic hybrid resins were evaluated and compared. The resin hydrolysed at pH 2 have low molecular weight with high filler loading capacity (325 phr) than the one hydrolysed at pH 10. Photocured polymeric composite fabricated from resin hydrolysed at pH 2 showed lower polymerisation shrinkage, better depth of cure, good diametral tensile strength, non-cytoxic to L929 fibroblasts with good cell viability and cell adhesion. This new biocompatible polymer with low polymerisation shrinkage stands as a potent candidate in biomedical applications, especially in the field of dental, orthopaedic and coating applications.