In the present study, the synthesis of PMMA was carried out by emulsion polymerization under ultrasonic radiation, varying the concentration of the anionic surfactant and monomer concentration. Redox process was introduced in order to observe if an increment in conversion was obtained. Characterization was performed by FTIR, DSC, SEM, and H-1-NMR of protons. The synthesis with redox initiation produced PMMA with majorly syndiotatic triads. The synthesis carried out under redox initiation resulted in a large increased in conversion, showing that there is an optimum surfactant/monomer ratio. Scanning Electron Microscopy showed that for low concentrations of surfactant (0.5% p/v) the latex particles presented a rough surface but high surfactant concentration showed nanometric spherical particles with a smooth surface. The study of in vitro biocompatibility by adhesion of osteoblasts on the materials resulted in higher cell adhesion in materials synthesized without redox initiation.