Setting Properties along Bone Cement Preparation and its Effect on Material Properties

Bone cement is a material used in many orthopedic surgeries. Polymethyl Methacrylate (PMMA) is one of the acrylic-based bone cement materials. PMMA will be mixed with an activator (N, N-Dimethyl-p-toluidine (DMPT)), initiator (Benzoyl Peroxide (BPO)), radiopacifier / filler (BaSO4), and Methyl Methacrylate monomer. Once the materials were mixed, the activator react with the initiator to form radicals and activate the bulk polymerization reaction between the MMA monomer and PMMA molecules. The bulk polymerization reaction occurs exothermically and increases the bulk temperature. Barium sulfate (BaSO4) is an inorganic compound that can be acted as both radiopacifier and filler in bone cement. The specific objective of this study was to describe the effect of BaSO4 in bone cement composite formation. The solid material; PMMA, BPO, and BaSO4 were mixed firstly. The liquid portions; N, N-Dimethyl-p-toluidine (DMPT), and MMA were mixed and then poured into the solids one in a stainless-steel bowl. The bulk temperature was recorded after a one-minute mixing process. The samples were characterized by Gel Permeation Chromatography (GPC) and Differential Scanning Calorimetry (DSC). The highest setting temperature and setting time were 107.3°C and 10.6 min which was obtained in BaSO4 content variables of 7% and 11%, respectively. The average molecular weight of the samples was 561.5-1,332.0 kDa. From the DSC result, the glass temperature of the samples was 119.17-119.87°C.