IADR Abstract Archives
The effect of using prepolymerized filler on mechanical behaviour of dental composite
Objectives: Mechanical properties of dental composite resins need to be improved in order to enhance their performance for applications. A dental composite has a high filler loading and low shrinkage thereby providing good strength. The use of prepolymerized filler particles (PRPF) inhibit the shrinkage of the composite. The prepolymerized filler particles are composed of a reinforcing filler and a nanofiller. The aim of this study was to compare composite systems that comprised of prepolymerized filler and M8000-R709 micro-midsize filler according to mechanical property.
Methods: The organic matrix comprised of 2,2-Bis[4-(2-hydroxy-3-methacryloyloxypropyl)phenyl]-propane, urethanedimethacrylate, and tri-ethleneglycoldimethacrylate and small quantity of initiators. The micro-midsize fillers consisted a mixture of only R709 and M8000 were modified with MPTS. We prepared PRPF which comprised of 70wt% reinforcing filler (M8000), 5wt% microfiller (R709) and 20wt% organic matrix. For three point bending test, 5 plate specimens, 2mmx2mmx25mm, were prepared for each composite and test at 0,75mm/min. FlexuralStrength (n=5) was measured by the method in ISO 4049.
Results: Particle size distribution of the PRPF was determined using Zeta-nanosizer(Malvern, MasterSizer 2000) which employs laser diffraction method. Three point flexural tests were utilized to determine which was more strong.
Conclusions: Particle size measurement reveals that particle size distribution of the synthesized PRPF was homogenous in the water. The prepolymerized filler consists of particles having a particle size distribution including a mean particle size in the range of about 5 µm to about 55 µm. It is important to note the use of prepolymerized filler particles in terms of mechanical properties of the composite. The composite exhibits very low shrinkage. The flexural strenght of PRPF contains composite resin was much higher than the composite which was prepared by using micron particles.
Methods: The organic matrix comprised of 2,2-Bis[4-(2-hydroxy-3-methacryloyloxypropyl)phenyl]-propane, urethanedimethacrylate, and tri-ethleneglycoldimethacrylate and small quantity of initiators. The micro-midsize fillers consisted a mixture of only R709 and M8000 were modified with MPTS. We prepared PRPF which comprised of 70wt% reinforcing filler (M8000), 5wt% microfiller (R709) and 20wt% organic matrix. For three point bending test, 5 plate specimens, 2mmx2mmx25mm, were prepared for each composite and test at 0,75mm/min. FlexuralStrength (n=5) was measured by the method in ISO 4049.
Results: Particle size distribution of the PRPF was determined using Zeta-nanosizer(Malvern, MasterSizer 2000) which employs laser diffraction method. Three point flexural tests were utilized to determine which was more strong.
Conclusions: Particle size measurement reveals that particle size distribution of the synthesized PRPF was homogenous in the water. The prepolymerized filler consists of particles having a particle size distribution including a mean particle size in the range of about 5 µm to about 55 µm. It is important to note the use of prepolymerized filler particles in terms of mechanical properties of the composite. The composite exhibits very low shrinkage. The flexural strenght of PRPF contains composite resin was much higher than the composite which was prepared by using micron particles.