IADR Abstract Archives
The effect of filler modification on mechanical behaviour of dental composite
Objectives: A dental composite typically contains an organic matrix and an inorganic filler. Usually, the filler particles are coated with a coupling agent to bond to the resin matrix. In particular, modification of filler’s surface has affected properties of composites. In this study, the effect of filler modification on flexural strength of the composites has been evaluated.
Methods: The organic matrix is comprised of 2,2-Bis[4-(2-hydroxy-3-methacryloyloxypropyl)phenyl]-propane, urethanedimethacrylate, and tri-ethleneglycoldimethacrylate and small quantity of initiators. The filler are consisted of a mixture of OX50 and M6000 which were modified with methacryloxypropyltrimethoxysilane(MPTS). While OX50 were modified with MPTS in the ratio of 5wt%, 6,3wt% and 9,5wt%, M6000 were modified with MPTS in the ratio of 0,63wt%, 0,95wt% and 5wt%. For three point bending test, 5 plate specimens, 2mmx2mmx25mm, were prepared for each composite and tested at 0,75mm/min. Flexural Strength (n=5) was measured by the method in ISO 4049.
Results: Three point flexural tests were utilized to determine which was more durable. Maximum FS value was obtained at second system. While the modification ratio of OX50 was decreased to 5wt%, the modification ratio of M6000 was increased from 0,63wt% to 0.95wt%.
Conclusions: The behaviour of the composite materials depends on their fillers: percentages, composition, dimensions and shape as well as the polymerization degree of the resin matrix. It has been shown that mechanical properties are highly correlated to the filler fraction of the dental composites. As a result of this study, we determined that modification of the filler surface is a very important fact and influence on the mechanical behaviour of the dental composites. The silane coupling agent bonds both silicon-oxygen in the fillers and methacrylate groups in the resin matrix. At high filler levels and small filler sizes, the silane coating of filler particles begins to rival the volume content of monomers in the dental composites.
Methods: The organic matrix is comprised of 2,2-Bis[4-(2-hydroxy-3-methacryloyloxypropyl)phenyl]-propane, urethanedimethacrylate, and tri-ethleneglycoldimethacrylate and small quantity of initiators. The filler are consisted of a mixture of OX50 and M6000 which were modified with methacryloxypropyltrimethoxysilane(MPTS). While OX50 were modified with MPTS in the ratio of 5wt%, 6,3wt% and 9,5wt%, M6000 were modified with MPTS in the ratio of 0,63wt%, 0,95wt% and 5wt%. For three point bending test, 5 plate specimens, 2mmx2mmx25mm, were prepared for each composite and tested at 0,75mm/min. Flexural Strength (n=5) was measured by the method in ISO 4049.
Results: Three point flexural tests were utilized to determine which was more durable. Maximum FS value was obtained at second system. While the modification ratio of OX50 was decreased to 5wt%, the modification ratio of M6000 was increased from 0,63wt% to 0.95wt%.
Conclusions: The behaviour of the composite materials depends on their fillers: percentages, composition, dimensions and shape as well as the polymerization degree of the resin matrix. It has been shown that mechanical properties are highly correlated to the filler fraction of the dental composites. As a result of this study, we determined that modification of the filler surface is a very important fact and influence on the mechanical behaviour of the dental composites. The silane coupling agent bonds both silicon-oxygen in the fillers and methacrylate groups in the resin matrix. At high filler levels and small filler sizes, the silane coating of filler particles begins to rival the volume content of monomers in the dental composites.