This study was designed to evaluate the wear resistance, fracture toughness and flexural strength of a nanofilled composite resin restorative material in comparison with a conventional hybrid composite resin. A total ...This study was designed to evaluate the wear resistance, fracture toughness and flexural strength of a nanofilled composite resin restorative material in comparison with a conventional hybrid composite resin. A total of 60 specimens were prepared from both types composite resins. Specimens were cured with a light curing device according to the manufacturer’s instructions. Wear resistance was evaluated through subjecting the specimens to wear testing at 0.1 bar wet pressure against carbide abrasive counter-body using wear testing machine under water as lubricant. The test conditions were;speed = 265 rpm, load = 0.1 bar, time = 5 min. Flexural strength and fracture toughness were tested using three-point bending test in universal testing machine at a cross head speed of 2 mm/min until failure occurred. The nanofilled composite resin material exhibited higher wear resistance than the hybrid composite resin material. On the other hand, there were no significant differences between the two materials in values of flexural strength and fracture toughness. It was concluded that the nanofilled composite resin was harder but it does not stronger than the conventional hybrid composite resin.展开更多
The role of nanofillers in reducing the microleakage of dental composite resins has not been previously investigated. So this study was designed to evaluate microleakage of nanofilled composite resin in comparison to ...The role of nanofillers in reducing the microleakage of dental composite resins has not been previously investigated. So this study was designed to evaluate microleakage of nanofilled composite resin in comparison to the conventional hybrid composite. Twenty extracted sound molars were selected. Class II cavities were prepared. All cavities were etched (enamel and dentin) with 37% phosphoric acid. Dentin bonding agents were applied to etched tooth surfaces and restored with nanofilled and hybrid composite restorative materials. The restored teeth were thermocycled. Specimens were immersed in 2% methylene blue dye, sectioned along the mesio-distal direction;dye penetration of occlusal and gingival margins of each section was evaluated using a stereo-microscope. No significant difference was found between the microleakage of nanofilled and hybrid composite restorations at occlusal / enamel and at gingival / dentin margins. Also, there were no significant differences for nanofilled composite restorations at occlusal / enamel margins and gingival / dentin margins. On the other hand, there were a significant differences for hybrid composite restorations at occlusal / enamel margins and gingival / dentin margins.展开更多
文摘This study was designed to evaluate the wear resistance, fracture toughness and flexural strength of a nanofilled composite resin restorative material in comparison with a conventional hybrid composite resin. A total of 60 specimens were prepared from both types composite resins. Specimens were cured with a light curing device according to the manufacturer’s instructions. Wear resistance was evaluated through subjecting the specimens to wear testing at 0.1 bar wet pressure against carbide abrasive counter-body using wear testing machine under water as lubricant. The test conditions were;speed = 265 rpm, load = 0.1 bar, time = 5 min. Flexural strength and fracture toughness were tested using three-point bending test in universal testing machine at a cross head speed of 2 mm/min until failure occurred. The nanofilled composite resin material exhibited higher wear resistance than the hybrid composite resin material. On the other hand, there were no significant differences between the two materials in values of flexural strength and fracture toughness. It was concluded that the nanofilled composite resin was harder but it does not stronger than the conventional hybrid composite resin.
文摘The role of nanofillers in reducing the microleakage of dental composite resins has not been previously investigated. So this study was designed to evaluate microleakage of nanofilled composite resin in comparison to the conventional hybrid composite. Twenty extracted sound molars were selected. Class II cavities were prepared. All cavities were etched (enamel and dentin) with 37% phosphoric acid. Dentin bonding agents were applied to etched tooth surfaces and restored with nanofilled and hybrid composite restorative materials. The restored teeth were thermocycled. Specimens were immersed in 2% methylene blue dye, sectioned along the mesio-distal direction;dye penetration of occlusal and gingival margins of each section was evaluated using a stereo-microscope. No significant difference was found between the microleakage of nanofilled and hybrid composite restorations at occlusal / enamel and at gingival / dentin margins. Also, there were no significant differences for nanofilled composite restorations at occlusal / enamel margins and gingival / dentin margins. On the other hand, there were a significant differences for hybrid composite restorations at occlusal / enamel margins and gingival / dentin margins.
