IADR Abstract Archives
Surface Hardness Evaluation of Different Light Curing Composite Resin Restorative Materials
Objectives: The aim of this study was to evaluate the surface hardness of ten nanohybrid ( Charisma Opal/Heraeus Kulzer/Germany, Charisma Diamond/Heraus Kulzer/Germany, Filtek Ultimate Dentin, Enamel, Body/3M ESPE/USA, Quadrant/Cavex/Holland, Majesty Esthetic/Kuraray/Japan, Estelite ∑ Quick/Tokuyama/Japan, Restorative Z250/3M ESPE/USA, Grandio/Voco/Germany ), a microhybrid (Charisma Classic/Heraus Kulzer/Germany ) and a nanohybrid flowable restorative material Charisma Opal Flow/Heraus Kulzer/Germany).
Methods: Teflon molds ( 5mm diameter and 2 mm depth) were used to fabricate the specimens . Restorative materials were placed to these molds and light cured with a 1000mW/cm2 LED device (Bluephase, Ivoclar Vivadent, Liechtenstein ) from the top surface. 5 samples were prepared from each composite resin restorative material. All samples were stored in 370C distile water for 24 h. After 24 h the top and the bottom surface hardness of the samples were measured using a Vicker’s hardness tester ( Shimadzu HMV-2, Japan ) under 100 g load with a dwell time of 10 s. 3 measurements were performed from each sample’s top and bottom surfaces and recorded as the hardness value. Statistical analyses were performed using SPSS for Windows.
Results: The results of the microhardness test indicated that there was statistically difference between the top and bottom surfaces of microhybrid composite resin Charisma Classic and nanohybrid composite resins Charisma Diamond, Charisma Opal, Cavex, Filtek Ultimate Dentin, Majesty Esthetic. The highest hardness values were obtained from nanohybrid composite resin Grandio. Flowable nanohybrid composite resin Charisma Opal Flow showed the lowest microhardness values at all groups.
Conclusions: According to the results of this study 20 s light curing could not adequately polmerize the bottom surfaces of some composite resins used in this study. Accelerating curing time may be recommended to cure the bottom surfaces of resin restorative materials.
Methods: Teflon molds ( 5mm diameter and 2 mm depth) were used to fabricate the specimens . Restorative materials were placed to these molds and light cured with a 1000mW/cm2 LED device (Bluephase, Ivoclar Vivadent, Liechtenstein ) from the top surface. 5 samples were prepared from each composite resin restorative material. All samples were stored in 370C distile water for 24 h. After 24 h the top and the bottom surface hardness of the samples were measured using a Vicker’s hardness tester ( Shimadzu HMV-2, Japan ) under 100 g load with a dwell time of 10 s. 3 measurements were performed from each sample’s top and bottom surfaces and recorded as the hardness value. Statistical analyses were performed using SPSS for Windows.
Results: The results of the microhardness test indicated that there was statistically difference between the top and bottom surfaces of microhybrid composite resin Charisma Classic and nanohybrid composite resins Charisma Diamond, Charisma Opal, Cavex, Filtek Ultimate Dentin, Majesty Esthetic. The highest hardness values were obtained from nanohybrid composite resin Grandio. Flowable nanohybrid composite resin Charisma Opal Flow showed the lowest microhardness values at all groups.
Conclusions: According to the results of this study 20 s light curing could not adequately polmerize the bottom surfaces of some composite resins used in this study. Accelerating curing time may be recommended to cure the bottom surfaces of resin restorative materials.