Farklı CAD/CAM restoratif materyallerinin mekanik ve optik özelliklerinin karşılaştırılması

This study was conducted to compare the mechanical, optical properties and effect of thermocycling on four types of CAD/CAM (Computer Aided Design/Computer Aided Manufacturing) monolithic restorative materials. A total of 120 specimens from IPS Empress CAD (Ivoclar Vivadent, AG, Schaan, Liechtenstein), Celtra DUO (Dentsply, Sirona, Hana-Wolfgang, Germany), inCoris TZI C (Dentsply, Sirona, Hana-Wolfgang, Germany) and IPS e.max ZirCAD (Ivoclar Vivadent, AG, Schaan, Liechtenstein) were used. 80 specimens with 14 mm x 1.2 mm x 4 mm dimensions for 2 subgroups with and without thermocycling were prepared for mechanical tests and sizes of 12 mm x 12 mm square shaped 10 samples from each material were prepared for optical tests before and after thermocycling. The inCoris TZI C and IPS e.max ZirCAD blocks were sintered in a furnace according to their manufacturer instructions before cutting. Each sample was polished and cleaned using ultrasonic cleaner. The flexural strength was determined by three-point flexural tests using a universal testing machine according to ISO 6872:2015. The surface microhardness was calculated using a Vickers hardness test device. Color change (∆E), translucency (TP) and opalescence parameters (OP) of all tested monolithic restorative materials were examined using spectrophotometer. Three samples from each group of material were randomly selected and evaluated under a scanning electron microscope (SEM). The statistical analysis was accomplished by SPSS (statistical package for social sciences) V.25 program. For flexural strength test, the effect of thermal aging was not statistically significant (p>0.05), while the effect of material type was statistically significant (p<0.05). The highest flexural strength value was for IPS e.max ZirCAD (1447.6±286.3MPa), while IPS Empress CAD demonstrated the lowest value (155.8±27.2MPa) of flexural strength. There were statistically significant differences in surface microhardness values between material groups and subgroups (p<0.05). Thermal aging Celtra DUO subgroup had a statistically significantly lower surface microhardness (VHN) value than non-thermal aging subgroup (p=0.001), and IPS Empress CAD thermal aging subgroup had a statistically significantly higher VHN value than non-thermal aging subgroup (p=0.000). There were no statistically significant differences between the thermal aging and non-thermal aging subgroups of two zirconia materials in terms of surface microhardness values (p>0.05). There was a statistically significant difference in ΔE between material groups with thermal aging (p=0.000). After thermal aging, ΔE was the highest in IPS Empress CAD (2.78±1.21), while Celtra DUO, IPS e.max ZirCAD and inCoris TZI C had similar ΔE values with each other (0.54±0.18, 0.53±0.31, 0.42±0.09, respectively). Thermocycling led to statistically significant color change on all materials except for InCoris TZI C (p<0.05). Regarding the translucency parameter (TP) and opalescence parameter (OP), the effect of thermal aging was not statistically significant for any groups [TP (p=0.664), OP (p=0.502)]. The highest TP value was for IPS Empress CAD (20.73±0.79) and highest OP value was for Celtra DUO (12.97±0.34). Monolithic zirconia ceramics have higher mechanical properties than glass ceramic materials. The reinforced glass ceramic material has superior optical properties than monolithic zirconia ceramics. The OP value for all tested groups showed lower value than criteria for natural tooth OP values.