IADR Abstract Archives
Optical and Structural Properties of Speed Sintered Zirconia
Objectives: To evaluate optical properties, crystal phase composition and flexural strength of two zirconia materials designed for different chairside speed sintering processes according to manufacturer instructions.
Methods: Investigated materials were 3M Chairside Zirconia(3MCZ) and KATANA Zirconia Block STML(KZB). Samples were cut from mill blanks and smoothened with P2500 sandpaper. CEREC Speedfire furnace was used for chairside speed sintering processes faster than 31min. Long term sintering was conducted in Dekema µSiC for up to 6h:48min. Samples were sintered according to manufacturer’s instruction to final dimensions of 16x4x1.2mm for bending bars and 14x14x1mm platelets.
Shade values (L*,a*,b*) and translucency were measured by an spectrophotometer (X-RiteColor-i7), crystal phase composition by X-ray diffraction (BrukerD6) and flexural strength(FS) according to ISO6872:2015(3-point-bending,12mm load-span,1mm/min,Instron6655). Average values and standard deviation were calculated. Shade deviation deltaE was calculated against fastest sintering cycle.
Results: Shade deviation dE for 3MCZ was found between 0.8-3.2 and 2.5-4.2 for KZB comparing to fastest material specific sintering schedules. Translucency varies over all sintering programs by 24±3% for 3MCZ and 25±2% for KZBs dentin proportion. Tetragonal crystal phase composition was observed in a range of 69-75wt.% for 3MCZ and 41-77wt.% for KZB. 3MCZ shows a FS-values from 1039-1141MPa. KZBs FS of 683-841MPa is related to materials tetragonal crystal phase content which depends on the applied sintering regime.
Conclusions: Both materials fulfill the FS requirement of 500MPa for ISO6872:2015 type II, class 4 materials (maximum 3-unit posterior bridges). Surprisingly the zirconia crystal phase content can be affected by sintering conditions which may lead to varying strength values of KZB. 3MCZ exhibit a higher and more constant strength level and a more constant crystal phase composition. Translucency shows a relatively stable behavior after different sintering schedules, whereas shade was found to differ either within an acceptable dE limit of ≤3.3 for 3MCZ but also to a higher extend for KZB.
Methods: Investigated materials were 3M Chairside Zirconia(3MCZ) and KATANA Zirconia Block STML(KZB). Samples were cut from mill blanks and smoothened with P2500 sandpaper. CEREC Speedfire furnace was used for chairside speed sintering processes faster than 31min. Long term sintering was conducted in Dekema µSiC for up to 6h:48min. Samples were sintered according to manufacturer’s instruction to final dimensions of 16x4x1.2mm for bending bars and 14x14x1mm platelets.
Shade values (L*,a*,b*) and translucency were measured by an spectrophotometer (X-RiteColor-i7), crystal phase composition by X-ray diffraction (BrukerD6) and flexural strength(FS) according to ISO6872:2015(3-point-bending,12mm load-span,1mm/min,Instron6655). Average values and standard deviation were calculated. Shade deviation deltaE was calculated against fastest sintering cycle.
Results: Shade deviation dE for 3MCZ was found between 0.8-3.2 and 2.5-4.2 for KZB comparing to fastest material specific sintering schedules. Translucency varies over all sintering programs by 24±3% for 3MCZ and 25±2% for KZBs dentin proportion. Tetragonal crystal phase composition was observed in a range of 69-75wt.% for 3MCZ and 41-77wt.% for KZB. 3MCZ shows a FS-values from 1039-1141MPa. KZBs FS of 683-841MPa is related to materials tetragonal crystal phase content which depends on the applied sintering regime.
Conclusions: Both materials fulfill the FS requirement of 500MPa for ISO6872:2015 type II, class 4 materials (maximum 3-unit posterior bridges). Surprisingly the zirconia crystal phase content can be affected by sintering conditions which may lead to varying strength values of KZB. 3MCZ exhibit a higher and more constant strength level and a more constant crystal phase composition. Translucency shows a relatively stable behavior after different sintering schedules, whereas shade was found to differ either within an acceptable dE limit of ≤3.3 for 3MCZ but also to a higher extend for KZB.
3223981_File000000.jpg