IADR Abstract Archives
Chemical durability of CAD/CAM glass-ceramic blocks
Objectives: CAD/CAM ceramic blocks have become popular as materials for dental restoration fabrication. Recently a new lithium-disilicate based glass-ceramic CAD/CAM block, Initial LiSi block, was developed by GC Corporation. Materials for molar restoration are required high physical properties and chemical durability, which affect longevity of restorations. The aim of this study is to evaluate the chemical solubility of the commercially available glass-ceramic blocks.
Methods: Six materials were selected for analysis: 1) Initial LiSi block (LIS, GC); 2) IPS e.max CAD (EMA, Ivoclar Vivadent); 3) CeltraDUO (CEL, Dentsply Sirona); 4) SUPRINITY (SUP, VITA); 5) IPS Empress CAD (EMP, Ivoclar Vivadent); 6) MarkΙΙ (MAK, VITA). Flat specimens were cut out from the blocks. The specimens of EMA and SUP were heat-treated for crystallization following the manufacturer’s instructions. Chemical solubility test was conducted according to ISO 6872 (2015).
The solubility of material was calculated from mass weight loss and total surface area of the specimen (µg/cm2). After the chemical solubility test, the surface properties were observed with scanning electron microscope (SEM). Crystal structure was determined before and after the test using X-ray diffraction (XRD) measurement.
Results: Results of chemical solubility test are shown in Table. After the test, dissolution of the material was confirmed for all glass-ceramic blocks. The chemical solubility of LIS was significantly lower than that of other glass-ceramic blocks. XRD analysis revealed that there was no change in the crystal structure in all the samples after the acid challenge.
Conclusions: These results suggested that the glass-ceramic blocks dissolves against acid. The acid solubility greatly differed depending on the materials, which may be influenced by the crystal system, the amount of crystals, the composition of the glass matrix.
Initial LiSi block showed the highest durability against acid among all ceramic blocks tested.
Methods: Six materials were selected for analysis: 1) Initial LiSi block (LIS, GC); 2) IPS e.max CAD (EMA, Ivoclar Vivadent); 3) CeltraDUO (CEL, Dentsply Sirona); 4) SUPRINITY (SUP, VITA); 5) IPS Empress CAD (EMP, Ivoclar Vivadent); 6) MarkΙΙ (MAK, VITA). Flat specimens were cut out from the blocks. The specimens of EMA and SUP were heat-treated for crystallization following the manufacturer’s instructions. Chemical solubility test was conducted according to ISO 6872 (2015).
The solubility of material was calculated from mass weight loss and total surface area of the specimen (µg/cm2). After the chemical solubility test, the surface properties were observed with scanning electron microscope (SEM). Crystal structure was determined before and after the test using X-ray diffraction (XRD) measurement.
Results: Results of chemical solubility test are shown in Table. After the test, dissolution of the material was confirmed for all glass-ceramic blocks. The chemical solubility of LIS was significantly lower than that of other glass-ceramic blocks. XRD analysis revealed that there was no change in the crystal structure in all the samples after the acid challenge.
Conclusions: These results suggested that the glass-ceramic blocks dissolves against acid. The acid solubility greatly differed depending on the materials, which may be influenced by the crystal system, the amount of crystals, the composition of the glass matrix.
Initial LiSi block showed the highest durability against acid among all ceramic blocks tested.