Materials and procedures Nine specimens of IPS e.max glass-ceramics (Ivoclar Vivadent, Schaan, Liechtenstein) were made in the form of plates with dimensions 10 mm x 12 mm x 0.8 mm ± 0.05 mm in three colours (A2, C2, B3). The tested glass-ceramics specimens are presented in Table 1. The grade of IPS e.max Press and IPS e.max CAD ceramics was HT (high translucency). All specimens were prepared by the same dental technician by standard procedures in accordance with the IPS e.max Press specimens were made by manufacturer’s directions. using wax models, which were, after firing, pressed in moulds by the technique of of ingots. IPS e.max Ceram Dentin specimens were made by powder condensation technique, by manual mixing of the ceramic powder with distilled water and firing (Programat EP 5000, Ivoclar Vivadent, Schaan, Liechtenstein). IPS e.max CAD specimens were made from factory-made blocks with the use of a milling machine (Amann Girrbach Ceramill Motion 2, Koblach, Austria). After preparation, unglazed specimens were polished to obtain a smooth and even surface by using polishers, rubbers and silicon carbamide discs (Komet Dental, Gebr. Brasseler GmbH & Co. KG, Lemgo, Germany) and were ultrasonically washed and cleaned in distilled water for 15 minutes (ISO 3696). In the first part of the study, measurements of L*a*b* values of glass-ceramic specimens in three colours (A2, C2 and B3), fabricated by three different fabrication techniques were determined. Measurements were conducted instrumentally by using a calibrated spectrophotometer and colorimeter X-Rite DTP 20 Pulse (45°/0°measuring geometry, 2°standard observer, illuminant D65). The numerical value of translucency is based on the CIE L*a*b* three-dimensional system and represents the difference in colour of a specific specimen measured on achromatic backgrounds. Consequently, two series of measurements were
Materials and procedures Nine specimens of IPS e.max glass-ceramics (Ivoclar Vivadent, Schaan, Liechtenstein) were made in the form of plates with dimensions 10 mm x 12 mm x 0.8 mm ± 0.05 mm in three colours (A2, C2, B3). The tested glass-ceramics specimens are presented in Table 1. The grade of IPS e.max Press and IPS e.max CAD ceramics was HT (high translucency). All specimens were prepared by the same dental technician by standard procedures in accordance with the manufacturer’s directions. IPS e.max Press specimens were made by using wax models, which were, after firing, pressed in moulds by the technique of of ingots. IPS e.max Ceram Dentin specimens were made by powder condensation technique, by manual mixing of the ceramic powder with distilled water and firing (Programat EP 5000, Ivoclar Vivadent, Schaan, Liechtenstein). IPS e.max CAD specimens were made from factory-made blocks with the use of a milling machine (Amann Girrbach Ceramill Motion 2, Koblach, Austria). After preparation, unglazed specimens were polished to obtain a smooth and even surface by using polishers, rubbers and silicon carbamide discs (Komet Dental, Gebr. Brasseler GmbH & Co. KG, Lemgo, Germany) and were ultrasonically washed and cleaned in distilled water for 15 minutes (ISO 3696). In the first part of the study, measurements of L*a*b* values of glass-ceramic specimens in three colours (A2, C2 and B3), fabricated by three different fabrication techniques were determined. Measurements were conducted instrumentally by using a calibrated spectrophotometer and colorimeter X-Rite DTP 20 Pulse (45°/0°measuring geometry, 2°standard observer, illuminant D65). The numerical value of translucency is based on the CIE L*a*b* three-dimensional system and represents the difference in colour of a specific specimen measured on achromatic backgrounds. Consequently, two series of measurements were