RESEARCH AND EDUCATION
Marginal and internal fit of pressed lithium disilicate inlays fabricated with milling, 3D printing, and conventional technologies Foudda R. Homsy, DCD, DES,a Mutlu Özcan, Dr Med Dent, PhD,b Marwan Khoury,c and Zeina A. K. Majzoub, DCD, DMD, MScDd Synthetic lithium disilicate ABSTRACT glass-matrix ceramics (IPS Statement of problem. The subtractive and additive computer-aided design and computer-aided e.max) are widely used in the manufacturing (CAD-CAM) of lithium disilicate partial coverage restorations is poorly documented. fabrication of tooth- and Purpose. The purpose of this in vitro study was to compare the marginal and internal fit accuracy of implant-supported prostheses lithium disilicate glass-ceramic inlays fabricated with conventional, milled, and 3-dimensional (3D) because of their excellent esprinted wax patterns. thetics and mechanical properMaterial and methods. A dentoform mandibular first molar was prepared for a mesio-occlusal ties.1,2 IPS e.max lithium ceramic inlay. Five groups of 15 inlays were obtained through conventional impression and disilicate (Ivoclar Vivadent AG) manual wax pattern (group CICW); conventional impression, laboratory scanning of the stone restorations can be fabricated by die, CAD-CAM milled wax blanks (group CIDW) or 3D printed wax patterns (group CI3DW); and using either computer-aidedscanning of the master preparation with intraoral scanner and CAD-CAM milled (group DIDW) or designed and computer-aided3D printed wax patterns (group DI3DW). The same design was used to produce the wax patterns in the last 4 groups. The replica technique was used to measure marginal and internal manufactured (CAD-CAM) adaptation by using stereomicroscopy. Mixed-model ANOVA was used to assess differences milling procedures (IPS e.max according to the groups and discrepancy location (a=.05). CAD) or the lost-wax tech3 niques (IPS e.max Press). The Results. Group DIDW showed the smallest marginal discrepancy (24.3 mm) compared with those of groups CICW (45.1 mm), CIDW (33.7 mm), CI3DW (39.8 mm), and DI3DW (39.7 mm) (P
Marginal and internal fit of pressed lithium disilicate inlays fabricated with milling, 3D printing, and conventional technologies Foudda R. Homsy, DCD, DES,a Mutlu Özcan, Dr Med Dent, PhD,b Marwan Khoury,c and Zeina A. K. Majzoub, DCD, DMD, MScDd Synthetic lithium disilicate ABSTRACT glass-matrix ceramics (IPS Statement of problem. The subtractive and additive computer-aided design and computer-aided e.max) are widely used in the manufacturing (CAD-CAM) of lithium disilicate partial coverage restorations is poorly documented. fabrication of tooth- and Purpose. The purpose of this in vitro study was to compare the marginal and internal fit accuracy of implant-supported prostheses lithium disilicate glass-ceramic inlays fabricated with conventional, milled, and 3-dimensional (3D) because of their excellent esprinted wax patterns. thetics and mechanical properMaterial and methods. A dentoform mandibular first molar was prepared for a mesio-occlusal ties.1,2 IPS e.max lithium ceramic inlay. Five groups of 15 inlays were obtained through conventional impression and disilicate (Ivoclar Vivadent AG) manual wax pattern (group CICW); conventional impression, laboratory scanning of the stone restorations can be fabricated by die, CAD-CAM milled wax blanks (group CIDW) or 3D printed wax patterns (group CI3DW); and using either computer-aidedscanning of the master preparation with intraoral scanner and CAD-CAM milled (group DIDW) or designed and computer-aided3D printed wax patterns (group DI3DW). The same design was used to produce the wax patterns in the last 4 groups. The replica technique was used to measure marginal and internal manufactured (CAD-CAM) adaptation by using stereomicroscopy. Mixed-model ANOVA was used to assess differences milling procedures (IPS e.max according to the groups and discrepancy location (a=.05). CAD) or the lost-wax tech3 niques (IPS e.max Press). The Results. Group DIDW showed the smallest marginal discrepancy (24.3 mm) compared with those of groups CICW (45.1 mm), CIDW (33.7 mm), CI3DW (39.8 mm), and DI3DW (39.7 mm) (P
