IADR Abstract Archives
Mechanical Property and Aesthetics of Lithium-disilicate Press Ceramics
Objectives: Lithium-disilicate (LDS) press ceramics are useful materials clinically, providing high mechanical strength and aesthetics. New-shade LDS press ceramics ideal for fabrication of monolithic restorations were developed. In this study, properties required for monolithic restorations were evaluated.
Methods: Each evaluation was performed using Initial LiSi Press LTA2 (LiSi, GC) and IPS e.max Press LTA2 (e.max, Ivoclar Vivadent). Biaxial flexure strength of LiSi and e.max were evaluated following ISO 6872-2015. To evaluate a reproducibility of color-tone to commonly used shade guide, color differences of each samples against VITAPAN classical shade (VITA) were measured. 3D image of shade guide was scanned by ATOS I 2M (GOM). Wax-pattern of crown was prepared by cutting JDS wax disc (Japan Dental Supply Corp.) with Aadva Mill LD-I (GC) as milling machine. Shade guide-shape restorations were obtained using each press systems. Colorimetry was performed using CM-700d (Konica Minolta) after polishing restorations with Meisinger polisher FP9771M.
Results: Biaxial flexure strength of LiSi and e.max were 554 ± 61 MPa and 431 ± 42 MPa (t-test, p<0.01). In colorimetry of shade guide-shape restorations, color difference against VITAPAN classical shade of LiSi and e.max were 3.15 and 3.52.
Conclusions: Compared to e.max, LiSi showed 29% higher biaxial flexure strength. Color-tone of LiSi was closer to VITAPAN classical shade guide than that of e.max. These results suggest that LiSi is the excellent material with low fracture risk and ease of color-tone adjustment.
Methods: Each evaluation was performed using Initial LiSi Press LTA2 (LiSi, GC) and IPS e.max Press LTA2 (e.max, Ivoclar Vivadent). Biaxial flexure strength of LiSi and e.max were evaluated following ISO 6872-2015. To evaluate a reproducibility of color-tone to commonly used shade guide, color differences of each samples against VITAPAN classical shade (VITA) were measured. 3D image of shade guide was scanned by ATOS I 2M (GOM). Wax-pattern of crown was prepared by cutting JDS wax disc (Japan Dental Supply Corp.) with Aadva Mill LD-I (GC) as milling machine. Shade guide-shape restorations were obtained using each press systems. Colorimetry was performed using CM-700d (Konica Minolta) after polishing restorations with Meisinger polisher FP9771M.
Results: Biaxial flexure strength of LiSi and e.max were 554 ± 61 MPa and 431 ± 42 MPa (t-test, p<0.01). In colorimetry of shade guide-shape restorations, color difference against VITAPAN classical shade of LiSi and e.max were 3.15 and 3.52.
Conclusions: Compared to e.max, LiSi showed 29% higher biaxial flexure strength. Color-tone of LiSi was closer to VITAPAN classical shade guide than that of e.max. These results suggest that LiSi is the excellent material with low fracture risk and ease of color-tone adjustment.