Factory Crystallized Silicates for Monolithic Metal-Free Restorations: A Flexural Strength and Translucency Comparison Test

Abstract

Flexural strength (FS) and translucency (Contrast Ratio-CR) of three different factory crystallized silica-based glass ceramics, Celtra Duo (CD), N!ce (NI) and Li-Si Block, a lithium disilicate, IPS e.max CAD (LD), and a leucite-reinforced feldspathic ceramic, Empress CAD (EM), in two different translucencies (HT and LT) for use in chairside dental restorations have been compared. CAD blocks of the materials were cut into beams and tiles and processed following manufacturers’ instructions. The beams were tested (3-PBT) to determine flexural strength, Weibull characteristic strength, and Weibull modulus; and tiles were tested to determine CR. All data were statistically analyzed. In addition, SEM analysis of the materials was performed. Differences in flexural strength (FS) and translucency (CR) between the materials were found to be statistically significant. FS decreased as follows (MPa): LDHT 350.88 ± 19.77 (a) = LDLT 343.57 ± 18.48 (a) > LSLT 202.15 ± 17.41 (b) = LSHT 196.93 ± 8.87 > NIHT 186.69 ± 13.06 (c) = CDLT 184.73 ± 13.63 (c) = CDHT 174.15 ± 21.76 (c) = NILT 172.12 ± 11.98 (c) > EMHT 131.16 ± 13.33 (e) = EMLT 127.65 ± 11.09. CR decreased as follows (mean ± sd): CDLT 74.1 ± 1.1 (a); LSLT 74.0 ± 1.1 (ab); NILT 73.3 ± 0.8 (ab); EMLT 73.0 ± 1.5 (ab); NIHT 72.4 ± 1.0 (bc); LDLT 71.3 ± 1.1 (bc); LTHT 65.2 ± 0.9 (de); LSHT 63.8 ± 1.1 (def); EMHT 636 ± 1.2 (ef); CDHT 62.2 ± 0.8 (f). Our findings show that factory-crystallized lithium silicate glass ceramics fulfill ISO standards for Classes 1 and 2. Therefore, they can be considered viable alternatives to produce single-unit restorations with a chairside procedure not requiring thermal treatment.

SEM Evaluation of the Marginal Accuracy of Zirconia, Lithium Disilicate, and Composite Single Crowns Created by CAD/CAM Method: Comparative Analysis of Different Materials

“…Among the other investigated factors influencing marginal adaptation are the acquisition and fabrication workflow and the choice of restorative material. Up to now, various materials with different compositions, physical and optical properties have become available for CAD/CAM workflow [ 40 , 41 ], nevertheless, investigations on their effects on restoration’s marginal adaptation have reported conflicting findings [ 42 , 43 ].…”

Masking capacity of minimally invasive lithium disilicate restorations on discolored teeth—The impact of ceramic thickness, the material's translucency, and the cement color

“…1,10,11 Lithium disilicate is available in different translucencies to match the optical characteristics of neighboring teeth and for achieving a restoration that blends with the adjacent natural teeth. 12 The translucency increases with decreasing material thickness, which in turn can affect the masking capacity. 13 A previous study has shown that the translucency has an impact on the masking capacity, but has also stated that the ceramic thickness seems to have a greater impact on the masking capacity then the translucency.…”

“…In cases where minimally invasive restorative alternatives are desired, silica ceramics such as lithium disilicate are suitable due to their mechanical and optical characteristics 1,10,11 . Lithium disilicate is available in different translucencies to match the optical characteristics of neighboring teeth and for achieving a restoration that blends with the adjacent natural teeth 12 . The translucency increases with decreasing material thickness, which in turn can affect the masking capacity 13 .…”

Flexural Behavior of Biocompatible High-Performance Polymer Composites for CAD/CAM Dentistry

“…According to a study by Lucsanszky et al, the composite CAD/CAM blocks had weaker flexural strengths compared to the ceramics, specifically lithium disilicate [44]. In a previous study conducted by Vichi et al, the flexural strengths of leucite-reinforced glass ceramic, lithium aluminosilicate, and lithium silicate zirconia ranged between 120 and 170 MPa [45]. According to a study by Vichi et al, the CAD/CAM lithium disilicates that require firing after milling had a comparable flexural strength of approximately 350 MPa [45], which is comparable to the flexural strength of PEEK in the current study.…”