Fit of zirconia all-ceramic crowns with different cervical margin designs, before and after porcelain firing and glazing

Abstract

The purpose of this study is to investigate the fit of zirconia cores and all-ceramic crowns prepared with different cervical margin designs. The radius of curvature between the axial wall and the occlusal surface was set to 1 mm in an abutment using the cervical shoulder marginal design (S) and to 0.2 and 0.5 mm in abutments with round shoulders (0.2RS and 0.5RS, respectively). The internal gaps of the cores were 45-138 μm (S), 41-141 μm (0.2RS), and 43-133 μm (0.5RS). The internal gaps of the all-ceramic crowns were 40-115 μm (S), 45-113 μm (0.2RS), and 42-126 μm (0.5RS). There were no significant differences in one-way ANOVA for any region in any marginal design before and after firing the porcelain. The marginal gaps between the all-ceramic crowns and dies were 27±25 (S), 30±29 (0.2RS), and 24±27 μm (0.5RS), again with no significant differences in one-way ANOVA.

Influence of the resin cement thickness on the fatigue failure loads of CAD/CAM feldspathic crowns

“…However, in these studies, the cement thickness was varied in a narrower range than the current study: 50-100 m [1] and 80-100 m [2]. Recent literature has shown that the mean values of occlusal misfit in CAD/CAM crowns can center around 100-250 m [8][9][10][11][12]. In addition, the cement shrinkage was not considered in these simulations.…”

“…Colpani et al [4] found a narrow space in the occlusal area of CAD/CAM zirconia copings (45.2 and 55.2 m). An average occlusal space centered on 100-250 m is quite common in the recent literature [5][6][7][8][9][10][11][12]. However, variable occlusal misfits, of 24 m and 634 m beneath cusp tips and central fossa [13] and as large as 1316 m [14], have also been reported.…”

SEM evaluation of the precision of fit of CAD/CAM zirconia and metal-ceramic posterior crowns

“…This research attempts to compare the accuracy of fit of three different CAD/CAM zirconia systems and conventional metal-ceramic tecbnique, and vertical gap was measured to permit comparison with previous studies 8,9,15,17,18,[21][22][23] . The data obtained in the study support the partial rejection of the null hypothesis because differences in marginal fit were shown among the groups, however no differences were observed between external and internal marginal discrepancy values.…”

“…Most methods for evaluating the internal marginal fit, however, involve the use of an intermediate material to create a replica of the interface. One such material is fluid silicone 24,25,28,31) , which may be subsequently weighed to calculate the gap or whose thickness is measured, by cross-sectional measurements of the replica material, examined under microscope or photographed for analysis using image management software, to ascertain the space occupied by the cement 22,24,26,[32][33][34] . This type of evaluation has inherent errors, such as cut being oblique and resulting in the introduction of error into the measurement 34) .…”

A systematic review on the accuracy of zirconia crowns and fixed dental prostheses

“…Scanner/CAD system CAM system Zirconia material 3M Lava COS [27,28] 3M Lava [27,28] 3M Lava CNC 500 [27,28] 3M Lava Zirconia [28] 3Shape TRIOS [24][25][26]29,36,47] 3Shape D700 [26,48] Ceramill Motion 2 [24,48] Ceramill Zi [43,45,48] Cerec Omnicam [25] 3Shape D800 [29] Cercon Brain expert [44,48] Cercon ZR [44,48] iTero [9] 3Shape N/S [24] Cerec MC XL [25] Denzir [36,47] N/S [46] Ceramill MAP400 [43,48] DMG Mori Ultrasonic 20 linear [26] DD Bio ZW 3Y-TZP [36,47] Cercon Eye [44] Imes iCore Coritec 250i [25] InCoris [43] Cerec inEOS X5 [25] Straumann milling [9] Metoxit Zirkonia [26] Cerec inLab [43] VHF 450 classic [45] Straumann Zerion [9] Dental Wings [25,…”