scholarly journals Marginal and Internal Fit of All-ceramic Crowns Fabricated with Two Different CAD/CAM Systems

2008 ◽  
Vol 27 (3) ◽  
pp. 422-426 ◽  
Author(s):  
Kyu-Bok LEE ◽  
Charn-Woon PARK ◽  
Kyo-Han KIM ◽  
Tae-Yub KWON
Keyword(s):  
All Ceramic ◽  
Cad Cam ◽  
Ceramic Crowns ◽  
Internal Fit ◽  
Cam Systems

scholarly journals Marginal and Internal Fit of Ceramic Prostheses Fabricated from Different Chairside CAD/CAM Systems: An In Vitro Study

2021 ◽  
Vol 11 (2) ◽  
pp. 857
Author(s):  
Keunbada Son ◽  
Kyu-Bok Lee
Keyword(s):  
Computer Aided Design ◽  
In Vitro Study ◽  
Vitro Study ◽  
Marginal Gap ◽  
Significant Difference ◽  
Cad Cam ◽  
Ceramic Crowns ◽  
Internal Fit ◽  
Cam Systems

The purpose of this in vitro study was to evaluate marginal and internal fits of ceramic crowns fabricated with chairside computer-aided design and manufacturing (CAD/CAM) systems. An experimental model based on ISO 12836:2015 was digitally scanned with different intraoral scanners (Omnicam (CEREC), EZIS PO (DDS), and CS3500 (Carestream)). Ceramic crowns were fabricated using the CAD/CAM process recommended by each system (CEREC, EZIS, and Carestream systems; N = 15). The 3-dimensional (3D) marginal and internal fit of each ceramic crown was measured using a 3D inspection software (Geomagic control X). Differences among the systems and various measurements were evaluated using the Kruskal–Wallis test. Statistically significant differences were validated using pairwise comparisons (α = 0.05). Occlusal gaps in the CEREC, EZIS, and Carestream groups were 113.0, 161.3, and 438.2 µm, respectively (p < 0.001). The axial gaps were 83.4, 78.0, and 107.9 µm, respectively. The marginal gaps were 77.8, 99.3, and 60.6 µm, respectively, and the whole gaps were 85.9, 107.3, and 214.0 µm, respectively. Significant differences were observed with the EZIS system compared with the other two systems in terms of the marginal gap sizes. The CEREC system showed no significant differences among the four measured regions. However, the EZIS and Carestream systems did show a statistically significant difference (p < 0.05). All three systems were judged to be capable of fabricating clinically acceptable prostheses, because the marginal gap, which is the most important factor in the marginal fit of prostheses, was recorded to be below 100 µm in all three systems.

scholarly journals In Vitro Study on Marginal and Internal Fit of CAD/CAM All-ceramic Crowns

2005 ◽  
Vol 24 (3) ◽  
pp. 456-459 ◽  
Author(s):  
Takashi NAKAMURA ◽  
Hideaki TANAKA ◽  
Soichiro KINUTA ◽  
Takeshi AKAO ◽  
Kei OKAMOTO ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Vitro Study ◽  
All Ceramic ◽  
Cad Cam ◽  
Ceramic Crowns ◽  
Internal Fit

scholarly journals A Comparative Evaluation of Marginal Fit of Crowns Fabricated by Three All Ceramic CAD-CAM Systems Using Their Respective Scanners - An in vitro study

2012 ◽  
Vol 2 (1) ◽  
pp. 10-19
Author(s):  
Sabita M. Ram ◽  
Niku Agarwal
Keyword(s):  
Laser Scanner ◽  
Mean Value ◽  
Marginal Gap ◽  
Marginal Fit ◽  
Optical Scanner ◽  
All Ceramic ◽  
Cad Cam ◽  
Ceramic Crowns ◽  
The Mean ◽  
Cam Systems

Abstract Aim To evaluate and compare the marginal fit of crowns fabricated by three All Ceramic CAD-CAM systems using their respective scanners. Objectives 1. To evaluate the marginal fit of All Ceramic crowns fabricated using Contact scanner- Procera system. 2. To evaluate the marginal fit of All Ceramic crowns fabricated using Optical scanner-Lava system. 3. To evaluate the marginal fit of All Ceramic crowns fabricated using Laser scanner-Cercon system. 4. To compare the marginal fit of crowns fabricated by three All Ceramic CAD-CAM systems using their respective scanner-Contact scanner, Optical scanner and Laser scanner. Materials and Methods 5 crowns fabricated with Contact scanner- Procera system (Group I), 5 crowns fabricated with Optical scanner-Lava system (Group II), 5 crowns fabricated with Laser scanner-Cercon system(Group III). The marginal fit would be evaluated at two stages for each group: A- Pre-veneering stage (coping) B-Post-veneering stage (crown). Results The mean value of marginal gap with Group IA was 27.48 +2.63 and IB was 26.13+ 0.85 and that of Group IIA was 23.27 + 0.99 and IIB 19.22 + 0.88. The mean value of marginal gap of Group IIIA was 32.80 + 2.46 and IIIB was 28.77 + 1.94. Conclusion The marginal gap was maximum with Group III and minimum with group II amongst the three used systems. The mean marginal gap values of subgroup B were less than subgroup A.

scholarly journals The Tooth as a Basis for Biomimetic Design

2000 ◽  
Author(s):  
Van P. Thompson ◽  
Stephen Kao ◽  
Ivory Kirkpatrick
Keyword(s):  
High Cycle Fatigue ◽  
Critical Role ◽  
Contact Loads ◽  
All Ceramic ◽  
Cad Cam ◽  
Molar Teeth ◽  
Natural Teeth ◽  
Wide Transition ◽  
Ceramic Crowns ◽  
Improved Performance

Abstract Teeth are uniquely capable of withstanding high forces (&gt;200 N) with small contact area (&lt; 0.5 mm2) and a high number of fatigue cycles (&gt; 107) with little evidence of damage. Yet the tooth is comprised of an outer very brittle, anisotropic, highly crystalline enamel layer supported by an inner soft, but tough dentin. These structures are joined by a small (appoximately 30 microns wide) transition zone called the dento-enamel junction (DEJ). The DEJ plays a critical role in transfer of stress across the layers of the tooth. How the enamel-dentin complex (EDC) comprised of these layers and the DEJ is able to withstand the high contact loads and high cycle fatigue is not well understood. An understanding of the interplay of the various components would serve as the basis for design of dental ceramic or resin based composite crowns capable of service lives approaching those on natural teeth. Current all ceramic crowns have high failure rates (1–5% per yr) on molar teeth and improved performance is required before CAD-CAM restorations can be successful.

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