scholarly journals Marginal fit of all-ceramic crowns fabricated using two extraoral CAD/CAM systems in comparison with the conventional technique

2017 ◽  
Vol Volume 9 ◽  
pp. 13-18 ◽  
Author(s):  
Fawaz Alqahtani
2012 ◽  
Vol 2 (1) ◽  
pp. 10-19
Author(s):  
Sabita M. Ram ◽  
Niku Agarwal

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.


2021 ◽  
Vol 7 (2) ◽  
pp. 104-109
Author(s):  
Himanshu Aeran ◽  
Megha Sagar ◽  
Jyotsna Seth

The survival of fixed prosthodontic restorations depends on the state of the marginal adaptation. Marginal gaps can create a favourable condition for biofilm deposition, thereby contributing to the development of caries and periodontal disease. The longevity of fixed prosthodontic restorations depends on the condition of the marginal adaptation to the abutment teeth. The presented work aimed to study, evaluate and compare the marginal adaptation of All-Ceramic crowns fabricated using conventional laboratory procedures with those fabricated using the CAD/CAM technology.To compare the marginal fit and adaptation of All- Ceramic crowns obtained by conventional techniques and crowns obtained by CAD/CAM technique. The presented study focused on a total of 20 samples divided into two groups viz. Group I (Conventional) and Group II (CAD/CAM) having 10 sample each. The samples were prepared with the straight abutment having a standardized collar height of 2mm, HIOSSEN that was mounted on acrylic blocks using implant analogue, HIOSSEN. A set of crowns was produced by 5-axis milling lithium disilicate using glass-ceramic blocks with laboratory fabrication methods. Another set of zirconia crowns was produced using CAD/CAM technology. Circumferential marginal gap measurements were taken at 12 measurement locations on the hexagonal die marked equidistant to each other. Both the samples were measured for marginal discrepancy at under the stereomicroscope.The results obtained showed that the mean vertical gap for the group II samples showed the least variation in the marginal discrepancy. Although the mean obtained for both the groups showed that the mean vertical marginal discrepancy was within the clinically acceptable level.It can be concluded that within the limitation of the study the data obtained showed that The Mean vertical gap was the maximum for Group I (Conventional group) i.e. 49.25 µm showing maximum variation in marginal fit. While the CAD/CAM Group had shown least vertical marginal discrepancy which depicts statistically significant better marginal fit than those fabricated using conventional laboratory procedures.


2019 ◽  
Vol 28 (9) ◽  
pp. 1037-1043 ◽  
Author(s):  
Ibrahim Salim Duqum ◽  
Christian Brenes ◽  
Gustavo Mendonca ◽  
Thiago Almedia Prado Naves Carneiro ◽  
Lyndon F. Cooper

2008 ◽  
Vol 27 (3) ◽  
pp. 422-426 ◽  
Author(s):  
Kyu-Bok LEE ◽  
Charn-Woon PARK ◽  
Kyo-Han KIM ◽  
Tae-Yub KWON

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Ki-Hong Lee ◽  
In-Sung Yeo ◽  
Benjamin M. Wu ◽  
Jae-Ho Yang ◽  
Jung-Suk Han ◽  
...  

Purpose. The purpose of this study was to investigate the marginal fit of metal-free crowns made by three different computer-aided design/computer-aided manufacturing (CAD/CAM) systems.Materials and Methods. The maxillary left first premolar of a dentiform was prepared for all-ceramic crown restoration. Thirty all-ceramic premolar crowns were made, ten each manufactured by the Lava system, Cercon, and Cerec. Ten metal ceramic gold (MCG) crowns served as control. The marginal gap of each sample was measured under a stereoscopic microscope at 75x magnification after cementation. One-way ANOVA and the Duncan’s post hoc test were used for data analysis at the significance level of 0.05.Results. The mean (standard deviation) marginal gaps were 70.5 (34.4) μm for the MCG crowns, 87.2 (22.8) μm for Lava, 58.5 (17.6) μm for Cercon, and 72.3 (30.8) μm for Cerec. There were no significant differences in the marginal fit among the groups except that the Cercon crowns had significantly smaller marginal gaps than the Lava crowns(P<0.001).  Conclusions. Within the limitation of this study, all the metal-free restorations made by the digital CAD/CAM systems had clinically acceptable marginal accuracy.


Author(s):  
Youssef Y. Ashour

Background: Veneered all-ceramic restorations are associated with a high incidence of chipping and veneer delamination from the inner core. Monolithic all-ceramic crowns facilitate the fabrication process and minimize residual stresses between core and veneer. A new material,zirconia-reinforced lithium silicate(ZRL), Celtra Duo was recently introduced for fabrication of monolithic anterior crowns to overcome the aesthetic drawbacks of traditional zirconia and also to improve the strength of the lithium disilicate. Aim of the study: To examine the marginal fit of CAD/CAM: zirconia reinforced lithium disilicatand to evaluate it with Lithium silicate glass-ceramic crowns. Materials and methods: Thirty monolithic ceramic specimens will be fabricated and divided into THREE main groups; Group I: CAD/CAM ZLS Celtra Duo milled and polished, Group II CAD /CAM ZLS Celtra Duo milled and glazed & Group III: CAD/CAM Lithium silicate glass-ceramic (e.max CAD). For evaluation of the marginal fit 30 ceramic crown specimens ten specimens from each material(N=10), subgroups Ia, IIa, IIIa will be fabricated according to the manufacturers’ instructions and thermocycled to simulate one year clinical service. Marginal fit will be measured for the same specimens by using CBCT (Ia, IIa, IIIa). For evolution of marginal fit 30 ceramic crowns will be fabricated, ten crowns from each material (N=10), subgroups Ia, IIa, IIIa. Results: Will be arrangeand statistically analyzed.


2021 ◽  
Vol 11 (2) ◽  
pp. 857
Author(s):  
Keunbada Son ◽  
Kyu-Bok Lee

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.


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