Influence of different zirconia coping designs on the fracture resistance of all-ceramic crowns: An in vitro study

Abstract Aim The aim of this study was to investigate the influence of three different thicknesses of In-Ceram core on the load at fracture of all-ceramic crowns. Methods and Materials Thirty standardized crown-shaped nickel-chromium alloy dies were fabricated using a milling machine. Twenty dies were prepared with a 1 mm shoulder for Groups A and B. The only difference in the ten dies used for Group C was a smaller 0.5 mm lingual shoulder. The thicknesses of In-Ceram were 0.5 mm, 1.5 mm, and 0.75 mm for Groups A, B, and C. All all-ceramic crowns were fabricated in accordance with the manufacturer's instructions. After cementation of the crowns, their fracture resistance was tested with a universal testing machine. The load was directed to a point located 3 mm from the lingual aspect of the incisal edge at 30 degrees to the long axis of each specimen until catastrophic failure occurred. Results The mean loads at fracture for Groups A, B, and C were 1117±388 N, 2083±385 N, and 1439±368 N, respectively. No statistically significant difference in load at fracture between Groups A and C was found (p>0.05). However, the differences were statistically significant between Groups A and B (p<0.001) and Groups B and C (p<0.001). Conclusion Under the guidelines of this study, increasing the thickness of the In-Ceram core increased the fracture resistance of the all-ceramic crowns. Clinical Significance The sufficient thickness of the In-Ceram core of all-ceramic crowns is an important factor in fracture resistance. Therefore, dental practitioners should be careful in patient selection; if the horizontal overlap of a tooth to be restored is too limited, then all-ceramic crowns may not be a feasible option. Citation Gokce S, Celik-Bagci E, Turkyilmaz I. A Comparative in vitro Study of the Load at Fracture of Allceramic Crowns with Various Thicknesses of In-Ceram Core. J Contemp Dent Pract 2008 May; (9)4:017-025.

Download Full-text

Evaluation of Remaining Dentin Thickness (RDT) Following Tooth Preparation for All Ceramic Crowns - An in Vitro Study.

IOSR Journal of Dental and Medical Sciences ◽

10.9790/0853-1510036670 ◽

2016 ◽

Vol 15 (10) ◽

pp. 66-70

Author(s):

Dr. S. Seyedasharafali ◽

Dr. Suma Karthigeyan ◽

J. Sankar ◽

R. Madhan ◽

Dr. R. Krishnaraj ◽

...

Keyword(s):

In Vitro Study ◽

Vitro Study ◽

All Ceramic ◽

Ceramic Crowns ◽

Tooth Preparation ◽

Dentin Thickness

Download Full-text

INFLUENCE OF PORCELAIN FIRING AND CORE THICKNESS ON MARGINAL GAP OF CAD/CAM AND PRESSABLE ALL-CERAMIC CROWNS (IN-VITRO STUDY)

Egyptian Dental Journal ◽

10.21608/edj.2021.69248.1561 ◽

2021 ◽

Vol 67 (3) ◽

pp. 2377-2385

Author(s):

Mohamed Abdullah ◽

Laila Kenawi

Keyword(s):

In Vitro Study ◽

Vitro Study ◽

Marginal Gap ◽

Porcelain Firing ◽

All Ceramic ◽

Cad Cam ◽

Core Thickness ◽

Ceramic Crowns

Download Full-text

The Marginal Fitness of CAD / CAM All Ceramic Crowns Constructed by Two Types of Direct Digitization Techniques : An in Vitro Study

Journal of Baghdad College of Dentistry ◽

10.12816/0028210 ◽

2016 ◽

Vol 28 (2) ◽

pp. 30-33

Author(s):

Rana M. Khdeir ◽

Adel F. Ibraheem

Keyword(s):

In Vitro Study ◽

Vitro Study ◽

All Ceramic ◽

Cad Cam ◽

Ceramic Crowns

Download Full-text

Marginal Fit Evaluation of CAD/CAM All Ceramic Crowns Obtained by Two Digital Workflows: An In Vitro Study Using Micro‐CT Technology

Journal of Prosthodontics ◽

10.1111/jopr.13115 ◽

2019 ◽

Vol 28 (9) ◽

pp. 1037-1043 ◽

Cited By ~ 3

Author(s):

Ibrahim Salim Duqum ◽

Christian Brenes ◽

Gustavo Mendonca ◽

Thiago Almedia Prado Naves Carneiro ◽

Lyndon F. Cooper

Keyword(s):

In Vitro Study ◽

Vitro Study ◽

Micro Ct ◽

Marginal Fit ◽

All Ceramic ◽

Cad Cam ◽

Ct Technology ◽

Ceramic Crowns

Download Full-text

Accuracy of Ceramic Restorations Made Using an In-office Optical Scanning Technique: An In Vitro Study

Operative Dentistry ◽

10.2341/12-309-l ◽

2014 ◽

Vol 39 (3) ◽

pp. 308-316 ◽

Cited By ~ 24

Author(s):

P Tidehag ◽

K Ottosson ◽

G Sjögren

Keyword(s):

Glass Ceramic ◽

In Vitro Study ◽

Vitro Study ◽

Digital Impression ◽

All Ceramic ◽

Computer Aided ◽

Cad Cam ◽

Ceramic Crowns ◽

Ceramic Crown

SUMMARY The present in vitro study concerns determination of the pre-cementation gap width of all-ceramic crowns made using an in-office digital-impression technique and subsequent computer-aided design/computer-aided manufacturing (CAD/CAM) production. Two chairside video camera systems were used: the Lava Oral scanner and Cadent's iTero scanner. Digital scans were made of a first molar typodont tooth that was suitably prepared for an all-ceramic crown. The digital impressions were sent via the Internet to commercial dental laboratories, where the crowns were made. Also, an impression of the typodont tooth was made, poured, and scanned in order to evaluate the pre-cementation gap of crowns produced from scanning stone dies. These methods and systems were evaluated by creating replicas of the intermediate space using an addition-cured silicone, and the gap widths were determined using a measuring microscope. Hot-pressed leucite-reinforced glass-ceramic crowns were selected as a reference. The mean value for the marginal measuring points of the control was 170 μm, and the values for all the evaluated crowns ranged from 107 to 128 μm. Corresponding figures for the internal measuring points were 141-210 μm and 115-237 μm, respectively. Based on the findings in the present study, an in-office digital-impression technique can be used to fabricate CAD/CAM ceramic single crowns with a marginal and internal accuracy that is on the same level as that of a conventional hot-pressed glass-ceramic crown. In the present study, however, slight differences could be seen between the two types of ceramic crowns studied with respect to the internal fit obtained.

Download Full-text