Advisory Committee Chair
Nathaniel Lawson
Advisory Committee Members
John Burgess
Amjad Javed
Keith Kinderknecht
Perng-Ru Liu
Document Type
Thesis
Date of Award
2016
Degree Name by School
Master of Dentistry (MDent) School of Dentistry
Abstract
Purpose: To compare the fracture load of monolithic Zirconia crowns and E-max crowns with different margin designs and to create a guideline for margin design for monolithic Zirconia crowns. Methods: Digital design of prep maxillary molar tooth was performed with TOC 20 degrees and occlusal reduction 1 mm and axial reduction 1 mm and two different margin designs (group 1: Shoulder 0.8mm group 2: Light Chamfer 0.3mm). Dies were milled using Ultra Crystal material. Monolithic Zirconia crowns were milled (n=9 in group 1 and n=8 in group 2). Crowns were cemented with Rely X luting Plus. The specimens were stored in deionized water in an incubator maintained at oral temperature (37°C) for 24 hours, tested in the Alabama wear machine for 400,000 cycles and thermocycled for 5,000 cycles (5,000 warm, 5,000 cold) and loaded to failure in the universal testing maching (Instron 5565). The null hypothesis was that there was no difference in the fracture strength of monolithic zirconia crowns with two margins types(0.3mm chamfer, 0.8mm shoulder) cemented with resin modified glass ionomer. Results: Two crowns in the 0.8mm shoulder group and one crown in the 0.3mm chamfer group broke during the fatigue test. There was no statistical difference between the two groups after the fracture test but the values on second group are higher. Conclusion: Within the limitations of this study there is no effect of margin design on fracture strength of zirconia crowns. The values of fracture strength of zirconia crowns are significantly higher than the average biting forces or clenching forces.
Recommended Citation
Voltidi, Eleni, "Effect of Margin Design on Fracture Strength of Zirconia Crown" (2016). All ETDs from UAB. 3232.
https://digitalcommons.library.uab.edu/etd-collection/3232
