Effects of labial margin design on stress distribution of a porcelain-fused-to-metal crown.
OBJECTIVE
This study compared the stress distribution of three porcelain-fused-to-metal labial margins on a central incisor under simulated occlusal force.


METHODS
The margin designs were rounded-shoulder, rounded-shoulder with a bevel, and a chamfer.


RESULTS
Evaluation of mean equivalent Mises tensile stress did not show any difference at the cement-dentin and metal-cement interfaces of the three margins. The mean equivalent Mises tensile stress at the porcelain-metal interface was found to be significantly higher for rounded-shoulder when compared with the chamfer. There was no significant difference in the axial stresses along the three interfaces among the three margin designs. Statistically significant differences in radial stresses at some interfaces of the three margin designs were found.


CONCLUSIONS
The change of cement thickness of the chamfer margin is significantly greater than that of either the rounded-shoulder or the bevelled-shoulder margin.
Chai
J Y
JY
Advanced Education Prosthodontics, Northwestern University Dental School, Chicago, IL.
Steege
J W
JW
D003442:Crowns; D003738:Dental Cements; D017267:Dental Prosthesis Design; D003799:Dental Stress Analysis; D003804:Dentin; D006801:Humans; D016876:Metal Ceramic Alloys; D013499:Surface Properties; D013718:Tensile Strength
D003738:Dental Cements; D016876:Metal Ceramic Alloys