Three-dimensional finite element stress analysis of different core materials in maxillary implant-supported fixed partial dentures.
OBJECTIVE
The purpose of this study was to evaluate compressive and tensile stress values and patterns on implant-supported all-ceramic restorations applied in maxillary partially edentulous cases by utilizing the 3-dimensional (3-D) finite element stress analysis.


METHODS
Two different 3-D finite element designs representing a maxillary implant-supported fixed partial denture (from maxillary canine to second premolar) were constructed with 3 different core materials (Inceram-Zirconia, IPS 2 disilicate glass-ceramic, cobalt-chromium). In the first design, the cross-sectional connector areas of the dentures were constructed to be 3.5 3 3.5 mm. In the second design, the cross-sectional areas were decreased to 2 3 2 mm. A load of 550 N was applied in oblique direction onto the pontic.


RESULTS
The compressive and tensile stress levels obtained in the second design were higher than the first one for all materials. The compressive and tensile stresses were higher when the loads were directly applied onto the cores and the framework than when they were applied onto the porcelain sets. The cross-sectional connector area between the abutment and the pontic component has a great effect on the success of all-ceramic implant-supported fixed partial dentures.


CONCLUSIONS
All 3 materials seem to have sufficient characteristic strength for 3-unit posterior implant-supported fixed partial dentures. Only the tensile stress value obtained for IPS 2 disilicate glass core material in the second design was higher than the material's characteristic strength value when the load was applied directly onto the core.
Ozen
Julide
J
Department of Prosthetic Dentistry, Gülhane Military Medical Academy, Ankara, Turkey. julideozen@yahoo.com <julideozen@yahoo.com>
Caglar
Alper
A
Beydemir
Bedri
B
Aydin
Cemal
C
Dalkiz
Mehmet
M
D000537:Aluminum Oxide / Q000737:chemistry*; D000538:Aluminum Silicates / Q000737:chemistry*; D002858:Chromium Alloys / Q000737:chemistry*; D019245:Compressive Strength; D003764:Dental Materials / Q000737:chemistry*; D003776:Dental Porcelain / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000379:methods*; D003830:Denture, Partial, Fixed; D020342:Finite Element Analysis; D006801:Humans; D013718:Tensile Strength
D000538:Aluminum Silicates; D002858:Chromium Alloys; D003764:Dental Materials; C075815:IPS-Empress ceramic; D003776:Dental Porcelain; C070870:In-Ceram; D000537:Aluminum Oxide