Finite element analysis of stress distribution of 2 different tooth preparation designs in porcelain-fused-to-metal crowns.
OBJECTIVE
The aim of this clinical simulation study was to investigate the effect of anatomic and nonanatomic occlusal preparation design on stress distribution in different metal-ceramic crowns and tooth and bone.


METHODS
For the finite element analysis method, a 2-dimensional mathematical model of a mandibular second premolar tooth and its supporting tissues was used. The analysis was performed by using a structural analysis program. Four groups were designed: gold-palladium alloy/anatomic occlusal preparation (Au-Pd/A), Au-Pd alloy/nonanatomic (flat) occlusal preparation (Au-Pd/N), nickel-chromium alloy/anatomic occlusal preparation (Ni-Cr/A), and Ni-Cr alloy/nonanatomic occlusal preparation (Ni-Cr/N). A distributed type load of 400 N (total) was applied to the centric stop points on the tip of the buccal cusp and on the central developmental groove in centric occlusion to all types of restorations.


RESULTS
The results demonstrated that shear stresses in the dentin tissues and restorations in Au-Pd/A and Ni-Cr/A were similar. The shear stresses within the restorations in Au-Pd/N and Ni-Cr/N were similar.


CONCLUSIONS
Anatomic occlusal preparation designs were advantageous in stress distribution in the dentin tissue. Nonanatomic occlusal preparation designs were found to be advantageous in the stress amount and distribution in the porcelain structure. Occlusal preparation designs and restorative materials showed no differences in stress distribution and amount in the pulp tissue and bone tissues.
Oyar
Perihan
P
School of Dental Technology, Hacettepe University, Ankara, Turkey. drdtperihan@yahoo.com
Ulusoy
Mutahhar
M
Eskitascioglu
Gurcan
G
D000539:Alveolar Process / Q000502:physiology; D001641:Bicuspid / Q000502:physiology; D002858:Chromium Alloys / Q000737:chemistry; D003198:Computer Simulation; D003442:Crowns; D003768:Dental Occlusion, Centric; D003776:Dental Porcelain / Q000737:chemistry*; D003782:Dental Pulp / Q000502:physiology; D003804:Dentin / Q000502:physiology; D020342:Finite Element Analysis; D006047:Gold Alloys / Q000737:chemistry; D006801:Humans; D008334:Mandible / Q000502:physiology; D016876:Metal Ceramic Alloys / Q000737:chemistry*; D008954:Models, Biological; D010165:Palladium / Q000737:chemistry; D033081:Shear Strength; D013314:Stress, Mechanical; D013499:Surface Properties; D019231:Tooth Preparation, Prosthodontic / Q000379:methods*
D002858:Chromium Alloys; D006047:Gold Alloys; D016876:Metal Ceramic Alloys; D003776:Dental Porcelain; D010165:Palladium