Three-dimensional finite element analysis of custom-made ceramic dowel made using CAD/CAM technology.
OBJECTIVE
This study compares the stress distribution in the structure of a loaded endodontically treated maxillary extracted canine restored with either custom-made zirconia (Cercon) or cast gold dowel and core.


METHODS
Standard treatments were implemented to prepare the gutta-percha-filled root canal and dowel space. The tooth along with the dowel and core fabricated pattern resin were prepared to receive an all-ceramic (Cercon) crown. An impression was made for the tooth preparation with the zirconia milled dowel and core in place to fabricate the Cercon crown using CAD/CAM. The restored canine was scanned, and from the scan two models were constructed with the surrounding ligament and bone. Three-dimensional finite element elastic analysis was then carried out for the stress distribution within the different regions of the two models due to a concentrated force of 100 N applied at the mid-lingual area. Analyses were made for three load angulations, vertical, buccolingual horizontal, and an in-between oblique force at 45(o) . Each region of the models was assumed isotropic and homogeneous. The two restored canines with zirconia and gold were compared in terms of the resulting maximum tensile, compressive, and Von Mises stresses.


RESULTS
Generally, there were no significant differences in the maximum stresses in most regions for both models. Von Mises stresses for zirconia dowel and core was 8.966 MPa and for cast gold dowel and core was 8.752 MPa. The maximum tensile stress for zirconia dowel and core was 9.326 MPa, and for cast gold dowel and core was 8.166 MPa.


CONCLUSIONS
The present work validates the use of CAD/CAM zirconia material for ceramic dowel and cores.


CONCLUSIONS
CAD/CAM Zirconia can be used for a custom-made dowel and core in an esthetically demanding zone as an esthetic replacement for a metal cast dowel and core when restoring endodontically treated teeth.
Department of Oral and Maxillofacial Rehabilitation, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia. tmarghalani@kau.edu.sa
Thamer Yousif
TY
Marghalani
Mohamed Tharwat
MT
Hamed
Mohamed Abdelmageed
MA
Awad
Ghada Hussein
GH
Naguib
Ahmed Fouad
AF
Elragi
D019245:Compressive Strength; D017076:Computer-Aided Design; D003442:Crowns; D003481:Cuspid; D003776:Dental Porcelain; D017267:Dental Prosthesis Design / Q000379:methods*; D003799:Dental Stress Analysis / Q000379:methods*; D055119:Elastic Modulus; D020342:Finite Element Analysis; D006047:Gold Alloys; D006801:Humans; D011176:Post and Core Technique; D012390:Root Canal Therapy / Q000295:instrumentation*; D013718:Tensile Strength; D015019:Yttrium; D015040:Zirconium
D006047:Gold Alloys; C499362:yttria stabilized tetragonal zirconia; D003776:Dental Porcelain; D015019:Yttrium; D015040:Zirconium