Influence of alveolar bone loss, post type, and ferrule presence on the biomechanical behavior of endodontically treated maxillary canines: strain measurement and stress distribution.
BACKGROUND
Teeth restored with posts are more frequently associated with bone loss, but there is no evidence to suggest that the post type and the presence of bone loss influence biomechanical behavior.


OBJECTIVE
The purpose of this study was to evaluate the effect of alveolar bone loss, post type, and ferrule presence on the biomechanical behavior of endodontically treated maxillary canines.


METHODS
For the experimental analysis, 40 human canine teeth were selected and divided into 8 experimental groups (n=5) according to 3 treatment variations: with or without 5.0 mm of bone loss (bl), with or without a ferrule, and restored with cast post and cores or glass fiber post. The restored canines were loaded at 15 degrees, and deformation was measured with strain gauges placed on the buccal and proximal root surfaces. Strain results were analyzed by 3-way analysis of variance (ANOVA) and the Tukey HSD tests (α=.05). For the finite element analysis, eight 3D models were created by following the same variations of the experimental analysis. The models were analyzed by using the maximum principal stress criteria for stress distribution analysis.


RESULTS
The absence of a ferrule significantly increased the buccal and proximal strain values. The post type influenced the stress distribution, mainly at the interface of post and dentin. The bone loss significantly increased the stress concentration and strain values, mainly on root dentin and surrounding cortical bone.


CONCLUSIONS
The presence of a ferrule improved the mechanical behavior. The 5.0 mm of bone loss significantly increased the stress concentration and the strain on the root dentin.
Biomechanics Group, Department of Operative Dentistry and Dental Materials, School of Dentistry, Federal University of Uberlândia, Uberlândia, MG, Brazil.
Marina Guimarães
MG
Roscoe
Pedro Yoshito
PY
Noritomi
Veridiana Resende
VR
Novais
Carlos José
CJ
Soares
D016301:Alveolar Bone Loss / Q000473:pathology*; D000539:Alveolar Process / Q000473:pathology; D001696:Biomechanical Phenomena; D002858:Chromium Alloys / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D003481:Cuspid / Q000473:pathology*; D003764:Dental Materials / Q000737:chemistry; D017267:Dental Prosthesis Design; D003804:Dentin / Q000473:pathology; D020342:Finite Element Analysis; D005898:Glass / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008437:Maxilla; D011176:Post and Core Technique / Q000295:instrumentation*; D019279:Resin Cements / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D013314:Stress, Mechanical; D019231:Tooth Preparation, Prosthodontic / Q000379:methods*; D014092:Tooth Root / Q000473:pathology; D019553:Tooth, Nonvital / Q000628:therapy*
D002858:Chromium Alloys; D003188:Composite Resins; D003764:Dental Materials; C483701:Rely X Unicem; D019279:Resin Cements; D012821:Silanes; C009753:fiberglass; C533204:filtek Z350