Fracture strength of flared bovine roots restored with different intraradicular posts.
OBJECTIVE
The aim of this study was to evaluate the fracture strength and failure mode of flared bovine roots restored with different intraradicular posts.


METHODS
Fifty bovine incisors with similar dimensions were selected and their roots were flared until 1.0 mm of dentin wall remained. Next, the roots were allocated into five groups (n=10): GI- cast metal post-and-core; GII- fiber posts plus accessory fiber posts; GIII- direct anatomic post; GIV- indirect anatomic post and GV- control (specimens without intraradicular post). A polyether impression material was used to simulate the periodontal ligament. After periodontal ligament simulation, the specimens were subjected to a compressive load at a crosshead speed of 0.5 mm/min in a servo-hydraulic testing machine (MTS 810) applied at 135 masculine to the long axis of the tooth until failure. The data (N) were subjected to ANOVA and Tukey's post-hoc test (alpha=0.05).


RESULTS
GI and GIV presented higher fracture strength (p<0.05) than GII. GIII presented intermediate values without statistically significant differences (p>0.05) from GI, GII and GIV. Control specimens (GV) produced the lowest fracture strength mean values (p<0.05). Despite obtaining the highest mean value, GI presented 100% of unfavorable failures. GII presented 20% of unfavorable failures. GIII, GIV and GV presented only favorable failures.


CONCLUSIONS
Although further in vitro and in vivo studies are necessary, the results of this study showed that the use of direct and indirect anatomic posts in flared roots could be an alternative to cast metal post-and-core.
Clavijo
Victor Grover Rene
VG
Department of Restorative Dentistry, São Paulo State University, Araraquara, SP, Brazil.
Reis
José Maurício dos Santos Nunes
JM
Kabbach
William
W
Silva
André Luis Faria e
AL
Oliveira Junior
Osmir Batista de
OB
Andrade
Marcelo Ferrarezi de
MF
D000818:Animals; D002417:Cattle; D002484:Cementation / Q000379:methods; D002858:Chromium Alloys / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000473:pathology / Q000503:physiopathology; D005898:Glass / Q000737:chemistry; D007180:Incisor / Q000473:pathology / Q000503:physiopathology; D008422:Materials Testing; D008953:Models, Anatomic; D010513:Periodontal Ligament / Q000503:physiopathology; D011176:Post and Core Technique / Q000295:instrumentation*; D019279:Resin Cements / Q000737:chemistry; D012387:Root Canal Filling Materials / Q000737:chemistry; D018915:Root Canal Preparation / Q000379:methods; D013314:Stress, Mechanical; D014082:Tooth Fractures / Q000503:physiopathology*; D014092:Tooth Root / Q000473:pathology / Q000503:physiopathology*
D002858:Chromium Alloys; D003188:Composite Resins; D003764:Dental Materials; D019279:Resin Cements; D012387:Root Canal Filling Materials; C009753:fiberglass