Fracture resistance of endodontically treated teeth restored with intra-radicular post: the effects of post system and dentine thickness.
To investigate the influence of post system and amount of remaining root tissue on the fracture resistance of endodontically treated teeth. Seventy upper canine teeth were divided into seven groups (n=10), one control (sound teeth) and six experimental groups resulting from the interaction between the two study factors: post system (FB, fiber post; FPC, fiber post relined with resin composite; CPC, cast Ni-Cr alloy post and core) and amount of remaining root tooth tissue (2 or 1mm of thick root). All teeth were restored with metal crowns and exposed to 250,000 cycles in a controlled chewing simulator. The samples were submitted to the fracture resistance test in a universal testing machine, at an angle of 135° and speed of 0.5mm/min, until fracture occurred. Failure modes were observed, and the data of fracture resistance, in Newtons, were submitted to the analysis of variance (ANOVA), followed by Tukey's test (α=0.05). Roots restored with FPC had the highest fracture strength of the experimental groups, being statistically similar to the intact teeth group (P>0.05). FP and CPC did not differ statistically (P>0.05) and were statistically lower than those of FPC (P<0.05). No statistically significant difference was observed between amounts of remaining root tooth tissue to the same post systems (P>0.05). A prevalence of irreparable failures was observed in specimens restored with CPC, whereas FP and FPC posts showed more repairable failures. The post system had an influence significant on fracture resistance. However, the remaining dentine with 2- or 1-mm thickness was not an important factor for the fracture resistance.
Department of Restorative Dentistry, Passo Fundo Dental School, University of Passo Fundo, UPF, Passo Fundo, RS, Brazil.
Ramiro Rocha
RR
Barcellos
Débora Pereira Diniz
DP
Correia
Ana Paula
AP
Farina
Marcelo Ferraz
MF
Mesquita
Caio Cezar Randi
CC
Ferraz
Doglas
D
Cecchin
D000328:Adult; D003442:Crowns; D005260:Female; D006801:Humans; D007180:Incisor; D008297:Male; D008422:Materials Testing / Q000379:methods*; D012387:Root Canal Filling Materials; D014082:Tooth Fractures / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*
D012387:Root Canal Filling Materials
Cast post and core; Endodontically treated teeth; Fracture resistance; Glass fiber post; Root fracture