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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Effect of remaining dentine structure and thermal-mechanical aging on the fracture resistance of bovine roots with different post and core systems

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Author(s):
Marchi, G. M. [1] ; Mitsui, F. H. O. [1] ; Cavalcanti, A. N. [1]
Total Authors: 3
Affiliation:
[1] Univ Estadual Campinas, Piracicaba Dent Sch, Dept Restorat Dent, BR-13414903 Piracicaba, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: International Endodontic Journal; v. 41, n. 11, p. 969-976, NOV 2008.
Web of Science Citations: 24
Abstract

Aim To evaluate the influence of remaining dentine thickness around post and core systems and the thermo-mechanical stresses on fracture resistance of bovine roots. Methodology This study involved 288 bovine incisor roots with standardized dimensions. Roots were randomly distributed into 24 groups (n = 12) according to root conditions {[}intact, semi-weakened, or weakened] and post and core systems {[}custom cast core, composite resin core, prefabricated metallic post, or prefabricated carbon fibre post], submitted or not to thermomechanical aging {[}5000 thermal cycles and 100 000 mechanical cycles at a 135-degree angle to the long axis of the root]. Specimens were submitted to a tangential compressive load (135 degrees angle) at a crosshead speed of 0.5 mm min(-1) until failure. Fracture resistance data were analyzed using 3-way ANOVA and Tukey test: alpha = 5%. Results Roots restored with composite resin cores demonstrated no resistance to mechanical aging. No statistically significant difference was observed between aged and nonaged specimens involving all post-systems. Roots restored with custom cast cores had the highest fracture strength, followed by prefabricated metallic posts and carbon fibre posts, regardless of root conditions and thermomechanical aging. The remaining dentine thickness affected significantly roots restored with custom cast cores; weakened roots had a lower fracture resistance. Conclusions Although custom cast cores had a higher fracture resistance when compared to the other techniques, the results were highly dependent on remaining dentine thickness. Prefabricated posts performed in a similar manner in intact, semi-weakened and weakened roots reinforced with composite resin. (AU)