Fracture resistances of zirconia, cast Ni-Cr, and fiber-glass composite posts under all-ceramic crowns in endodontically treated premolars

Abstract

PURPOSEThe aim of the present study was to evaluate the fracture resistances of zirconia, cast nickel-chromium alloy (Ni-Cr), and fiber-composite post systems under all-ceramic crowns in endodontically treated mandibular first premolars.MATERIALS AND METHODSA total of 36 extracted human mandibular premolars were selected, subjected to standard endodontic treatment, and divided into three groups (n=12) as follows: cast Ni-Cr post-and-core, one-piece custom-milled zirconia post-and-core, and prefabricated fiber-glass post with composite resin core. Each specimen had an all-ceramic crown with zirconia coping and was then loaded to failure using a universal testing machine at a cross-head speed of 0.5 mm/min, at an angle of 45 degrees to the long axis of the roots. Fracture resistance and modes of failure were analyzed. The significance of the results was assessed using analysis of variance (ANOVA) and Tukey honest significance difference (HSD) tests (α=.05).RESULTSFiber-glass posts with composite cores showed the highest fracture resistance values (915.70±323 N), and the zirconia post system showed the lowest resistance (435.34±220 N). The corresponding mean value for the Ni-Cr casting post and cores was reported as 780.59±270 N. The differences among the groups were statistically significant (P<.05) for the zirconia group, as tested by ANOVA and Tukey HSD tests.CONCLUSIONThe fracture resistance of zirconia post-and-core systems was found to be significantly lower than those of fiberglass and cast Ni-Cr post systems. Moreover, catastrophic and non-restorable fractures were more prevalent in teeth restored by zirconia posts.

Fracture resistance of tilted premolars restored with different post-core systems

“…Because of the reported similarities to tooth biomechanical characters, fiber post and composite core restorative system could facilitate normal on-loading flexure of roots resulting in minimal values of harmful stresses. [ 4 35 ] In agreement with the results of the current study, Gu et al [ 36 ] reported higher incidence of restorable failures (crown or core fracture) in teeth restored by fiber post, in comparison to teeth restored by cast post and core those most of the time showed non-restorable root fractures. Freedman[ 37 ] indicated that vertical root fracture usually the result of accumulation of higher stresses at the apical area of roots having cast post-cores.…”

In-Vitro Effect of G-Bond and Z-Prime Plus on Fracture Resistance of Prefabricated Zirconia Posts Bonded to Root Canal Walls

“…(18) However, in our study, the application of G-Bond and Z-Prime Plus as surface treatment increased the fracture resistance of zirconia posts. Habibzadeh et al (19) evaluated the fracture resistance of zirconia, cast nickel-chromium (Ni-Cr), and FRC post systems under all-ceramic crowns and reported significantly lower fracture resistance (435.34 N) and non-restorable fractures for zirconia posts, which is consistent with the results of the present study. In a recent study, prefabricated zirconia posts demonstrated higher fracture resistance than carbon fiber posts.…”

Retenção intracanalar na reconstrução coronária de dentes tratados endodonticamente – uma revisão narrativa

“…Os retentores intracanalares podem ser produzidos pelos seguintes materiais metálicos: AuPd, PdAg, PdAu, aço inoxidável, latão, titânio comercialmente puro (cp Ti), ligas de titânio e ligas à base de cobalto-crómium (ex. CoCrWMo) (Dewangan & Shrivastava, 2012;Habibzadeh et al, 2017). O titânio e as suas ligas possuem uma alta resistência à corrosão e biocompatibilidade associados a uma alta resistência mecânica (Bueno et al, 2012;Moyin et al, 2019).…”

“…bruxismo). Por outro lado, ligas de metais básicos, como CoCrWMo, têm a vantagem de terem resistência à corrosão e propriedades mecânicas clinicamente satisfatórias e ainda a vantagem adicional de ter um reduzido custo (Dewangan & Shrivastava, 2012;Habibzadeh et al, 2017). Estes materiais de retenção, apesar de terem sido usados durante muitas décadas com taxas de sucesso elevadas apresentam um elevado módulo de elasticidade, o qual resulta em uma maior concentração de tensões na zona radicular.…”