Effect of luting agents and reconstruction techniques on the fracture resistance of pre‐fabricated post systems

Abstract

Fracture resistance and fracture modes of endodontically treated maxillary central incisors restored with different post-and-core systems covered with all-ceramic copings were evaluated. Ten samples were prepared for each group. Groups 1, 2 and 3 consisted of tooth-coloured post-and-core, zirconia post (Cosmopost) with a composite core (Tetric Ceram), zirconia post (Cosmopost) with a custom made ceramic core (Cosmo Ingot), glass fibre-reinforced post (FRC Postec) with a composite core (Tetric Ceram), respectively. Group 4 consisted of a titanium post (ERpost) with a composite core (Tetric Ceram). The control group (group 5) consisted of root-filled incisors without posts. Tooth-coloured posts were cemented in the roots using Variolink-2, while titanium posts were cemented in the roots using Harvard cement. The all-ceramic copings were cemented using Variolink-2. Static load was applied to 2 mm below the incisal edge on the palatinal surface of each sample until they were fractured. Fracture data were obtained and statistically analysed with One-way anova and a Tukey's test. The results of the means and standard deviations of the fracture resistance during static loading were: 497.5 +/- 61.94 (1), 474.61 +/- 96.84 (2), 494.61 +/- 104.67 (3), 581.34 +/- 105.36 (4), 420.42 +/- 127.48 (5). There were statistically significant differences between groups 4 and 5. Glass fibre-reinforced posts and composite cores (group 3) showed the most catastrophic failure. Consequently, zirconia ceramic posts can be used in clinical practice.

Zirconia ceramic post systems: a literature review and a case report

“…On the other hand, exceptions were found in some of the studies reviewed. One study by Toksavul et al 46) reported higher fracture strength with a composite core (497.5 N) than with a ceramic core (474.6 N), although there was no statistically significant difference. Similarly, Wan et al 47) found no significant differences in the fracture strength of zirconia posts when used with ceramic and composite cores.…”

“…Fracture strength The fracture strength of zirconia posts was evaluated using natural teeth in 15 studies 12,14,33,39,[41][42][43]48,49,51,55,58,[60][61][62] ( Table 1) and artificial roots in three studies 29,53,59) , and according to core material (composite resin core versus ceramic core) in nine studies 35,40,[44][45][46][47]52,54,57) (Table 2). Table 1 shows that the fracture strengths of teeth with zirconia posts and composite cores ranged between 300 N and 700 N. However, when ceramic cores were used, these values ranged between 800 N and 1500 N. These results concurred with studies which evaluated the fracture strength of zirconia posts according to core material 35,40,44,45,54) .…”

Stress prediction in a central incisor with intra-radicular restorations

“…According to some authors 22,40 , the cervical third is the region which has more propensity to fracture in intra-radicular post restored teeth, particularly in those with reduced periodontal support. High von Mises equivalent stress levels encountered at the apical end of the posts in both models seem to suggest that the geometry of the post in this extremity can contribute to the stress state acting there.…”

Post systems in prosthetic dentistry

“…Beyaz, translusent veya opak olmak üzere 3 temel renk tonunda ilk defa 1992 yılında geliştirilmişlerdir (15,27,32). Bu postların elastik modülleri düşük olduğu için mekanik özellikleri dentine karbon fiberlere göre daha yakındır.…”

“…Işık geçirgenliği vardır (32). Bükülme dayanımı dentine benzerdir ve stresleri geniş yüzey alanlarına dağıtırlar (15,32).…”