An in vitro evaluation of a prototype CFRC prefabricated post developed for the restoration of pulpless teeth

Abstract

Carbon fibre reinforced carbon (CFRC) in the form of a prefabricated post has recently been developed and is theoretically acceptable for consideration in an endodontic post-retained crown system. This study compared four different types of postcore system cemented into 40 extracted anterior human teeth. The test groups consisted of CFRC posts cemented with a composite resin luting agent, and used with either a cast gold alloy core (Group B) or a composite resin core (Group C). Two existing post-core techniques were used as controls for comparison with the CFRC groups. One control was a prefabricated wrought precious alloy post having a cast gold alloy core, and cemented with zinc phosphate cement (Group A). The other was a prefabricated stainless steel post with a composite resin core, and cemented with a composite resin luting agent (Group D). All specimens were restored with a gold alloy crown and tested to failure with an obliquely applied compressive load at 130 degrees in an Instron using a cross-head speed of 5 cm min-1. The results showed that post-retained crowns using a prefabricated CFRC post exhibited properties comparable with, and in some cases better than, those of existing prefabricated posts. The mode of failure of specimens restored with a CFRC post was more favourable to the remaining tooth tissue than was that of specimens restored with a metallic post.

Fracture resistance of premolars with one remaining cavity wall restored using different techniques

“…Several authors reported that high fracture resistance was obtained when the elastic moduli of both post and dentin were compatible 2,8,[18][19][20] . It is believed that the creation of a mono-block dentin-post-core system through dentinal bonding would allow better distribution of applied forces evenly along the root 21) .…”

“…On mechanical reasons for FRC posts, laboratory-based studies have shown that these posts have a high tensile strength 2) and a modulus of elasticity similar to that of dentin 3) . It is thought that FRC posts flex under load, thereby leading to an improved stress distribution between post and dentin [4][5][6][7] .…”

The influence of elastic moduli of core materials on shear stress distributions at the adhesive interface in resin built-up teeth

“…However, they present poor aesthetic features and have much higher elastic moduli compared to dentin, causing catastrophic root fractures because of stress concentrations at the post end 1,2) . Ideally, post and core materials should have physical properties similar to dentin, so they are able to bond to tooth structures and distribute torqueing forces to radicular dentin, protecting root integrity 3,4) . If post and core materials have similar elastic moduli to dentin, they avoid the stress concentrations at the post end 2,5,6) and reduces root fractures, compared with cast or prefabricated metallic posts [7][8][9][10][11] .…”

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

“…On the other hand, while it is important to ensure that a post is firmly cemented to provide adequate retention for the restoration and adequate protection of the remaining tooth structure, it should yet be easily removed if retreatment were required 13,14) . Traditionally, titanium, carbon, polyethylene fiber, and stainless steel posts are used for the anterior region [15][16][17] . However, when all-ceramic restorations are preferred, metal posts may negatively affect the esthetic results 18) .…”