Method: Eight groups of posts (n=10) were divided into those with and without silane treatment. Four different core foundation materials were paired with their recommended posts and bonding agents as follows: Corecem + SealBond Ultima + Macro-Lock; Zircules + MPa+ Macro-Lock; RockCore + Prelude + IcePost; and ParaCore + ParaBond + ParaPost Fiber Lux. Following application of bonding agent, resin composite was injected around the post in a customized mold and light cured for 20s. For µTBS, specimens (1mm x 1mm cross-section and 8mm long) were produced. Testing was conducted using a universal Inston machine at a crosshead speed of 1mm/min. Statistical analysis was carried out using one-way ANOVA and Tukey-HSD test, p=0.05.
Result: The µTBS values ranged from 18.59 MPa for Paracore without silane to 43.09 MPa for Corecem with silane. Silane treated Macro-Lock post paired with Zircules and Corecem exhibited the highest µTBS amongst groups, p<0.05, while ParaPost Fiber Lux without silane exhibited the lowest µTBS, p<0.05. SEM analysis demonstrated mixed adhesive/cohesive failures. FRC posts tend to lose surface fibers or break during stress failure, most notably in IcePost.
Conclusion: Macro-Lock post associated with Corecem or Zircules, give the best results with and without silane. Silane coupling improved significantly the µTBS for three core foundation materials (p<0.05) with the exception of RockCore + IcePost.