Effect of surface treatments on the bond strength of CAD/CAM fiberglass posts

Abstract

BackgroundThere is no ideal protocol for the surface treatment of fiber posts, especially when using a computer-aided design/computer-aided manufacturing (CAD/CAM) experimental fiberglass block. The purpose of this study was to evaluate the bond strength of a CAD/CAM customized glass fiber post and core after applying different surface treatment techniques.Material and MethodsForty premolars were prepared to receive a customized CAD/CAM glass-fiber post and core obtained from an experimental block of glass fiber and epoxy resin. The specimens were randomly distributed in 4 groups (n=10) according to the post and core surface treatment: ETH - 70% ethanol; HP - 24% hydrogen peroxide for 1 minute; ETH/S - 70% ethanol + silane; HP/S - 24% hydrogen peroxide + silane. The universal adhesive containing silane was applied on the posts and prepared post spaces in all groups. The posts were cemented using dual cure resin cement. The specimens were stored in distilled water at 37°C for 24 h, cut (two slices of 1 mm for each root third - coronal, middle, and apical) and subjected to push-out test (0.5 mm/min). Data was subjected to two-way ANOVA (surface treatment and root third) and Tukey’s test (α=0,05).ResultsThere was no significant difference of bond strength values among groups, regardless the surface treatment (p >0.05). There was significant difference on bond strength values for the different root thirds (p<0.05) (coronal>middle=apical).ConclusionsThe different surface treatment and application of additional silane in the CAD/CAM customized glass-fiber post and core does not interfere on bond strength values. The root dentin third interfered on the bond strength, with higher values for the coronal third. Key words:Post and core technique, cad/cam, shear strength, hydrogen peroxide.

Effect of CAD CAM and prefabricated glass fiber post adaptation on the push-out bond strength to root canal dentin

“…The customized post in this study was constructed of unidirectional glass fiber that was created using CAD-CAM technology without any extra interfaces, which might favour the stress distribution to the root. 1,11 The first hypothesis was accepted after it was demonstrated that well-adapted CAD-CAM glass fiber posts had significantly superior bond strength to root canal dentin in comparison to the prefabricated post cemented with the same self-adhesive resin cement. This may be due to the CAD-CAM post group's good adaption, which results in a thin and homogeneous resin cement coating with fewer voids and gaps between the cement and the root dentin.…”

“…Earlier research has shown that this method of surface treatment, at this concentration and time, will partly remove the epoxy resin covering of the glass fiber post, uncovering the glass fibers (without harming the post architecture), allowing for silanization and resin cement bonding. 1,26,27 In the current study, we used a self-adhesive resin cement because of the less clinical time required and also less sensitive technique than traditional resin cements, which required the use of adhesive systems. It also had superior dentin retention due to chemical reactions between both the functional methacrylate phosphoric acid esters and the hydroxyapatite present in the dentin .…”

“…Using a Pin mounted on a universal testing machine (Instron universal testing machine model 3345 England), push out forces were transmitted to each slice in an apical to coronal direction at a crosshead speed of 0.1 mm/minute until dislodgment of the post, Figure (1). The maximum failure load was measured in Newtons (N), and the applied force was divided by the bonded area to be converted to MPa.…”

“…The remaining tooth structure, the supporting tissues condition and the restoration aesthetics all play a role in the effective rehabilitation of teeth that have undergone endodontic treatment. 1 Root post systems are frequently used to restore teeth that have been endodontically treated and have a weakened dental crown structure. The purpose of the post is to offer retention and strength for prospective prosthetic restorations that will reconstruct the missing coronal tooth structure.…”

Effect of intracanal diode laser irradiation on fracture resistance of roots restored with CAD/CAM posts

“…Simple procedures are indicated, such as use of 70% alcohol during cleaning of the posts and use of an universal adhesive. Different surface treatments of CAD/CAM glass fiber posts with 24% hydrogen peroxide and a moisture of silane and ethanol solution did not influence in bond strength values 7,8 .…”