Bond Strength Of Fiber Posts Research Articles

Influence of chlorhexidine application at longitudinal push-out bond strength of fiber posts

The objective of this study was to evaluate the influence of chlorhexidine application after dentin phosphoric acid etching at immediate and long-term bond strength of a fiber post cemented to root dentin. Seventy-two single-rooted, human upper teeth were selected. After phosphoric acid etching, each group received a different dentin treatment: no pretreatment or chlorhexidine 0.2% or 2.0%. Three-step etch-and-rinse adhesive and dual-cured resin cement was used to cementation procedure. Half of the teeth were submitted to push-out bond strength test after 24 hours and the other half after 6 months. Data were analyzed by 2-way ANOVA and Tukey. Chlorhexidine application had no influence on bond strength when teeth were stored at the same aging time (P > .05). The storage time significantly decreased the bond strength values of 24 hours to 6 months in all groups (P < .05). After 6 months, chlorhexidine application did not effectively arrest bond strength degradation of fiber posts cemented in human roots.

Effect of Cement Type, Relining Procedure, and Length of Cementation on Pull-out Bond Strength of Fiber Posts

Introduction As opposed to the cementation metal posts, the cementation of fiber posts has several details that can significantly influence the success of post retention. This study evaluated the effect of the relining procedure, the cement type, and the luted length of the post on fiber posts retention. Methods One hundred eighty bovine incisors were selected to assess post retention; after endodontic treatment, the canals were flared with diamonds burs. Post holes were prepared in lengths of 5, 7.5, and 10 mm; the fiber posts were relined with composite resin and luted with RelyX ARC, RelyX Unicem, or RelyX Luting 2. All cements are manufactured by 3M ESPE (St. Paul, MN). Samples were subjected to a pull-out bond strength test in a universal testing machine; the results ( N) were submitted to a three-way analysis of variance and the Tukey post hoc test (α = 0.05). Results The improvement of post retention occurred with the increase of the post length luted into the root canal; the relining procedure improved the pull-out bond strength. RelyX Unicem and RelyX ARC showed similar values of retention, both showing higher values than RelyX Luting 2. Conclusion Post length, the relining procedure, and the cement type are all important factors for improving the retention of fiber posts.

The effect of chlorhexidine pre-treatment on the bond strength of fiber posts

The effect of chlorhexidine pre-treatment on the bond strength of fiber posts

Effect of light-curing units on push-out fiber post bond strength in root canal dentin

The purpose of this study was to evaluate the effectiveness of different light-curing units on the bond strength (push-out) of glass fiber posts in the different thirds of the root (cervical, middle and apical) with different adhesive luting resin systems (dual-cure total-etch; dual-cured and self-etch bonding system; and dual-cure self-adhesive cements), Disks of the samples (n = 144) were used, with approximately 1 mm of thickness of 48 bovine roots restored with glass fiber posts, that were luted with resin cements photo-activated by halogen LCU (QTH, Optilux 501) and blue LED (Ultraled), with power densities of 600 and 550 mW/cm2, respectively. A universal testing machine (MTS 810 Material Test System) was used with a 1 mm diameter steel rod at cross-head speed of 0.5 mm/min until post extrusion, with load cell of 50 kg, for evaluation of the push-out strength in the different thirds of each sample. The push-out strength values in kgf were converted to MPa and analyzed through Analysis of Variance and Tukey’s test, at significance level of 5%. The results showed that there were no statistical differences between the QTH and LED LCUs. The self-adhesive resin cement had lower values of retention. The total-etch and self-adhesive system resin cements seem to be a possible alternative for glass fiber posts cementation into the radicular canal and the LED LCU can be applied as an alternative to halogen light on photo-activation of dual-cured resin cements.

Push‐out stress for fibre posts luted using different adhesive strategies

The influence of thermocycling on the bond strength of fibre posts cemented with different luting approaches was investigated. A total of 84 human incisors were selected for the study. Sixty teeth were assigned to one of the following adhesive/cement combinations for push-out bond-strength evaluation: group 1, XP Bond/CoreXFlow + DT Light-Post; group 2, Panavia F 2.0 + Tech 21; or group 3, RelyX Unicem + RelyX. Bonded specimens were cut into 1-mm-thick slabs and either thermocycled (40,000 cycles) or stored in artificial saliva (control specimens) before push-out bond-strength testing. Additional specimens were processed for quantitative interfacial nanoleakage analysis. Thermocycling decreased the bond strength in specimens of groups 2 and 3, but did not affect the specimens from group 1. No difference was observed among luting approaches in control specimens. Thermocycling resulted in increased silver nitrate deposition (i.e. interfacial nanoleakage) in all groups. Within the limitations of the study, the use of an etch-and-rinse adhesive in combination with a dual-cure cement to lute fiber posts is the most stable luting procedure if compared with a self-etch resin-based cement or a self-adhesive cement, as assayed by thermocycling of the bonded specimens.

Effect of thermocycling on bond strength of fiber posts

Effect of thermocycling on bond strength of fiber posts

An In Vitro Evaluation of Effect of Ionizing Radiotherapy on Push-out Strength of Fiber Posts under Cyclic Loading

Ionizing radiotherapy has a deleterious effect on all vital cells and thus might affect the collagen fibril network of dentin and formation of hybrid layer of composite resins. The present study evaluated the effect of ionizing x-ray radiotherapy on push-out bond strength of fiber posts. Sixty mandibular premolar roots were divided into 4 groups: group I, control group with no irradiation, restored with a quartz fiber post system with cyclic loading; group II, samples were exposed to 60 Gy radiation dosage and than restored; group III, samples were restored and then irradiated; and group IV, samples were restored during irradiation. A push-out bond strength test was done. Radiotherapy significantly reduced the push-out bond strength of fiber posts. Patients undergoing ionizing radiotherapy might have a less than ideal prognosis of fiber posts luted with dual cure resin cement with total etch bonding system, if restorations are done after radiotherapy.

Bond Strength of Fiber Posts after the Application of Erbium:Yttrium-Aluminum-Garnet Laser Treatment and Gaseous Ozone to the Root Canal

The aim of the present study was to investigate the effects of antibacterial agents (erbium:yttrium-aluminum-garnet [Er:YAG] laser or gaseous ozone) intended to disinfect root canals on bond strengths of fiber posts compared with canals that were finally irrigated using chlorhexidine (CHX). One hundred forty-four human anterior teeth were divided into three groups ( n = 48); root canal instrumentation was performed, and antimicrobial pretreatment was conducted as follows: control group: CHX, group 2: Er:YAG laser, and group 3: gaseous ozone. In all groups, fiber posts were inserted using Panavia F 2.0 (Kuraray, Osaka, Japan), Variolink II (Ivoclar Vivadent, Schaan, Liechtenstein), RelyX Unicem (3M Espe; Seefeld, Germany), or Ketac Cem (3M Espe) ( n = 12 each). Push-out bond strengths to root canal dentin were affected by the type of luting agent but not by the antimicrobial pretreatment regimen. However, significant interactions between the luting agent and pretreatment could be observed, and adhesion of the self-adhesive resin cement RelyX Unicem was significantly reduced after using gaseous ozone.

The effect of luting techniques on the push-out bond strength of fiber posts

Aim: This study aimed to evaluate the effect of using a chemical co-initiator and/or an additional coat of a hydrophobic resin on the bond strength of fiber posts luted with a dual-cured resin cement. In addition, the use of the resin cement only was also evaluated. Methods: Fiber posts were luted with dual-cured resin cement (Enforce) and using one of five adhesive procedures: G1 - Prime&Bond 2.1 (PB), G2 - PB + Self-cure activator (SC), G3 - PB + bonding agent of Scotchbond Multi-Purpose (SMP), G4 – PB + SC + SMP and G5 – no adhesive. The root samples were sectioned transversally into three slabs (coronal, middle and apical third) that were submitted to push-out testing. Data were submitted to split-plot ANOVA and Tukey’s test (α = 0.05). Results: When the adhesives were used, the hydrophobic resin application (G3 and G4) increased fiber post retention in comparison to G2 only in the coronal third. For the other thirds, there was no difference between the adhesive methods. G5 presented the lowest values in the coronal and middle thirds, but it was similar to all other groups in the apical third. Conclusion: post retention seemed not to benefit from the adhesive application in the apical region.

Influence of endodontic post type (glass fiber, quartz fiber or gold) and luting material on push-out bond strength to dentin in vitro

Objectives To determine the influence of post type and luting material on bond strength to dentin. Methods The root canals of extracted human upper central incisors were instrumented and post space was prepared using the respective drills for each post system. Glass fiber posts (Luscent Anchor, Dentatus [LA]) were luted using three dual-curing adhesive systems (Excite DSC/Variolink II, Vivadent [VL2]; EnaBond/EnaCem, Micerium [ENA]; Prime & Bond NT/Calibra, DentSply DeTrey [CAL]). A different brand of glass fiber post (EasyPost, DentSply Maillefer [EP]) and quartz fiber post (DT Light Post, VDW [DT]) were luted using CAL. Gold posts (Perma-dor, VDW) were luted either adhesively following tribo-chemical silicate coating (Rocatec, ESPE-Sil, 3M ESPE; CAL) or conventionally using glass ionomer cement (Ketac Cem, 3M ESPE). Three slices of 2 mm height were cut perpendicular to the post from each restored root. Bond strength was determined by pushing out the post using a universal testing machine (/1449, Zwick). Results For all experimental groups combined, bond strength increased from the coronal to the apical section (Friedman test: P < 0.001). Significant differences were observed among the fiber posts (DT/CAL > LA/CAL; Mann–Whitney U-test with Bonferroni–Holm adjustment: P < 0.05; EP/CAL ranging in between) but not among luting materials (LA/VL2, LA/ENA, LA/CAL: n.s.). The gold posts were equivalent to DT/CAL with both luting procedures. Significance Selection of post type may be more important for bond strength than luting material. Bond strength of fiber posts was equivalent but not superior to adhesively or conventionally luted gold posts.

The Effect of Dowel Space on the Bond Strengths of Fiber Posts

The purpose of this study was to evaluate the effect of the degree of mismatch between post space and post diameters on the bond strength of a fiber-reinforced resin post. Thirty-two extracted human maxillary central incisors and canines were endodontically treated and assigned to four groups: Group 1--Canal prepared with a D.T. Light Post #1 drill (control); Group 2--Canal prepared with a D.T. Light Post #2 drill; Group 3--Canal prepared with a D.T. Light Post #3 drill; Group 4--Canal prepared with a Gates Glidden #6 drill. A D.T. Light Post size 1 was then luted into the canal using One-Step Adhesive and Post Cement Hi-X. A push-out test was performed on three sections of each root to measure push-out bond strengths. Data were analyzed with ANOVA and Bonferroni's test at p < 0.05. Two extra teeth for each group were restored in the same fashion and processed for SEM observation. (in MPa): Group 1: 15.7 +/- 6.9; Group 2: 14.7 +/- 6.5; Group 3: 14.0 +/- 5.0; Group 4: 14.0 +/- 5.1. The variable "post space" resulted in no statistically significant difference in mean bond strengths (p > 0.05). For the variable "root region," the coronal third (17.5 +/- 6.0) resulted in statistically greater mean bond strengths than the apical third (12.3 +/- 6.0) at p < 0.008. The middle third (14.0 +/- 5.3) resulted in no statistically significant different mean bond strengths from the coronal third at p > 0.119 and from the apical third at p > 0.999. Under the SEM, some areas of the canal system still displayed residual gutta-percha, which resulted in debonding of the interface between the resin cement and dentin. Areas with incomplete dentin hybridization were observed in localized areas of all groups. The diameter of the post space did not affect the push-out bond strengths. Bonding at the coronal level of the root canal is more reliable than bonding at the apical level. The presence of residual gutta-percha and the deficient dentin hybridization may result in deficient seal of the resin-dentin interface.

The effect of silane on the bond strengths of fiber posts

Objectives Esthetic posts have been developed to maximize the foundation of esthetic restorations. The purpose of this study was to evaluate the effect of silane on the bond strength of three fiber-reinforced resin posts (fiber posts). Methods Fifty-four extracted human maxillary central incisors and canines were endodontically treated. D.T. Light Post (DT, Bisco), FRC Postec (FR, Ivoclar Vivadent), and ParaPost Fiber White (PP, Coltène/Whaledent) were inserted using the resin adhesive system provided by the respective manufacturer. For half of the specimens in each group, the fiber posts were treated with a silane solution (Monobond S, Ivoclar Vivadent). A push-out test was performed on three different sections of each root to measure bond strengths. Data were analyzed with ANOVA and Bonferroni's post hoc test at P < 0.05. Results The use of silane did not result in any statistically significant difference at any level of the root. Silane did not result in any significant different bond strengths (MPa) for each of the posts. When the data were pooled, the use of silane did not result in statistically significant different bond strengths at P > 0.403: No silane = 12.7 ± 8.4; Silane = 14.1 ± 7.0. The coronal third of the root (17.5 ± 6.7) resulted in statistically greater bond strengths than the medium third (12.9 ± 6.8) and than the apical third (9.8 ± 7.3) at P < 0.002 and P < 0.0001, respectively. The medium third and the apical third resulted in no statistically significant different bond strengths from each other at P > 0.07. The type of post did not result in statistically significant different bond strengths at P > 0.417: DT = 14.7 ± 6.8 MPa; FR = 13.3 ± 6.6 MPa; PP = 12.2 ± 6.6 MPa. Significance The use of a silane coupling agent did not increase the push-out bond strengths of the three fiber posts used in this study. All posts bonded to root dentin at the same magnitude. Bonding is more predictable at the most coronal level of the root.

The adhesion between fiber posts and root canal walls: comparison between microtensile and push-out bond strength measurements.

Aim of the study was to compare the trimming and non-trimming variants of the microtensile technique with the 'micro' push-out test in the ability to measure accurately the bond strength of fiber posts luted inside root canals. In 15 endodontically treated teeth (Group A), fiber posts were cemented with Excite DSC in combination with Variolink II (Ivoclar-Vivadent). In 15 roots RelyX Unicem (3M-ESPE) was used for fiber post luting (Group B). Within each group, the bond strength of cemented fiber posts was assessed with the trimming and non-trimming microtensile technique, as well as with the push-out test. The great number of premature failures (16.9% in Group A, 27.5% in Group B) and the finding of high standard deviation values make questionable the reliability of the trimming microtensile technique. With the non-trimming microtensile technique, only five sticks were obtained from a total of six roots. The remaining specimens failed prematurely during the cutting phase. With the push-out test no premature failure occurred, the variability of the data distribution was acceptable, and regional differences in bond strength among root levels could be assessed. Relatively low values of bond strength were, in general, recorded for luted fiber posts. In conclusion, when measuring the bond strength of luted fiber posts, the push-out test appears to be more dependable than the microtensile technique.