To evaluate bond strength of a self-adhesive resin cement to a quartz-fiber post and to dentin after different root canal irrigantion protocols and with or without bonding agent application.
Methods:
Roots of thirty-six human premolars were endodontically treated and divided into six groups. All roots were drilled for post spaces in a standardized manner. Before post cementation, root canals were pretreated with one of three irrigation protocols (5.25% NaOCl, 18% EDTA, 2% Chlorhexidine) and with or without a dual-cure adhesive bonding agent (Prime&Bond NT, Dentsply). Application procedures and groups (G) were: G1-5.25% NaOCl with (w/bonding) and without bonding agent application (w/o bonding), G2-18% EDTA→5.25% NaOCl w/o bonding and w/bonding agent, G3-18% EDTA→5.25% NaOCl→2% Chlorhexidine w/o bonding and w/bonding agent. Afterwards, quartz fiber posts (Unicore, Ultradent) were luted with self-adhesive resin cement (G-CEM, GC Corporation). The roots were then thermocycled for 2000 cycles between 5-55° C and cut into 1 mm thick dentin slabs. The bond strength of slabs was measured with an hourglass microtensile test method at a cross-head speed of 0.5 mm/minute. Failure modes were assessed with a stereomicroscope and data analyzed with two-way ANOVA and Tukey HSD test.
Results:
|
Bond Strength [MPa]±SD |
|
Groups |
w/o bonding |
w/ bonding |
G1 |
12.6±4.15a |
19.1±3.42b |
G2 |
10.8±1.92a |
15.0±4.15ab |
G3 |
12.6±2.52a |
18.0±1.89b |
*Means with same letter are not significantly different
The different irrigation procedures did not influence bond strength of a quartz fiber post to root canal dentin (P>0.05). Bonding application did, in general, increase bond strength values. The groups with bonding agent application showed mainly adhesive failures between resin cement and post surface.
Conclusions:
Dentin bonding agent application significantly increases bond strength of a self-adhesive resin cement to a fiber post and root canal dentin, independent of the root canal irrigation protocol.
Keywords: Cements, Dentin bonding agents, Endodontics and Fiber Posts
See more of: Dental Materials 1: Adhesion - Bond Strength Testing and Mechanisms