Effect of Different Irrigants on the Adhesive Interface and Influence on the Push Out Strength of Fiber Posts
The aim of this study was to evaluate the effects of a new irrigant solution on the post space cleaning and the adhesive resistance of fiber posts. Eighty roots of bovine teeth were randomly allocated into eight groups (n=10 for each group). Evaluations were performed in two different time points for each irrigant. The irrigants included a control group with distilled water (DW), 2.5% NaOCl and 17% EDTA (SH), 1% peracetic acid (PA), and 5% boric acid and 1% citric acid (EX). The time points were 24 hours (I-immediate) and 6 months (D-delayed). The push-out test was performed using a universal testing machine with a 5 kN load cell operating at a crosshead speed of 0.5 mm/minute. The dentinal cementation system was analyzed using a laser confocal microscope (LSM5, Zeiss, Jena, Germany), and incidence of residue on radicular dentin was evaluated by scanning electron microscopy (SEM). The incidence of residue was evaluated by the Kruskal-Wallis test and push-out bond strength and dentin penetrability were evaluated via a one-way analysis of variance (ANOVA) and Tukey tests (α=0.05). The EX irrigation protocol demonstrated the lowest incidence of residue on the dentin surface (p<0.05), independently of the evaluated third. In the cervical and the middle post thirds, EXI, EXD, SHI, and SHD groups exhibited similar push-out bond strength values (p>0.05). EXI, EXD, PAI, and PAD exhibited the greatest dentinal penetrability of the cementation system in all the post thirds (p<0.05). A solution containing 5% boric acid and 1% citric acid can be a promising irrigant for radicular post space cleaning. It has adequate potential for cleaning the dentin surface without interfering with the adhesive interface between the dentin and the cementation system.SUMMARY
Purpose
Methods and Materials
Results
Conclusions
Representative scanning electron microscopy images of site dentin residues due to irrigation protocols and thirds evaluated. Original magnification 10 mm.
Percentage of modes of failure in each experimental group. DWI, distilled water, 24 h-distilled water; SHI, 24h-2.5% sodium hypochlorite associated with 17% EDTA; PAI, 24 h-1% peracetic acid solution; EXI, 24 h-5% boric acid solution associated with 1% citric acid; DWT, 6 months-distilled water; SHT: 6 months-2.5% sodium hypochlorite associated with 17% EDTA; PAT, 6 months-1% peracetic acid solution; EXT, 6 months-5% boric acid solution associated with 1% citric acid.
Representative images of dual resin cement penetration (Ambar and AllCem Core) into dentin due to root canal thirds and different irrigating solutions, after 24 hours. DWI, distilled water (control); SHI, 2.5% sodium hypochlorite associated with 17% EDTA; PAI, 1% peracetic acid solution; EXI, 5% boric acid solution associated with 1% citric acid. Original magnification 20×. The arrows show dentin penetrability.
Representative image of dual resin cement penetration (Ambar and AllCem Core) into dentin due to root canal thirds and different irrigating solutions, after 6 months. DWI, distilled water (control); SHI, 2.5% sodium hypochlorite associated with 17% EDTA; PAI, 1% peracetic acid solution; EXI, 5% boric acid solution associated with 1% citric acid. Original magnification 20×. The arrows show dentin penetrability.
Contributor Notes
Clinical Relevance
The influence of post irrigation procedures on the bond strength of a dual resin cement to the root canal dentin and its dentin penetrability are still unclear. A solution containing 5% boric acid associated with 1% citric acid appears to be a good option.