Bonding Protocols to Reverse the Bond Strength of a Universal Adhesive to Hemostatic Agent-contaminated Dentin
To evaluate the effect of different bonding protocols on the microtensile bond strength (μTBS) of a universal adhesive to dentin contaminated with a hemostatic agent. Ninety-five extracted premolars were used in this study. For the μTBS test, 80 teeth were cut to expose mid-coronal dentin and randomly divided into two groups (uncontaminated dentin and hemostatic agent-contaminated dentin). Each group was further divided into five subgroups (n=8/group): 1) SE: no additional treatment, 2) ER: etching with 32% phosphoric acid, 3) CHX: rinsing with 0.2% chlorhexidine, 4) EDTA: rinsing with 17% EDTA, and 5) T40: application of universal adhesive for 40 seconds. A universal adhesive was applied followed by resin composite build-up. μTBS test was performed after 24 hours of water storage. Two-way analysis of variance (ANOVA) was calculated followed by the Duncan testing (α=0.05). The failure mode was analyzed using light microscopy. Additional teeth were prepared for energy-dispersive X-ray (EDX) analysis (n=1/group) and resin-dentin interface observation (n=2/group) using scanning electron microscopy. Adverse effects of hemostatic agent contamination on the bonding performance of a universal adhesive was found in the SE, CHX, and T40 groups (p<0.05). Fewer and shorter resin tags were observed in the SE, CHX, and T40 groups. A higher percentage of adhesive failure and mixed failure was found in contaminated dentin. All bonding protocols revealed lower amounts of Al and Cl after dentin contamination, except for the SE group. Hemostatic agent contamination adversely affected dentin bond strength. However, this bond strength could be reversed using the etch-and-rinse technique or rinsing with EDTA prior to adhesive application.SUMMARY
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The percentage of failure mode analysis results. Abbreviations: SE, no additional treatment; ER, etching with 32% phosphoric acid; CHX, rinsing with 0.2% chlorhexidine; EDTA, rinsing with 17% EDTA; T40, apply universal adhesive for 40 seconds.
EDS mapping of aluminium (Al; a-f) and chloride (Cl; g-l); a) Al mapping of uncontaminated dentin surface, b) Al mapping of hemostatic agent-contaminated dentin surface, c) Al mapping of hemostatic agent-contaminated dentin surface after cleaning with 32% phosphoric acid, d) Al mapping of hemostatic agent-contaminated dentin surface after rinsing with 2% chlorhexidine, e) Al mapping of hemostatic agent-contaminated dentin surface after rinsing with 17% EDTA, f) Al mapping of hemostatic agent-contaminated dentin surface after application of Single Bond Universal adhesive for 40 seconds and light-cured, g) Cl mapping of uncontaminated dentin, h) Cl mapping of hemostatic agent-contaminated dentin surface, i) Cl mapping of hemostatic agent-contaminated dentin surface cleaned with 32% phosphoric acid, j) Cl mapping of the hemostatic agent-contaminated dentin surface rinsed with 2% chlorhexidine, k) Cl mapping of the hemostatic agent-contaminated dentin surface cleaned with 17% EDTA, l) Cl mapping of hemostatic agent-contaminated dentin surface after application of Single Bond Universal adhesive for 40 seconds and light-cured.
Representative SEM micrographs of the resin-dentin interface (3000× magnification): A) uncontaminated dentin in SE group; B) uncontaminated dentin in ER group; C) uncontaminated dentin in CHX group; D) uncontaminated dentin in EDTA group; E) uncontaminated dentin in T40 group; F) contaminated dentin in SE group; G) contaminated dentin in ER group; H) contaminated dentin in CHX group; I) contaminated dentin in EDTA group; J) contaminated dentin in T40 group. Abbreviations: SE, no additional treatment; ER, etching with phosphoric acid; CHX, rinsing with 0.2% chlorhexidine; EDTA, rinsing with 17% EDTA; T40, apply universal adhesive for 40 seconds.
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