Influence of Different Pretreatments on the Microtensile Bond Strength to Eroded Dentin.

Purpose: To evaluate the influence of different pretreatments on the microtensile bond strength (μTBS) of an etchand- rinse adhesive to eroded dentin. Materials and Methods: Thirty-six human teeth were ground down to their dentin layer and randomly divided into six groups (G1-G6; n = 6), G1 being the control group. Only in the test groups (G2-G6) were samples subjected to erosion using citric acid (pH 2.6) 10 x 2 min per day for five days. Between the erosive attacks, samples were stored in artificial saliva. After pretreatment - none (G1); none (G2); 2% chlorhexidine (30 s) (G3); prolonged primer application (1 min) (G4); roughening with a diamond bur (G5) and 10.5% NaOCl (1 min) (G6) - the adhesive Opti- Bond FL was applied. After the application of composite, samples were stored in water (7 d) and μTBS was determined. Data were evaluated using one-way ANOVA and Dunnett-T post-hoc test (p < 0.05). Results: Eroded dentin without pretreatment (G2) resulted in significant reduction of μTBS compared with uneroded dentin (G1). μTBS after pretreatment with a diamond bur (G5) or NaOCl (G6) was not significantly different from that of the uneroded control group (G1). μTBS after pretreatment with chlorhexidine (G3) or with prolonged primer application (G4) was significantly lower than in the uneroded control group (G1), and not significantly different from the eroded control group (G2). Conclusion: The present data suggests that μTBS to eroded dentin pretreated with bur abrasion or NaOCl is similar to the μTBS to sound, uneroded dentin. [ABSTRACT FROM AUTHOR]