Efecto de la clorhexidina en la resistencia microtensional de adhesivos autograbadores

Abstract

The use of self-etching dental adhesives has become very practical and popular in dental practice; the effect of chlorhexidine prior bonding with them is not known. The objective was to determine the effect of chlorhexidine pretreatment on the micro-tensile bond strength (μTBS) of two different one-step self-etch dental adhesives, One Coat Bond 7.0, Coltene® (OC) and Futurabond NR, Voco® (FB). To this purpose was exposed flat oclusal dentine surface of 16 human molars were polished up to 320-grit silicon carbide paper. Teeth were assigned into 4 groups: Group a (OC), Group B (OC) + Chlorhexidine gluconate 2%, Group C (FB), and Group D (FB) + Chlorhexidine gluconate 2%. A 4-mm layer of Z250 hybrid composite applied in two increments. 4 micro-specimens samples were cut from each tooth. Micro-specimens were glued to two stiff acetate veneers and tested to failure in tension at 1 mm/min using a Shimadzu universal testing machine. Data was recorded in MPa and analyzed with ANOVA and Tukey post hoc test in SPSS software. Mean μTBS expressed in MPa and standard deviation (±SD) are shown here: Group A: 20.33 ± 6.9; Group B 14.21 ± 7.49; Group C 16.17 ± 6.65; Group D 10.05 ± 7.32. There was statistically significant difference (p=0.0015) among the groups, being A>B and C>D. The two one-step self-etch dental adhesives used in this study showed decrease in the bond strength when a 2% chlorhexidine treatment was applied prior to composite bonding thus such pretreatment should be used with caution with self-etch adhesives.