One-component self-etching primer: a seventh generation of orthodontic bonding system?

The purpose of this study was to compare the bond strengths and to evaluate the debonding site using the adhesive remnant index (ARI) provided by a conventional acid-etch conditioner and a new self-etching adhesive system, Xeno IV (Dentsply Caulk). One hundred and eighty bovine lower incisors were randomly divided into six groups (n = 30). In groups 1, 2, and 3, Transbond XT (3M Unitek) composite was used to bond the brackets to enamel samples conditioned with 37 per cent phosphoric acid + XT primer (3M Unitek), Xeno IV + XT primer, or Xeno IV only, respectively. In groups 4, 5, and 6, the bonding procedures were performed using Fuji Ortho LC (GC Corp.) resin-modified glass ionomer cement unconditioned, enamel conditioned with 37 per cent phosphoric acid, or Xeno IV, respectively. All samples underwent thermocycling and then shear bond strength (SBS) testing was performed using a universal testing machine (Emic DL 10.000). Analysis of variance was applied. For the post hoc test, the Tukey's test was used. Kruskal-Wallis and Mann-Whitney U-tests were used to assess ARI scores. The results demonstrated no statistical differences between groups 1, 2, and 3. However, statistically significant differences were found between these samples and groups 4, 5, and 6. With regard to ARI score, the highest mean value was found in group 5 (Fuji Ortho LC + 37 per cent acid conditioning), whereas group 4 (Fuji Ortho LC + no conditioning) had the lowest SBS. Xeno IV self-etching bonding agent was able to bond orthodontic brackets in association with Transbond XT composite as well as with Fuji Ortho LC, thus maximizing bracket bonding.