Objectives : To evaluate the morphology of the hybrid layer of one total etch and one self-etch DBA alter water storage and the effect of the application of 2% clorhexidine on its longevity.
Materials and methods : Twelve maxillary teeth (molars and premolars) had a class II cavity prepared with a 558 carbide bur leaving an enamel wall to separate a mesial cavity from a distal cavity. Teeth were separated in two groups ( n = 6), to receive either Adper Single Bond 2 (SB2) or Adper SE Plus (SEP) (3 M ESPE). In one cavity the DBA was applied following manufacturer’s instructions, on the other, 2% clorhexidine was applied for 30 s before the application of the DBA. After acid-etching with SB2 and before application of bottle A with SEP. Teeth were sectioned with a slow speed diamond disk (Isomet Slowspeed Saw) M-D and stored in water at 37 °C for 125 days. Then teeth were prepared for SEM observation and morphology of the hybrid layer was observed and measured under 3 parameters: clear image of hybrid layer; presence of resin tags in tubules; and length of resin tags. A grade of either 0 or 1 was given to each parameter (not present and present). Data was analyzed with a Kruskal–Wallis test calculated at a 0.05 significance level.