Effect of blood contamination and decontamination protocols on acetone-based and ethanol-based total etch adhesive...

The efficacy of various decontamination protocols to reverse the effect of blood contamination after acid-etching may depend on the type of adhesive.

To compare the effect of blood contamination and various decontamination protocols on acetone-based and ethanol-based total-etch adhesive systems.

Occlusal dentin of 64 human molars was etched and contaminated with fresh human blood. The samples were assigned to two groups as per adhesive used: Prime & Bond NT (acetone-based) and Adper Single Bond 2 (ethanol-based) and then subdivided into eight groups: (1) control, (2) no decontamination, (3) water rinsing, (4) re-etching, (5) sodium hypochlorite, (6) sodium hypochlorite/sodium ascorbate, (7) hydrogen peroxide, and (8) ethanol. Adhesives were applied and specimens were prepared for μTBS after composite buildup. The data were subjected to analysis of variance followed by post hoc Tukey test.

Blood contamination significantly reduced μTBS of both the adhesives. Re-etching and NaOCl/Asc were effective in restoring μTBS to the level of control for both the adhesives whereas NaOCl was effective only for Prime & Bond NT.

Both re-etching and NaOCl can be used for regaining μTBS of blood-contaminated acid-etched dentin. NaOCl/Asc yields better results than NaOCl alone, specifically for ethanol-based adhesive.

Knowing the adverse effects of prolonged acid-etching, other alternatives for decontamination of etched dentin after blood contamination should be considered. NaOCl alone or NaOCl followed by sodium ascorbate may prove to be good alternatives. These choices also may determine the type of adhesive system.