Introduction: In spite of rapid development in adhesive technologies over recent decades, contamination of bonding surfaces is still a major problem. It was the aim of this study to evaluate the influence of contamination on bond strengths and to investigate possible decontamination procedures.
Method: Four different bonding systems were evaluated for their shear bond strengths under five different bonding situations: control (without contamination and decontamination), contamination with blood/saliva, decontamination with water, air and repriming following the above mentioned contaminations. The 25 specimens of each group consisted of composite blocks bonded to bovine teeth. Shear forces were measured with an Instron 4444 after thermo-cycling.
Results: The 3 composite primers showed similar behaviour. With the exception of Transbond SEP with saliva contamination, all contaminations resulted in strongly reduced shear forces. The controls as well as the decontaminated groups showed shear forces of around 20 MPa. The resin modified glass ionomer however did not reach clinically sufficient bond strengths in either setup.
Conclusion: Decontamination with water, air and repriming is sufficient after contamination with blood or saliva. Reetching is not necessary. The bond strength of Transbond SEP is not significantly altered by saliva contamination and can be recommended for conventional bonding procedures.