Tensile bond strength of two adhesive systems in combination with flowable composites

Objectives: Previous studies have shown a correlation between the clinical performance of dentin adhesive systems and the use of flowable composites. The aim of the present study was to evaluate the difference of the tensile bond strength of two different composite/ dentin adhesive combinations depending on the additional use of the corresponding flowable composite. Methods: In this study forty freshly extracted third molars were included. All teeth were prepared in a special manner allowing the simulation of dentin perfusion. The specimens were randomly assigned to four experimental groups of ten samples each: group A: Tetric Ceram combined with Excite; group B: like group A plus Tetric flow; group C: Admira used with Admira Bond; group D: group C plus Admira flow. All materials were applied on a standardized surface area of 2 mm in diameter. Tensile bond strength was evaluated 15 minutes after application using a universal testing machine. Results: For the four test series following tensile bond strength values were evaluated (mean and standard deviation): In group A mean tensile bond strength of 4.74 MPa (plusmn; 1.81) was observed. The additional use of Tetric flow showed bond strength of 10.02 MPa (plusmn; 4.72). In the case of the ormocer Admira tensile bond strength was 3.59 MPa (plusmn; 1.37) and 7.36 MPa (plusmn; 3.91) when Admira flow was additionally applied. Statistical analysis showed a significant influence of the used dentin bonding agents on tensile bond strength in both modifications (p Conclusions: Within the limitations of an in vitro study, it can be concluded that the use of flowable composites might increase tensile bond strength for the used materials. Keywords: dentin, dentin bonding agent, bond strength, composite material