Adhesion to dentin with and without smear layer under varying degrees of wetness

The bond strengths of glass ionomer cements to prepared dentin ranged between 2.1 and 4.7 MPa for all test conditions and did not appear to be adversely affected by the presence of fluid under physiologic pressure or by the presence or absence of a smear layer. On the other hand, the resin dentin adhesive was adversely affected by the presence of moisture (1 +/- 1.3 MPa when the tubules were full of fluid and under pressure; 9.4 +/- 10.6 MPa when the tubules were full of fluid but not under pressure; and 18.3 +/- 7.6 MPa when the tubules were empty.