Bonding of restorative materials to dentine: the present status in the Federal Republic of Germany.

It is desirable for filling materials to adhere over the entire area of contact with enamel and dentine. At present we try to achieve adhesion to dentine either by intermediate linking layers (primers) or by the use of 'adhesive' filling materials. Bond strength to dentine attainable with the adhesive glass ionomer cements ChemFil II, Fuji-Ionomer Type II and Ketac-Fil and the primers Scotchbond and Dentin-Adhesit were determined. The tests were carried out on specimens stored for 3 and 21 days in distilled water at 37 degrees C; they were also subjected to thermal cycling. The highest measured bond strength with the glass ionomer cements was about 3.2 MN/m2; etching of the dentine did not generally intensify the bond, while thermal cycling had a slightly negative effect on adhesion. The highest bond strength measured with the primers was about 4.7 MN/m2. There were clear differences between the individual products; in those with very strong primary adhesion, etching of the dentine resulted in impairment of the bond, while thermal cycling had a clear adverse effect.