Adhesion and Erbium-Lased Enamel and Dentin

Abstract

The quality of bonding to the enamel and dentin is of utmost importance for the long life of adhesive fi lling materials. At present, adhesive systems have evolved in a positive way. Much is the result of a better understanding of the interaction between adhesive system and substrate. Both the dentin and enamel have different surface characteristics after laser preparation with erbium lasers as compared to conventionally bur-cut surfaces. For some, the characteristic irregularity and retentiveness of lased surfaces permit to adhere without etching. In the mean time, investigations have demonstrated that it is better to etch the lased surface (both the enamel and dentin) before bonding with non-self-etching systems. Also here, the original 'gold standard', i.e. a three-step etch-and-rinse system, results in clinically acceptable bond strengths. Furthermore, two-step 'mild' self-etch adhesives containing 10-MDP used with enamel etching and without dentin etching appear to perform at least equally well. As the quality of the adhesion is also infl uenced by the substrate, it has to be emphasised that it is recommended not to rely on enamel laser conditioning (previ-ously called laser etching) and to fi nish the dentin at low fl uency before adhesion. At present, there is insuffi cient information to take a position for glass ionomers.