SEM evaluation of surface cracking in glass-ionomer cement.

In an effort to assess the influence of acid etching and air drying on the production of cracks in the surface of glass-ionomer cement, the two procedures were employed over progressively increased durations, and any resulting surface cracks in the cement, were examined by replica techniques under an SEM (Scanning Electron Microscope). The results showed that acid etching alone did not produce cracks, but air-drying by compressed air produced cracks at durations between 5 and 30 sec.