The effects of differing acid concentrations, techniques and etch time on the etch pattern of enamel of erupted and...

The effects of varying acid concentration, etch time and agitation, on the etch properties of enamel from unerupted and erupted human teeth, were examined using the scanning electron microscope. Results showed that whilst there are differences in behaviour between erupted and unerupted enamel when conditions are varied, under most circumstances unerupted enamel will behave in a similar manner to erupted enamel. With low acid concentration both the duration of etch and agitation seem to be important factors in producing a roughened surface. It is suggested that the manufacturers' recommendations be more precise for a new low acid concentration orthodontic bonding package.