The effects of differing etch times on the etch pattern on enamel of unerupted and erupted human teeth examined using the scanning electron microscope.

The etch pattern produced on enamel from unerupted and erupted human teeth with varying periods of acid etching using 37 per cent phosphoric acid was examined using a scanning electron microscope. For erupted enamel etch scores were fairly consistent above 10 seconds etching, for unerupted enamel etch scores matched those for erupted enamel for etch times above 30 seconds. The etch type was more consistent on unerupted enamel.