The use of a caries detector dye in cavity preparation.

The aim of this study was to compare the conventional visual and tactile method of detecting carious dentine during cavity preparation using a mirror, probe and excavator with a visual method enhanced by a dye. The dye, 1% acid red in propylene glycol, was used on 100 cavities prepared by dental students and passed as clinically satisfactory by their teachers. Results showed dye stain at the enamel-dentine junction in 57 cavities (57%) which had been assessed as caries-free in this area using conventional visual and tactile means. Subsequent laboratory work on extracted carious teeth confirmed histologically that the dye stains demineralised dentine. If clinicians consider it important to render the enamel-dentine junction caries-free, it might be prudent to use the dye as an aid to diagnosis in this area.