The present invention is a method of treating residual caries utilizing a matched laser and dye combination. After initial preparation and excavation of a caries site, a dye is flooded into the site which stains areas of residual caries. A laser with a complimentary wavelength is then used to ablate stained areas. Since healthy dental tissue will not receive the dye and allow staining, diseased tissue will be the only tissue that is stained, not only providing a visual indicator, but also providing a more efficient surface to receive laser energy and allow for more efficient ablation of the compromised tissue. According to the method, the dye may contain and enhancing, oxidizing compound or an anesthetic, and surrounding tissues may be protected by the use of substances opaque to the radiant energy. Indocyanine green has shown particular effectiveness as a dye in this and related methods.