Combined effect of carbon-dioxide laser and neutral 2% NaF on acid resistance of human tooth enamel.

Specimens of human enamel were treated topically with 2% sodium fluoride solution before and after laser irradiation. The samples were examined using wet chemical analysis and SEM. The results showed that samples treated with neutral 2% NaF after irradiation caused a remarkable increase in acid resistance of the enamel, while samples treated with neutral 2% NaF before irradiation showed a lesser effect. The results were consistent with observations made by using wet chemical analysis and SEM findings.