Effect of sodium fluoride plus tricalcium phosphate with and without CO(2) laser on remineralization of white spot lesions

OBJECTIVES: The aim of this in vitro study was to evaluate the effect of NaF plus TCP with and without CO(2) laser irradiation on management of demineralized enamel using microhardness test and digital microscopy. METHODS: Eighty intact extracted human premolar teeth were randomly divided into 4 groups (20/each). Each group was subjected to a demineralizing solution to create white spot lesion. Group 1 was treated with 3M Vanish™. Group 2 was irradiated with CO(2) laser. Group 3 was subjected to CO(2) laser followed by 3M Vanish™. Group 4 was treated by 3M Vanish™ then CO(2) laser. The teeth were immersed in artificial saliva. Surface microhardness was measured for each tooth before demineralization at base line (M1 as a control), after demineralization (M2) and after management (M3). Comparison of microhardness values between groups was performed using one way ANOVA test with significant level (0.05) followed by multiple comparisons post-hoc Tukey test between groups. Enamel surface was photographed by digital microscope. RESULTS: All intervention methods used in the current study significantly increased microhardness values of demineralized enamel (P < 0.001). Little improvement of enamel appearance was observed in all groups meanwhile using CO(2) laser on demineralized enamel directly led to signs of white and black dots affecting the appearance of enamel surface. SIGNIFICANCE: The most effective intervention regarding microhardness was group 2 followed by group 3, group 4 and group 1. Coating the enamel surface with 3M Vanish™ before CO(2) laser irradiation acted as a protective layer from the undesirable effects of laser on the teeth with increasing enamel microhardness values more than using Vanish alone. So the promising intervention method regarding both microhardness and appearance was group 4.