Introduction: Er: YAG laser is contemplated as a preventive dental caries strategy when combined with topical fluoride varnish. Information regarding their combined effect on the enamel of primary teeth is still not established.
Objectives: The present study aimed to evaluate the effect of combined treatment by Er: YAG laser irradiation prior to topical fluoride varnish application on the acid resistance of enamel in primary teeth compared to fluoride varnish by elemental analysis.
Materials and Methods: Twenty caries-free exfoliated human primary molars were painted with nail varnish, leaving one window 4 x 4 mm on the buccal surface. The samples were assigned to 2 groups (10 each), according to the surface treatment: (G I) 5% sodium fluoride varnish (Enamel Pro® Varnish) only and (G II) Er: YAG laser irradiation followed by sodium fluoride varnish. The baseline value for each specimen was recorded before the test procedure. The enamel specimens underwent pH changes over 14 days. EDX was used to assess the mineral content of the specimens after pH challenge.
Results: A significant increase occurred in the mean values of the Ca at%, P at%, and Ca/P ratio in the enamel in both groups compared to the baseline values (p≤0.001). No significant difference was found in the mean percent change (p ≥ 0.05) of the mineral content between the study groups.
Conclusions: The combined treatment by laser and fluoride is as efficient as fluoride varnish alone for increasing the acid resistance of enamel in primary teeth.