effects of two remineralizing agents in combination with er:yag and co2 laser irradiation on microhardness of demineralized enamel: a preliminary in vitro study

Objectives:  this study assessed the effects of two remineralizing agents namely mi paste plus containing casein phosphopeptide amorphous calcium phosphate fluoride (cpp-acfp) and remin pro containing hydroxyapatite, fluoride and xylitol (hfx) with/without erbium-doped yttrium aluminium garnet (er:yag) and co2 laser irradiation on demineralized enamel microhardness.materials and methods: in this in vitro study, 70 sound human premolars were mesiodistally sectioned, demineralized at a ph of 4.6 for 8 hours, and randomly divided into 7 remineralization groups (n=10): of (i) mi paste plus (cpp-acfp), (ii) remin pro (hfx), (iii) mi paste plus+co2 laser (0.7 w power, 50 hz), (iv) remin pro+co2 laser, (v) mi paste plus+er:yag laser (1 w power, 10 hz), (vi) remin pro+er:yag laser, and (vii) negative control. the vickers hardness number of specimens was then measured. the groups were compared by one-way anova and tukey’s test (α=0.05).results: the mean microhardness was 319.8±49.9, 325.3±44.6, 359.4±35.7, 296.4±33.7, 319.9±58.1, 358.9±28.4, and 240.0±41.6 kg/mm2 in groups 1 to 7, respectively. the difference in microhardness was significant among the groups (p<0.0001). pairwise comparisons revealed significant differences in microhardness between all groups (p≤0.03) except between groups 1 and 2, 1 and 5, 2 and 5, and 3 and 6 (p>0.05).conclusion: both remin pro (containing hfx) and mi paste plus (containing cpp-acfp) can cause enamel remineralization.  mi paste plus+co2 laser irradiation and remin pro+er:yag laser irradiation were significantly more effective than the application of each remineralizing agent alone.