Effects of Two Remineralizing Agents in Combination with Er:YAG and CO(2) Laser Irradiation on Microhardness of Demineralized Enamel: A Preliminary In Vitro Study

Abstract

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 CO(2) 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+CO(2) laser (0.7 W power, 50 Hz), (IV) Remin Pro+CO(2) 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 (alpha=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+CO(2) laser irradiation and Remin Pro+Er:YAG laser irradiation were significantly more effective than the application of each remineralizing agent alone.