Evaluation of different remineralizing agents on microhardness and surface roughness of bleached enamel

Abstract

Purpose To evaluate remineralization efficacy of self-assembling peptide (Curodont) and sodium calcium phosphosilicate (Novamin) on bleached teeth. Materials and methods Twenty freshly extracted human premolars were selected, roots were separated, and crowns were impregnated in acrylic resin then kept in artificial saliva. Specimens were randomly divided into two equal groups (10 specimens for each group). Group 1 specimens were bleached and treated with Curodont and group 2 specimens were bleached and treated with Novamin. Enamel microhardness and surface roughness changes were measured for both groups using Vickers hardness testing machine and Surface Profile Gage (Positector), respectively. Results Bleaching increased enamel surface roughness value (0.6 ± 0.10 μm) more than the baseline value (0.3 ± 0.09 μm) and decreased enamel microhardness (239.4 ± 5.33 MPa) compared to unbleached group (334.9 ± 4.26 MPa). After remineralization with Curodont, surface roughness decreased (0.4 ± 0.06 μm) and microhardness increased (300.3 ± 5.92 MPa) while after remineralization with Novamin surface roughness slightly decreased (0.5 ± 0.08 μm) and enamel microhardness slightly increased (252.8 ± 7.35 MPa). Spearman’s correlation test revealed an inverse relationship between surface roughness and microhardness after bleaching (r s=−0.177, −0.818) for groups 1 and 2, respectively, and a strong correlation between surface roughness and microhardness after treatment with Curodont and Novamin as whenever surface roughness decreased, microhardness increased (r s=−0.921, P < 0.001) in group 1 and (r s=−0.855, P < 0.002) in group 2. Conclusion Both Curodont and Novamin have a reasonable potential to remineralize bleached teeth by increasing enamel microhardness and decreasing surface roughness. However, Curodont is better than Novamin in the remineralization effect.