Evaluation of Mechanical, Optical and Surface Changes of Pretreated Enamel Surface Bonded to Orthodontic Bracket Using Different Remineralizing Agents

Objective: This study aimed to evaluate the effect of CPP-ACP, CPP-ACPF and nano-hydroxyapatite on enamel remineralization during fixed Orthodontic treatment. The treated specimens with different remineralizing agents were compared with their untreated and demineralized ones regarding surface roughness, surface microhardness, and color measurement.
Materials and methods:A total number of 120 specimens from extracted orthodontic patient teeth was collected and divided into 4 equal groups (10 specimens each) according to the enamel surface treatment applied immediately after PH cycling; group A received no surface treatment and served as a control group. In group B, the enamel surface was treated by CPP-ACP, while group C enamel surface was treated by CPP-ACFP, and group D was treated by Desensibilize NanoP. The surface roughness was obtained using surface Profilometer and Vickers microhardness was measured using Digital Display Vickers Microhardness Tester. Evaluation for each specimen was performed before, after pH cycling and after using different remineralizing agents. The color change was analyzed for each specimen in different groups under the Spectrophotometer. The change in color from control specimens compared to the color of the demineralized specimens (ΔE₁), the difference in color between control specimens and after remineralization (ΔE₂) and the change in color between demineralized and remineralized specimens (ΔE₃) were calculated. The results were then statistically analyzed and compared using ANOVA and LSD test at level of significance 0.05.
Results: The use ofCPP-ACP, CCP-ACFP and NanoP significantly improved surface roughness, surface microhardness especially with NanoP with non-significant difference between the three remineralizing materials. NanoP exhibited the lowest change in color compared with CPP-ACFP and CPP-ACP paste.
Conclusion: The use of CPP-ACP, CPP-ACFP and NanoP could be used as preventive materials during orthodontic treatment and be effective in repairing the demineralized enamel restoring its surface smoothness, hardness, and color.