الفهرس 
AbstractOnly 14 pages are availabe for public view
 |  | from | 88 |  |  |
| | | from | 88 | | |
Abstract
A chemical bleaching agent containing 35% hydrogen peroxide and five remineralizing agents which are artificial saliva, fluoride varnish, casein phosphopeptide amorphous calcium phosphate, phosphorylated chitosan amorphous calcium phosphate and self assembling peptide P11-4 were used in this study. One hundred permanent mandibular molars which were free of cracks or white spot lesions were chosen for this study. All teeth surfaces were covered by double layer acid resistant nail varnish leaving a 4×4 mm window on the buccal surfaces. Baseline laser fluorescence measurements (LFMs) readings were recorded using Diagnodent Pent then teeth were randomly divided into two groups(A&B). Only teeth of group A were bleached using Pola office bulk kit. Teeth in each group were divided into five subgroups (n=10) according to the used remineralizing agent. After remineralization, teeth of all subgroups were subjected to demineralization with acid. Diagnodent Pen and scanning electron microscope were used to evaluate the level of enamel mineralization at baseline, after bleaching, after remineralization and after demineralization. Results : Regarding group A, there was a statistically significant difference between baseline values with all study steps which are bleaching, after remineralization and after demineralization again except for phosphorylated chitosan amorphous calcium phosphate and self assembling peptide p11-4 subgroups which attained no significant difference between baseline and after remineralization recorded readings. Phosphorylated chitosan amorphous calcium phosphate and self assembling peptide p11-4 subgroups showed the best results while artificial saliva subgroup showed the worst result. Regarding group B, there was a statistically significant difference between baseline values with all study steps which are after remineralization and after demineralization again except for artificial saliva group which attained no significant difference between baseline and after remineralization recorded readings and also for self assembling peptide P11-4 subgroup which attained no significant difference between baseline and after demineralization. Conclusion : 1- Bleaching causes some sort of enamel demineralization but this demineralization is reversible and could be remineralized again using remineralizing agents. 2- Phosphorylated chitosan amorphous calcium phosphate and self assembling peptide P11-4 are promising remineralizing materials and showed the best results for remineralization of demineralized enamel.