الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 90 |  |  |
| | | from | 90 | | |
Abstract
This in-vitro study was conducted to evaluate the immediate color improvement of white spot lesions after combined microabrasion / resin infiltration treatments and after resin infiltration treatment alone, also to evaluate the color stability after aging concerning the two treatment modalities and finally to evaluate the abrasion resistance and wear description after implementing aging procedures.
The sample size collected was 45 human premolar teeth which were freshly extracted from orthodontically treated patients and they were randomly assigned into three groups; group I (untreated enamel), group II (combined microabrasion and resin infiltration treatments) and group III (resin infiltration treatment alone)
A black putty mold and a removable eyelet was fabricated so that the specimens was put sequentially in it with an opening facing the middle third of the left half of each crown of the specimens, baseline color measurements were taken (T1) then the rest of the crown was painted with acid resistant nail polish and immersed in demineralizing solution to induce WSLs then color measurements were taken for the second time (T2). Different treatment approaches were applied for group II (microabrasion then resin infiltration) and group III (resin infiltration alone) and color measurements were taken for the third time (T3). Finally, aging procedures were performed including thermocycling, mechanical abrasion and extrinsic staining then color measurements were taken for the last time (T4) and ΔE was calculated. Specimens were scanned under SEM to evaluate surface morphology and wear resistance after aging.
Results showed that mean color difference between the baseline measurements and treatments applied (T1-T3); for group I there was no significant difference since there was no
64
treatment applied, for group II the mean color difference was less than that in group III. When baseline color measurements were compared to those taken after aging it was found that for group I there was a significant color change, for group II the mean color difference was less than that in group III where the mean color difference in group three was close to that of group I showing significant color change after induction of WSLs, after treatment application and after aging.
Results of the SEM showed that there were no microfissures or microcracks in group II (the combined treatments group) all over the surface of the tested area that appeared smooth. While, in group III (the resin infiltration group) there were areas containing microfissures and microcracks and other smooth areas presented together in the tested area of the enamel.