Dina Mohamed Wahied  <br/><br/>
The effect of combining laser and nanohydroxy-apatite on the  surface properties of enamel with initial defects /  
  تاثير استخدام كل من الليزر والنانو - هيدروكسى ابتيت على خواص سطح المينا ذات العيوب المبدئية 
Dina Mohamed Wahied ; Supervised Ali Mohamed Elhosseni Saafan , Dina Hassan Moustafa , Marwa Adel Elsayed Hamed  
 - Cairo :   Dina Mohamed Wahied ,   2018 
 - 80 P. :   charts , facsimiles ;   25cm 
<br/><br/>Thesis (Ph.D.) - Cairo University - Faculty of Oral and  Dental Medicin - Department of Laser Applications in Oral Surgery 
<br/><br/> Background: The aim of this study was to evaluate the effect of combining fractional CO₂  LASER and nanohydroxy apatite on surface microhardness and color of enamel with initial  defects.  Material and methods: Two types of nano hydroxyapatite (nHAP) was prepared; Pure  hydroxyapatite (nHA) and Fluoro hydroxyapatite (nFHA), Sixty extracted premolar teeth  without visible caries or structural defects on enamel surface were used, immersed in 10 ml of a  demineralizing solution for 2 weeks to create artificial white spot lesions, they were randomly  allocated into two groups; Group 1: nHA, Group 2: nFHA, each group is then subdivided into 2  subgroups (A and B) where two different in vitro remineralization procedures have been  performed, the first procedure utilizes a 10wt% nHA aqueous slurries only, the second was first  exposed to irradiation from a fractional CO2 laser then (nHAP) was applied then laser was  applied once again . Microhardness and color were measured using a micro-Vickers hardness  tester and spectrophotometer respectively, then the surface topography was assessed using  scanning electron microscope 
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<br/><br/><label>Subjects--Index Terms: </label>Laser  Nanohydroxy-apatite  Surface properties of enamel