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003 EG-GiCUC
005 20250223031523.0
008 160618s2015 ua o f m 000 0 eng d
040 _aEG-GiCUC
_beng
_cEG-GiCUC
041 0 _aeng
049 _aDeposite
097 _aM.Sc
099 _aCai01.09.06.M.Sc.2015.Sa.D
100 0 _aSally Magdi Riad Makram
245 1 0 _aDirect versus indirect loading of mini screws during maxillary canine rretraction :
_bA split mouth randomized clinical trial /
_cSally Magdi Riad Makram ; Supervised Fatma Abdou Abdelsayed , Fady Hussein Fahim
246 1 5 _aالتحميل المباشر مقابل التحميل غير المباشر للبراغى الصغيرة اثناء جر الناب بالفك العلوى تقنية الفم المقسم :
_bدراسة سريرية عشوائية
260 _aCairo :
_bSally Magdi Riad Makram ,
_c2015
300 _a151 P. :
_bphotographs ;
_c25cm
502 _aThesis (M.Sc.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Orthodontics
520 _aThis in vitro study was carried out to assess the shear bond strength of composite resin bonded to enamel and dentin pretreated with acid etchant and Er, Cr : Ysgg. Non carious 66 sound human premolars were selected to prepare. 132 specimens for this study. Buccal surfaces were flattened and were ground under copious water coolant to obtain a flat enamel surface while the lingual surfaces were ground to obtain a uniform flat surface of superficial dentin. Subsequently, the surfaces were polished with 240 grit, 400 grit and 600 grit sandpaper disks to standardize the smear Layer. Prepared specimens were randomly divided into two main groups, 66 specimens each, according to etching methods (A); group (A1) etching by an Er, Cr : YSGG laser system (waterlase MD, biolase); and (A2) etching by phosphoric acid using scotchbond universal etchant. Each group was further divided into two subgroups 33 specimens each according to tooth substrate tested (S); where (S1) was for enamel, while (S2) was for dentin. Each subgroup was divided into three classes 11 specimens each according to storage time (T); stored for 1 day (T1), stored for 7 days (T2) and stored for 30 days (T3). The adhesive was applied on the substrate and cured then a plastic tube (Tygon tube), 0.7 mm in diameter and 1mm in length was held securely and immobilized using cotton pliers on the indicated substrate. Then resin composite (Z 350 X T) was packed into the tube and cured. Microshear bond strength test was conducted using universal testing machine at crosshead speed of 0.5 mm/min till specimens fail, bond strength was calculated in MPs. The results of the current study revealed that laser-etched enamel showed the lowest significant microshear bond strength mean compared to acid-etched enamel. On the other hand, laser etched dentin showed the lowest insignificant mean compared to acid etching treatment. It was also found that time exhibited an insignificant effect on mean microshear (MPa) on both substrates
530 _aIssued also as CD
653 4 _aDirect versus indirect loading
653 4 _aMini screws during maxillary
653 4 _aOrthodontics
700 0 _aFady Hussein Fahim ,
_eSupervisor
700 0 _aFatma Abdou Abdelsayed ,
_eSupervisor
856 _uhttp://172.23.153.220/th.pdf
905 _aNazla
_eRevisor
905 _aSamia
_eCataloger
942 _2ddc
_cTH
999 _c56959
_d56959