TY - BOOK AU - Alaa Fathi Abdelsalam Abdelsalam AU - Mohamed Fouad Haridy , AU - Mohamed Riad farid , TI - Fracture resistance of mesio-occluso-distal cavities in maxillary premolars restored with nanohybrid composite or bulk fill composite with and without fiber reinforced bulk fill base : : In vitro study / PY - 2016/// CY - Cairo : PB - Alaa Fathi Abdelsalam Abdelsalam , KW - Fracture resistance KW - Maxillary premolars restored KW - Mesio-occluso-distal cavities N1 - Thesis (M.Sc.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Operative Dentistry; Issued also as CD N2 - This study was conducted to evaluate the fracture resistance of maxillary premolars weakened by extensive MOD cavities and restored with nanohybrid resin based composite or bulk fill composite with and without a newly introduced fiber reinforced bulk fill base. A total of 60 sound non cavitated human premolar indicated for extraction were anonymously collected. All teeth were free from caries, cracks or restorations. Teeth were randomly allocated into six main groups (n=10) by the researcher. Group 1: Sound premolars. Group 2: Unrestored premolars with MOD cavity preparation. Group 3: Premolars with MOD cavity preparation restored incrementally with nanohybrid composite (Grandio®, Voco{u2122}). Group 4: Premolars with MOD cavity preparation restored by bulk fill composite(x-tra fil®, Voco{u2122}). Group 5: Premolars with MOD cavity preparation restored by 2mm fiber reinforced bulk fill composite (Ever X posterior®, GC{u2122}) and with 2 mm nanohybrid composite veneer (Grandio®, Voco{u2122}). Group 6: Premolars with MOD cavity preparation restored by 2 mm fiber reinforced bulk fill composite base (Ever X posterior®, GC{u2122}) and veneered by 2mm bulk fill composite (x-tra fil®, Voco{u2122}). All prepared teeth received restorations except group 2 2cavity preparation without restorations3 to act as the negative control. After adhesive application, a matrix retainer system, a holder and a metal matrix, (tofflemire, miltex Inc, York, PA, USA) was used to simulate the clinical conditions ER -