Dina Ihab Kamal Amin Yacoub <br/><br/>
Effect of bulk-fill and incremental ormocer-based versus conventional resin composites on the fracture resistance of mesio-occlusal-distal cavity preparations :   In vitro study /  
 تأثير الحشو اساسى اورموسير بالكتلة و الطبقاث مقارنة بالراتينج المركب الإعتيادى على مقاومة الكسر للتجاويف المُعدَّة أنُسىى إطباقى أقصى :   دراسة معمليه 
Dina Ihab Kamal Amin Yacoub ; Supervised Amr A. Shabka , Maha Elbaz , Mona Fadel 
 - Cairo :   Dina Ihab Kamal Amin Yacoub ,   2017 
 - 66 P. :   charts , photographs ;   25cm 
<br/><br/>Thesis (M.Sc.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Operative Dentistry 
<br/><br/> Numerous clinical negative effects in resin based composite restorations as cusp fractures are detected in restorations with modern resin based composites. Mechanical fracture tests are employed to measure the impact of restorative material and cavity preparation characteristics on fracture resistance. This study was conducted to evaluate the fracture resistance of four different resin composite materials; two ormocer based (bulk-fill or incremental) and two non-ormocer based materials (bulk-fill or incremental), used to restore mesioocclusal-distal cavity preparations of different cavity widths. A total number of 80 freshly extracted human premolar teeth were selected. The mesio-distal (MD) and bucco-lingual (BL) dimensions of the collected teeth were measured using a digital caliper. Teeth with MD and BL dimensions of (6 ±0.5 mm) were only included in this study, and were randomly divided into 2 groups of 40 teeth each, according to cavity width. Group B1: cavity width was prepared 1/3 the inter-cuspal distance and Group B2: cavity width prepared 1/2 the inter-cuspal distance. Each group was furtherly subdivided into 4 subgroups of 10 teeth each, according to the type of restorative material used. MOD cavities were prepared and standardized in all dimensions except for the BL width of the cavity which was prepared either 1/3 or 1/2 the ICD. One bonding system was used in all the specimens, etch and rinse adhesive system Futurabond M+. Resin composite restoration was applied either incremental or bulk according to the type of restorative material: Admira fusion Xtra (ormocer-based bulk-fill composite); admira fusion (ormocer-based incremental composite); Xtra Fil (conventional bulk-fill composite); or grandioSo conventional incremental composite 
<br/><br/>
<br/><br/><label>Subjects--Index Terms: </label>Bulk-fill and incremental  Fracture resistance  Resin composites