The aim of this in vitro study is to compare the shear bond and bi-axial flexural strengths of samples veneered with, CAD/CAM-fabricated zirconia core, and Press-on technique, with the definition its mode of failure. Twenty zirconia core discs were made using IPs e.max ZirCAD and CAD/CAM technology. These were divided equally in to two groups. Group one was veneered by CAD-on technique using IPs e.max CAD, and group two was veneered by Press-on technique using IPs e.max ZirPress, then all the discs are thermocycled. The specimens were exposed to shear bond and biaxial flexural strength testing. Mode of failure was evaluated by SEM. All data were collected and analyzed statistically by SPSS, with significance level 5%, where P≤ 0.05. The t- test analysis of shear strength test showed statistically significant difference at (p < 0.05) for CAD-on group. While there were no statistically significant difference at (p < 0.05) for the biaxial flexural strength test between the two groups. CAD-on group showed adhesive/cohesive failure, while press-on group showed cohesive failure within the veneering ceramic. This study concluded that, the bond strength between zirconia core and veneer was affected by the veneering technique. CAD-on technique showed statistically significant high bond strength over Press-on technique arabic 20 English 98
Seham Ali Elsawaay*, Milad Mustafa Eshah, Mohamed Al basher Zeglam(1-2018)

All -ceramic restorations are nowadays widely accepted in the anterior and posterior regions. The geometry of tooth preparation has been the subject of many debates without clear evidence that one type of finish line provides consistently superior marginal fit. Therefore, the main interest of the present research was directed toward the influence of margin configuration on marginal adaptation of all ceramic crowns. Articles were selected on the basis of they had sufficient information related to types of the finish line and related factors effect on marginal adaptation of all ceramic crowns. The results of this study revealed that the best finish line chose for all ceramic restorations still remains a difficult goal to be achieved. arabic 14 English 84
Seham Ali Elsawaay*, Milad Mustafa Eshah, Mohamed Albasher Zeglam(1-2019)

The aim of the present study was to evaluate abutments of crowns and conventional fixed dental prosthesis in terms of complying Ante’s law, and periapical lesions through a retrospective analysis of orthopantomographs (OPTGs) of patients in private dental clinic. In this study, the digital OPTGs of adult patients between the ages of 30 and 75 who appealed to private dental clinic for the first time to have their fixed prosthetic treatment needs met were used. The routine dental radiographs were taken in the first appointment of the patients. The periapical health of all teeth restored with crowns and bridges were evaluated by radiographic criteria according to periapical index (PAI). The present study comprised panoramic radiographs belongs to43 women and 27 men with an age range of 30 to 75 years old. No relationship was observed between gender and periapical lesion. While the amount of fixed prosthesis was highest in the lower jaw with 54%. The most commonly used abutment tooth were premolar teeth.36% of bridges didn’t meet the requirements of Ante’s law. More periapical lesion were observed among the restorations which doesn’t meet the requirements of Ante’s law. According to the results of the present study, the restoring of missing teeth with FPDs may cause different periapical pathologies. Optimum evaluation of abutments regarding to Ante’s law and periapical status may decrease the complications that could be observed in long term prognosis of FPDs arabic 11 English 76
Seham A. Elsawaay, Enas A.Khamakhim(5-2019)