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)

Treatment carried out with a fixed partial denture (FPD) is one of the most accepted and desired by patients. However, it is a long procedure and cause high expectations from the patient. Once the clinician knows the factors that make dissatisfaction or related to failures, the dentist could reduce them and so meet all the patient’s need and set up the most suitable planning. The aim of this study was to evaluate the incidence of failures/clinical complications of the fixed prosthesis and to document the failure related factors that may affect the length of service of crown and fixed partial bridge (FPD) in Tripoli Central Dental Clinic/Libya. Also, the number of retainers, pontics, and the types of restoration were recorded. By examining 74 patients with 297 crown and bridge unites from the Tripoli Central Dental Clinic and collecting data related to the bridge area the data collated were subjected to descriptive analysis. A total of 74 patients were included in the study. Clinical evaluations of the patients were performed. Data were tabulated and patients with failure in prosthesis were calculated in percentage. The result of the study revealed that the pain was the most frequent complication observed on 56.8% of all the patients, under contour of the retainer has been found in 56.8% with an open margin in 73% and open proximal spaces with 48.6% of all subjects. Pain and open margins were the most frequent complications observed on 56.8%, 73% of all the patients respectively. Position of 78% of the cases were in the upper arch and four unites bridges found to be most frequent failed bridges in 27% of the subjects.
Amina rajah Elsa (2-2021)

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)