Ashraf Hussien Abdel Fattah Sherif

Mona H Mandour

16/06/2023

https://www.sciencedirect.com/science/article/abs/pii/S0022391323003311

Ashraf Hussien Abdel Fattah Sherif

Ahmed Gouda - Tarek Morsi

05/01/2023

https://link.springer.com/article/10.1007/s00784-022-04829-8

Ashraf Hussien Abdel Fattah Sherif

Tarek Salah Morsi

05/01/2023

https://link.springer.com/article/10.1007/s00784-022-04829-8

Ashraf Hussien Abdel Fattah Sherif

Mona Hossam El-Din Mandour

05/06/2022

https://digitalcommons.aaru.edu.jo/cgi/viewcontent.cgi?article=1135&context=fdj

Ashraf Hussien Abdel Fattah Sherif

mona Hossam

01/06/2022

https://digitalcommons.aaru.edu.jo/cgi/viewcontent.cgi?article=1135&context=fdj

Ashraf Hussien Abdel Fattah Sherif

01/07/2019

Ashraf Hussien Abdel Fattah Sherif

Tarek Salah Morsi

01/06/2019

Objective: Despite the higher translucency of nano-crystalline Y-TZP than the conventional Y-TZP, it couldn’t be used in the anterior region of the mouth in its fully anatomical form without veneering for better esthetics. This study evaluated the color change (ΔE) and translucency parameter (TP) of the bilayered nano-crystalline zirconia restorations after different treatments of the zirconia surface before and after accelerated aging. Material and Methods: Forty samples of inCoris TZI were cut in the form of discs 15 mm (diameter) and 1mm (thickness) so that after sintering each disc dimensions’ would be 12 mm (diameter) and 0.8 mm (thickness). All discs were colored by dipping in aqueous zirconia coloring solution of shade A2, then divided into four groups according to the type of surface treatment received before sintering; being tribochemical silica coating, zirconia powder deposition, glass grading, and a control untreated group. After sintering, all discs were veneered with a layer of porcelain 0.7 mm (thickness) and 12 mm (diameter). (ΔE) and TP were measured using VITA Easyshade Compact spectrophotometer before and after accelerated autoclave aging. Results: Different surface treatments applied had significant effect (P<0.05) over ΔE and TP. Glass graded group showed the highest ΔE value and the least TP value among both un-aged and aged sub-groups. Conclusion: Different surface treatments applied affected the color and translucency negatively where the control untreated group showed the highest TP and the least color deviation from the A2 color parameters. On the other hand, accelerated autoclave aging had no effect over translucency or color.

Ashraf Hussien Abdel Fattah Sherif

M.Wahsh, T.Salah

01/06/2018

Purpose The objective of the study was to investigate the effect of different immersion times, in coloring liquid, and sintering temperatures on translucency of monolithic nanocrystalline zirconia. Materials and methods Forty five specimens of nanocrystalline zirconia were obtained by cutting InCoris TZI blocks into slices using a stainless steel disc mounted on a custom made milling machine. The slices were divide into three groups (n = 15) according to immersion times (3,5 and 7 min) then each group was further subdivided into 3 subgroups (n = 5) according to the sintering temperatures (1400°c, 1500°c and 1600°c). CIE-Lab coordinates were measured for each slice against black and white backgrounds using Vita easy shade spectrophotometer and translucency parameter (TP) was calculated. One way analysis of variance combined with a Tukey-post hoc test were used to analyze the data obtained (P = 0.05). Results Results of the present study showed that at temperature 1400°c there was statistically significant decrease in TP between 7 min immersion time and the other two groups, while there was no statistically significant difference in TP using different immersion times at temperatures 1500°c and 1600°c. Conclusion Our results showed that the best translucency was obtained by the combination between lower dipping times and higher sintering holding temperatures.

Ashraf Hussien Abdel Fattah Sherif

01/12/2016

Improved material strength, enhanced esthethic and high biocompatibility give Zirconia ceramic a great possibility to be used for a wide range of promising clinical applications. This review presents the different types of zirconia materials available for dental application, the effect of machining procedures on these materials, the esthetic of zirconia ceramics and bonding of the veneering ceramics in addition to the biologic properties of these new materials.

Ashraf Hussien Abdel Fattah Sherif

O.Abdelbary M.Wahshb Sherif T.Salah

01/06/2016

Purpose The objective of the study was to evaluate the translucency of different thickness of a translucent zirconia before and after accelerated aging. Materials and methods Sixty slices of translucent zirconia were obtained by cutting InCoris TZI blocks into slices using Micracut precision cutting machine. The slices were divide into four groups (n = 15) according to their thickness (0.5 mm, 0.8 mm, 1 mm and 1.2 mm). CIE lab coordinates were measured for each slice against black and white backgrounds using vita easy shade and TP was calculated. All specimens were subjected to accelerated aging using autoclave (134 ºC, 0.2 MPa) and TP was calculated after accelerated aging. One way analysis of variance combined with a Tukey-post hoc test was used to analyze the data obtained (P = 0.05). Results Results of the present study showed that thickness of zirconia has determinal effect on its translucency as there was no statistically significant difference in TP between 0.5 mm and 0.8 mm thicknesses while there were statistically significant differences in TP between 0.8 mm, 1.0 mm, 1.2 mm. Effect of aging was significant on 0.5 mm thickness. Conclusion Thickness of zirconia has significant effect on translucency. Aging has significant effect on thinner sections of zirconia. More research is required on zirconia towards making the material more translucent for its potential use as esthetic monolithic restoration.