الفهرس 
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Abstract
SUMMARY AND CONCLUSION
The purpose of the present study was to evaluate effect of silica infiltration on bond with partially stabilized tetragonal monolithic zirconia to adhesive resin cement, on their surface roughness and flexural strength
Forty two nanocrystalline zirconia plates were constructed with standardized dimensions for this study.
Zirconia samples was divided into main three group according to the surface treatment received:
group 1: With no surface treatment used as a control group (n=14).
group 2: Were sandblasting by AL203 (n=14).
group 3: Treated by layer of sodium silicate powder with novel method adopted from selective infiltration etching technique (n=14).
Each group was subdivided into two subgroups according to the test:
Subgroup (A): Translucent zirconia disc –like specimens for shear bond strength (n=21).
Subgroup (B): Translucent zirconia beam specimens for flexural strength (n=21).
Samples of group A were bonded to resin composite discs Rely X Unicem resin cement. The shear bond strength to adhesive Rely X Unicem resin cement, compared with the control. Finally, deboneded samples were examined under the scan electron microscope to determine their mode of failure.
Samples of group B were placed on a 3-point bending test device. The central load was applied with a head diameter of 2.0 mm at a crosshead speed of 1.0 mm/min till fracture.
The mean and standard deviation for flexural strength and flexural modulus were calculated for specimens.
Data were collected and statistically analysis was performed in several steps.
The results of effect of shear bond strength test showed that there was significant difference between the values of samples treated with different surface treatments. Samples treated with silica infiltration had the highest (mean±SD) value followed by air abraded samples while the lowest value was found in untreated samples.
The results of effect of flexural strength test showed there was no significant difference between the values of samples treated with different surface treatments. Air abraded samples had the highest (mean±SD) value followed by samples treated with silica infiltration while the lowest value was found in untreated samples.
There was a moderate positive correlation between flexural and shear bond strength that was statistically significant.
Conclusion:
Within the limitations of this study, the following conclusions were drawn:
1. Shear bond strength value of ceramic systems are affected by surface treatment performed.
2. Surface topography of the ceramic systems are affected by surface treatment performed.
3. Silica infiltration surface treatment is a promising surface treatment to be used with translucent zirconia with resin cement.
4. Sandblasting with 110-μm alumina improved the flexural strength for translucent zirconia.
5. Although silica infiltration showed lower flexural than air abrasion, it can be used as an effective surface treatment.