الفهرس 
Difference between Crystalline and Amorphous SolidsOnly 14 pages are availabe for public view
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Abstract
Modified Hench’s bioglass divided by two systems of the basic
composition xAg2O (45 B2O3, 24.5 CaO, 24.5 Na2O, 6 P2O5) as (x= 0.1, 0.2, 0.4,
0.6, and 0.8 wt.%) for first system was successfully prepared via the melt
quenching route. Immersion in phosphate solution (PS) varying times (1→4
weeks) was used to assess the in-vitro behavior of the bulk glassy samples with
different silver oxide content. X-ray diffraction XRD, scanning electron
microscopy (SEM), and other spectroscopic measurements including Fourier
transform infrared (FT-IR) analytical techniques and UV/visible optical
measurements before and after prolonged immersion times were used to
estimate the bioactive behaviors and to explain the efficiency of bone-bonding.
Besides, antimicrobial tests against pathogenic grams were examined and silver
ions show varying levels of action against certain bacteria. It was noticed that
prolonged immersion periods cause distinct variations that link the vibrational
bands because of a preferential attack or ion exchange and modifier replacement
by silver ions in the glass network causing the hydroxyapatite formation as an
indication for bone-bonding ability. Antimicrobial experiments reveal that
studied material can be used efficiently as an antibacterial agent.
Second system Samples of Hench’s bioglass of the composition Borate
glasses have the formula according to, xAg2O and xCeO2 and (45 B2O3, 24.5
CaO, 24.5 Na2O, 6 P2O5) as (x= 0.1, 0.2, 0.4, 0.6, and 0.8 wt. %) added
overweight to the batch, whereas Na2O and CaO were introduced in the form of
their respective carbonates while P2O5 was added in the form of ammonium
dihydrogen phosphate (NH4H2PO4) were prepared. In vitro cases of the bulk
glass samples with high concentration of silver oxide and cerium oxide content
were tested by immersion in phosphate solution for different periods of time
(1→4 weeks). Formation of a hydroxyl carbonate apatite (HCA) layer on
samples surfaces and bioactivity, was confirmed by XRD, FTIR, SEM and
microbial test while presence of Ce2+/Ag2+in the glasses before and afterphosphate solution (PS)) immersion was determined. The general goal of the
extended research is to justify the bone-bonding efficiency when both X-Ray
diffraction and immersion durations are present. Experiments show that FTIR
spectra are stable, but prolonged immersion times induce distinct variations that
touch the vibrational bands as a result of ion exchange or preferential attack and
substitute of modifiers by silver and cerium ions for the system of samples,
resulting in the formation of hydroxyapatite as a bone-bonding ability indicator.
The antimicrobial test reveals certain differences in the activity and quantity of
silver ions added in the presence of cerium ions against various bacteria.