الفهرس 
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Abstract
This study aimed to synthesize PAMAM and evaluate the effect of adding both PAMAM and BAG to GICs on their antibacterial, compressive strength, solubility, ion release, pH, and setting time properties. One commercially available GIC was used in this study: High strength posterior restorative GC gold.
In the present study, PAMAM was prepared in National Research Centre and characterized by FTIR and 1H NMR. At the same time, BAG was obtained from the Chemistry laboratory, Faculty of Science, Suez Canal University, and characterized by FTIR, XRD, FESEM, and EDX. A total of 168 samples were prepared; twelve samples from all groups were used (2 samples from each group and subgroup) for chemical characterization (FTIR). For the antibacterial test, 36 samples were prepared (6 samples per group and subgroup) using a biofilm assessment test through counting forming unit count. For the compressive strength test, 48 samples were used (8 samples per group and subgroup), using a universal testing machine at a cross-head speed of .5 mm/min. For the solubility test, 36 samples (6 samples per group and subgroup) according to the ANSI/ADA specification No.66-1989 for glass ionomer cement with slight modification in the samples ‘dimensions as suggested by Carvalho- Junior et al. 218
The solution obtained from each sample of the solubility test was used for the ion release test. A total of 36 samples (6 samples per group and subgroup) were used. The solution was collected after 7 days. The analyzed solution was used to quantify the amount of the released silica, calcium, phosphorus, and sodium ions in mg/L using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Furthermore, the solution obtained from each sample of the solubility test was used to measure pH after 24 hours and after 7 days from the specimen preparation. A total of 36 samples (6 samples per group and subgroup) were used. The pH of each sample solution was measured using the Adwa AD8000 electrode. For the setting time test, 36 samples were prepared (6 samples per group and subgroup) to determine the initial and final setting time according to the ISO method for water-based dental cement (ISO 9917- 1:2007).
All samples were prepared according to the manufacturer’s instructions using split teflon molds with different dimensions according to each test specifications: The antibacterial and solubility tests samples were prepared with dimensions of (7.75 mm x 1.5 mm) and measured after 24 hours and after 7 days, respectively. For the compressive strength test, samples were prepared with dimensions of (4 mm x 6 mm) and measured after 24 hours. For the setting time test, samples were prepared with dimensions of 5 mm high and 10 mm in diameter.
The results of the synthesis of PAMAM showed that both FTIR and 1H NMR proved the existence of the main constituting chemical functional groups. Also, the results of BAGs particle characterization showed that the XRD and FTIR revealed the amorphous nature of the prepared BAG powder and proved the existence of the main constituting chemical functional groups. Furthermore, the FESEM and EDX revealed that the BAG powder was in the nano-sized range and confirmed the existence of Kα radiation of the BAG powder’s Si, Ca, P, and Na peaks.
The results of the biofilm assessment test (CFU) revealed a significant decrease in the biofilm activity of S. mutans and a reduction in the recovered bacterial counts in all groups compared to those of control G I.
The compressive strength test results showed a significant decrease in the compressive strength of all groups compared to that of G I. Although, there was a significant increase in the compressive strength in SG II (12%) compared to all other modified groups.
The results of the solubility test showed that there was a significant increase in solubility in GIII compared to all other groups.
The results of the ion release test showed that for Si ion release, there was a significant increase in the amount of Si ion in the solution in all groups compared to the control group. For Ca ion release, there was a significant increase in the amount of Ca ion released in G III and G IV compared to control G I. For P ion release, there was a significant increase in the amount of P ion released in SG II (24%), G III, and G IV, compared to that of the control G I. For Na ion release, there was a significant increase in the amount of Na ions released in all groups compared to those of control G I.
The results of the setting time test showed that for the initial setting time test, there was an insignificant difference in the initial setting time between control G I and G III. While there was a significant increase in the initial setting time in G II and G IV, compared to that of the control G I. For final setting time test, the control group had the shortest final setting time, with a significant difference to all other groups. In contrast, the SG IV (24%) had the longest final setting time with a significant difference among all groups except SG II (24%).
The results of the pH test showed that for the pH of the soaking solution after 24 hours, there was an insignificant difference in the pH of the solution after 24 hours between G I, G II (12% and 24%), and G III. While there was a significant decrease in the pH of the soaking solution in G IV, compared to G I. For the pH of the soaking solution after 7 days, there was an insignificant difference in the pH of the solution after 7 days between control G I, SG II (12%), and G III. While there was a significant decrease in the pH in SG II (24%), and in G IV, compared to G I.
7.2. Conclusions:
Within the limits of this current study, the following conclusions are drawn:
1. Modifications of GICs with PAMAM and BAGs significantly enhance their antibacterial properties and ion release ability but worsens their compressive strength.
2. Modification of GIC with PAMAM has no adverse effect on its solubility.
3. This study shows that GIC modified with 12%V of PAMAM has excellent antibacterial properties and a good compressive strength, which may help provide a modified GIC suitable for pediatric dentistry.
4. The pilot study showed that the coating process of BAG particles with PAMAM has a lesser antibacterial property than using BAG and PAMAM separately with GICs.