الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
 |  | from | 98 |  |  |
| | | from | 98 | | |
Abstract
Aim: The aim of the current study was to measure the pH changes, solubility percentage, the final setting time and the cytotoxicity in experimentally prepared nano-zinc phosphate cement as compared to conventional zinc phosphate cement when used in a base consistency.
Methods: Nano-zinc phosphate powder was prepared by the sol-gel chemistry according to the results obtained from the X-ray fluorescence chemical analysis for the conventional zinc phosphate powder. Optimum P/L ratio of the nano-zinc phosphate cement was determined according to a pilot study. The pH changes were measured at different time periods by the pH meter. The solubility (%) was evaluated after 24 hours for both tested cements. The Final setting time was measured according to ISO 9917-1 specifications. The Cytotoxicity effect was evaluated against epithelial cell line MA-104 according to ANSI/ADA no. 41. Data were statistically analyzed by Kolmogorov-Smirnov, Shapiro-Wilk, Mann-Whitney, Independent sample t, Repeated measure ANOVA and Paired sample t tests. The significance level was set at P ≤ 0.05.
Results: The pH values of the nano-zinc phosphate cement were significantly higher than those of the conventional zinc phosphate cement at all tested time periods. Additionally, the nano-zinc phosphate cement revealed a faster rise in the pH values until the neutrality level was reached. The solubility (%) of the nano-zinc phosphate cement was significantly higher than that of the conventional zinc phosphate cement. The final setting time of the nano-zinc phosphate cement was significantly lower than that of the conventional zinc phosphate cement but still within the practical limits stated by the ISO 9917-1 specifications. The cytotoxicity results of both cements were non-significantly different and ranged from mild to moderate cell response.
Conclusion: Nano-zinc phosphate cement has a higher initial pH and reaches neutrality faster than the conventional zinc phosphate cement without compromising the final setting time or the cytotoxicity of the cement. However, the solubility (%) of the experimentally prepared nano-zinc phosphate cement was negatively affected.