Abstract
Objective:To compare the elastic modulus, flexural strength, and hardness of an experimental resin based composite (RBC) with and without containing silver nanoparticles (AgNPs) and bioactive glass (BAG) with a commercially available RBC.Methods:This study was conducted, during the period August 2016-May 2018, at the Department of Dental Materials, Peshawar Dental College, Peshawar (Pakistan) and Department of Chemistry, University of Montreal, Canada. Test specimens made in the commercial RBC acted as Group-1 (G1). An experimental RBC containing 70 wt % filler content was synthesized. It was first used as such to prepare test specimens to act as the experimental control group (G2). This RBC was then modified by adding various amounts of BAG (5%, 10% and 15%) and a fixed amount of 0.009% AgNPs to use the so modified RBCs for preparing the test specimens to belong to three groups (G3, G4 & G5). The AgNPs had been synthesized in situ by reduction of salt during photo-polymerization. Flexural strength (FS), elastic modulus (EM) and Vickers hardness were determined using universal testing machine and hardness tester respectively. Data were analyzed using one-way ANOVA and Tukey post-hoc test.Results:Except for G3 restorations showing significantly lower mean FS value, the FS for those in the other groups were not significantly different (p>0.05). Elastic modulus of the experimental RBC restorations was though higher than those of the others but the difference was statistically insignificant (p>0.05). Reduced Vickers hardness values were documented for the restorations in the G4 and G5 compared to those in the G3 but again the difference was insignificant (p>0.05). Flexural strength and hardness values of the test specimens in the experimental RBCs were significantly lower than those made in the commercial hybrid RBC (p<0.05).Conclusion:BAG and AgNPs addition to the experimental RBC in the mentioned concentration adversely affected the tested mechanical properties.
Highlights
Resin based composites (RBC) are frequently employed in modern dental practice to restore carious lesions.[1]
The flexural strength (FS) values of the various RBC specimens in the various groups are shown in Table-IV
FS of RBC specimens groups (G2, Group 3 (G3), Group 4 (G4), and Group 5 (G5)) was significantly less than those of G1 or the commercial RBC (p< 0.001). It appears that the impregnation of AgNp-bioactive glass (BAG) in the RBC reduced flexural strength (FS) of test specimens in the G3 as compared to those in the Group 2 (G2) while the FS of G4, G5 were higher in comparison to those in the G2 (Table-IV and V)
Summary
Resin based composites (RBC) are frequently employed in modern dental practice to restore carious lesions.[1]. Amjad Hanif & Fazal Ghani restoration.[3] RBCs exhibit higher level of harboring of microorganism as compared to other restorative materials.[4] The lack of antibacterial property of polymerized resin composites leads to increased bacterial attachment and plaque buildup on its surface than the other dental restorative materials including silver amalgam. The latter exhibit some antibacterial activity due to release of metal ions.[5]
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