Effects of Silica Nanoparticles and Silica-Zirconia Nanoclusters on Tribological Properties of Dental Resin Composites

Abstract

Roughness and hardness are among the most important variables in the wear (resistance) performance of dental resin composites. In this study, silica nanoparticles and nanoclusters of silica and silica-zirconia nanoparticles were evaluated for use as reinforcement agents in dental resin composites. Nanoclusters with spherical morphology were obtained from aqueous dispersions of nanoparticles by spray drying. Roughness was measured through atomic force microscopy (AFM) while nanohardness was evaluated by nanoindentation. The roughness values obtained with silica nanoparticles were lower (22.6 ± 6.6 nm) than those obtained with silica and silica-zirconia nanoclusters (138.1 ± 36.6 nm, 116.2 ± 32.2 nm, resp.), while the hardness values of all composites were similar (nanoparticles = 0.24 ± 0.01 GPa, silica nanoclusters = 0.25 ± 0.04 GPa, and silica-zirconia nanoclusters = 0.22 ± 0.02 GPa). Based on this study, it can be established that particle size is a determining factor in the roughness of the final material, while the key variable for nanohardness was the concentration of the reinforcement materials.

Evaluation of Synergic Potential of rGO/SiO2 as Hybrid Filler for BisGMA/TEGDMA Dental Composites

“…Surface modification of silica (A200) was confirmed via Fourier transform infrared (FTIR) spectroscopy ( Figure 3 ). The characteristic peaks corresponding to the hydrophilic silica (A200) were observed at 3430 cm −1 for OH stretching, at 1632 cm −1 for silanol OH bending as well as for water twisting band, at 1105 and 809 cm-1 for asymmetric and symmetric stretching mods of siloxane (Si–O–Si) framework and at 470 cm −1 for Si–O rocking vibrations [ 32 , 33 , 39 ]. The spectrum of the silanized silica, S-A200, revealed additional peaks at 3010 cm −1 for =C–H (carbon-sp 2 ) stretching, 2924 and 2853 for C–H (carbon-sp 3 ), 1708 for C=O stretching, 1420 for C=C stretching and at 1366 cm −1 for C–H bending mode all assigned to the γ-MPS molecules, thus indicating successful modification of A200 silica.…”

“…The fillers used in this investigation was silanated using the organosilane, γ-MPS, prior to application. Aerosil ® 200 (A200) was silanated using 10 wt.% of γ-MPS (enough to completely cover the surface of the silica and to attain tenacious interphase) following a method reported elsewhere [ 32 , 33 , 34 ]. The minimum amount of silane ( X %) required for filler particles coverage can be calculated using Equation (1) [ 32 , 35 ], in which A is the surface area of the filler (A200, 200 m 2 /g) and w is the surface area coverage per g of silane which is 2525 m 2 /g for γ-MPS [ 35 , 36 ].…”

“…Modification of rGO with the coupling agent γ-MPS was attempted using a method modified from literature [ 32 , 33 , 37 ]. In this case, γ-MPS (0.05 mL) was separately prehydrolyzed in 15 mL ethanolic aqueous solution (70 wt.%) for 2 h. The silane solution was added dropwise into a pre-suspended rGO (400 mg) in 250 mL of 70 wt.% ethanolic solution and refluxed at 60 °C for 2 h, then kept on stirring overnight at room temperature.…”

Antibacterial Activity of Mouthwash Incorporated with Silica Nanoparticles against S. aureus, S. mutans, E. faecalis: An in-vitro Study

“…It is also biodegradable in nature, has reduced toxicity and stimulates macrophages [10]. Silica has been known as an abrasive agent used mostly in dentifrices, other functional versatility includes its use as a dentin blocking agent used for desensitization, teeth whitening, remineralization of teeth [11]. Previously, we have successfully completed numerous epidemiological and in vitro studies for the betterment of our community [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30].…”

Synergistic Effect of Bioactive Inorganic Fillers in Enhancing Properties of Dentin Adhesives—A Review

“…Resin tag formation is enhanced by the presence of silica particles [ 91 ]. The probable reason for this could be that silica nanoparticles are spherical-shaped, and this morphology helps the material to disperse and flow properly without any significant effect on the viscosity [ 98 ].…”