Effect of Surface Treated Silicon Dioxide Nanoparticles on Some Mechanical Properties of Maxillofacial Silicone Elastomer

Abstract

Current materials used for maxillofacial prostheses are far from ideal and there is a need for novel improved materials which mimic as close as possible the natural behavior of facial soft tissues. This study aimed to evaluate the effect of adding different concentrations of surface treated silicon dioxide nanoparticles (SiO2) on clinically important mechanical properties of a maxillofacial silicone elastomer. 147 specimens of the silicone elastomer were prepared and divided into seven groups (n = 21). One control group was prepared without nanoparticles and six study groups with different concentrations of nanoparticles, from 0.5% to 3% by weight. Specimens were tested for tear strength (ASTM D624), tensile strength (ASTM D412), percent elongation, and shore A hardness. SEM was used to assess the dispersion of nano-SiO2 within the elastomer matrix. Data were analyzed by one-way ANOVA and Scheffe test (α = 0.05). Results revealed significant improvement in all mechanical properties tested, as the concentration of the nanoparticles increased. This was supported by the results of the SEM. Hence, it can be concluded that the incorporation of surface treated SiO2 nanoparticles at concentration of 3% enhanced the overall mechanical properties of A-2186 silicone elastomer.

Effect of Nano Titanium Oxide Addition on Color Stability on Two Types of Maxillofacial Silicone Materials

“…The matrix and the bottom parts and the cover of the mold were previously coated with petroleum jelly (12,16) for HTV silicone elastomer molds and separating medium for RTV silicone elastomer molds, then the matrix parts and bottom parts were securely attached for the two types molds (metal molds for HTV silicone elastomer and acrylic molds for RTV silicone elastomer) and placed on the vibrator for RTV silicone elastomer with the mold spaces coated with separating medium The material was injected from the syringe into the mold and a cover (RTV silicone molds) and a glass slab (HTV silicone molds), was laid onto the matrix filled with the material. Lying of the cover part, the glass slab was started from one side by resting the bottom edge of the slab and holding the topedge, while the covers, the glass slab was carefully and slowly lowered onto matrix to force excess material and air out ahead of it.…”

“…Then, samples were conditioned at a standard laboratory temperature of 23±2°C for a minimum of 3 hours after removal of flash (43) . The flash was removed with a scalpel and sharp surgical blade # 11 (12) .…”

“…Mixing of the silicone base with nanoTiO 2 As recommended by manufacturer's instructions the mixing of VST50F and Cosmesil M511 silicone elastomers were in a proportion 10:1 of the base and catalyst for VST50F, and the base with thinner for Cosmesil M511.NanoTiO 2 and intrinsic pigment were hand-mixed with the base for 1minute±1second by a clean stiff flat ended spatula followed for 2 minutes±1second mixing by a mechanical mixer in a mixer container without vacuum 10,11 , then mixing for 7minutes±1second by a mechanical mixer with vacuum to prevent air bubbles formation . (12) The vacuum pressure was 28 inches Hg as recommended by the manufacturer (13) . Before adding catalyst, the mixture was left for 2 minutes because the rotation of the mixer create heat and this lead to decrease the working time of the material according to pilot study and other studies (14) .…”

Mechanical Properties and Simulated Aging of Silicone Maxillofacial Elastomers: Advancements in the Past 45 Years

“…Another study followed and found the addition of intrinsic silicone pigments significantly influenced dynamic mechanical properties of the silicone elastomer tested over low frequencies from 0.5 to 2.5 Hz . Furthermore, incorporation of surface‐treated SiO 2 nanoparticles at 3% concentration enhanced overall mechanical properties of A‐2186 …”

Detection of gain enhancement in laser-induced fluorescence of rhodamine B lasing dye by silicon dioxide nanostructures-coated cavity

“…These closed paths provide the coherent feedback mechanism [28][29][30]. The scatterers within the laser media contribute in trapping light photons due to multiple scattering; in doing so, the light path inside these media will be long (long time interval), and this is one reason for a decrease in the threshold intensity [31,32].…”