Evaluation of Intrinsic Color Stability of Facial Silicone Elastomer Reinforced With Different Nanoparticles

Abstract

INTRODUCTION: Maxillofacial defects are located in a highly visible body area that is identified with one's identity. An aesthetic and comfortable maxillofacial prosthesis relieves many concerns of the patient and may improve quality of life. Silicone elastomers are more color stable than other materials used in maxillofacial prostheses thus many authors investigated the color stability of those materials under weathering conditions. OBJECTIVES: This study evaluates the effects of two types of nano-oxides particles at different concentration on the color stability of pigmented silicone MDX4-4210 maxillofacial prosthetic elastomers after artificial aging. MATERIALS AND METHODS: MDX4-4210 silicone elastomer specimens were fabricated. The control group was incorporated with intrinsic coloring agents, one of nanoparticles group was incorporated with intrinsic coloring agents and titanium oxide nanoparticles (TiO2) at different concentration (2%, 2.5 and 3%), other nanoparticles group was incorporated with intrinsic coloring agents and aluminum oxide nanoparticles (AL2O3) at different concentration (2%, 2.5% and 3%). All specimens were exposed to sunlight, sweat and ultraviolet light for one months. Easy shade spectrophotometer was used to determine the CIELAB (L*a*b*) parameter before and after aging of each specimen, and the values were noted. RESULTS: The majority of the color changes in all groups were above 3.3 ΔE* units, which indicates that they were visually observed color change. After one month aging period TiO2 group was more stable than Al2O3 regarding ultraviolet light. Regarding sweat TiO2 group showed more color alteration. Al2O3 group showed lower color alteration on exposure to sunlight. CONCLUSIONS: Artificial aging procedures affected the color stability of the maxillofacial silicone with or without nanoparticles incorporation.

Evaluation of the Mechanical and Physical Properties of Maxillofacial Silicone Type A-2186 Impregnated with a Hybrid Chitosan–TiO2 Nanocomposite Subjected to Different Accelerated Aging Conditions

“…This could also be influenced by the interaction between TiO 2 nanoparticles and the chemical components of sweat [38]. Notably, finer nanoparticles tend to have a more profound interaction with the silicone's polymeric chain [70]. These insights align with Radey et al's [34] research.…”

Hybrid Chitosan–TiO2 Nanocomposite Impregnated in Type A-2186 Maxillofacial Silicone Subjected to Different Accelerated Aging Conditions: An Evaluation of Color Stability

“…The first of these conditions was storage in a commercial antibacterial silicone-cleaning solution (B-200-12, Daro Inc., Lakeside, AZ, USA) for thirty hours. The second condition was storage in a simulated sebum solution for six months; the sebum was prepared by dissolving 10% palmitic acid with 2% glyceryl tripalmitate in 88% linoleic acid (all w/w ) [ 30 , 40 , 41 , 42 ]. The third condition was storage in simulated acidic perspiration (sweat) for six months; the sweat was prepared according to the specifications of the International Organization for Standardization (ISO 105-E04:96) [ 43 ] and comprised the following components (per liter of distilled water): 0.5 g of L-histidine monohydrochloride monohydrate, 5 g of sodium chloride, and 2.2 g of sodium dihydrogen orthophosphate dehydrate [ 30 , 40 , 41 , 42 ].…”

“…The second condition was storage in a simulated sebum solution for six months; the sebum was prepared by dissolving 10% palmitic acid with 2% glyceryl tripalmitate in 88% linoleic acid (all w/w ) [ 30 , 40 , 41 , 42 ]. The third condition was storage in simulated acidic perspiration (sweat) for six months; the sweat was prepared according to the specifications of the International Organization for Standardization (ISO 105-E04:96) [ 43 ] and comprised the following components (per liter of distilled water): 0.5 g of L-histidine monohydrochloride monohydrate, 5 g of sodium chloride, and 2.2 g of sodium dihydrogen orthophosphate dehydrate [ 30 , 40 , 41 , 42 ]. The fourth group of specimens was subjected to exposure to accelerated weathering with artificial ultraviolet (UV) radiation for 720 h. This was facilitated by an accelerated UV aging chamber equipped with two lightbulb fixtures positioned directly above the specimens.…”

“…The specimens that underwent natural outdoor weathering were meticulously suspended from stainless steel racks with ligature wire. The entire assembly was deliberately positioned on the roof of the College of Dentistry, University of Sulaimani, for six months [ 30 , 40 , 45 , 46 ] from February 2022 to August 2022. The monthly average high and low temperatures and climatic data were documented during the outdoor weathering, as shown in Table 1 .…”

The Effect of Nano Zinc Oxide Particles on Color Stability of MDX4-4210 Silicone Prostheses

“…31 The outcome supports the finding of Kiat-Amnuay et al, 29 who demonstrated that the intrinsic coloring and opacifiers in a MDX4-4210 silicone could protect color change over time, as did Han et al, 31 who found that filling nano oxides (nano-CeO 2 and 2 and 2.5% nano-TiO 2 ) into facial silicone did help to improve color stability of silicone A-2186. But Nada et al 32 found contrast results as they demonstrated that nanoparticle groups exposed to UV light increased in color change compared with the control, and the more the concentration of nanoparticles, the more the color changed. A possible explanation for this could be that the concentration of nanoparticles in their study was too high (≥2%) which increased the agglomeration resulting in the weak distribution in the elastomer matrix.…”