Dynamic Mechanical Properties of a Maxillofacial Silicone Elastomer Incorporating a ZnO Additive

Abstract

The main objective of the current study was to investigate the dynamic mechanical properties of a room-temperature vulcanizing silicone incorporating different fractions of zinc oxide (ZnO) after indoor and outdoor photoaging. Forty-eight samples were produced by adding different amounts of ZnO into a commercial maxillofacial silicone (EPISIL-E). The samples were divided into 4 groups containing 0.0, 0.2, 0.5, and 1 wt% ZnO additive, respectively. Samples were exposed to sunlight (subgroup 2), ultraviolet (subgroup 3), and fluorescence (subgroup 4) aging, whereas nonaged samples comprised the control subgroup (subgroup 1). Dynamic mechanical analysis was used to determine the storage modulus (E'), loss modulus (E″), and damping capacity (tanδ). General linear statistic model was conducted to evaluate the effects of aging, testing frequency, and composition on the dynamic mechanical properties of the silicone with the ZnO additive. Post hoc analysis was performed using Tukey test. Statistical analysis revealed a significant impact of composition on tanδ (P < 0.05). Aging influenced E' and E″ (P < 0.01). The combination of aging and composition had a significant effect on all dynamic properties (P < 0.01).

Dynamic Mechanical Thermal Analysis of Maxillofacial Prosthetic Elastomers

“…44 One important factor affecting the thermomechanical properties of maxillofacial silicones is the percentage of cross-linking and crystallinity as it has been proven by DMA. 38,45 The decrement of Tg values could be associated with decreased density of cross-links after disinfection procedures or chain scissions due to continuous polymerization of elastomer or absorption phenomena. Goiato et al 11,24 have reported possible increment in cross-linking density after disinfecting silicone maxillofacial elastomers using neutral soap and effervescent denture cleanser tablets.…”

“…Moreover, the combination of solar aging and elastomer composition could cause significant alterations on all dynamic properties. 38 Thus, the DMA proved to be a rapid, reliable, and convenient method for the determination of viscoelastic properties of maxillofacial materials. 29 Relationships between physical structure and mechanical properties allow the understanding of dynamic mechanical behavior of elastomers.…”

Comprehensive review on additives of topical dosage forms for drug delivery

“…(5) Zinc oxide (Mouzakis et al, 2010): It is also known as flowers of zinc and zinc white. It is an inorganic compound, and occurs naturally as the mineral zincite but mostly zinc oxide is produced synthetically.…”

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

“…A work published in 2010 showed that the combination of indoor and outdoor photo‐aging and different fractions of zinc oxide had significant effect on all silicone dynamic properties. MDX 4‐4210 silicone containing opacifiers showed greater hardness after 1008 hours of accelerated aging independent of disinfectant type …”