Influence of opacifiers on dimensional stability and detail reproduction of maxillofacial silicone elastomer

Abstract

BackgroundWe evaluated the influence of chemical disinfection and accelerated aging on the dimensional stability and detail reproduction of a silicone elastomer containing one of two opacifiers.MethodsA total of 90 samples were fabricated from Silastic MDX 4-4210 silicone and divided into groups (n = 10) according to opacifier content (barium sulfate or titanium dioxide) and disinfectant solution (neutral soap, Efferdent, or 4% chlorhexidine). The specimens were disinfected 3 times per week during 60 days and then subjected to accelerated aging for 1008 hours. Dimensional stability and detail reproduction tests were performed after specimens' fabrication (baseline), chemical disinfection and periodically during accelerated aging (252, 504, and 1008 hours). The results were analyzed using 3-way repeated-measures ANOVA and the Tukey HSD test (α = 0.05).ResultsAll groups exhibited dimensional changes over time. The opacifier (p = .314), period (p < .0001) and their interactions (p = .0041) affected the dimensional stability of the silicone. Statistical significant dimensional differences occurred between groups with (0.071) and without opacifiers (0.053). Accelerated aging influenced the dimensional stability of the samples. All groups scored 2 in the detail reproduction tests, which represents the fully reproducing of three test grooves with accurate angles.ConclusionsIncorporation of opacifiers alters the dimensional stability of silicones used in facial prosthetics, but seems to have no influence on detail reproduction. Accelerated aging is responsible for most of the dimensional changes in Silastic MDX4 4210, but all dimensional changes measured in this study remained within the limits of stability necessary for this application.

Influence of Pigment and Opacifier on Dimensional Stability and Detail Reproduction of Maxillofacial Silicone Elastomer

“…1,12,28,29 A total of 120 samples were divided into 12 groups (n = 10) according to opacifier and/or pigment content (none [ Table 1).…”

“…After manipulation, the mixture was placed in the mold and cured at room temperature during 3 days according to the manufacturer's instructions. 1,10,21,28,29 The sample was carefully removed from the mold to avoid distortions. 1,29,30 Dimensional stability and detail reproduction tests were carried out initially, after 60 days of disinfection, and after different times of accelerated aging (252, 504, and 1008 hours).…”

“…Both sample's and matrix's images were imported into the software using the ''Raster image'' tool. 1,29 This tool allows working with bitmap images within vector-based files constructed using straight lines. The vertical lines of the block were used as a 25-mm dimensional reference (C-D) within the software.…”

Influence of nanoparticles on color stability, microhardness, and flexural strength of acrylic resins specific for ocular prosthesis

“…Several studies have found satisfactory results by incorporating nanoparticles (NPs) into polymeric materials (mainly silicone elastomers used for facial prostheses), in terms of protecting such materials from degradation. [10][11][12][13][14][15][16] Research has…”

“…In the cosmetic industry, BaSO 4 is used in sunscreen lotions to create a physical barrier against ultraviolet rays and to provide a better product appearance. 15,16 In addition to improving polymer properties, it has been suggested that incorporating NPs into an organic polymer could provide resistance to environmental stress-related cracking and aging. 23 However, to date, no study has been performed to examine the influence of NPs on the physical and mechanical properties of acrylic resins specific for artificial sclera.…”