Surface Coating of Gypsum‐Based Molds for Maxillofacial Prosthetic Silicone Elastomeric Material: The Surface Topography

Abstract

Silicone elastomers with lower surface roughness of maxillofacial prostheses can be obtained simply by coating a gypsum mold.

Surface Coating of Gypsum‐Based Molds for Maxillofacial Prosthetic Silicone Elastomeric Material: Evaluating Different Microbial Adhesion

“…The mean surface roughness (Ra) of the modified silicone elastomers molded in coated gypsum materials was 0.12 ± 0.08 μm, lower than unmodified silicone elastomers molded in non‐coated gypsum materials (0.67 ± 0.22 μm). This result was dependent on the surface at which the materials were placed, and one of these modifications was intended to decrease surface roughness . This in vitro study was performed to investigate whether surface topography modifications of silicone elastomers could decrease the adherence of C. albicans , S. mutans , and S. aureus to external maxillo‐facial prostheses or obturators made of silicone elastomers.…”

“…Silicone elastomer material was packed in the molds. This technique has been previously described in the first part of this series of investigations …”

“…Several materials, such as die sealants, cyanoacrylate, acrylic styrene, epoxy, and resins, have been used to coat gypsum molds with a resin film to increase abrasion resistance; these materials have also been commonly used to develop convenient applications at low costs . ‐ In general, these coatings reduce surface abrasion and surface fracture, particularly at critical margin areas of a mold; however, the surface roughness of silicone maxillofacial tissue should be improved, because the tissue surface of prostheses significantly affects microbial adhesion and proper tissue adaptation of prostheses …”

Surface roughness of pigmented and non-pigmented maxillofacial silicone elastomer before and after artificial aging

“…Half of the specimens (eight per group) were tested for surface roughness before aging by AFM (JPK BioAFM; Bruker Optics, Berlin, Germany), which provides images with near-atomic resolution for measuring surface topography and can also quantify surface roughness down to the angstrom-scale [22]. The other half of the samples were subjected to artificial aging in an aging chamber (QUV Accelerated Weathering Tester; Q-Lab, Cleveland, OH, USA) according to American Society for Testing and Materials (ASTM) G154 cycle 1 (approximate wavelength: 340 nm; energy irradiance: 0.89 W m −2 nm −1 ; the exposure cycle included 8 h of UV irradiation at 60 °C ± 3 °C black panel temperature and 4 h of condensation at 50 °C ± 3 °C black panel temperature) [33] for 750 h. Afterward, the aged samples were removed and examined for surface roughness using AFM.…”

“…Similarly, Goiato et al [21] reported a decline in surface roughness following 60 days of storage in a chemical disinfection solution. Another study demonstrated a decrease in roughness for maxillofacial silicone elastomers processed against coated gypsum materials, with AFM analysis indicating noticeable variations in surface roughness [22]. Alwan et al [23] observed a proportional increase in the surface smoothness of maxillofacial silicone with the increase in the duration of artificial aging.…”