Factors affecting color stability of maxillofacial prosthetic silicone elastomer: A systematic review and meta-analysis

Abstract

Purpose: This systematic review and meta-analysis explored the factors involved in the color stability and degradation of Maxillo-Facial Prosthetic Silicone Elastomer (MFPSE). Further exploration was done to analyze past literature discussing the potential benefits to color stability when nano-particles were combined with pigmented MFPSE. Method: The search for the articles was done according to PRISMA guidelines. Articles were searched from “Scopus” and “Web of Sciences” from the year 1970 to 2019. Searches were carried out by two reviewers until November 2019. Articles for systematic review were selected based on predefined eligibility criteria. Information regarding weathering conditions, pigments and filler-particle inclusion were extracted as appropriate. Further screening was done for meta-analyze case-control studies of red, blue and yellow pigments according to predefined scoring criteria. Meta-analysis was conducted on case-control studies that incorporated 5%,10% and 15% TiO2 in MFPSE with the said pigments and was carried out using Cochrane Review Manager 5.3. Results: 30 studies were selected for systematic review and 6 studies were eligible for meta-analysis. The most prominent influencers of color stability were nano-fillers and the type of color used in the mixing. Furthermore, experimental conditions, weathering, color of investment plaster and the method of color detection all affected the degree of degradation. There was an overall significant difference found when TiO2 was incorporated with the pigmented silicone. There is significant difference when 10% ( P = 0.0004) TiO2 is incorporated with the red pigment, 5% ( P = 0.03) TiO2 with the yellow and 10% ( P < 0.0001) and 15% ( P = 0.02) TiO2 with the blue pigment. Conclusion: Type of pigment and nano-filler incorporated into the silicone play a role in influencing color stability. Incorporation of 10% TiO2 with red pigment,5% with yellow pigment and 10% or 15% TiO2 with blue pigment provided some protection to the silicone elastomer from color degradation.

Optimization of Prosthodontic Computer‐Aided Designed Models: A Virtual Evaluation of Mesh Quality Reduction Using Open Source Software

“…This also creates issues for extraoral prostheses which are later converted to silicone. Sharp angles may result in uneven force distribution and uneven exposure to weather, leading to premature mechanical and color degradation 31,32 . Similar to past findings, this issue was virtually more noticeable for larger prostheses like auricle and denture 33 …”

Color variations during digital imaging of facial prostheses subjected to unfiltered ambient light and image calibration techniques within dental clinics: An in vitro analysis

“…Results from the current in vitro study were primarily different because living skin tissue showed higher variations based on its patho-physiologic distribution and weather exposure otherwise absent in prosthetic silicone material [ 5 ]. As there are limited studies on color space, digitization and property analyses in maxillofacial prosthetic silicone, this may further limit the conclusiveness and detailed explanations for the current findings [ 33 , 55 – 57 ].…”

“…A digital weight machine (Analytical Digital Balance BSA423S; Sartorius, Goettingen, Germany) was used to measure the pigments (2% by weight) [ 29 ] and A-103 silicone elastomer with a ratio of 10:1 (according to the manufacturer instruction). The silicone and pigments were first hand mixed [ 33 ] and then processed through a vacuum mixer (MIXYVAC T; Manfredi, San Secondo di Pinerolo, Italy) to allow for even dispersion of pigments within the silicone matrix [ 34 , 35 ]. Afterwards, the pigmented silicone was packed and polymerized following conventional standard protocol [ 29 ] and marked from where the measurements were taken.…”

Computer-aided design and 3-dimensional artificial/convolutional neural network for digital partial dental crown synthesis and validation

“…The gingival margins were extended gingivally 30 . The prepared teeth were coated in titanium dioxide spray to reduce surface reflection of ambient light for scanning 31 , 32 .…”