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Gradinariu AI, Racles C, Stoica I, Stelea CG, Simionescu AMA, Jehac AE, Costan VV. Silicones for Maxillofacial Prostheses and Their Modifications in Service. MATERIALS (BASEL, SWITZERLAND) 2024; 17:3297. [PMID: 38998378 PMCID: PMC11243296 DOI: 10.3390/ma17133297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Revised: 06/28/2024] [Accepted: 07/02/2024] [Indexed: 07/14/2024]
Abstract
The biomedical applications of silicones are countless due to their outstanding properties. In dentistry, silicone for maxillofacial and plastic surgery has become indispensable, from both physiological and aesthetic points of view. In this mini-review, silicone materials for dentistry and facial prostheses are discussed, focusing on their properties and alterations when exposed for long periods to different environments. A significant number of studies reported in the literature have been conducted in vitro, mimicking some of the main degradative factors which have been identified as triggers for discoloration and deterioration of the mechanical properties. Among these, in artificial aging and accelerated natural aging studies, UV radiation is considered the most important. Other weathering factors, biological contamination, and disinfection agents may have dramatic effects as well. Several general properties of silicones are described at the beginning, with a focus on biocompatibility, cross-linking mechanisms, and applications in dentistry and maxillofacial prosthetics. We discuss the ongoing cross-linking and/or possible exudation after manufacturing, which also affects the stability of the prosthesis over time, and possibly the patient. Next, the main environmental factors that affect the prostheses in service are presented, including the role of cigarettes smoke, which has been discussed very little so far. A few aspects, such as biofilm formation, its negative effects, and proposed solutions to overcome this phenomenon regarding silicones, are also described. We conclude by proposing a set of topics for future research and development based on the gaps that have been identified in the literature. Although silicones are probably irreplaceable in maxillofacial prosthetics, improvements in terms of base materials, additives, surface treatments, and maintenance are possible and necessary for long-lasting and safer prostheses.
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Affiliation(s)
- Anca Irina Gradinariu
- Department of Oral and Maxillofacial Surgery, "Grigore T. Popa" University of Medicine and Pharmacy, 16 University Street, 700511 Iasi, Romania
| | - Carmen Racles
- Department of Inorganic Polymers, "Petru Poni" Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi, Romania
| | - Iuliana Stoica
- Physical Chemistry of Polymers Department, "Petru Poni" Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi, Romania
| | - Carmen Gabriela Stelea
- Department of Oral and Maxillofacial Surgery, "Grigore T. Popa" University of Medicine and Pharmacy, 16 University Street, 700511 Iasi, Romania
| | - Ana-Maria Andreea Simionescu
- Department of Oral and Maxillofacial Surgery, "Grigore T. Popa" University of Medicine and Pharmacy, 16 University Street, 700511 Iasi, Romania
| | - Alina Elena Jehac
- Department of Oral and Maxillofacial Surgery, "Grigore T. Popa" University of Medicine and Pharmacy, 16 University Street, 700511 Iasi, Romania
| | - Victor Vlad Costan
- Department of Oral and Maxillofacial Surgery, "Grigore T. Popa" University of Medicine and Pharmacy, 16 University Street, 700511 Iasi, Romania
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Titanium Dioxide/Polysiloxane Composites: Preparation, Characterization and Study of Their Color Stability Using Thermochromic Pigments. JOURNAL OF COMPOSITES SCIENCE 2022. [DOI: 10.3390/jcs6070195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In order to improve thermomechanical, antibacterial and temperature-controlled color-response performance of polydimethylsiloxane (PDMS) in maxillofacial prostheses, the incorporation of titania (TiO2) nanoparticles and thermochromic pigments (TCP) into PDMS was examined. The thermal transitions of TiO2/PDMS nanocomposites, investigated by differential scanning calorimetry (DSC), remain almost unaffected, while an increase of the crystallinity of PDMS was recorded in specimens with higher titania concentrations. The incorporation of titania improves the thermal stability, as it was revealed by thermogravimetric analysis (TGA), as well as the tensile properties of the reinforced elastomer. Nanocomposites with 10 wt% titania presented antibacterial activity against Escherichia Coli, leading to 72% reduction of the bacterial colony after 3 h of exposure. Specimens colored with red TCP (0.2 and 0.6 wt%) showed significant color change at a lower temperature (−20 °C) in comparison with that at an ambient temperature, especially at lower TCP concentration (0.2 wt%). Accelerating aging experiments, consisting of repeated cycles of combined exposure to UV-radiation and damp heating, of PDMS colored with TCP showed poor color stability of the specimens, from the first hours of exposure. The addition of titania to polysiloxane specimens works as an opacifier providing a positive effect on the color stability of the examined thermochromic pigment.
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Gao Q, Li J, He Y, Zhao J, Li J, Shao D, Wang M, Hu J. High-performance antioxidant behavior of zeolitic imidazolate framework-67 at low filler content in silicone rubber. Polym Degrad Stab 2021. [DOI: 10.1016/j.polymdegradstab.2021.109622] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Zarrati S, Safi M, Mohammad Rezaei SM, Shadan L. Effect of nano-oxides on the color stability of maxillofacial silicone elastomers. J Prosthet Dent 2020; 127:362-367. [PMID: 33279161 DOI: 10.1016/j.prosdent.2020.07.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 07/31/2020] [Accepted: 07/31/2020] [Indexed: 10/22/2022]
Abstract
STATEMENT OF PROBLEM A significant challenge of craniofacial prostheses is their limited service life because of degradation and color instability. In spite of improvements in the materials and techniques used for the fabrication of silicone maxillofacial prostheses, undesirable color change over time remains a challenge. Zn and Ti nano-oxides (nano-TiO2) have been reported to impart an ultraviolet- (UV) shielding property to silicone elastomers. However, studies examining the effects of nanopigments on the color stability of craniofacial prostheses are sparse. PURPOSE The purpose of this in vitro study was to evaluate the color stability of a room-temperature vulcanizing (RTV) silicone elastomer with the addition of iron oxide and titanium dioxide nanopigments under accelerated artificial aging. MATERIAL AND METHODS Sixty disks (Ø15×2 mm) were fabricated from RTV silicone 4408 Q. The specimens were divided into 5 groups containing iron oxide nanopigment, iron oxide nanopigment and rutile nano-TiO2 (as an opacifier), burnt sienna pigment, burnt sienna and nano-TiO2, and silicone without pigment or opacifier. The specimens were subjected to accelerated aging in a Xenotest chamber for 1000 hours. CIELab color coordinates and the total color difference (ΔE∗) values were determined before and after aging. ΔE∗ values were compared between the groups by using 1-way ANOVA and Tamhane multiple comparisons (α=.05), and a standard deviation of 1.09 was considered. RESULTS ANOVA showed that the values of ΔE∗ differed among all groups (P<.05). The minimum amount of a color change perceived (ΔE∗ approximately =1.1) by the visual system as the threshold was observed in the specimens treated with burnt sienna and nano TiO2. The greatest color change occurred in the specimens treated with iron oxide nanopigment. As per the acceptable clinical threshold, the color change was satisfactory in all groups. CONCLUSIONS Nano-TiO2 with burnt sienna groups had a lower color change than the other groups. The color change in all groups was within a clinically acceptable range.
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Affiliation(s)
- Simindokht Zarrati
- Assistant Professor, Department of Prosthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
| | - Mahdi Safi
- Assistant Professor, Department of Color Physics, Institute for Color, Science and Technology, Tehran, Iran
| | - Susan Mir Mohammad Rezaei
- Associate Professor, Department of Prosthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Leila Shadan
- Assistant Professor, Department of Prosthodontics, Golestan University of Medical Sciences, Gorgan, Iran
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Anjos DSC, Revoredo ECV, Galembeck A. Microwave‐assisted processing of silicone/
PMMA
blends for maxillofacial prostheses. POLYM ENG SCI 2020. [DOI: 10.1002/pen.25494] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Débora S. C. Anjos
- Departamento de Química Fundamental/CCEN Universidade Federal de Pernambuco Recife Pernambuco Brazil
- Coordenação de Licenciatura em Química Instituto Federal do Sertão Pernambucano, Campus Petrolina Petrolina Pernambuco Brazil
| | - Eliane C. V. Revoredo
- Departamento de Prótese e Cirurgia Buco‐Facial/CCS Universidade Federal de Pernambuco, Programa de Pós‐Graduação em Odontologia Recife Pernambuco Brazil
| | - André Galembeck
- Departamento de Química Fundamental/CCEN Universidade Federal de Pernambuco Recife Pernambuco Brazil
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Cruz RLJ, Ross MT, Powell SK, Woodruff MA. Advancements in Soft-Tissue Prosthetics Part B: The Chemistry of Imitating Life. Front Bioeng Biotechnol 2020; 8:147. [PMID: 32391336 PMCID: PMC7191111 DOI: 10.3389/fbioe.2020.00147] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 02/12/2020] [Indexed: 11/13/2022] Open
Abstract
Each year, congenital defects, trauma or cancer often results in considerable physical disfigurement for many people worldwide. This adversely impacts their psychological, social and economic outlook, leading to poor life experiences and negative health outcomes. In many cases of soft tissue disfigurement, highly personalized prostheses are available to restore both aesthetics and function. As discussed in part A of this review, key to the success of any soft tissue prosthetic is the fundamental properties of the materials. This determines the maximum attainable level of aesthetics, attachment mechanisms, fabrication complexity, cost, and robustness. Since the early-mid 20th century, polymers have completely replaced natural materials in prosthetics, with advances in both material properties and fabrication techniques leading to significantly improved capabilities. In part A, we discussed the history of polymers in prosthetics, their ideal properties, and the application of polymers in prostheses for the ear, nose, eye, breast and finger. We also reviewed the latest developments in advanced manufacturing and 3D printing, including different fabrication technologies and new and upcoming materials. In this review, Part B, we detail the chemistry of the most commonly used synthetic polymers in soft tissue prosthetics; silicone, acrylic resin, vinyl polymer, and polyurethane elastomer. For each polymer, we briefly discuss their history before detailing their chemistry and fabrication processes. We also discuss degradation of the polymer in the context of their application in prosthetics, including time and weathering, the impact of skin secretions, microbial growth and cleaning and disinfecting. Although advanced manufacturing promises new fabrication capabilities using exotic synthetic polymers with programmable material properties, silicones and acrylics remain the most commonly used materials in prosthetics today. As research in this field progresses, development of new variations and fabrication techniques based on these synthetic polymers will lead to even better and more robust soft tissue prosthetics, with improved life-like aesthetics and lower cost manufacturing.
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Affiliation(s)
- Rena L J Cruz
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
| | - Maureen T Ross
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
| | - Sean K Powell
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
| | - Maria A Woodruff
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
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GÜNGÖR MBANKOĞLU, NEMLİ SKARAKOCA, İNAL CB, BAĞKUR M, DİLSİZ N. Effect of plasma treatment on the peel bond strength between maxillofacial silicones and resins. Dent Mater J 2020; 39:242-250. [DOI: 10.4012/dmj.2018-259] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
| | | | - Ceyda Başak İNAL
- Department of Prosthodontics, Faculty of Dentistry, Gazi University
| | - Meral BAĞKUR
- Department of Prosthodontics, Faculty of Dentistry, Gazi University
| | - Nursel DİLSİZ
- Department of Chemical Engineering, Faculty of Engineering and Architecture, Gazi University
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Kashi S, De Souza M, Al-Assafi S, Varley R. Understanding the Effects of In-Service Temperature and Functional Fluid on the Ageing of Silicone Rubber. Polymers (Basel) 2019; 11:polym11030388. [PMID: 30960372 PMCID: PMC6473404 DOI: 10.3390/polym11030388] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 02/05/2019] [Accepted: 02/16/2019] [Indexed: 11/16/2022] Open
Abstract
With an organic/inorganic hybrid nature, silicone elastomers are amongst the most versatile engineering materials, exploited in a wide range of applications either as end-products or in manufacturing processes. In many industrial machines, silicone components are exposed to in-service conditions, such as high or low temperatures, contact with functional fluids, mechanical loading, and deformations, which can adversely affect these components and reduce their lifespan, leading to machine failure in turn. The present study investigates the behaviour of a silicone component of a manufacturing equipment and the variations in the part’s properties due to in-service conditions (temperature, exposure to heat transfer fluid, and mechanical deformation) to develop a monitoring tool. An experimental design was employed to study the main and the interaction effects of temperature (22 °C, 180 °C), medium (air, synthetic heat transfer fluid), and strain (0%, 200%) on the silicone component’s properties. Results showed that while the chemistry of the component remains intact, its thermal and in particular mechanical properties are largely influenced by the in-service conditions. Consequently, leading to a physical rather than a chemical failure of the component and limiting its service life. Statistical analysis revealed that high temperature and the exposure to the heat transfer fluid have the most sever effects. Moreover, these two manufacturing parameters were found to have a significant interaction with one another, whose effect cannot not be neglected.
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Affiliation(s)
- Sima Kashi
- Institute for Frontier Materials, Deakin University, Waurn Ponds, VIC 3216, Australia.
| | - Mandy De Souza
- Institute for Frontier Materials, Deakin University, Waurn Ponds, VIC 3216, Australia.
| | - Salwan Al-Assafi
- Quickstep Technologies Pty Ltd, Waurn Ponds, VIC 3216, Australia.
| | - Russell Varley
- Institute for Frontier Materials, Deakin University, Waurn Ponds, VIC 3216, Australia.
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Zhang H, Yang H, Shentu B. Effect of surface modification of titanium dioxide on the UV-C aging behavior of silicone rubber. J Appl Polym Sci 2018. [DOI: 10.1002/app.47170] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Hui Zhang
- State Key Lab of Chemical Engineering; College of Chemical and biological Engineering, Zhejiang University; 38 Zheda Road, Hangzhou 310027 China
| | - Hao Yang
- State Key Lab of Chemical Engineering; College of Chemical and biological Engineering, Zhejiang University; 38 Zheda Road, Hangzhou 310027 China
| | - Baoqing Shentu
- State Key Lab of Chemical Engineering; College of Chemical and biological Engineering, Zhejiang University; 38 Zheda Road, Hangzhou 310027 China
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Cevik P, Yildirim-Bicer AZ. Effect of different types of disinfection solution and aging on the hardness and colour stability of maxillofacial silicone elastomers. Int J Artif Organs 2017; 41:0. [PMID: 29148020 DOI: 10.5301/ijao.5000659] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2017] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Understanding the effect of aging and different disinfecting agents on the physical properties of pigmented maxillofacial silicones may help eliminate the current uncertainty as to the best follow-up suggestions for the patients treated with silicone prostheses. METHODS One hundred fifty specimens (14 × 2 mm) were evaluated for colour and 75 specimens (30 × 10 mm) for hardness (total, 225 specimens). Five specimens were used for hardness testing in each disinfecting solution while 10 silicone specimens were used for colour evaluation. The samples were separated into 5 groups and the initial hardness and colour evaluations were performed and placed in disinfectant solution (neutral soap, effervescent tablet, 0.2% chlorhexidine, 4% chlorhexidine, sodium hypochlorite). A second set of colour and hardness measurements was taken after 48 hours of disinfection and 1,008 hours of artificial aging in a QUV-accelerated weathering tester. Two-way and 1-way analysis of variance with Tukey tests and paired t-test were used for statistical analysis (α = 0.05). RESULTS Before artificial aging, the hardness value of the red pigment group was found to be significantly lower than that of the brown pigment group. After aging, the lowest Shore A value was seen in the neutral soap group, while the highest was seen in the effervescent tablet. CONCLUSIONS Based on the results of this study, chlorohexidine 0.2% was found to be most suitable agent for disinfection of the prostheses. Washing with neutral soap caused loss of pigment from the surface of the silicones. Sodium hypochlorite was found to have a colour-fading effect on silicone specimens.
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Affiliation(s)
- Pinar Cevik
- Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara - Turkey
| | - Arzu Z Yildirim-Bicer
- Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara - Turkey
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Dziki JL, Huleihel L, Scarritt ME, Badylak SF. Extracellular Matrix Bioscaffolds as Immunomodulatory Biomaterials<sup/>. Tissue Eng Part A 2017; 23:1152-1159. [PMID: 28457179 PMCID: PMC6112165 DOI: 10.1089/ten.tea.2016.0538] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 04/18/2017] [Indexed: 01/03/2023] Open
Abstract
Suppression of the recipient immune response is a common component of tissue and organ transplantation strategies and has also been used as a method of mitigating the inflammatory and scar tissue response to many biomaterials. It is now recognized, however, that long-term functional tissue replacement not only benefits from an intact host immune response but also depends upon such a response. The present article reviews the limitations associated with the traditionally held view of avoiding the immune response, the ability of acellular biologic scaffold materials to modulate the host immune response and promote a functional tissue replacement outcome, and current strategies within the fields of tissue engineering and biomaterials to develop immune-responsive and immunoregulatory biomaterials.
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Affiliation(s)
- Jenna L. Dziki
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Luai Huleihel
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Michelle E. Scarritt
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Stephen F. Badylak
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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Color and structural changes of a maxillofacial elastomer: the effects of accelerated photoaging, disinfection and type of pigments. J Appl Biomater Funct Mater 2015; 13:e87-91. [PMID: 26108429 DOI: 10.5301/jabfm.5000229] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2014] [Indexed: 11/20/2022] Open
Abstract
PURPOSE The aim of this study was to investigate the color and structural changes of a maxillofacial silicone colored with 2 different pigments, after photoaging and immersion in disinfectants. METHODS Ninety-six cylindrical specimens were fabricated and divided into 3 equal groups. The specimens of the first group consisted of unpigmented silicone (Multisil Epithetik), those of the second group consisted of unpigmented silicone, colored with red functional liquid pigment (Cosmesil Reactive 0.2% wt). The specimens of the third group were fabricated using unpigmented silicone colored with red powder pigment Cosmesil Dry at 0.2% wt. Specimens of each group were divided into 4 equal subgroups (immersed in soap solution, ethanol 95° or distilled water or placed in a photoaging apparatus for 174 hours). Structural changes were examined by infrared spectroscopy (ATR-FTIR) before and after aging. Color changes (ΔΕ*) were measured using the CIE L*a*b* system. Two-way ANOVA and Tukey's test for post hoc comparison were used at a = 0.05. RESULTS Infrared spectroscopy showed no structural changes after immersion in solutions and photoaging, for all the materials tested. No statistically significant differences for ΔΕ* among the tested groups were found. CONCLUSIONS It can be concluded that no structural changes of pigmented and unpigmented silicone elastomers were observed among all aging procedures. Recorded color changes for the materials tested were within the limits of clinical acceptability after all aging procedures. Immersion in distilled water presented the best color stability, whereas photoaging, the poorest, for all materials.
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Effect of surface treated silicon dioxide nanoparticles on some mechanical properties of maxillofacial silicone elastomer. Int J Biomater 2014; 2014:750398. [PMID: 25574170 PMCID: PMC4276352 DOI: 10.1155/2014/750398] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Revised: 11/10/2014] [Accepted: 11/21/2014] [Indexed: 11/17/2022] Open
Abstract
Current materials used for maxillofacial prostheses are far from ideal and there is a need for novel improved materials which mimic as close as possible the natural behavior of facial soft tissues. This study aimed to evaluate the effect of adding different concentrations of surface treated silicon dioxide nanoparticles (SiO2) on clinically important mechanical properties of a maxillofacial silicone elastomer. 147 specimens of the silicone elastomer were prepared and divided into seven groups (n = 21). One control group was prepared without nanoparticles and six study groups with different concentrations of nanoparticles, from 0.5% to 3% by weight. Specimens were tested for tear strength (ASTM D624), tensile strength (ASTM D412), percent elongation, and shore A hardness. SEM was used to assess the dispersion of nano-SiO2 within the elastomer matrix. Data were analyzed by one-way ANOVA and Scheffe test (α = 0.05). Results revealed significant improvement in all mechanical properties tested, as the concentration of the nanoparticles increased. This was supported by the results of the SEM. Hence, it can be concluded that the incorporation of surface treated SiO2 nanoparticles at concentration of 3% enhanced the overall mechanical properties of A-2186 silicone elastomer.
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Polyzois G, Pantopoulos A, Papadopoulos T, Hatamleh M. Effect of light aging on silicone-resin bond strength in maxillofacial prostheses. J Prosthodont 2014; 24:215-9. [PMID: 25081922 DOI: 10.1111/jopr.12202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2014] [Indexed: 11/30/2022] Open
Abstract
PURPOSE The aim of this study was to investigate the effect of accelerated light aging on bond strength of a silicone elastomer to three types of denture resin. MATERIALS AND METHODS A total of 60 single lap joint specimens were fabricated with auto-, heat-, and photopolymerized (n = 20) resins. An addition-type silicone elastomer (Episil-E) was bonded to resins treated with the same primer (A330-G). Thirty specimens served as controls and were tested after 24 hours, and the remaining were aged under accelerated exposure to daylight for 546 hours (irradiance 765 W/m(2) ). Lap shear joint tests were performed to evaluate bond strength at 50 mm/min crosshead speed. Two-way ANOVA and Tukey's test were carried out to detect statistical significance (p < 0.05). RESULTS ANOVA showed that the main effect of light aging was the most important factor determining the shear bond strength. The mean bond strength values ranged from 0.096 to 0.136 MPa. The highest values were recorded for auto- (0.131 MPa) and photopolymerized (0.136 MPa) resins after aging. CONCLUSIONS Accelerated light aging for 546 hours affects the bond strength of an addition-type silicone elastomer to three different denture resins. The bond strength significantly increased after aging for photo- and autopolymerized resins. All the bonds failed adhesively.
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Affiliation(s)
- Gregory Polyzois
- Associate Professor and Chief of Maxillofacial Prosthetics Unit, Department of Prosthodontics, Dental School, University of Athens, Athens, Greece
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The effect of different storage conditions on the physical properties of pigmented medical grade I silicone maxillofacial material. ISRN DENTISTRY 2013; 2013:582051. [PMID: 23606978 PMCID: PMC3625596 DOI: 10.1155/2013/582051] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 02/19/2013] [Indexed: 11/29/2022]
Abstract
Objective. This study aimed to evaluate the effect of different storage solutions that simulate acidic, alkaline, and sebum conditiions on the physical properties of pigmented (colorant elastomer) cosmesil M511 maxillofacial prosthetic material. Materials and Methods. Sixty specimens were prepared according to the manufacturer's instructions and were tested before and after immersion of different storage conditions for six months at 37 °C. The following tests were performed: color changes (group I), solution absorption (group II), surface roughness (group III), and scanning electron microscopy (group IV). Results. There were no significant changes observed in the color and solution absorption tests while surface roughness revealed significant difference between control group and other testing storage medium groups, and this result was supported by SEM analysis that revealed limited surface changes. Conclusions. Cosmaseil material is an acceptable cross-linked formulation that withstands storage in different solutions with variable pH. The addition of pigment cannot vary the physical properties of these materials. Surface roughness test as well as SEM microscopic study showed moderate changes indicating a limited effect on the surface of the material.
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Filié Haddad M, Coelho Goiato M, Micheline Dos Santos D, Moreno A, Filipe D'almeida N, Alves Pesqueira A. Color stability of maxillofacial silicone with nanoparticle pigment and opacifier submitted to disinfection and artificial aging. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:095004. [PMID: 21950913 DOI: 10.1117/1.3625401] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The purpose of this study was to evaluate the color stability of a maxillofacial elastomer with the addition of a nanoparticle pigment and∕or an opacifier submitted to chemical disinfection and artificial aging. Specimens were divided into four groups (n = 30): group I: silicone without pigment or opacifier, group II: ceramic powder pigment, group III: Barium sulfate (BaSO(4)) opacifier, and group IV: ceramic powder and BaSO(4) opacifier. Specimens of each group (n = 10) were disinfected with effervescent tablets, neutral soap, or 4% chlorhexidine gluconate. Disinfection was done three times a week during two months. Afterward, specimens were submitted to different periods of artificial aging. Color evaluation was initially done, after 60 days (disinfection period) and after 252, 504, and 1008 h of artificial aging with aid of a reflection spectrophotometer. Data were analyzed by three-way ANOVA and Tukey test (α = 0.05). The isolated factor disinfection did not statistically influence the values of color stability among groups. The association between pigment and BaSO(4) opacifier (GIV) was more stable in relationship to color change (△E). All values of △E obtained, independent of the disinfectant and the period of artificial aging, were considered acceptable in agreement with the norms presented in literature.
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Affiliation(s)
- Marcela Filié Haddad
- UNESP, Araçatuba Dental School, Department of Dental Materials and Prosthodontics, Rua José Bonifácio, 1193. CEP 16015-050. Araçatuba, SP, Brazil
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Park PIP, Makoid M, Jonnalagadda S. The design of flexible ciprofloxacin-loaded PLGA implants using a reversed phase separation/coacervation method. Eur J Pharm Biopharm 2011; 77:233-9. [DOI: 10.1016/j.ejpb.2010.11.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2010] [Revised: 10/18/2010] [Accepted: 11/22/2010] [Indexed: 02/04/2023]
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