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Annamma LM, Hattori M, Ali IE, Dsouza J, Waqar A, Chugh A, Sumita YI. Frequently used extraoral maxillofacial prosthetic materials and their longevity - A comprehensive review. JAPANESE DENTAL SCIENCE REVIEW 2024; 60:137-147. [PMID: 38595985 PMCID: PMC11001625 DOI: 10.1016/j.jdsr.2024.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 02/27/2024] [Accepted: 03/19/2024] [Indexed: 04/11/2024] Open
Abstract
The longevity of an extraoral prosthesis depends on its physical and mechanical properties and user maintenance. Faced with multiple outcome measures, researchers find it difficult to determine the most appropriate extraoral prosthetic material. This comprehensive review evaluates the most used extraoral prosthesis materials and qualitatively assesses their longevity and function. The study aims to identify and interpret the results of current updates on the factors that affect longevity and functionality. This comprehensive review summarizes and evaluates differences in the properties of commonly used extraoral maxillofacial prosthetic materials. The review was planned to focus on all factors related to the longevity and function of the extraoral maxillofacial prosthetics. An electronic search covered English articles in PubMed, Scopus, Google Scholar, Web of Science, and grey literature. Manual searching was also performed. Six authors participated in the screening. Search engines extracted 1107 records, and 88 studies were included for qualitative and bias assessments. Silicones are the most frequently used extraoral maxillofacial prosthetic materials. Heat-cured silicones are more color-stable than those cured at room temperature. Additional ingredients and processing techniques affect prosthesis longevity.
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Affiliation(s)
- Lovely M. Annamma
- Department of Clinical Sciences, College of Dentistry, Ajman University, Ajman, United Arab Emirates
| | - Mariko Hattori
- Advanced Prosthodontics, Tokyo Medical and Dental University, Tokyo, Japan
| | - Islam E. Ali
- Advanced Prosthodontics, Tokyo Medical and Dental University, Tokyo, Japan
- Department of Prosthodontics, Faculty of Dentistry, Mansoura University, Mansoura, Egypt
| | - Jovita Dsouza
- Department of Periodontics, Gulf Medical University, Ajman, United Arab Emirates
| | - Anam Waqar
- AI Hayat Medical Center, UmAl Quain, UAE
| | - Anshul Chugh
- Advanced Prosthodontics, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yuka I. Sumita
- Division of General Dentistry 4, Nippon Dental University Hospital, Tokyo, Japan
- Tokyo Medical and Dental University, Tokyo, Japan
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Chugh A, Hattori M, Towithelertkul C, Sumita YI, Wakabayashi N. Evaluation of the color stability of three maxillofacial silicone materials after exposure to beverages: An in vitro study. Heliyon 2024; 10:e25529. [PMID: 38370236 PMCID: PMC10867345 DOI: 10.1016/j.heliyon.2024.e25529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 01/26/2024] [Accepted: 01/29/2024] [Indexed: 02/20/2024] Open
Abstract
Purpose Oral cancer often requires treatments like surgical intervention, involving surgical resection of lips and other facial parts. For those patients, prosthetic rehabilitation following surgery promotes social reintegration. This study explores the color stability of various commercially available silicone materials for facial prostheses when exposed to everyday beverages like coffee and tea. The hypothesis is that these beverages can induce color changes in silicones, simulating conditions of daily use. Material and methods A total of 90 specimens were fabricated. There were 30 specimens deefor each of 3 nonpigmented silicone elastomers: Silfy, A-2186-F and VST-50 and were immersed in tea or coffee at drinking temperature and evaluated for color changes at time points of 0 h, 1 h, and 6 h. The color was measured with a colorimeter that used the CIE L*a*b* system and the color change ΔΕ was calculated to quantify the color change. Statistical analysis was performed by using the Kruskal-Wallis test, the Mann-Whitney U test, and the Wilcoxon signed-rank Test. The threshold for statistical significance was P < .05. Results Color change was observed for each of the silicones exposed to the beverages (P < .05). The value of ΔE was significantly higher for A-2186-F compared with VST-50 and Silfy (P < .05 in all beverages at 6 h). The color of the elastomers progressively changed while immersed in the beverages over 6 h. The change in color was significantly greater for coffee compared with tea (P < .05). Conclusions The color stability of nonpigmented silicone elastomers is inherently low, which contributes to the overall color change of silicone prostheses when they are exposed to beverages that contain pigments. The elastomer A-2186-F had greatest values of ΔE among the materials tested. Color changes of silicone prostheses can be lessened by selecting materials with consideration of color stability to improve their longevity and extend their period of use.
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Affiliation(s)
- Anshul Chugh
- Department of Advanced Prosthodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
- Department of Prosthodontics, Crown and Bridge, Postgraduate Institute of Dental Sciences, Haryana, India
| | - Mariko Hattori
- Department of Advanced Prosthodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Cheewin Towithelertkul
- Department of Prosthodontics, Maxillofacial prosthetics services, Mahidol University, Bangkok, Thailand
| | - Yuka I. Sumita
- Division of General Dentistry 4, The Nippon Dental University Hospital, Tokyo, Japan
- Tokyo Medical and Dental University, Tokyo, Japan
| | - Noriyuki Wakabayashi
- Department of Advanced Prosthodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
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Khanna M, Sehgal K, Singla S, Kumar V. Effect of Organic and Inorganic Nanoparticles on Colour Stability and Mechanical Properties of Heat Vulcanised Maxillofacial Silicone Elastomer: a Comparative Study. J Oral Maxillofac Res 2024; 15:e4. [PMID: 38812952 PMCID: PMC11131375 DOI: 10.5037/jomr.2024.15104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Accepted: 03/31/2024] [Indexed: 05/31/2024]
Abstract
Objectives The purpose of this comparative study in vitro was to evaluate the effect of organic and inorganic nanoparticles on colour stability, tear strength and hardness of maxillofacial silicone elastomer at baseline and when subjected to outdoor weathering for 6 months. Material and Methods A total of 240 specimens were fabricated using M511 platinum silicone which were divided into total 4 groups (n = 60) based on the type of nanoparticles (control, polytetrafuoroethylene [PTFE], titanium dioxide [TiO2], zinc oxide [ZnO]) added and each group was further divided into 3 subgroups (n = 20) for colour, tear strength (TS) and hardness (H) testing. The tests were conducted and data was obtained both before and after outdoor weathering of 6 months. Results Minimum colour change after weathering was observed in PTFE group (∆E = 2.23). TiO2 group showed maximum TS (12.01 N/mm) followed by PTFE group (10.85 N/mm) before weathering. After weathering, maximum TS was shown by TiO2 group (12.9 N/mm) and PTFE group (12.54 N/mm). TiO2 group showed maximum hardness (24.15 shore A) before weathering and PTFE group showed maximum hardness (33.43 shore A) after weathering. Conclusions Within the limitations of this study, it can be concluded that the addition of polytetrafuoroethylene nanoparticles to the polymer enhances both the optical as well as mechanical properties and can be considered favourable for the extended life of the prosthesis.
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Affiliation(s)
- Manisha Khanna
- Department of Prosthodontics and Crown & Bridge, Dr. Harvansh Singh Judge Institute of Dental Sciences and Hospital, Panjab University, ChandigarhIndia.
| | - Komal Sehgal
- Department of Prosthodontics and Crown & Bridge, Dr. Harvansh Singh Judge Institute of Dental Sciences and Hospital, Panjab University, ChandigarhIndia.
| | - Shefali Singla
- Department of Prosthodontics and Crown & Bridge, Dr. Harvansh Singh Judge Institute of Dental Sciences and Hospital, Panjab University, ChandigarhIndia.
| | - Virender Kumar
- Department of Prosthodontics and Crown & Bridge, Dr. Harvansh Singh Judge Institute of Dental Sciences and Hospital, Panjab University, ChandigarhIndia.
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Peter M, Kanathila H, Bembalagi M, Santhosh VN, Vas R, Patil S, Roy TR, Monsy M, Gopu BN, Chindak S. An In Vitro Comparative Evaluation of Conventional and Novel Thymus vulgaris Derived Herbal Disinfectant Solutions against Pathogenic Biofilm on Maxillofacial Silicones and Its Impact on Color Stability. J Contemp Dent Pract 2023; 24:967-973. [PMID: 38317394 DOI: 10.5005/jp-journals-10024-3602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
AIM This study aims to assess the antimicrobial efficacy and impact on color stability of Thymus (T.) vulgaris solution compared to conventional disinfectants on maxillofacial silicones. MATERIALS AND METHODS Various solutions were evaluated, including T. vulgaris solutions at 5 and 10%, saline (control), chlorhexidine (4%), and soap water. The substrates were MDX4-4210 silicone elastomers, and the microorganisms tested were Candida (C.) albicans and Staphylococcus (S.) aureus. The viability of microorganisms was determined through an 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) reduction assay, and color stability was measured using a spectrophotometer with X-Rite Europe software. Statistical analysis was performed using the Kruskal-Wallis test, Mann-Whitney U post hoc test, and Wilcoxon Signed Rank test. RESULTS Soap water demonstrated superior disinfectant action against both microorganisms, while T. vulgaris solutions at 5 and 10% exhibited comparable antimicrobial efficacy. Chlorhexidine and 10% T. vulgaris solution showed minimal color changes in the silicone material. In contrast, soap water and the 5% T. vulgaris solution resulted in clinically unacceptable color alterations. CONCLUSION This study underscores the potential of T. vulgaris as an herbal disinfectant for combating microbial biofilms on maxillofacial silicones, particularly at concentrations of 5 and 10%. The importance of maintaining color stability is emphasized, with Chlorhexidine and the 10% T. vulgaris solution demonstrating effective preservation of esthetics. These findings suggest the viability of considering T. vulgaris as an alternative disinfectant in clinical settings for maxillofacial silicone prostheses. CLINICAL SIGNIFICANCE Maxillofacial silicones are vital in restoring aesthetic features for individuals with facial trauma, congenital deformities, or post-surgical interventions. Yet, biofilm-related infections jeopardize their durability and visual integrity. Clinically, T. vulgaris signifies a potential advance in prosthodontic care, offering valuable insights for improving antimicrobial performance and aesthetic durability in maxillofacial prostheses. How to cite this article: Peter M, Kanathila H, Bembalagi M, et al. An In Vitro Comparative Evaluation of Conventional and Novel Thymus vulgaris Derived Herbal Disinfectant Solutions against Pathogenic Biofilm on Maxillofacial Silicones and Its Impact on Color Stability. J Contemp Dent Pract 2023;24(12):967-973.
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Affiliation(s)
- Meekha Peter
- Department of Prosthodontics, KLE Vishwanath Katti Institute of Dental Sciences & Hospital, KLE Academy of Higher Education and Research (KLE University), Belagavi, Karnataka, India, Orcid: https://orcid.org/0000-0001-7509-4070
| | - Hema Kanathila
- Department of Prosthodontics, KLE Vishwanath Katti Institute of Dental Sciences & Hospital, KLE Academy of Higher Education and Research (KLE University), Belagavi, Karnataka, India, Orcid: https://orcid.org/0000-0002-5876-1377
| | - Mahantesh Bembalagi
- Department of Public Health Dentistry, KLE Vishwanath Katti Institute of Dental Sciences & Hospital, KLE Academy of Higher Education and Research (KLE University), Belagavi, Karnataka, India, Orcid: https://orcid.org/0000-0002-2809-7313
| | - Varkey Nadakkavukaran Santhosh
- Department of Public Health Dentistry, Department of Prosthodontics, KLE Vishwanath Katti Institute of Dental Sciences & Hospital, KLE Academy of Higher Education and Research (KLE University), Belagavi, Karnataka, India, Phone: +91 9108858449, e-mail: , Orcid: https://orcid.org/0000-0001-9197-2646
| | - Rhea Vas
- Department of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, United Kingdom, Orcid: https://orcid.org/0000-0003-4401-5696
| | - Suvidha Patil
- Department of Prosthodontics, KLE Vishwanath Katti Institute of Dental Sciences & Hospital, KLE Academy of Higher Education and Research (KLE University), Belagavi, Karnataka, India
| | - Treasa Richa Roy
- Department of Prosthodontics, KLE Vishwanath Katti Institute of Dental Sciences & Hospital, KLE Academy of Higher Education and Research (KLE University), Belagavi, Karnataka, India
| | - Mibin Monsy
- JSS Dental College and Hospital, Mysuru, India
| | | | - Shreya Chindak
- Department of Prosthodontics, KLE Vishwanath Katti Institute of Dental Sciences & Hospital, KLE Academy of Higher Education and Research (KLE University), Belagavi, Karnataka, India
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Bugden M. An investigation of the effects of topical sunscreen protection products under natural weather conditions on intrinsic color stability in maxillofacial silicones. J Indian Prosthodont Soc 2023; 23:363-372. [PMID: 37861613 DOI: 10.4103/jips.jips_339_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2023] Open
Abstract
Aim The relatively short lifespan of maxillofacial prostheses (ranging from 3-24 months) is mostly a result of colour instability of silicone elastomers caused by ultraviolet (UV) radiation, requiring frequent remakes. An improvement in colour preservation could result in fewer remakes, thus saving time and money for both clinician and patient. In the quest for a suitable colour protection method, sunscreen protection products were considered; the most recent study on this subject was carried out in 1994, albeit using a low protection factor. The aim of this research was to determine if there is value in using topical sun protection products on extraoral silicone prostheses to prevent colour degradation. Settings and Design This was an in vitro quantitative study. Materials and Methods Three commercially available sunscreen products were studied, Riemann P20, Boots Soltan, and Garnier Ambre Solaire all with a sun protection factor of 50. A total of 144 silicone elastomer samples were produced using a Caucasian (light) shade 1.2 (n = 72) and dark skin shade 3.2 (n = 72) from the Technovent Ltd. Reality Shade range. Each shade group (n = 72) was divided into three groups to be subjected to outdoor weathering (n = 24), indoor (n = 24), and dark storage (n = 24). Within each environmental group, samples were divided into groups of six samples (n = 6) to receive the three sunscreens plus a control group with no sunscreen. The CIEL* a* b* formula was used to obtain the color measurements. Statistical Analysis Used One way ANOVA test and Tukey's HSD test for multiple comparisons was used to analyse the data. Results The ΔE values had changed for all samples throughout the aging process. Conclusion Soltan showed promising results in protecting the dark-shaded samples in the outdoor environment only.
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Affiliation(s)
- Melanie Bugden
- Department of Life Sciences, Manchester Metropolitan University, Manchester; Academic Centre of Reconstructive Science, King's College London, London; Maxillofacial Prosthetics Service Department, Poole Hospital, Poole, UK
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Abdalqadir M, Mohammed K, Azhdar B. The impact of zirconium dioxide nanoparticles on the color stability of artificially aged heat-polymerized maxillofacial silicone elastomer. Sci Prog 2023; 106:368504231205392. [PMID: 37814535 PMCID: PMC10566275 DOI: 10.1177/00368504231205392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/11/2023]
Abstract
The limited service life of craniofacial prostheses due to degradation and color instability is a significant challenge. This in vitro study aimed to determine how zirconium dioxide (ZrO2) nanoparticles affect the color stability of M511 heat temperature vulcanizing (HTV) maxillofacial silicone elastomers after artificial aging. ZrO2 nanoparticles were added at concentrations of 1, 2, and 3 wt% to M511 HTV silicone elastomer. Two intrinsic silicone pigments were used (red and mocha). Silicone with pigment and without ZrO2 nanoparticles were used as the control. Eighty disk-shaped specimens were fabricated and divided into eight experimental groups, each containing ten specimens (n = 10). All specimens were subjected to artificial aging, and color changes were recorded at 252, 504, and 1008 h intervals. The L*a *b * values were measured using a colorimeter and the CIE-Lab system. To interpret the recorded color differences, a 50:50 percent perceptibility threshold (ΔE* = 1.1) and acceptability threshold (ΔE* = 3.0) were implemented. A one-way analysis of variance and Tukey's post hoc test at a significance level of 0.05 were used for the statistical analysis. We found that every evaluated specimen group exhibited a chromatic change (ΔE* > 0). The ΔE* values for the mocha pigments with and without ZrO2 nanoparticles were below the perceptible threshold (1.1 units). The ΔE* values of the red pigment with and without ZrO2 nanoparticles were significantly higher than the acceptable threshold (P < 0.000). According to the findings of this in vitro study, all the specimens underwent color changes (ΔE* > 0). The red pigment exhibited highly significant chromatic alterations. In contrast, mocha pigments with and without ZrO2 nanoparticles exhibited the least color change and were below the perceptible threshold. ZrO2 nanoparticles provided important protection and showed a reduction in color change.
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Affiliation(s)
- Mohammed Abdalqadir
- Department of Prosthodontics, College of Dentistry, University of Sulaimani, Sulaimani, Iraq
| | - Kaml Mohammed
- Department of Prosthodontics, College of Dentistry, University of Sulaimani, Sulaimani, Iraq
| | - Bruska Azhdar
- Nanotechnology Research Laboratory, Department of Physics, College of Science, University of Sulaimani, Sulaimani, Iraq
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Maqableh AM, Hatamleh MM. Cohesive Zone Modeling of Pull-Out Test for Dental Fiber-Silicone Polymer. Polymers (Basel) 2023; 15:3668. [PMID: 37765521 PMCID: PMC10538124 DOI: 10.3390/polym15183668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/02/2023] [Accepted: 09/03/2023] [Indexed: 09/29/2023] Open
Abstract
BACKGROUND Several analytical methods for the fiber pull-out test have been developed to evaluate the bond strength of fiber-matrix systems. We aimed to investigate the debonding mechanism of a fiber-silicone pull-out specimen and validate the experimental data using 3D-FEM and a cohesive element approach. METHODS A 3D model of a fiber-silicone pull-out testing specimen was established by pre-processing CT images of the typical specimen. The materials on the scans were posted in three different cross-sectional views using ScanIP and imported to ScanFE in which 3D generation was implemented for all of the image slices. This file was exported in FEA format and was imported in the FEA software (PATRAN/ABAQUS, version r2) for generating solid mesh, boundary conditions, and material properties attribution, as well as load case creation and data processing. RESULTS The FEM cohesive zone pull-out force versus displacement curve showed an initial linear response. The Von Mises stress concentration was distributed along the fiber-silicone interface. The damage in the principal stresses' directions S11, S22, and S33, which represented the maximum possible magnitude of tensile and compressive stress at the fiber-silicone interface, showed that the stress is higher in the direction S33 (stress acting in the Z-direction) in which the lower damage criterion was higher as well when compared to S11 (stress acting in the XY plane) and S23 (stress acting in the YZ plane). CONCLUSIONS The comparison between the experimental values and the results from the finite element simulations show that the proposed cohesive zone model accurately reproduces the experimental results. These results are considered almost identical to the experimental observations about the interface. The cohesive element approach is a potential function that takes into account the shear effects with many advantages related to its ability to predict the initiation and progress of the fiber-silicone debonding during pull-out tests. A disadvantage of this approach is the computational effort required for the simulation and analysis process. A good understanding of the parameters related to the cohesive laws is responsible for a successful simulation.
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Affiliation(s)
- Ayman M. Maqableh
- School of Electro-Mechanical Engineering, Luminus Technical University College (LTUC), Amman 11118, Jordan
| | - Muhanad M. Hatamleh
- Faculty of Applied Medical Science, Allied Dental Sciences Department, Jordan University of Science and Technology (JUST), Irbid 22110, Jordan;
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Kiat-amnuay S, Cevik P, Kurtoglu C. Effect of Thixotropic Agent on the Color Stability of Platinum-Based Silicone Maxillofacial Elastomers after Artificial Aging. MATERIALS (BASEL, SWITZERLAND) 2023; 16:5867. [PMID: 37687559 PMCID: PMC10488689 DOI: 10.3390/ma16175867] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 08/20/2023] [Accepted: 08/25/2023] [Indexed: 09/10/2023]
Abstract
Maxillofacial prostheses are essential for restoring natural appearance and function in individuals with defects in the head and neck regions. Thixotropic agents, as liquid additives, are known to increase the viscosity of silicone elastomers. However, color deterioration remains a challenge in facial prostheses, leading to the need for refabrication. Despite this, there is limited research on the effect of thixotropic agents on the color stability of silicone maxillofacial elastomers. This study aims to investigate the impact of different thixotropic agent amounts on the color degradation of various maxillofacial silicone elastomers. Three elastomers (A-2000, A-2006, and A-2186) were combined with five pigments (no pigment as control, red, yellow, blue, and a mixture of red, yellow, and blue), and mixed with six thixotropic agent quantities (0, 1, 2, 3, 4, and 5 drops). A total of 450 specimens were fabricated (n = 5) and aged in an artificial aging chamber. L*, a*, b* readings were obtained before and after aging using a digital spectrophotometer. Color difference (ΔE*) means and standard deviations for 150 kj/m2, 300 kj/m2, and 450 kj/m2 were calculated. Statistical analyses, including four-way ANOVA and Fisher's PLSD test, were conducted to determine any significant differences (p < 0.05) among the groups. A comprehensive analysis revealed significant four-way interactions among the groups. In the mixed-pigmentation group, adding 4 drops of thixotropic agent resulted in ΔE* above 3 only in A-2186 silicone at 300 and 450 kj/m2 energy levels. However, the color stability of mixed-pigmented A-2000 and A-2006 remained within the acceptable thresholds of 3 ΔE* at all irradiance levels in this study. At each energy level, A-2006 exhibited the highest color stability with an increasing thixotropic agent quantity among all the silicones. Conversely, A-2186 was more affected by the increased number of thixotropic agent drops in each pigmentation group, including the control group at 450 kj/m2. The quantity of thixotropic agent plays a crucial role in determining the color stability of different silicone elastomers pigmented with various intrinsic pigments. The thixotropic agent amount has a more significant impact on color stability than the type of pigment used in the silicone elastomers. A key overarching insight from this investigation is the identification of a safety threshold for the thixotropic agent quantity of 3 drops for each silicone type, pigmentation, and energy level. These findings highlight the importance of considering the proper combination of thixotropic agents, pigments, and silicone materials to achieve optimal color stability in maxillofacial prosthetic applications.
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Affiliation(s)
- Sudarat Kiat-amnuay
- Department of General Practice and Dental Public Health, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX 77054, USA
- Houston Center for Biomaterials and Biomimetics, Houston, TX 77054, USA
| | - Pinar Cevik
- Department of General Practice and Dental Public Health, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX 77054, USA
- Houston Center for Biomaterials and Biomimetics, Houston, TX 77054, USA
- Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara 06490, Türkiye;
| | - Cem Kurtoglu
- Department of Prosthodontics, Faculty of Dentistry, Cukurova University, Adana 01250, Türkiye
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Al-Kadi FK, Abdulkareem JF, Azhdar BA. Hybrid Chitosan-TiO 2 Nanocomposite Impregnated in Type A-2186 Maxillofacial Silicone Subjected to Different Accelerated Aging Conditions: An Evaluation of Color Stability. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2379. [PMID: 37630964 PMCID: PMC10460059 DOI: 10.3390/nano13162379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 08/07/2023] [Accepted: 08/18/2023] [Indexed: 08/27/2023]
Abstract
This study explores the impact of the incorporation of a chitosan-TiO2 nanocomposite on the color stability of pigmented room-temperature vulcanization maxillofacial silicone under various accelerated aging conditions. Five hundred disk-shaped specimens were formed with type A-2186 silicone elastomer, and they were distributed into groups based on pigment types and nanoparticle treatments. The color difference (ΔE) was assessed using a colorimeter in the CIELAB color system before and after exposure to aging conditions, including UV-accelerated aging and outdoor weathering. ANOVA, Dennett's T3, and Tukey HSD tests revealed significant color alterations across all silicone types, with the most pronounced being in the red-colored 3% chitosan specimens and the least pronounced being in the 2% TiO2 specimens that underwent UV-accelerated aging. Outdoor weathering consistently increased the ΔE values across all categories. This study suggests that while nanoparticles may offer some resistance against accelerated aging, they fall short in adequately defending against UV radiation during outdoor weathering.
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Affiliation(s)
- Faten K. Al-Kadi
- Department of Prosthodontics, College of Dentistry, University of Sulaimani, Sulaymaniyah 46001, Iraq;
| | - Jwan F. Abdulkareem
- Department of Prosthodontics, College of Dentistry, University of Sulaimani, Sulaymaniyah 46001, Iraq;
| | - Bruska A. Azhdar
- Nanotechnology Research Laboratory, Department of Physics, College of Science, University of Sulaimani, Sulaymaniyah 46001, Iraq;
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Bankoğlu Güngör M, Kaynak Öztürk E, Karakoca Nemli S, Turhan Bal B. Effect of 2-ethylhexyl salicylate incorporation on the color stability of different maxillofacial silicone elastomers after outdoor weathering. J Prosthet Dent 2023:S0022-3913(23)00343-8. [PMID: 37336678 DOI: 10.1016/j.prosdent.2023.05.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 05/17/2023] [Accepted: 05/17/2023] [Indexed: 06/21/2023]
Abstract
STATEMENT OF PROBLEM Silicone elastomers are considered the most favorable materials for the prosthetic rehabilitation of facial defects. However, color change, because of the ultraviolet (UV) light, limits the life of facial prostheses. The addition of 2-ethylhexyl salicylate as a UV-protective may improve the color stability of different maxillofacial silicone elastomers. PURPOSE The purpose of this in vitro study was to evaluate the effect of 2-ethylhexyl salicylate on the color stability of 3 different maxillofacial silicone elastomers after outdoor weathering. MATERIAL AND METHODS Three different ratios of UV-protective 2-ethylhexyl salicylate (UV-ES) were incorporated into 3 different types of maxillofacial silicones (M511, TechSil S25, and A-2000) in 1%, 2%, and 5% ratios, and a control group for each silicone was generated. A total of 120 Ø15×2-mm disk-shaped specimens were prepared from 3 different silicone elastomers according to the 4 different UV-ES ratio groups (n=10). The specimens were subjected to outdoor weathering in Ankara, Türkiye, from June 2021 to June 2022. Color differences in the specimens were measured at 3 months and 1 year of weathering. The color change values (ΔE) were statistically analyzed by using repeated measures of 3-way ANOVA. The differences were compared by using the Tukey honest significant difference test (α=.05). RESULTS No interaction was found among the factors (silicone type, UV-ES ratio, and aging) (P=.29). The highest ΔE values were found in TechSil S-25 (P<.001), while the results were not significantly different between the M511 and A2000 groups (P=.324) The higher ΔE values were found in the control group when compared with those of the UV-ES added group of each material, while the results were not significantly different among the 1%, 2%, and 5% groups (P>.05). CONCLUSIONS Incorporating 2-ethylhexyl salicylate into the tested maxillofacial silicones reduced color change.
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Affiliation(s)
- Merve Bankoğlu Güngör
- Associate Professor, Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Türkiye.
| | - Esra Kaynak Öztürk
- Research Assistant, Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Türkiye
| | - Seçil Karakoca Nemli
- Professor, Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Türkiye
| | - Bilge Turhan Bal
- Professor, Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Türkiye
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Turhan Bal B, Bankoğlu Güngör M, Karakoca Nemli S, Aydın C, Kaşko Arıcı Y. Effect of ultraviolet protective agents on maxillofacial silicone elastomer, part 1: Color stability after artificial aging. J Prosthet Dent 2023; 129:513-519. [PMID: 34330532 DOI: 10.1016/j.prosdent.2021.06.033] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 06/28/2021] [Accepted: 06/29/2021] [Indexed: 10/20/2022]
Abstract
STATEMENT OF PROBLEM Silicone elastomers have been widely used for rehabilitation of facial defects for more than 50 years. However, color change is the most common problem limiting the service life of facial prostheses. Whether the addition of ultraviolet protectives may enhance color stability of these materials is unclear. PURPOSE The purpose of this in vitro study was to investigate the effect of ultraviolet protectives on the color stability of maxillofacial silicones after artificial aging. MATERIAL AND METHODS Six color groups (unpigmented, white, yellow, red, blue, and mixed) of addition-type maxillofacial silicone were prepared. Four ultraviolet protectives benzophenone-3, ethylhexyl methoxycinnamate, titanium dioxide, and ethylhexyl salicylate at 0.5% and 1% concentrations by weight were incorporated into the silicone before polymerization. The specimens were artificially aged in an accelerated weathering chamber for 300 and 600 hours and in a thermocycling device. The color change values (E) of the maxillofacial silicones were evaluated. Data were statistically analyzed by using 4-way ANOVA. The differences were compared by the Tukey honestly significant difference test (α=.05). RESULTS Benzophenone-3 and ethylhexyl methoxycinnamate protectives did not reduce the ΔE values, and the 1% titanium dioxide groups exhibited lower ΔE values than the 0.5% titanium dioxide groups. Ethylhexyl salicylate protective generally reduced the ΔE values significantly in all color and aging groups when compared with the control groups (P<.05). In all control and ultraviolet protective groups, the highest ΔE values were seen with the red color in 300 and 600 hours of aging. Generally, no significant difference (P>.05) was seen in the ΔE values, which were clinically acceptable among the thermocycled color groups. After 600 hours of accelerated aging, the ΔE values were found to be higher than the values of 300-hour aging. CONCLUSIONS Ethylhexyl salicylate protective incorporated into maxillofacial silicones may improve color stability.
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Affiliation(s)
- Bilge Turhan Bal
- Professor, Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey
| | - Merve Bankoğlu Güngör
- Associate Professor, Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey.
| | - Seçil Karakoca Nemli
- Professor, Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey
| | - Cemal Aydın
- Professor, Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey
| | - Yeliz Kaşko Arıcı
- Assistant Professor, Biostatistics and Medical Informatics, Faculty of Medicine, Ordu University, Ordu, Turkey
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Effects of Disinfection Methods on the Color Stability of Precolored and Hand-Colored Maxillofacial Silicone: An In Vitro Study. Int J Biomater 2022; 2022:7744744. [PMID: 35734282 PMCID: PMC9208998 DOI: 10.1155/2022/7744744] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/02/2022] [Accepted: 05/25/2022] [Indexed: 11/18/2022] Open
Abstract
Maxillofacial prostheses are used in rehabilitation of patients with facial defects. Typically, these prostheses are fabricated with medical grade silicone and are tinted corresponding to the patients' natural skin color. However, exposure to environment and disinfectants can result in color changes. This study aimed to evaluate the effects of four different disinfection methods on the color stability of precolored and hand-colored maxillofacial silicones. Forty specimens each of precolored and hand-colored silicone were prepared. The specimens were randomly divided into eight groups (n = 10) and cleansed with four different disinfection methods. Disinfection was carried out six times/day for 60 days, simulating once-a-day disinfection for a year. Color evaluation was carried out at day 0 and day 60 using a UV-vis spectrophotometer. Color alterations were calculated by the CIE L ∗ a ∗ b ∗ system. Data were analyzed by two-way ANOVA with post hoc Tukey HSD and t-tests (α = 0.05). Disinfectants can affect the color stability of maxillofacial silicone. In our study, chlorhexidine solution and liquid soap resulted in the highest color change. Precolored silicone showed higher color stability than its hand-colored counterpart.
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Mahale H, Deshpande S, Radke U, Patil PG. Opacifiers on color stability of maxillofacial silicone under aging and Indian weathering conditions: An in vitro study. J Prosthet Dent 2021; 129:805-810. [PMID: 34649721 DOI: 10.1016/j.prosdent.2021.08.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 08/14/2021] [Accepted: 08/16/2021] [Indexed: 11/20/2022]
Abstract
STATEMENT OF PROBLEM Resistance to long-term color change is a desirable property for facial prosthetic elastomers. Evidence for the color stability of maxillofacial silicones under aging and hot and humid Indian weathering conditions is lacking. PURPOSE The purpose of this in vitro study was to evaluate the effect of adding opacifiers on the color stability of maxillofacial silicone under human aging and Indian weather conditions. MATERIAL AND METHODS A total of 93 specimen disks were obtained from the A-2186, platinum-based, room-temperature vulcanized, maxillofacial silicone elastomer by using a Ø30×6-mm stainless-steel die. The specimens were divided into 3 main groups (n=30), C (control), T (titanium dioxide), and B (barium sulfate), and 1 additional specimen (n=1) from each group was stored in a closed box and further subgrouped as outdoor weathering (COut, TOut, BOut), acidic perspiration (CAcid, TAcid, BAcid), sebum (CSebum, TSebum, BSebum) (n=10), and visual comparison (CVis, TVis, BVis) (n=1). Baseline L∗, a∗, b∗ values were recorded by using a spectrophotometer and visual perception. The specimens were subjected to human and extraoral aging conditions, and the values were recorded again after 6 months. Data were analyzed statistically by using analysis of variance (ANOVA) and post hoc analysis with the Tukey post hoc test. RESULTS In group C, the mean color change for COut was 3.69 ±0.49; CAcid, 3.58 ±0.68; and CSebum, 7.53 ±0.22 (P<.001). In group T, the mean color change for TOut was 2.60 ±0.24; TAcid, 2.35 ±0.13; and TSebum, 4.91 ±0.44 (P<.001). In group B, BOut was 1.59 ±0.28, BAcid was 1.46 ±0.28, and BSebum was 4.03 ±0.71 (P<.001). The specimens containing barium sulfate showed the maximum color stability. The least color stability was observed in all specimens exposed to sebum solution and was significantly different (P<.001) from the outdoor weather and acidic perspiration specimens. Visually perceivable color changes were observed in specimens exposed to the sebum solution. CONCLUSIONS The addition of titanium dioxide and barium sulfate as opacifiers resulted in clinically acceptable color change when exposed to outdoor weathering and acidic perspiration but not in sebum solution.
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Affiliation(s)
| | - Saee Deshpande
- Associate Professor, Department of Prosthodontics, VSPM Dental College and Research Centre, Nagpur, India
| | - Usha Radke
- Professor and Head, Department of Prosthodontics, VSPM Dental College and Research Centre, Nagpur, India
| | - Pravinkumar G Patil
- Senior Lecturer in Prosthodontics, Division of Restorative Dentistry, School of Dentistry, International Medical University, Kuala Lumpur, Malaysia.
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Gupta P, Deshpande S, Radke U, Ughade S, Sethuraman R. The color stability of maxillofacial silicones: A systematic review and meta analysis. J Indian Prosthodont Soc 2021; 21:138-149. [PMID: 33938863 PMCID: PMC8262445 DOI: 10.4103/jips.jips_253_19] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 03/20/2021] [Accepted: 03/25/2021] [Indexed: 12/03/2022] Open
Abstract
Aim This systematic review aims to identify and interpret results of studies that evaluated the changes in the color stability of maxillofacial prosthetic materials due to chemical instability of silicones and pigments and the effect of exposure to environmental conditions and aging factors on the same. Settings and Design This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines (PRISMA). Materials and Methods Relevant articles written in English only, before November 15, 2019, were identified using an electronic search in the PubMed/Medline conducted to identify pertinent articles. The relevancy of the articles was verified by screening the title, abstract, and full text, if they met the inclusion criteria. A total of 42 articles satisfied the criteria, from which data were extracted for qualitative synthesis. This review protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO registration number CRD42019124562). Statistical Analysis Used Since considerable data heterogenicity was present in all studies except the ones on incorporation of TiO2 for which meta-analysis using random effects model was performed. Results The database search resulted in 234 studies, of which 202 articles were excluded due to lack of relevance, duplication, and unavailability of data. The remaining 32 fulltext articles were assessed for eligibility, out of which 2 articles were excluded. Twelve articles were yielded by manual search. A total of 42 studies were included in the present systematic review. Due to heterogeneous data, meta-analysis could be only carried out with the effect of TiO2 nano particle on color stability. Conclusions Although there has been extensive amount of research in this field, an ideal maxillofacial silicone exhibiting good color stability in various human and environmental aging conditions is yet to be identified. Human and environmental aging conditions have an adverse effect on the color stability and addition of TiO2 nano particle seems to improve the same.
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Affiliation(s)
- Priya Gupta
- Department of Prosthodontics, VSPMDCRC, VSPM Dental College, Nagpur, Maharashtra, India
| | - Saee Deshpande
- Department of Prosthodontics, VSPM Dental College, Nagpur, Maharashtra, India
| | - Usha Radke
- Department of Prosthodontics, VSPMDCRC, VSPM Dental College, Nagpur, Maharashtra, India
| | - Suresh Ughade
- Department of PSM, Government Medical College, Nagpur, Maharashtra, India
| | - Rajesh Sethuraman
- Department of Prosthodontics, K. M. Shah Dental College, Vadodara, Gujarat, India
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15
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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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Powell SK, Cruz RLJ, Ross MT, Woodruff MA. Past, Present, and Future of Soft-Tissue Prosthetics: Advanced Polymers and Advanced Manufacturing. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2001122. [PMID: 32909302 DOI: 10.1002/adma.202001122] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 05/23/2020] [Indexed: 06/11/2023]
Abstract
Millions of people worldwide experience disfigurement due to cancers, congenital defects, or trauma, leading to significant psychological, social, and economic disadvantage. Prosthetics aim to reduce their suffering by restoring aesthetics and function using synthetic materials that mimic the characteristics of native tissue. In the 1900s, natural materials used for thousands of years in prosthetics were replaced by synthetic polymers bringing about significant improvements in fabrication and greater realism and utility. These traditional methods have now been disrupted by the advanced manufacturing revolution, radically changing the materials, methods, and nature of prosthetics. In this report, traditional synthetic polymers and advanced prosthetic materials and manufacturing techniques are discussed, including a focus on prosthetic material degradation. New manufacturing approaches and future technological developments are also discussed in the context of specific tissues requiring aesthetic restoration, such as ear, nose, face, eye, breast, and hand. As advanced manufacturing moves from research into clinical practice, prosthetics can begin new age to significantly improve the quality of life for those suffering tissue loss or disfigurement.
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Affiliation(s)
- Sean K Powell
- School of Mechanical, Medical and Process Engineering, Science and Engineering Faculty, Queensland University of Technology, 2 George Street, Brisbane, QLD, 4000, Australia
| | - Rena L J Cruz
- School of Mechanical, Medical and Process Engineering, Science and Engineering Faculty, Queensland University of Technology, 2 George Street, Brisbane, QLD, 4000, Australia
| | - Maureen T Ross
- School of Mechanical, Medical and Process Engineering, Science and Engineering Faculty, Queensland University of Technology, 2 George Street, Brisbane, QLD, 4000, Australia
| | - Maria A Woodruff
- School of Mechanical, Medical and Process Engineering, Science and Engineering Faculty, Queensland University of Technology, 2 George Street, Brisbane, QLD, 4000, Australia
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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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Lu Z, Zhang T, Wang X, Wang J, Shen J, Xiao Z, Chen L, Zhang X. Zwitterionic Polymer-Based Nanoparticles Encapsulated with Linalool for Regulating Central Nervous System. ACS Biomater Sci Eng 2019; 6:442-449. [DOI: 10.1021/acsbiomaterials.9b01451] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Zhiguo Lu
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China
- School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Tianlu Zhang
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China
- School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Xiangyu Wang
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China
| | - Jianze Wang
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China
| | - Jie Shen
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China
- School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Zuobing Xiao
- Shanghai Research Institute of Fragrance and Flavor Industry, Shanghai 200232, PR China
- School of Perfume and Aroma Technology, Shanghai Institute of Technology, Shanghai 200233, PR China
| | - Lei Chen
- Department of Obstetrics and Gynecology, Navy General Hospital of People Liberation Army, Beijing 100048, PR China
| | - Xin Zhang
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China
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In vitro study of effects of aging and processing conditions on colour change in maxillofacial silicone elastomers. BMC Oral Health 2019; 19:122. [PMID: 31217006 PMCID: PMC6585052 DOI: 10.1186/s12903-019-0798-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 05/31/2019] [Indexed: 12/18/2022] Open
Abstract
Background The inherent colour change in maxillofacial silicone elastomers becomes perceptible 6–12 months after fabrication. Determining the factors that accelerate the degradation of the prosthesis can help the clinicians increase its life span. Therefore, the aim of the study was to investigate the effect of time passage, processing temperature, and molding-stone colour on the colour change of maxillofacial silicone elastomers after darkroom storage for 6000 h. Methods A total of ten study molds, each incorporating ten specimen gaps were fabricated using five different colors of dental stones. The gaps were filled with coloured Cosmesil M511 maxillofacial silicone elastomer. Five of the study molds, one of each stone color, were processed at room temperature (25 °C) for 24 h while the remainder were vulcanized at 100 °C for 1 h. Two stainless-steel molds were also fabricated to obtain a total of twenty control-group specimens of the same dimensions that were processed under the same conditions as the study molds. Colour measurements of the vulcanized silicone samples were performed using a Konica Minolta spectrophotometer. Initial measurements were obtained after the blocks were removed from the molds and the final measurements were recorded 6000 h after storage in the dark at 25 °C and 40% relative humidity. The CIEDE2000 colour-difference formula was used to measure the changes in the colour. One-way and two-way ANOVA, and an independent-sample t-test were used for statistical assessments. Results For every group, the colour change exceeded the perceptible thresholds. Thus, either the vulcanization temperature or the colour of the molding stone has a significant effect on the colour change over time. Those samples vulcanized in green and white molding stones at 100 °C exhibited a significantly higher ∆L*, ∆a*, and ∆b* values relative to the samples vulcanized at room temperature. Conclusion The molding-stone colour and vulcanization temperature both affect the degree of colour change after storage in a dark environment. The L*, a*, and b* values for the maxillofacial silicone elastomers are influenced by the direction of the increase or decrease according to the selected colour. This effect varies as the temperature increases.
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Çevik P. Evaluation of Shore A hardness of maxillofacial silicones: the effect of dark storage and nanoparticles. Eur Oral Res 2019; 52:99-104. [PMID: 30775710 DOI: 10.26650/eor.2018.469] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 07/17/2017] [Accepted: 07/25/2017] [Indexed: 01/13/2023] Open
Abstract
Purpose Little has been reported how the addition of nanoparticles could affect the hardness of maxillofacial silicones. The purpose of this study was to evaluate the effects of different types of nanoparticle additives and dark storage for 2-years on the Shore A hardness of two types of maxillofacial silicone elastomers. Materials and Methods A-2000 and A-2006 Room Temperature Vulcanized (RTV) silicone elastomers were tested in this study. Silaned silica, fumed silica and titanium dioxide nanoparticles at concentrations of 10% by volume were used as fillers for the maxillofacial silicone elastomers. A total of 64 silicone specimens were fabricated, which includes 8 samples, 30 × 10 mm in size, from each silicone elastomers for each subgroup and also controls. After the initial Shore A hardness measurements, specimens were kept in dark conditions at room temperature for 2 years. The final measurements were then taken from the silicone specimens. All data were statistically analyzed. Results For both types of silicones, there was statistically significant differences among study groups (p<0.001). Fumed silica group showed the lowest hardness values in A-2000 after storage. However, no significant difference was observed between control and fumed silica groups. Control group showed the lowest hardness values in A-2006, while the highest hardness values were found in fumed silica group; there was no significant difference between silica and silane groups. Conclusion Shore A values of the specimens were within the acceptable range for the maxillofacial silicones after aging. Nanoparticle addition did not prevent hardening of the silicone elastomers with time.
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Affiliation(s)
- Pınar Çevik
- Department of Prosthodontics, Gazi University Faculty of Dentistry, Ankara, Turkey
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21
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Mechanical and Morphological Effect of Plant Based Antimicrobial Solutions on Maxillofacial Silicone Elastomer. MATERIALS 2018; 11:ma11060925. [PMID: 29848959 PMCID: PMC6025512 DOI: 10.3390/ma11060925] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Revised: 05/25/2018] [Accepted: 05/25/2018] [Indexed: 11/29/2022]
Abstract
The objective of this study was to determine the effect of plant based antimicrobial solutions specifically tea tree and Manuka oil on facial silicone elastomers. The purpose of this in vitro study was to evaluate the effect of disinfection with plant extract solution on mechanical properties and morphology on the silicone elastomer. Test specimens were subjected to disinfection using tea tree oil, Manuka oil and the staphylococcus epidermidis bacteria. Furthermore, a procedure duration was used in the disinfection process to simulate up to one year of usage. Over 500 test specimens were fabricated for all tests performed namely hardness, elongation, tensile, tear strength tests, visual inspection and lastly surface characterization using SEM. A repeated measures ANOVA revealed that hardness and elongation at break varied significantly over the time period, whereas this was not observed in the tear and tensile strength parameters of the test samples.
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Farah A, Sherriff M, Coward T. Color stability of nonpigmented and pigmented maxillofacial silicone elastomer exposed to 3 different environments. J Prosthet Dent 2018; 120:476-482. [PMID: 29627205 DOI: 10.1016/j.prosdent.2017.11.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 11/14/2017] [Accepted: 11/14/2017] [Indexed: 10/17/2022]
Abstract
STATEMENT OF PROBLEM The color degradation of maxillofacial prostheses in clinical service requires their frequent renewal. How different materials compare is unclear. PURPOSE The purpose of this in vitro study was to investigate the color stability of a nonpigmented and pigmented maxillofacial silicone when stored in darkness and exposed to accelerated aging in a weathering chamber and natural outdoor weathering. MATERIAL AND METHODS M511 elastomer was colored with Spectromatch Pro colorants, stored in darkness, and exposed to accelerated aging and natural outdoor weathering for 1500 hours. Test groups included nonpigmented specimens (n=18), individually pigmented specimens (n=90), and Caucasian skin tone-colored specimens (n=18). The CIELab values of the test specimens were measured using the CM-2600d spectrophotometer (Konica Minolta Sensing) at base line (0 hours) and then every 100 hours up to 1500 hours of aging. Color changes (ΔE) were calculated based on the recorded CIELab values. All data were analyzed by using linear mixed models and the Šídák multiple comparison of means test (α=.05). RESULTS A significant effect of time was found on the ΔE of all test specimens in all environments (P=.001). All pigmented M511 specimens demonstrated good color stability with maximum ΔE below the acceptability threshold of 2 ΔE when stored in darkness and exposed to outdoor weathering. However, nonpigmented specimens crossed this acceptability threshold when exposed to outdoor weathering with maximum ΔE values of 3.65. The greatest color changes were observed for all specimens when exposed to accelerated aging and most exceeded the acceptability threshold. Nonpigmented (ΔE, 4.86) and Indian yellow (ΔE, 5.20) demonstrated the highest color changes after 1500 hours. CONCLUSIONS All environments resulted in visible color changes of nonpigmented and pigmented M511 elastomer. The lowest ΔE values were observed for specimens stored in darkness and the greatest for specimens exposed to accelerated aging. The organic pigment Logwood maroon demonstrated the best color stability with maximum ΔE values below the perceptibility threshold (PT) of 1 ΔE.
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Affiliation(s)
- Ariane Farah
- Doctoral student, Academic Centre for Reconstructive Science, King's College London, Guy's Hospital, London, United Kingdom
| | - Martyn Sherriff
- Visiting Professor, School of Oral and Dental Sciences, University of Bristol, Bristol, United Kingdom
| | - Trevor Coward
- Reader/Consultant, Academic Centre for Reconstructive Science, King's College London, Guy's Hospital, London, United Kingdom.
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Chamaria A, Aras MA, Chitre V, Rajagopal P. Effect of Chemical Disinfectants on the Color Stability of Maxillofacial Silicones: An In Vitro Study. J Prosthodont 2018. [DOI: 10.1111/jopr.12768] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Ankita Chamaria
- Department of Prosthodontics and Crown & Bridge; Goa Dental College and Hospital; Bambolim Goa India
| | - Meena A. Aras
- Department of Prosthodontics and Crown & Bridge; Goa Dental College and Hospital; Bambolim Goa India
| | - Vidya Chitre
- Department of Prosthodontics and Crown & Bridge; Goa Dental College and Hospital; Bambolim Goa India
| | - Praveen Rajagopal
- Department of Prosthodontics and Crown & Bridge; Goa Dental College and Hospital; Bambolim Goa India
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Kheur MG, Kakade D, Trevor CJ, Lakha TA, Sethi T. Effect of newly developed pigments and ultraviolet absorbers on the color change of pigmented silicone elastomer. J Indian Prosthodont Soc 2017; 17:395-400. [PMID: 29249884 PMCID: PMC5730925 DOI: 10.4103/jips.jips_148_17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 10/09/2017] [Indexed: 12/04/2022] Open
Abstract
Aim and Objective: The aim and objective of the study is to evaluate effect of ultraviolet (UV) stabilizer (UV absorber Chimassorb 81) on color change of pigmented silicone elastomer when commercially available (red and yellow), and newly developed pigments (sicotrans red and sicopal brown) were used. Materials and Methods: Two commercially available pigments – red (P112 Brilliant Red) and yellow (P106 Yellow) and two newly developed pigments – sicotrans red and sicopal brown were studied. In total eight groups made up of nine samples each were fabricated using elastomer with the combinations of the above pigments and UV stabilizer (Chimassorb 81). Groups 1, 3, 5, and 7 contain elastomer in combination with sicotrans red, sicopal brown, yellow and red pigments, respectively. Similarly, groups 2, 4, 6, and 8 along with elastomer and pigments (sicotrans sed, sicopal brown, yellow and red, respectively) contain the UV stabilizer (Chimassorb 81). Samples were subjected to aging in an accelerated weathering chamber (Weather-Ometer). Color values CIE (Commission Internationale d’Eclairage) L*, a*, and b * were measured at baseline and after 1000 h of weathering. Change in color (Delta E) was calculated. Results: All groups showed a significant color change at 1000 h. Groups 1, 2, 3, and 4 showed a statistically significant less change in both colors (sico trans red and sicopal brown) compared to groups 5,6,7, and 8 (commercial pigments-Red and Yellow). Overall, the change in the color in groups with the UV stabilizer (Chimassorb) was less when compared to the groups where the stabilizer was not used. Conclusion: The newly developed pigment led to increased color stability as compared to commercially available pigments. Addition of UV stabilizer, Chimassorb led to a further reduction in color change of the pigmented elastomer.
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Affiliation(s)
- Mohit G Kheur
- Department of Prosthodontics, M.A. Rangoonwala College of Dental Sciences and Research Centre, Pune, Maharashtra, India
| | - Dilip Kakade
- Department of Prosthodontics, Dr. D. Y. Patil Dental College, Dr. D. Y. Patil Vidyapeeth, Pune, Maharashtra, India
| | - Coward J Trevor
- Department of Maxillofacial Prosthetic Technology, Kings College, London, United Kingdom
| | - Tabrez Amin Lakha
- Department of Prosthodontics, M.A. Rangoonwala College of Dental Sciences and Research Centre, Pune, Maharashtra, India
| | - Tania Sethi
- Department of Prosthodontics, M.A. Rangoonwala College of Dental Sciences and Research Centre, Pune, Maharashtra, India
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Initial investigation of the corrosion stability of craniofacial implants. J Prosthet Dent 2017; 119:185-192. [PMID: 28533010 DOI: 10.1016/j.prosdent.2017.02.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 02/15/2017] [Accepted: 02/15/2017] [Indexed: 11/23/2022]
Abstract
STATEMENT OF PROBLEM Although craniofacial implants have been used for retention of facial prostheses, failures are common. Titanium undergoes corrosion in the oral cavity, but the corrosion of craniofacial implants requires evaluation. PURPOSE The purpose of this in vitro study was to investigate the corrosion stability of commercially pure titanium (CP Ti) exposed to simulated human perspiration at 2 different pH levels (5.5 and 8). MATERIAL AND METHODS Fifteen titanium disks were divided into 3 groups (n=5 per group). The control group was subjected to simulated body fluid (SBF) (control). Disks from the 2 experimental groups were immersed in simulated alkaline perspiration (SAKP) and simulated acidic perspiration (SACP). Electrochemical tests, including open circuit potential (3600 seconds), electrochemical impedance spectroscopy, and potentiodynamic tests were performed according to the standardized method of 3-cell electrodes. Data were analyzed by 1-way ANOVA and the Tukey honestly significant difference tests (α=.05). RESULTS Simulated human perspiration reduced the corrosion stability of CP Ti (P<.05). The SBF group presented the lowest capacitance values (P<.05). SAKP and SACP groups showed increased values of capacitance and showed no statistically significant differences (P>.05) from each other. The increase in capacitance suggests that the acceleration of the ionic exchanges between the CP Ti and the electrolyte leads to a lower corrosion resistance. SAKP reduced the oxide layer resistance of CP Ti (P<.05), and an increased corrosion rate was noted in both simulated human perspiration groups. CONCLUSIONS Craniofacial implants can corrode when in contact with simulated human perspiration, whereas alkaline perspiration shows a more deleterious effect. Perspiration induces a more corrosive effect than simulated body fluid.
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Mehta S, Nandeeshwar DB. A spectrophotometric analysis of extraoral aging conditions on the color stability of maxillofacial silicone. J Indian Prosthodont Soc 2017; 17:355-360. [PMID: 29249879 PMCID: PMC5730921 DOI: 10.4103/jips.jips_87_17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 07/31/2017] [Indexed: 11/29/2022] Open
Abstract
Context: Surveys have reported color fading as the most frequent reasons patients given for disliking their prostheses. Aim: The aim of the study is to compare the color variation between two maxillofacial silicone elastomers after subjecting them to extraoral aging conditions. Subjects and Methods: A total of 80 samples were made from M511 Maxillofacial Rubber (Part A: Part B = 10:1) and Z004 Platinum Silicone Rubber (Part A: Part B = 1:1) and divided into two main Groups A and B (40 each). These main groups were then subdivided into five subgroups (A1B1, A2B2, A3B3, A4B4, and A5B5) (n = 8); outdoor weathering, acidic perspiration, sebum (for 6 months), and neutral soap and disinfectant (for 30 h), respectively. Baseline L*a*b* values were recorded. The samples were subjected to the extraoral aging conditions, and the L* a*b* values were recorded after the aging period using a spectrophotometer. Statistical Analysis: The intergroup comparison was done by Kruskal–Wallis test, whereas the intragroup comparison was done by Mann–Whitney test. Results All groups exhibited visually detectable, mean color differences that ranged from 3.06–5.21, except for A4B4. There was no statistical significance between the two materials when subjected to extraoral aging conditions. Conclusions: Visually perceptible and clinically unacceptable color changes occur when exposed to various extraoral aging conditions except for neutral soap solution immersion, for which values of Δ E* were clinically acceptable (ΔE < 3). It can be said for all practical purposes, clinically, the choice between M511 Maxillofacial Rubber (Part A: Part B = 10:1) and Z004 Platinum Silicone Rubber (Part A: Part B = 1:1) would yield more or less the same results, with unacceptable norms in terms of color stability under extraoral aging conditions.
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Affiliation(s)
- Siddharth Mehta
- Department of Prosthodontics, Bapuji Dental College and Hospital, Davangere, Karnataka, India
| | - D B Nandeeshwar
- Department of Prosthodontics, Bapuji Dental College and Hospital, Davangere, Karnataka, India
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Kheur M, Sethi T, Coward T, Kakade D, Rajkumar M. Evaluation of the effect of ultraviolet stabilizers on the change in color of pigmented silicone elastomer: An in vitro study. J Indian Prosthodont Soc 2016; 16:276-81. [PMID: 27621548 PMCID: PMC5000559 DOI: 10.4103/0972-4052.176535] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Aim and Objective: To compare and evaluate the effect of ultraviolet (UV) stabilizers (Chimassorb 81 and Uvinul 5050) on the color change of pigmented elastomer. Materials and Methods: Two pigments - Red (P112 Brilliant Red) and Yellow (P106 Yellow) and two UV stabilizers Chimassorb 81 and Uvinul 5050 were studied. A total of six groups of 10 samples each were fabricated using a combination of the above colors and stabilizers: Group A1 - Red control, Group A2 - Red + Chimassorb 81, Group A3 - Red + Uvinul 5050. Group B1 - Yellow control, Group B2 - Yellow + Chimassorb 81, Group B3 - Yellow + Uvinul 5050. All samples were subjected to ageing in an accelerated weathering chamber (Weather-Ometer). Color values L, a, and b were measured at 500 and 1000 h for all samples before and after weathering and change in color (Delta E) was calculated. Results: All groups showed a significant color change. At 500 h, Chimassorb 81 showed a statistically significant lesser change in both colors (red - 3.66 and yellow - 2.8) compared to their control groups (red - 5.19 and yellow - 4.9). At 1000 h, both UV stabilizers showed lesser color change (A2 - 5.49, B2 - 4.28, A3 - 7.47 and B3 - 4.09) as compared to their respective control groups (A1 - 9.57 and B1 - 5.91). Overall, the change in the color with Group A was more than Group B. Conclusion: Addition of UV stabilizers helped the reduction of color change. Chimassorb 81 showed a greater reduction in color change in both colors consistently at 500 and 1000 h.
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Affiliation(s)
- Mohit Kheur
- Department of Prosthodontics, Dr. D. Y. Patil Dental College, Pimpri, Maharashtra, India
| | - Tania Sethi
- Department of Maxillofacial Prosthetics, Kings College, London, United Kingdom
| | - Trevor Coward
- Department of Maxillofacial Prosthetics, Kings College, London, United Kingdom
| | - Dilip Kakade
- Department of Prosthodontics, Dr. D. Y. Patil Dental College, Pimpri, Maharashtra, India
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Abstract
Implant-retained auricular prostheses are a successful prosthetic treatment option for patients who are missing their ear(s) due to trauma, oncology, or birth defects. The prosthetic ear is aesthetically pleasing, composed of natural looking anatomical contours, shape, and texture along with good color that blends with surrounding existing skin. These outcomes can be optimized by the integration of digital technologies in the construction process. This report describes a sequential process of reconstructing a missing left ear by digital technologies. Two implants were planned for placement in the left mastoid region utilizing specialist biomedical software (Materialise, Belgium). The implant positions were determined underneath the thickest portion (of anti-helix area) left ear that is virtually simulated by means of mirror imaging of the right ear. A surgical stent recording the implant positions was constructed and used in implant fixtures placement. Implants were left for eight weeks, after which they were loaded with abutments and an irreversible silicone impression was taken to record their positions. The right existing ear was virtually segmented using the patient CT scan and then mirror imaged to produce a left ear, which was then printed using 3D printer (Z Corp, USA). The left ear was then duplicated in wax which was fitted over the defect side. Then, it was conventionally flasked. Skin color was digitalized using spectromatch skin color system (London, UK). The resultant silicone color was mixed as prescribed and then packed into the mold. The silicone was cured conventionally. Ear was trimmed and fitted and there was no need for any extrinsic coloring. The prosthetic ear was an exact match to the existing right ear in shape, skin color, and orientation due to the great advantages of technologies employed. Additionally, these technologies saved time and provided a base for reproducible results regardless of operator.
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Sethi T, Kheur M, Coward T, Patel N. Change in color of a maxillofacial prosthetic silicone elastomer, following investment in molds of different materials. J Indian Prosthodont Soc 2016; 15:153-7. [PMID: 26929503 PMCID: PMC4762312 DOI: 10.4103/0972-4052.158077] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
PURPOSE In the authors' experience, the color of silicone elastomer following polymerization in molds made of gypsum products is slightly different from the color that was matched in the presence of the patient, before the silicone is packed. It is hypothesized that the investing materials and separating media have an effect on the color during the polymerization process of the silicone. MATERIALS AND METHODS This study compares and evaluates the change in color of silicone elastomer packed in three commonly used investing materials - Dental stone (white color), dental stone (green color), and die stone (orange color); coated with three different separating media - Alginate-based medium, soap solution and a resin-based die hardening material. Pigmented silicone samples of dimensions 1.5 cm × 2 cm × 0.5 cm were made from the elastomer in the above-mentioned mold materials using combinations of the mentioned separating media. These served as test group samples. Control group samples were made by packing a mix of the same pigmented elastomer in stainless steel molds. The L*, a*, b* values of the test and control group samples were determined using a spectrophotometer. The change in color (Delta E) was calculated between the control and test groups. RESULTS The mean L, a, b values for the control group were, 31.8, 26.2, and 36.3, respectively. Average values of change in color (Delta E) for samples packed utilizing alginate-based medium, die hardener, and soap solution, respectively in white dental stone (2.70, 2.74, and 2.88), green dental stone (2.19, 2.23, 2.42), and orange die stone (3.19, 2.72, 2.80) were tabulated. CONCLUSION Among the investing materials studied, die stone showed the most color change (3.19), which was statistically significant. Among the separating media, die hardener showed the least color change (2.23). The best combination of an investing material and separating media as per this investigation is a dental stone (green) and alginate-based separating medium.
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Affiliation(s)
- Tania Sethi
- Department of Prosthodontics, M.A. Rangoonwala Dental of College and Research Centre, Pune, Maharashtra, India
| | - Mohit Kheur
- Department of Prosthodontics, M.A. Rangoonwala Dental of College and Research Centre, Pune, Maharashtra, India
| | - Trevor Coward
- Department of Maxillofacial Prosthetic Technology, Kings College, London, United Kingdom
| | - Naimesha Patel
- Department of Maxillofacial Prosthetic Technology, Kings College, London, United Kingdom
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Antimicrobial activity of conventional and plant-extract disinfectant solutions on microbial biofilms on a maxillofacial polymer surface. J Prosthet Dent 2016; 116:136-43. [PMID: 26922209 DOI: 10.1016/j.prosdent.2015.12.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 12/11/2015] [Accepted: 12/11/2015] [Indexed: 12/13/2022]
Abstract
STATEMENT OF PROBLEM Dentists often note problems with infection in patients with maxillofacial prostheses. Conventional disinfection protocols are not always effective and may alter the properties of the polymer used in the prosthesis. Thus, the search for improved disinfection methods is important. PURPOSE The purpose of this in vitro study was to evaluate and compare the antimicrobial activity of conventional disinfectant solutions (water and neutral soap and 4% chlorhexidine) and plant extracts (Cymbopogon nardus and Hydrastis canadensis) on specimens of maxillofacial silicone contaminated with Candida albicans and Staphylococcus aureus biofilms. MATERIAL AND METHODS Seventy-two silicone (MDX4-4210) specimens were fabricated (5×2 mm) and sterilized. Thirty-six were contaminated with C albicans (10(6) cells/mL) and 36 with S aureus (10(8) cells/mL) to evaluate the antimicrobial activity of the cleaning protocols. After incubation (37°C/72 hours), the specimens were divided into 5 groups: not disinfected (positive control), soaking in saline solution for 10 minutes, soaking in 4% chlorhexidine for 10 minutes, soaking in C nardus for 10 minutes, soaking in H canadensis for 10 minutes, and washing by hand with water and neutral soap for 30 seconds. The viability of cells was evaluated by XTT (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) assay and by scanning electron microscope analysis. The results were analyzed by ANOVA and the Tukey HSD test (α=.05). RESULTS All disinfection solutions provided a statistically significant reduction in biofilm viability compared with the control group for both microorganisms (P<.05). Washing with water and neutral soap was significantly more effective in reducing biofilm viability than immersion in the disinfection solutions, with persistence of viable microorganisms between 1.05% for C albicans and 0.62% for S aureus after this cleaning protocol. Photomicrographs revealed that 4% chlorhexidine altered the surface of the polymer. CONCLUSIONS Within the limitations of this in vitro study, it was concluded that the cleaning protocols with different disinfectant solutions produced a significant reduction in the viability of C albicans and S aureus biofilms on the silicone polymer. Washing with water and neutral soap was the most effective protocol against both microorganisms.
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Hatamleh MM, Polyzois GL, Nuseir A, Hatamleh K, Alnazzawi A. Mechanical Properties and Simulated Aging of Silicone Maxillofacial Elastomers: Advancements in the Past 45 Years. J Prosthodont 2016; 25:418-26. [DOI: 10.1111/jopr.12409] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2015] [Indexed: 11/28/2022] Open
Affiliation(s)
- Muhanad M. Hatamleh
- Cranio-Maxillofacial Prosthetics Unit, King's College Hospital; King's College London Denmark Hill Campus; London UK
| | | | - Amjad Nuseir
- Facutly of Medicine, Jordan University of Science and Technology; King Abdullah University Hospital; Irbid Jordan
| | | | - Ahmad Alnazzawi
- Department of Substitutive Dental Science; Faculty of Dentistry, Taibah University; Madinah Saudi Arabia
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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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Al-Harbi FA, Ayad NM, Saber MA, ArRejaie AS, Morgano SM. Mechanical behavior and color change of facial prosthetic elastomers after outdoor weathering in a hot and humid climate. J Prosthet Dent 2015; 113:146-51. [DOI: 10.1016/j.prosdent.2014.09.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 09/24/2014] [Accepted: 09/24/2014] [Indexed: 11/25/2022]
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Akash RN, Guttal SS. Effect of Incorporation of Nano-Oxides on Color Stability of Maxillofacial Silicone Elastomer Subjected to Outdoor Weathering. J Prosthodont 2015; 24:569-575. [DOI: 10.1111/jopr.12252] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/25/2014] [Indexed: 11/29/2022] Open
Affiliation(s)
| | - Satyabodh S. Guttal
- Department of Prosthodontics, SDM College of Dental Sciences & Hospital; Dharwad Karnataka India
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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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Willett ES, Beatty MW. Outdoor weathering of facial prosthetic elastomers differing in Durometer hardness. J Prosthet Dent 2014; 113:228-35. [PMID: 25455266 DOI: 10.1016/j.prosdent.2014.09.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 09/29/2014] [Accepted: 09/29/2014] [Indexed: 11/26/2022]
Abstract
STATEMENT OF PROBLEM Facial prosthetic elastomers with wide ranges in hardness are available, yet material weatherability is unknown. PURPOSE The purpose of this study was to assess color, Durometer hardness, and tensile property changes after 3000 hours of outdoor weathering. MATERIAL AND METHODS Unpigmented elastomers with Durometer hardness 5, 30, 50, 70, and A-2186 were polymerized into dumbbells (ASTM D412) and disks, 34 mm in diameter by 6 mm thick. Materials were subjected to outdoor or time passage environments for 3000 hours. CIELab color (n=5), Durometer hardness (n=5), and tensile mechanical properties (n=10) were measured at 0 and 3000 hours, and group differences were assessed by material and weathering condition (ANOVA/Tukey, α=.05). RESULTS Except for A-2186, the mean Durometer changes for all materials were 1 unit or less, with no significant differences observed between time passage and weathered groups (P≥.05). Three-thousand-hour tensile mechanical property results demonstrated nonsignificant differences between time passage and weathered materials but significantly changed properties from immediately tested materials (P<.001). Outdoor weathering induced perceptible but acceptable color changes (1.7≤ΔE*≤2.6) for elastomers with Durometer hardness 5 and 30 and A-2186. CONCLUSIONS With a few exceptions, outdoor weathering produced relatively small changes in color, Durometer hardness, or tensile properties compared with time passage.
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Affiliation(s)
- Emily S Willett
- Graduate student, College of Dentistry, University of Nebraska Medical Center, Lincoln, Neb
| | - Mark W Beatty
- Researcher, Veteran Affairs Nebraska-Western Iowa Healthcare System, Omaha, Neb; Professor and Director of Biomaterials, Department of Adult Restorative Dentistry, College of Dentistry, University of Nebraska Medical Center, Omaha, Neb.
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Dynamic Mechanical Thermal Analysis of Maxillofacial Prosthetic Elastomers. J Craniofac Surg 2014; 25:e251-5. [DOI: 10.1097/scs.0000000000000556] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Eleni PN, Krokida MK, Polyzois GL, Gettleman L. Effect of different disinfecting procedures on the hardness and color stability of two maxillofacial elastomers over time. J Appl Oral Sci 2013; 21:278-83. [PMID: 23857654 PMCID: PMC3881904 DOI: 10.1590/1679-775720130112] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 05/03/2013] [Indexed: 11/21/2022] Open
Abstract
OBJECTIVE Disinfection procedures often cause deterioration in a maxillofacial prosthesis. Color and hardness alterations could lead to a replacement of the prosthesis. MATERIAL AND METHODS An experimental chlorinated polyethylene (CPE) and a commercial polydimethyl siloxane (PDMS) sample were treated with four different disinfection procedures for a period which simulates 1 year of clinical service. The applied disinfection procedures included microwave exposure and immersion in three solutions, sodium hypochlorite, neutral soap and a commercial disinfecting soap. Shore A hardness (∆H) and color differences (∆E) were determined before and after each procedure. All data were analyzed by Two Way Analysis of Variance (ANOVA) and Tukey's post hoc tests at a level of α=0.05. RESULTS The samples presented significant alterations in color and hardness after the different disinfection treatments. The color differences (∆E) were at least eye detectable in all cases and clinically unacceptable in most of the cases, with values ranging from 1.51 to 4.15 and from 1.54 to 5.92 for the PDMS and CPE material, respectively. Hardness was decreased after all the disinfection procedures in the PDMS, while for the CPE, a decrement was observed after disinfection with sodium hypochlorite and neutral soap and an increment after microwave exposure and the disinfection with a commercial antimicrobial agent. The PDMS samples presented greater alterations in color and hardness after disinfection with sodium hypochlorite solution, while the microwave exposure caused negligible effects. The CPE samples were affected most after disinfection when treated with neutral soap, and more slightly when disinfected with sodium hypochlorite solution. CONCLUSIONS The disinfection procedures caused alterations in color and hardness of the examined materials. The most suitable disinfection procedure for the PDMS material is microwave exposure, while disinfection with sodium hypochlorite solution is not recommended. The CPE material is suggested to be disinfected with sodium hypochlorite solution and the use of neutral soap is not recommended. Comparing the two materials, the PDMS material is most color stable, while the CPE material presented fewer changes in hardness.
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Affiliation(s)
- Panagiota N Eleni
- Laboratory of Process Analysis and Design, Department of Chemical Engineering, National Technical University of Athens, Zografou Campus, Athens, Greece.
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Eleni PN, Perivoliotis D, Dragatogiannis DA, Krokida MK, Polyzois GL, Charitidis CA, Ziomas I, Gettleman L. Tensile and microindentation properties of maxillofacial elastomers after different disinfecting procedures. J Mech Behav Biomed Mater 2013; 28:147-55. [DOI: 10.1016/j.jmbbm.2013.07.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 07/12/2013] [Indexed: 10/26/2022]
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Influence of pigments and pigmenting methods on color stability of different silicone maxillofacial elastomers after 1-year dark storage. J Craniofac Surg 2013; 24:720-4. [PMID: 23714866 DOI: 10.1097/scs.0b013e3182800f23] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PURPOSE The purpose of this study was to measure spectrophotometrically the color changes of pigmented maxillofacial silicone elastomers with different pigments and pigmenting methods after storing 1 year in the dark environment. METHODS Three maxillofacial silicones, Cosmesil M511 (CosM511), Cosmesil M522 (CosM522), and Multisil-Epithetic (Mult-Epit), were selected for this study. A total of 240 specimens were fabricated; 80 of each of the 3 elastomers (n = 5) (18 mm in diameter and 2 mm in thickness) were prepared in 6 colorant categories (5 colorant and 1 with no colorant). Specimens were stored in a black box representing a condition of total darkness and placed in a dark environment at ambient room temperature (22°C ± 10°C) and humidity (50% ± 10%) for 1 year. A color spectrophotometer was used to measure the ΔE* values of the test specimens to determine the color changes. RESULTS The lowest color changes were observed in CosM511 in white color (ΔE* = 1.31) and in Mult-Epit in white color (ΔE* = 1.82) in extrinsic coloration group. The highest color changes were observed in yellow color in CosM511 (ΔE*= 21.61) and CosM522 (ΔE*= 23.78) in silicone pigmented intrinsic coloration method. In coloration methods, intrinsic silicone pigmented groups in all colors except brown in Mult-Epit had the highest ΔE* values. CONCLUSIONS Significant color changes were observed in both pigmented and unpigmented specimens, which were stored in dark environment and not exposed to sunlight.
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Kantola R, Lassila LVJ, Tolvanen M, Valittu PK. Color stability of thermochromic pigment in maxillofacial silicone. J Adv Prosthodont 2013; 5:75-83. [PMID: 23755330 PMCID: PMC3675297 DOI: 10.4047/jap.2013.5.2.75] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 04/22/2013] [Accepted: 05/07/2013] [Indexed: 12/03/2022] Open
Abstract
PURPOSE Maxillofacial silicone elastomer is usually colored intrinsically with color pigments to match skin colors. The purpose of this study was to investigate the color stability of a maxillofacial silicone elastomer, colored with a thermochromic, color changing pigment. MATERIALS AND METHODS Disc-shaped maxillofacial silicone specimens were prepared and divided into 3 groups: a conventionally colored control group, one group additionally colored with 0.2 wt% thermochromic pigment , and one group with 0.6 wt% thermochromic pigment. Half of the surface of each specimen was covered with an aluminium foil. All of the specimens were exposed to UV radiation in 6 hour cycles over 46 days. In between the UV exposures, half of the specimens were stored in darkness, at room temperature, and the other half was stored in an incubator, at a humidity of 97% and a temperature of +37℃. Color measurements were made with a spectrophotometer and registered according to the CIELAB L*a*b* color model system. The changes in L*, a* and b* values during artificial aging were statistically analyzed by using paired samples t-test and repeated measures ANOVA. P-values <.05 were considered as statistically significant. RESULTS The UV exposure resulted in visually noticeable and statistically significant color changes in the L*, a* and b* values in both of the test groups containing thermochromic pigment. Storage in the incubator lead to statistically significant color changes in the a* and b* values of the specimens containing thermochromic pigment, compared to those stored at room temperature. CONCLUSION The specimens containing thermochromic pigment were very sensitive to UV radiation, and the thermochromic pigment is not suitable, as such, to be used in maxillofacial prostheses.
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Affiliation(s)
- Rosita Kantola
- Vaasa Central Hospital, Vaasa, Finland. ; University of Turku, Institute of Dentistry, Department of Biomaterials Science and Turku Biomaterials Centre - TCBC, Turku, Finland
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Hatamleh MM, Polyzois GL, Silikas N, Watts DC. Effect of Extraoral Aging Conditions on Mechanical Properties of Maxillofacial Silicone Elastomer. J Prosthodont 2011; 20:439-46. [DOI: 10.1111/j.1532-849x.2011.00736.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Abstract
PURPOSE Prosthesis color production and stability as a result of pore entrapment during mixing has not been investigated for maxillofacial silicone prostheses. The purpose of this study was to investigate pore numbers and percentages of a maxillofacial silicone elastomer mixed by two different techniques, using X-ray microfocus computerized tomography (Micro-CT), and to investigate the effect of porosity on color reproducibility and stability after two different aging conditions. MATERIALS AND METHODS Sixty-four disk-shaped specimens were prepared (8-mm diameter, 3-mm thick) by mixing TechSil S25 silicone elastomer (Technovent, Leeds, UK) following two techniques: manual mixing (n = 32) and mechanical mixing under vacuum (n = 32). Half the specimens in each group were intrinsically pigmented, and the other half remained unpigmented. Pore numbers, volumes, and percentages were calculated using the Micro-CT, and then specimens of each subgroup were stored in simulated sebum for 6 months (n = 8), and exposed to accelerated daylight aging for 360 hours (n = 8). Color change (ΔE) was measured at the start and end of conditioning. Pore numbers and percentages were analyzed using one-way Analysis of Variance (ANOVA) and Dunnett's-T3 post-hoc tests (p < 0.05). Independent t-test was used to detect differences (p < 0.05) in ΔE between manually and mechanically mixed specimens, in both unpigmented and pigmented states and to detect differences (p < 0.05) in ΔE before and after conditioning within each mixing method. RESULTS Mechanical mixing under vacuum reduced the number and percentage of pores in comparison to manual mixing, within pigmented and unpigmented silicone specimens (p < 0.05). Perceptible ΔE between manual and mechanical mixing techniques were 5.93 and 5.18 for both unpigmented and pigmented specimens, respectively. Under sebum storage, manually mixed unpigmented specimens showed lower ΔE (p < 0.05) than those that were mechanically mixed; however, pigmented silicone specimens showed the same ΔE (p > 0.05). After light aging, mixing method had no effect on ΔE of unpigmented specimens (p > 0.05). Furthermore, mechanically mixed pigmented specimens showed lower ΔE (p < 0.05). CONCLUSIONS Within silicone elastomers (whether pigmented or unpigmented), mechanical mixing under vacuum reduced pore numbers and percentages in comparison to manual mixing. For selected skin shade, pores affected the resultant color of prosthesis (color reproducibility). Additionally, silicone pores affected silicone color stability upon service. CLINICAL SIGNIFICANCE In fabricating maxillofacial prostheses, mechanically mixing silicone under vacuum produces pore-free prostheses, tending to enhance their color production and stability.
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Affiliation(s)
- Muhanad M Hatamleh
- Department of Allied Dental Science, Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, Jordan.
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