scholarly journals Effect of nanoparticles on color stability and mechanical and biological properties of maxillofacial silicone elastomer: A systematic review

2020 ◽  
Vol 20 (3) ◽  
pp. 244
Author(s):  
NithinKumar Sonnahalli ◽  
Ramesh Chowdhary
2020 ◽  
pp. 009524432094679 ◽  
Author(s):  
Farah Rashid ◽  
Aparna Barman ◽  
Taseef Hasan Farook ◽  
Nafij Bin Jamayet ◽  
Mohd Firdaus Bin Yhaya ◽  
...  

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


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Anju Verma ◽  
Rajni Srivastava ◽  
Pankaj Kumar Sonar ◽  
Ramprakash Yadav

Abstract Background Rosa alba L. belongs to the family Rosaceae. This species is widely cultivated in Europe, Asia, North America, and Northwest Africa due to its fragrance, ornamental, and medicinal values. It is commonly known as white oil-bearing rose, white rose, white rose of York, backyard rose, and sufaid gulab. Main text Rosa alba L. has many biological properties like antioxidant, antimicrobial, antifungal, antifertility, teratogenic, memory enhancing, cytotoxic, and genotoxic activities. The essential oil of Rosa alba L. possesses good antimicrobial activity and consists of many chemical constituents like- citronellol, geraniol, nerol, linalool, citral, carvacrol, eugenol, etc. Conclusion This article briefly reviews the cultivation, traditional uses, phytochemistry, and biological activities of Rosa alba L. Many research papers have been published on the proposed plant and still, there is a very vast scope of research on it. Therefore, this review will be very fruitful for those scientists who are doing or plan to do research work on this plant. All the scientific findings written in this review are explored from Google web, Google Scholar, PubMed, ScienceDirect, Medicinal and Aromatic Plants Abstracts (MAPA), and SciFinder. To date, it is the first systematic review article of such kind, on this plant.


2021 ◽  
Author(s):  
Mei Ting Tieh ◽  
John Neil Waddell ◽  
Joanne Jung Eun Choi

Author(s):  
Gêisa Aiane de Morais Sampaio ◽  
Larissa Rangel Peixoto ◽  
Gabriella de Vasconcelos Neves ◽  
Danielle do Nascimento Barbosa

Author(s):  
Caroline G. Macêdo ◽  
Kelly Christina F. Castro ◽  
Edilene Oliveira da Silva

Background: Leishmaniases are anthropozoonotic vector-borne diseases, caused by the protozoan Leishmania spp. These diseases have significant morbidity and mortality worldwide and, as there are currently no vaccines available for their treatment, chemotherapy remains the mainstay for anti-leishmanial therapeutics. However, the severe side effects, reduced bioavailability, high cost and chemoresistance, amongst other problems, limit the use of available drugs. In recent years, natural compounds have shown promise as anti-leishmanial agents, especially those extracted from medicinal plants. The genus Piper has been used in traditional medicine and widely explored for its biological properties and bioactive phytocompounds. Aim: The aim of this study was to conduct a systematic literature review of the biological activity of the genus Piper against the etiological agents of leishmaniasis, to provide a perspective for effective and safe phytotherapics, new drugs or potentially active prototype chemical substances. Methodology: This systematic review was prepared in accordance with PRISMA guidelines. The databases used for this review were SciELO, Pubmed, ScienceDirect and Google Scholar, using a temporal profile of 2009 to 2020. Conclusion: In this review, we summarize a wide range of isolated compounds, extracts and essential oils of the genus Piper that are worth screening given their potential for development as effective anti-leishmanial drugs.


2020 ◽  
Vol 04 (1) ◽  
pp. 27-40
Author(s):  
Jaymin Taher ◽  
Salem Salem

Poly methyl methacrylate (PMMA) is one of the most widely used materials in modern prosthodontics. It is widely known due to its simplicity in use and acceptable aesthetic. A new concept of polymerization fluid resin technique was instead of heat and gypsum material. Forty specimens were prepared from two brands of fluid acrylic resin. The samples were divided into two groups, the first one was the control while the other group was incorporated with silver nanoparticles(modified). The tests performed were impact strength, transverse strength, color stability and candida retention ability on the samples. 10 samples for each test were used. The results showed that modified group had significantly higher impact strength than the control group. There was non-significant difference between group of modified fluid acrylic and control group. Regarding color stability, there were highly significant color change after 10 days of immersion in the tea solution for the modified group the results of the biological test showed that the candida retention of the control group was significantly higher than modified group. Within the limitation of this study it can be concluded that addition of silver nanoparticles has resulted in significant difference between control and modified group for impact strength test. While non-significant difference was seen for transverse strength test. In regard to color stability, showed enhancement in color stability for both before and after placement in tea solution. Addition of silver nanoparticles also caused reduction in candida albicans retention in the added samples.


Author(s):  
K Lekha ◽  
H Dharanendra Kumar

ABSTRACT Maxillofacial prosthetic materials either resin or elastomer used for the fabrication of facial prostheses have their own physical and mechanical properties. Maxillofacial prosthesis frequent replacement because the elastomer or acrylic resin and its pigments undergo color changes. Purpose Evaluate the effect of outdoor weathering on color stability of silicone and heat-cure acrylic with two different pigments. Materials and methods Total of 80 circular disk specimens, 40 silicone elastomer and 40 heat-cure clear acrylic resin were fabricated in the prepared mold and two dry earth pigments burnt sienna and cobalt blue was added to the specimens and it was subjected to simulated outdoor weathering. Before and after weathering, CIE values of both control and weathering groups were recorded by using spectrophotometer and tabulated. The obtained data were subjected to statistical analysis. Results Silicone elastomer with burnt sienna showed more color change when exposed to weathering followed by silicone with cobalt blue. Heat-cure with cobalt blue had shown some color change, heat-cure and burnt sienna were the most color stable. Conclusion From the study, it can be concluded that heat-cure acrylic resin with burnt sienna most color stable than silicone elastomer. How to cite this article Lekha K, Kumar HD, Meshramkar R, Nadiger RK. The Effect of Outdoor Weathering on Color Stability of Silicone and Acrylic Resin, Pigments-A Comparative Evaluation: An in vitro Study. Int J Prosthodont Restor Dent 2015;5(3):81-85.


2022 ◽  
Vol 9 ◽  
Author(s):  
Laura W. Ploughe ◽  
Lauchlan H. Fraser

The global use of off-road vehicles (ORVs) in natural environments has accelerated rapidly over the last few decades, resulting in significant social and environmental consequences. As the demand, use, and promotion of light-duty ORVs like all-terrain vehicles (ATVs), motorcycles, four-wheel drive trucks and sport utility vehicles (SUVs) increases in remote wilderness, the landscape is becoming fragmented into disorganized and destructive networks of trails and roads. Substantial ecological impacts to a wide range of ecosystem structures and functions will likely result from ORV activity. Applying a global systematic review, we examine 105 publications about plant, soil, and wildlife responses to ORV traffic in different habitats to help guide the direction of future research, monitoring programs, and mitigation efforts. Most studies investigated impacts to animals, followed by soils, then vegetative responses. Soil studies primarily focused on physical impacts to the soil (i.e., compaction, erosion, rut depth), but some studies suggest that soil chemical and biological properties may also be impacted by ORV traffic. The literature on plant responses to ORV activities primarily explored vegetation loss, although impacts on the plant community were also investigated. Animal studies investigated impacts of ORV use on invertebrates, mammals, birds, and to a lesser extent reptiles/amphibians, including population-level, community-level, and behavioral responses. Overall, research on environmental impacts of ORV traffic is biased to coastal and desert ecosystems in the northern hemisphere (primarily in the US), often does not address mechanisms that may produce ecological impacts (e.g., intensity of vehicular disturbance and ecosystem- or species-specific sensitivity to ORV activities), and frequently focused on short-term responses. More research is needed to understand the mechanisms that cause the different responses of soil, plant, and animals to ORVs over the long-term in a broad range of ecosystems to support real-time management and conservation efforts.


2019 ◽  
Vol 8 (4) ◽  
pp. 6798-6802

Corn starch, chitosan and red cabbage extract act as natural pH indicator to determine fruit spoilage by developing pH sensitive film and coating as the color changes based on pH of fruit. The film color changed from pink to purple and brownish with the changes of pH. pH indicator film and coating were assessed for their physical, chemical, mechanical and biological properties. The stability of the pigment was evaluated for 4 days with the presence and absence of light and with or without cooling effects. The film incorporated with red cabbage extract proven to have higher stability when stored at room temperature with the exposure to light. It also exhibits better color stability when kept under cold temperature in comparison to room temperature.


Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1786 ◽  
Author(s):  
Heber Isac Arbildo-Vega ◽  
Barbara Lapinska ◽  
Saurav Panda ◽  
César Lamas-Lara ◽  
Abdul Samad Khan ◽  
...  

The objective of this systematic review and meta-analysis was to determine the clinical effectiveness of bulk-fill and conventional resin in composite restorations. A bibliographic search was carried out until May 2020, in the biomedical databases Pubmed/MEDLINE, EMBASE, Scopus, CENTRAL and Web of Science. The study selection criteria were: randomized clinical trials, in English, with no time limit, with a follow-up greater than or equal to 6 months and that reported the clinical effects (absence of fractures, absence of discoloration or marginal staining, adequate adaptation marginal, absence of post-operative sensitivity, absence of secondary caries, adequate color stability and translucency, proper surface texture, proper anatomical form, adequate tooth integrity without wear, adequate restoration integrity, proper occlusion, absence of inflammation and adequate point of contact) of restorations made with conventional and bulk resins. The risk of bias of the study was analyzed using the Cochrane Manual of Systematic Reviews of Interventions. Sixteen articles were eligible and included in the study. The results indicated that there is no difference between restorations with conventional and bulk resins for the type of restoration, type of tooth restored and restoration technique used. However, further properly designed clinical studies are required in order to reach a better conclusion.


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