Background: One of the most common problem associated with the used of soft denture lining material is microorganisms and fungal growth especially Candida albicans, which can result in chronic mucosal inflammation. The aim of this study was to evaluate the influence of chlorhexidine diacetate (CDA) salt Incorporation into soft denture lining material on antifungal activity; against Candida albicans, and the amount of chlorhexidine di-acetate salt leached out of soft liner/CDA composite. Furthermore, evaluate shear bond strength and hardness after CDA addition to soft liner Materials and methods: chlorhexidine diacetate salt was added to soft denture lining material at four different concentrations (0.05%, 0.1% and 0.2% by weight). Four hundred and fifty specimens were made and divided into four groups according to the test to be performed. Disk diffusion test was used to evaluate the antifungal activity of the soft liner/CDA composite after four different periods of incubation in artificial saliva. UV spectroscopy was used to evaluate the amount of accumulative and periodic CDA released in artificial saliva after 2 days, 2 weeks and 4 weeks incubation in artificial saliva. The shear bond strength and shore A hardness was measured after 2 and 4 weeks incubation in artificial saliva and the results were statistically analyzed. Results: All experimental groups showed a highly significant increase in diameter of inhibition zone around the test specimen in compare with control group. The release of Chlorhexidine showed to be dose dependent. The shore A hardness a highly significant increase with the addition of CDA and as for shear bonding strength, the addition of CDA at 0.5% and 1.5% percentage resulted in a highly significant decrease in bond strength, while 2.5% and 3.5% percentage showed non-significant differences in compare with control. Conclusion: soft denture lining material with antifungal properties was the result of CDA salt incorporation which indicate that chlorhexidine was released in affected concentration from soft liner/CDA composite. This incorporation resulted in Hardness increase and did not affect the shear bond strength for 2.5% and 3.5% percentage. Keywords: Soft denture liners, antifungal activity, chlorhexidine diacetate salt.
Objectives: Maxillofacial silicone is used to restore abnormalities due to congenital or acquired causes. However, the quality of silicone is far from ideal. This study was aimed at assessing the influence of the addition of cellulose nanofibers (CNFs; several nanometers wide and 2-5 micro m long) on the physical and mechanical characteristics of maxillofacial silicone elastomers. Methods: Two CNF weight percentages (0.5% and 1%) were tested, and 180 specimens were divided into one control and two experimental groups. Each group was subdivided into six subgroups. In each subgroup, ten specimens subjected to each of the following tests: tearing strength, Shore-A hardness, tensile strength, elongation percentage, surface roughness, and color
... Show MoreIn this research Epoxy resin was reinforced by nano alumina (AL2O3) particles in grain size(25-30 nm) with two weight ratios (2,4)% then compared with pure Epoxy. Four mechanical tests were performed on these materials include Hardness, flexural, impact & compression strengths before and after immersion in tap water and chemical solutions (CH3COOH) acid, (KOH) base at (0.5N) ,The diffusivity coefficients of all prepared samples were calculate after immersion in water and chemical solutions mentioned above , the results were showed that the Flexural, Impact & Hardness increase after addition the ceramic particles (AL2O3) while the immersion process results showed illustrated different values from sample to other.
Enzymatic hydrolysis process of lignocellulosic biomass materials is difficult because of inherent structural features of biomass, which represents barriers that prevent complete hydrolysis; therefore, pretreatment techniques are necessary to render biomass highly digestible in enzymatic hydrolysis process. In this research, (non?) oxidative short-term lime pretreatment of willow wood was used. A weight of 11.40 g of willow wood was mixed with an excess of calcium hydroxide (0.4 g Ca(OH)2/g raw biomass) and water loading (15 g/g raw biomass). Lime pretreatment was carried out for various periods of time including 1, 2, 3.5, 5 and 6 h, with temperatures at 100, 113, 130, 147 and 1600C, and oxygen pressures as o
... Show MoreBackground: The mechanical and physical properties of Polymethyl methacrylate (PMMA) don’tfulfill the entire ideal requirements of denture base materials. The purpose of this study was to produce new modified polymer nanocomposite (PMMA /ZrO2-TiO2) andassess itsimpact strength, transverse strength and thermal conductivity in comparison to the conventionalheat polymerized acrylic resin. Materials and Methods: Both ZrO2 and TiO2nano fillers were silanized with TMSPM (trimethoxysilyl propyl methacrylate) silane coupling agent before beingdispersed by ultrasonication with the methylmethacrylate (monomer) and mixed with the polymer by means of 2% by weight in (1:1) ratio, 60 specimens were constructed by conventional water bath processing
... Show MoreIn order to implement the concept of sustainability in the field of construction, it is necessary to find an alternative to the materials that cause pollution by manufacturing, the most important of which is cement. Because factory wastes provide siliceous and aluminous materials and contain calcium such as fly ash and slag that are used in the production of high-strength geopolymer concrete with specifications similar to ordinary concrete, it was necessary for developing this type of concrete that is helping to reduce CO2 (dioxide carbon) in the atmosphere. Therefore, the aim of this study was to study the influence of incorporating various percentages of slag as a replacement for fly ash and the effect of sl
... Show MoreThis study included preparation for the unsaturated polyester samples before and after reinforced by the Alumina oxide powder of different volume fraction amounting (2%,4%,6%). And this research included the study of some of mechanical properties such as (Hardness,compressive,wear). The results showed that the increase of the hardness and compressive strength after the reinforced and the increase with the volume fraction increase. As the wear test shows that the wear rate increases with applied load increase(5,10,15) from (10.6-18.6) gm/cm befor reninforced and from(5.4-15.2)gm/cm,(4.7-12.9)gm/cm,(48.1)gm/cm,after reinforced from the different volume fraction, and t
... Show MoreThin films of pure yttrium oxide (Y2O3) and doped with cerium oxide (CeO2) were prepared by the chemical spray pyrolysis(CSP)method. The structural, optical and electrical properties of the prepared films were investigated. The analysis of X-ray diffraction (XRD) thin films revealed that the undoped and doped Y2O3 were amorphous with a broad hump around 27o and narrow humps around 48o and 62o for all samples. Except for the Y2O3:6wt.%CeO2 thin film, all had signal preferential orientation along the (100) plane at 2θ=12.71o which belongs to CeO2, Field emission scanning electron mic
... Show MoreThe research involves using phenol – formaldehyde (Novolak) resin as matrix for making composite material, while glass fiber type (E) was used as reinforcing materials. The specimen of the composite material is reinforced with (60%) ratio of glass fiber.
The impregnation method is used in test sample preparation, using molding by pressure presses.
All samples were exposure to (Co60) gamma rays of an average energy (2.5)Mev. The total doses were (208, 312 and 728) KGy.
The mechanical tests (bending, bending strength, shear force, impact strength and surface indentation) were performed on un irradiated and irrad
... Show MoreThis study included preparation for the unsaturated polyester samples before and after reinforced by Alumina oxide powder and copper oxide powder of different volume fraction amounting (3%,5%,8%). And this reearch included study of some of mechanical properties such as (hardness,compressive and wear).The results showed that increase of the hardness and compressive strength after the reinforced and increase with the volume fraction increase.As the wear test show that the wear rate increases with applied load from the different load(5,10,15)N,and the wear rate decreases with the volume fraction increase.