The Potential of Natural Leaf Extracts as Green Inhibitors for Mild Steel Corrosion in Hydrochloric Acid Solutions

The inhibitive and thermodynamic behavior of Abelmoschus Esculentus and Citrus Maxima leaf extracts on the corrosion of mild steel in Hydrochloric acid solutions were investigated using potentiodynamic polarization curves measurements and electrochemical impedance spectroscopy (EIS) technique. Fourier transform infrared spectroscopy (FTIR) was done to predict some suggested chemical constituent of both leaf extracts. At any given concentration Abelmoschus Esculentus leaf extract is more efficient as a corrosion inhibitor for mild steel in 0.5 M HCl solutions than Citrus Maxima leaf extract. Potentiodynamic polarization curves indicated that both leaf extracts act as mixed type inhibitors for mild steel in 0.5 M HCl solutions. The impedance responses indicated that the corrosion process takes place under activation control. The inhibition of these plant leaf extracts depends on the physical adsorption of the chemical constituents of the extracts on mild steel surface as confirmed by Scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS)

Characteristics of dental fear among Arabic-speaking children: a descriptive study

BACKGROUND: Dental fear has not only been linked to poor dental health in children but also persists across the lifespan, if unaddressed, and can continue to affect oral, systemic, and psychological health. The aim of this study was to assess the factor structure of the Arabic version of the Children’s Fear Survey Schedule-Dental Subscale (CFSS-DS), and to assess the difference in factor structure between boys and girls. METHODS: Participants were 220 consecutive paediatric dental patients 6–12 years old seeking dental care at the Faculty of Dentistry, King Abdulaziz University, Saudi Arabia. Participants completed the 15-item Arabic version of the CFSS-DS questionnaire at the end of the visit. Internal consistency was assessed using Cronbach’s alpha. Factor analysis (principal components, varimax rotation) was employed to assess the factor structure of the scale. RESULTS: The Cronbach’s alpha was 0.86. Four factors with eigenvalues above 1.00 were identified, which collectively explained 64.45% of the variance. These factors were as follows: Factor 1, ‘fear of usual dental procedures’ consisted of 8 items such as ‘drilling’ and ‘having to open the mouth’, Factor 2, ‘fear of health care personnel and injections’ consisted of three items, Factor 3, ‘fear of strangers’, consisted of 2 items. Factor 4, ‘fear of general medical aspects of treatment’, consisted of 2 items. Notably, four factors of dental fear were found in girls, while five were found in boys. CONCLUSIONS: Four factors of different strength pertaining to dental fear were identified in Arabic-speaking children, indicating a simple structure. Most items loaded high on the factor related to fear of usual dental procedures. The fear-provoking aspects of dental procedures differed in boys and girls. Use of the scale may enable dentists to determine the item/s of dental treatment that a given child finds most fear-provoking and guide the child’s behaviour accordingly. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1472-6831-14-118) contains supplementary material, which is available to authorized users

Estimation of Population Total using Local Polynomial Regression with Two Auxiliary Variables

In this paper, the estimation for finite population total of a study variable will be considered, and the local linear regression will be used. The study variable is available for the sample and is supplemented by two auxiliary variables, which are available for every element in the finite population. Also, the resampling methods will be combined with the local linear regression method to estimate the total. The comparisons between different methods will be performed based on the mean squared error (MSE), mean absolute error (MAE), and mean absolute percentage error (MAPE). A simulation study is carried out to assess the effects

Estimation of Population Total using Local Polynomial Regression with Two Auxiliary Variables

In this paper, the estimation for finite population total of a study variable will be considered, and the local linear regression will be used. The study variable is available for the sample and is supplemented by two auxiliary variables, which are available for every element in the finite population. Also, the resampling methods will be combined with the local linear regression method to estimate the total. The comparisons between different methods will be performed based on the mean squared error (MSE), mean absolute error (MAE), and mean absolute percentage error (MAPE). A simulation study is carried out to assess the effects

The Use of Pit and Fissure Sealants—A Literature Review

This paper reviews the literature and discusses the latest updates on the use of pit and fissure sealants. It demonstrates the effectiveness of pit and fissure sealants in preventing caries and the management of early carious lesions. It compares the use of different sealant materials and their indications. It describes the application technique for sealants. It also reviews the cost-effectiveness of sealants as a preventive strategy. From this review and after the discussion of recently published studies on pit and fissure sealants, it is evident that sealants are effective in caries prevention and in preventing the progression of incipient lesions. It is therefore recommended that pit and fissure sealant be applied to high-caries-risk children for optimum cost-effectiveness. It is a highly sensitive technique that needs optimum isolation, cleaning of the tooth surface, etching, and the application of a thin bonding layer for maximum benefit. Recall and repair, when needed, are important to maximize the effectiveness of such sealant use

Improved corrosion resistance of permanganate-phosphate conversion coat on steel surface by surfactants

Abstract In the present work, we studied the effect of the presence of different concentrations of each of Triton-X-100 and Tween-80 surfactants in the bath of permanganate-phosphate conversion coating (PPC) on the corrosion resistance and the microstructure of the prepared coats. The coats were investigated using a scanning electron microscope (SEM), an energy dispersive X-ray spectrometer (EDX), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization techniques. The SEM results show that, on addition of the surfactants to the PPC bath, the porosity of the coat decreases and the coating layer becomes more compact. EIS results indicated that the presence of 0.01 M Triton-X-100 or 0.01 M Tween-80 in the coating solution caused an increase in the protection efficiency of the coat up to 93.7% and 84.1%, respectively. The potentiodynamic polarization results indicated that the two surfactants mainly act as anodic inhibitors due to the adsorption of their molecules at the anodic sites of the surface of steel and retard its oxidation reaction. The EDX and XPS results confirmed the results of the other techniques. A mechanism for the role of the surfactants in the coating process was proposed using the results of XPS and the other techniques

Myofunctional Trainer versus Twin Block in Developing Class II Division I Malocclusion: A Randomized Comparative Clinical Trial

This study aimed to evaluate and compare the dentoalveolar effects of the myofunctional trainer T4KTM versus twin block in children with class II division I malocclusion. Two parallel arm randomized comparative clinical trial was conducted, including twenty healthy children, 9–12 years old, showing Angle’s class II division I malocclusion due to mandibular retrusion. Children were randomly assigned into two groups according to the appliance used; Group 1: T4k, and Group II: twin block. Follow-up was done every 4 weeks for 9 months. Postoperative cephalometric X ray, study casts and photographs were taken for measurements and comparison. T4K showed a statistically significant reduction in the overjet (−2.50 ± 1.00 mm) (p < 0.0001), and a significant increase in the lower arch perimeter (LAP) (1.19 ± 0.96 mm) (p = 0.01). The twin block showed a statistically significant reduction in the overjet (−3.75 ± 1.10 mm) (p < 0.0001), a significant reduction in the overbite (−16.22 ± 17.02 %) (p = 0.03), and a significant increase in the LAP (1.69 ± 0.70 mm) (p < 0.0001). The overjet showed a higher significant decrease in the twin block group than in T4K (p = 0.03). The mean values of the overbite were significantly decreased in twin block than in T4k (p < 0.0001). Both groups showed significant dentoalveolar improvements toward class I occlusion; however, the twin block showed significantly better results than T4K appliance

Atraumatic Restorative Treatment and Interim Therapeutic Restoration: A Review of the Literature

This review discusses the techniques and uses of atraumatic restorative treatment (ART) and interim therapeutic restoration (ITR) and states the differences between these two approaches. ART and ITR are similar approaches and are performed using the same material, but they differ in the purpose of their use. ART is used in cases when there are obstacles to reaching dental care units and has been proven to have high success rates in primary and permanent dentitions. ITR is used as a temporary restoration that will be replaced with a more definitive one. ITR is used in cases when the ideal dental treatment cannot be performed. Conventional glass polyalkenoate (ionomer) restorative cement (GIC) is the material of choice that has been used for ART and ITR. This is because of its fluoride release properties, including its ability to bond to enamel and dentine, its pulpal biocompatibility, and its ease of manipulation. High-viscosity glass ionomer performed better than low and medium-viscosity glass ionomer in ART. Combining GIC with conditioner, as well as the use of a chemo-mechanical approach, improved the success rate of ART. Both ATR and ITR are acceptable strategies, with success rates comparable to the traditional treatment methods