Badreldin A. Mohamed

Sociodemographic Characteristics as Predictors of Satisfaction in Public and Private Dental Clinics

Objective: This study aimed to investigate influence of multiple sociodemographic characteristics on the patient satisfaction levels in outpatient public and private dental practices of Riyadh, Saudi Arabia. Methods: Questionnaire-based survey data were collected from 500 patients, 250 each from the public and private dental clinics of Riyadh, Saudi Arabia from September to December, 2017. Questions related to demographic factors and service attributes were included. A Likert scale of 5-points was used to measure satisfaction levels. Data was analyzed to calculate the descriptive and inferential statistics (analysis of variance and multiple regression analysis) to find the statistical difference (p < 0.01). Results: Satisfaction level differed significantly by education level (P< 0.001) and the type of clinic (P<0.001). The multiple regression analysis suggest that all variables influenced satisfaction, except age and marital status. The satisfaction score was higher by 27% for private clinics compared to public clinics. Conclusion: This study was exploratory and revealed an effect of individual variables on overall satisfaction score of the services attributes. Future plans for patient care could be developed with the help of this research.

Influence of primers on the properties of the adhesive interface between resin composite luting cement and fiber-reinforced composite

OBJECTIVES The purpose of this study was to characterize the adhesive interface formed due to the dissolving capability of 4 primer systems into pre-polymerized semi-interpenetrating polymer network (semi-IPN)-based fiber-reinforced composite (FRC) and luting cement. MATERIALS AND METHODS Semi-IPN FRC (everStick C&B, StickTech) prepregs stored for various durations (at 4 °C; 1, 1.5, and 3 years) were used to fabricate the specimens. FRC specimens (n = 10) were light-cured and treated with primers before adhering a luting cement onto them. Each age group was divided into four subgroups according to the primer used: no priming, a dimethacrylate adhesive primer, universal primer, and primer intended for composite surfaces. The degree of monomer conversion (DC%) of the luting cement; nanohardness, elastic modulus and structural information of the luting cement-FRC adhesive interface were measured. RESULTS According to analysis of variance (P ≤ 0.05), no statistical difference was observed in the DC% among the tested groups. However, both universal and composite primers showed increased nanohardness in 1- and 1.5-year-aged groups. The highest nanohardness (0.55 ± 0.21 GPa) and elastic modulus (14.27 ± 5.19 GPa) were observed in specimens of 1-year-aged FRC primed with the application of universal primer. Raman spectroscopy and scanning electron microscopy examination confirmed the presence of poly(methyl methacrylate) at the interface when the FRC prepregs were aged for 3 years before use. CONCLUSION Both primers improved diffusion of monomers of composite luting cement into the polymerized semi-IPN polymer structure and possible covalent binding with pendant methacrylate groups in the polymer matrix of FRC. The diffusing capability of universal and composite primers might increase the opportunity to form solid adhesive interface bonding between the FRC and composite luting cement.

Physical, mechanical, chemical and thermal properties of nanoscale graphene oxide-poly methylmethacrylate composites

The purpose of this laboratory study was to formulate and characterize the graphene oxide-poly(methyl methacrylate) resin composite with an intended use as bone cement. Graphene oxide was fabricated through ultrasonication route. The autopolymerization resin (Eco Cryl Cold, Protechno, Vilamalla Girona, Spain) was used to prepare the specimens of required dimensions for different testing parameters. The control group (C-group) was prepared as such. However, for GO1-group, 0.024 wt/wt.-% of graphene oxide was incorporated in a resin matrix and GO2-group was a composite with 0.048 wt/wt.-% of graphene oxide in a resin matrix. TEM examination of graphene oxide sheets demonstrated them in the range of ∼500 nm to ∼2 µm. The mechanical properties were characterized using three-point bending and wear resistance, while material properties were assessed through transmission electron microscope, scanning electron microscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, differential scanning calorimetry and thermo-gravimetric analysis. The results suggest that 0.024 wt/wt.-% and 0.048 wt/wt.-% of loading of GO have no effect on the physiochemical characteristics. However, thermal characteristics might slightly be improved. According to the analysis of variance results (p < 0.05, n = 5), wear resistance and bending strength of both GO1 and GO2 groups significantly improved compared to C-group. The bending strength of GO2 improved to 87.0 ± 7.2 MPa from 65.9 ± 11.5 MPa of C-group. Scanning electron microscopy examination of the fractured surface demonstrated granule like structure where the graphene oxide sheets might be covered inside PMMA. The use of GO-PMMA composites favorably enhances the mechanical properties of bone cement.

Correlates of condom use among males in North Sudan

UNLABELLED Objectives In sub-Saharan Africa countries, HIV infections are transmitted primary through heterosexual contact. Correct and consistent condom use has been promoted as a method to prevent sexually transmissible infections, including HIV. The aim of this study was to assess and determine the factors influencing condom use in Khartoum, Sudan. MATERIALS AND METHODS Out of the 45 voluntary counselling and testing centres in Khartoum region, 10 centres were selected. A random sample of 804 respondents aged 20-40 years was selected. Stepwise multiple logistic regression analysis was used to investigate the predictors of condom use. RESULTS About 12% of respondents reported using condoms consistently, 41.5% used them sporadically and 46.3% were nonusers. Most of the participants had problems with condom use (81.9%) and friends were the main source of condoms (72%). Knowledge about AIDS transmission, knowing someone who is infected with or had died of AIDS, experiencing condom problems, type of sexual partners, purchase embarrassment and education were the main predictors of condom use. CONCLUSIONS Condom use among the Sudanese is low. Strategies to promote condom use should focus on price support for condoms by the government, expanded private sector condom distribution and the integration of sex education in school curriculums or via frequent discussion on television.