Influences of Successive Exposure to Bleaching and Fluoride Preparations on the Surface Hardness and Roughness of the Aged Resin Composite Restoratives.

Background and Objectives: Surfaces of composite restorations are adversely affected upon bleaching and topical fluoride application. Such a procedure is normally carried out in the presence of restorations already serving in a different oral environment, although previous in vitro studies only considered the freshly-prepared composite specimens for assessment. The current study accordingly aimed to evaluate both the surface hardness and roughness of aged composite restoratives following their successive exposure to bleaching and topical fluoride preparations. Materials and Methods: Disc specimens were prepared from micro-hybrid, nano-filled, flowable and bulk-fill resin composites (groups 1-4, n = 60 each). All specimens were subjected to artificial aging before their intermittent exposure to surface treatment with: none (control), bleach or topical fluoride (subgroups 1-3, n = 20). All surface treatments were interrupted with two periods of 5000 thermal cycles. Specimens' surfaces were then tested for both surface hardness (Vickers hardness number (VHN), n = 10) and roughness (Ra, n = 10). The collected VHNs and Ras were statistically analyzed using two-way ANOVA and Tukey's comparisons at α = 0.05 to confirm the significance of differences between subgroups. Results: None of the tested composites showed differences in surface hardness and roughness between the bleached and the non-treated specimens (p > 0.05), but the bleached flowable composite specimens only were rougher than their control (p < 0.000126). In comparison to the control, fluoride treatment not only reduced the surface hardness of both micro-hybrid (p = 0.000129) and flowable (p = 0.0029) composites, but also increased the surface roughness of all tested composites (p < 0.05). Conclusion: Aged composite restoratives provide minimal surface alterations on successive bleaching and fluoride applications. Flowable resin composite is the most affected by such procedures. Although bleaching seems safe for other types of composites, the successive fluoride application could deteriorate the aged surfaces of the tested resin composites.

Patterns, Types, and Outcomes of Head Injury in Aseer Region, Kingdom of Saudi Arabia.

BACKGROUND: Head injuries contribute to almost 50% of all injuries. Head injuries are still one of the major causes of loss of life and loss of function among young adults. Nowadays, head injury has become a major community problem. Recently, head injury has become one of the biggest issues of almost more than 57 million people in the whole world living with the neurological problem raised by TBI, in which 10 million people require hospital base care. OBJECTIVES: To determine the epidemiological aspects of patients with head injury (HI) in Aseer Central Hospital (ACH). MATERIALS AND METHODS: This is a retrospective cross-sectional study. Data were gathered from patients' files and the registrar's database of ACH. The study duration was January 2015-December 2017. All patients with head injury admitted to ACH during the study duration were included in the study. SPSS software was used for analysis. Descriptive statistics were obtained (mean SD frequencies, percentages). Statistical tests, t test, and chi-squared test were applied to measure the significant difference among the variables. P-value less than 0.05 was considered as a significant difference. RESULTS: There were 353 patients with head injury, and the mean ± SD of age was 27.01 ± 13.9. Motor vehicle accidents (MVA) accounted for (89.3%) of head injury. A total of 87.3% of the patients were male while 12.7% were female. CONCLUSION: In this study, we observed that MVA is the leading cause of brain/head injuries in the KSA, despite the implementations of new speed rules. However, with new regulations of forbidding cell phone use while driving and forcing the seat belt regulations, a major impact on these numbers is expected in the future. Thus, a future study is recommended to assess these expectations.

Obesity and associated risk factors among students of health colleges of King Saud University, Saudi Arabia: A cross-sectional study.

OBJECTIVE: To determine the prevalence of obesity and associated risk factors among medical students in Saudi Arabia. METHODS: The cross-sectional study was conducted from December 2012 to March 2013 at King Saud University, Riyadh, Saudi Arabia. Using stratified sampling technique, undergraduate students of either gender from the health colleges were included. Information was collected through a pretested questionnaire. Measurements of the height and weight were noted and body mass index for all the subjects was calculated. RESULTS: Of the 292 students, 146(50%) were males and 146(50%) were females. Obesity was found in 40(13.7%)students. It was more prevalent among males than females (p<0.05) and among those who had chronic diseases (p<0.001). Family history of obesity was significantly associated with obesity (p=0.016). No significant association was found between physical activity and obesity (p=0.863). CONCLUSIONS: There was considerable prevalence of obesity among the medical students. Being male, having family history of obesity, and having chronic diseases were important risk factors.