Interplay between toothbrush stiffness and dentifrice abrasivity on the development of non-carious cervical lesions

Objective

This study investigated the effect of toothbrush stiffness and dentifrice slurry abrasivity on the development and progression of simulated non-carious cervical lesions (NCCLs).

Materials and methods

Human maxillary premolars were allocated to 12 groups generated by the association between toothbrushes, soft, medium, and hard stiffness, and simulated dentifrice slurries, lower, medium, and higher; deionized water (DI) served as negative control. Teeth were mounted on acrylic blocks, and their root surfaces partially covered with acrylic resin to simulate gingiva, leaving a 2-mm area apical to the cemento-enamel junction exposed to toothbrushing. Specimens were brushed with the test slurries for 35,000 and 65,000 double strokes. Impressions taken at baseline and after both brushing periods were scanned by a 3D optical profilometer. Dentin volume loss (mm³) was calculated by image subtraction. Data were analyzed using three-way ANOVA and Fisher’s PLSD tests.

Results

All toothbrushes caused higher volume loss when associated to higher abrasive slurry, compared to medium- and lower-abrasive slurries. Medium caused more volume loss than lower-abrasive slurry, which led to more volume loss than DI. Hard and medium toothbrushes were not different when used with medium- or higher-abrasive slurries. There were no differences among toothbrushes when used with DI and lower-abrasive slurry. Overall, 35,000 brushing strokes resulted in significantly less volume loss than 65,000.

Conclusions

Toothbrush stiffness was an important factor on NCCL development, especially when brushing with medium- and higher-abrasive slurries.

Clinical relevance

Medium and hard toothbrushes associated with medium- and high-abrasive toothpastes can yield more severe NCCLs.

     

Perspectives of physicians practicing in low and middle income countries towards generic medicines: A narrative review

Objectives

This review was conducted to document published literature related to physicians’ knowledge, attitudes, and perceptions of generic medicines in low- and middle-income countries (LMICs) and to compare the findings with high-income countries.

Methods

A systematic search of articles published in peer-reviewed journals from January 2001 to February 2013 was performed. The search comprised nine electronic databases. The search strategy involved using Boolean operators for combinations of the following terms: generic medicines, generic medications, generic drugs, generic, generic substitution, generic prescribing, international non-proprietary, prescribers, doctors, general practitioners, physicians, and specialists.

Results

Sixteen articles were included in this review. The majority (n = 11) were from high income countries and five from LMICs. The main difference between high income countries and LMICs is that physicians from high income countries generally have positive views whereas those from LMICs tend to have mixed views regarding generic medicines. Few similarities were identified among different country income groups namely low level of physicians’ knowledge of the basis of bioequivalence testing, cost of generic medicines as an encouraging factor for generic medicine prescribing, physicians’ concerns towards safety and quality of generic medicines and effect of pharmaceutical sales representative on generic medicine prescribing.

Conclusion

The present literature review revealed that physicians from LMICs tend to have mixed views regarding generic medicines. This may be due to differences in the health care system and pharmaceutical funding system, medicine policies, the level of educational interventions, and drug information sources in countries of different income levels.     

Effect of Dietary Protein and Processing on Gut Microbiota—A Systematic Review

The effect of diet on the composition of gut microbiota and the consequent impact on disease risk have been of expanding interest. The present review focuses on current insights of changes associated with dietary protein-induced gut microbial populations and examines their potential roles in the metabolism, health, and disease of animals. Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol was used, and 29 highly relevant articles were obtained, which included 6 mouse studies, 7 pig studies, 15 rat studies, and 1 in vitro study. Analysis of these studies indicated that several factors, such as protein source, protein content, dietary composition (such as carbohydrate content), glycation of protein, processing factors, and protein oxidation, affect the digestibility and bioavailability of dietary proteins. These factors can influence protein fermentation, absorption, and functional properties in the gut and, consequently, impact the composition of gut microbiota and affect human health. While gut microbiota can release metabolites that can affect host physiology either positively or negatively, the selection of quality of protein and suitable food processing conditions are important to have a positive effect of dietary protein on gut microbiota and human health.     

Outcomes of tracheostomy in COVID-19 patients in National Guard Health Affairs,Riyadh, Saudi Arabia

Objectives:To evaluate coronavirus disease 2019 (COVID-19) patient tracheostomy outcomes.Methods:All COVID-19 patients at the National Guard Hospital, Riyadh, Saudi Arabia, were retrospectively recruited. Those who had tracheostomies between April and December 2020 were included.Results:The population was 45 patients, of which 30 (66.7%) were males, 15 (33.3%) were females and the mean age was 66.76±12.74 years. The tracheostomy indications were anticipated prolonged weaning in 40 (88.9%) and failed extubation in 5 (11.1%) of the patients. The mean intubation to tracheostomy duration was 20.62±7.21 days. Mortalities were high, with most attributed to COVID-19. Mortality and a pre-tracheostomy C-reactive protein (CRP) uptrend were significantly related (p=0.039). Mortality and intubation to tracheostomy duration were not significantly related. The mean post-tracheostomy time to death was 10.64±6.9 days. Among the survivors, 20 (44.4%) males and 11 (24.4%) females were weaned off mechanical ventilation; 9 (20%) remained on ventilation during the study. The mean ventilation weaning time was 27.92±20 days.Conclusion:The high mortality rate was attributed to COVID-19. Mortality and a pre-tracheostomy CRP uptrend were significantly related; uptrend patients experienced far more mortalities than downtrend patients. Unlike previous findings, mortality and intubation to tracheostomy duration were not significantly related.     

Incretin Response to a Standard Test Meal in a Rat Model of Sleeve Gastrectomy with Diet-Induced Obesity

Background

Currently, the most effective treatment for obesity is bariatric surgery. Gastroduodenal bypass surgery produces sustained weight loss and improves glycemic control and insulin sensitivity. Previous studies have shown that sleeve gastrectomy (SG) produces similar results and implicate changes in incretin hormone release in these effects.

Methods

Male Sprague–Dawley rats were divided into four groups; lean control (lean), diet-induced obesity (DIO), DIO animals that had undergone SG (SG), and DIO animals that had undergone a sham operation (sham).

Results

After a 2-week recovery period, the incretin response to a standard test meal was measured. Blood sampling was performed in free-moving rats at various time points using chronic vascular access to the right jugular vein. There was a significant increase in the bodyweight of DIO animals fed a high-fat/high-sugar diet compared with the lean animals, which was reversed by SG. DIO caused an impairment of the GLP-1 response to a standard test meal, but not the GIP response. SG resulted in a dramatic increase in the GLP-1 response to a standard test meal but had no effect on the GIP response.

Conclusions

A rapid rise in blood sugar was observed in the SG group following a standard test meal that was followed by reactive hypoglycemia. SG dramatically increases the GLP-1 response to a standard test meal but has no effect on GIP in a rat model of DIO.