126 research outputs found
Effectiveness of Sports Mouthguards
Participants in a wide variety of sports commonly experience orofacial injuries. Dentists have a responsibility for both the treatment and prevention of these injuries. Equipment for the protection of the face and mouth includes facemasks and mouthguards.
There are three broad categories of mouthguards:
• Type 1 (Stock) mouthguards are purchased over the counter at sports shops;
• Type 2 (Mouth-formed) mouthguards are purchased in the same way but are modified in the mouth to improve fit;
• Type 3 (Custom-made) mouthguards are made in the laboratory on casts made from impressions of the mouth.
Evidence suggests that mouthguards can help prevent damage to soft tissues and teeth and possibly prevent concussion. Custom-made mouthguards are the most retentive and are best tolerated. Incidents have been recorded when ill-fitting mouthguards have been dislodged and blocked the airway. Many claims have been made regarding the relative effectiveness of different types of mouthguards. The evidence for the relative effectiveness of different mouthguard materials and designs will be described. The available data from in-vitro and in-vivo investigations must be interpreted with caution There is a need for further scientific research to develop
optimum protection for participants in sports
The contribution of PA-X to the virulence of pandemic 2009 H1N1 and highly pathogenic H5N1 avian influenza viruses
PA-X is a novel protein encoded by PA mRNA and is found to decrease the pathogenicity of pandemic 1918 H1N1 virus in mice. However, the importance of PA-X proteins in current epidemiologically important influenza A virus strains is not known. In this study, we report on the pathogenicity and pathological effects of PA-X deficient 2009 pandemic H1N1 (pH1N1) and highly pathogenic avian influenza H5N1 viruses. We found that loss of PA-X expression in pH1N1 and H5N1 viruses increased viral replication and apoptosis in A549 cells and increased virulence and host inflammatory response in mice. In addition, PA-X deficient pH1N1 and H5N1 viruses up-regulated PA mRNA and protein synthesis and increased viral polymerase activity. Loss of PA-X was also accompanied by accelerated nuclear accumulation of PA protein and reduced suppression of PA on non-viral protein expression. Our study highlights the effects of PA-X on the moderation of viral pathogenesis and pathogenicity
Effect of microwave disinfection on physical and mechanical properties of acrylic resins
Regional differences in multidimensional aspects of health: findings from the MRC cognitive function and ageing study
BACKGROUND: Differences in mortality and health experience across regions are well recognised and UK government policy aims to address this inequality. Methods combining life expectancy and health have concentrated on specific areas, such as self-perceived health and dementia. Few have looked within country or across different areas of health. Self-perceived health, self-perceived functional impairment and cognitive impairment are linked closely to survival, as well as quality of life. This paper aims to describe regional differences in healthy life expectancy using a variety of states of health and wellbeing within the MRC Cognitive Function and Ageing Study (MRC CFAS). METHODS: MRC CFAS is a population based study of health in 13,009 individuals aged 65 years and above in five centres using identical study methodology. The interviews included self-perceived health and measures of functional and cognitive impairment. Sullivan's method was used to combine prevalence rates for cognitive and functional impairment and life expectancy to produce expectation of life in various health states. RESULTS: The prevalence of both cognitive and functional impairment increases with age and was higher in women than men, with marked centre variation in functional impairment (Newcastle and Gwynedd highest impairment). Newcastle had the shortest life expectancy of all the sites, Cambridgeshire and Oxford the longest. Centre differences in self-perceived health tended to mimic differences in life expectancy but this did not hold for cognitive or functional impairment. CONCLUSION: Self-perceived health does not show marked variation with age or sex, but does across centre even after adjustment for impairment burden. There is considerable centre variation in self-reported functional impairment but not cognitive impairment. Only variation in self-perceived health relates to the ranking of life expectancy. These data confirm that quite considerable differences in life experience exist across regions of the UK beyond basic life expectancy
Genomic Polymorphism of the Pandemic A (H1N1) Influenza Viruses Correlates with Viral Replication, Virulence, and Pathogenicity In Vitro and In Vivo
The novel pandemic A (H1N1) virus was first identified in Mexico in April 2009 and quickly spread worldwide. Like all influenzas, the H1N1 strain-specific properties of replication, virulence, and pathogenicity are a result of the particular genomic sequence and concerted expression of multiple genes. Thus, specific mutations may support increased virulence and may be useful as biomarkers of potential threat to human health. We performed comparative genomic analysis of ten strains of the 2009 pandemic A (H1N1) influenza viruses to determine whether genotypes associated with clinical phenotypes, which ranged from mild to severe illness and up to lethal. Virus replication capacity was tested for each strain in vitro using cultured epithelial cells, while virulence and pathogenicity were investigated in vivo using the BALB/c mouse model. The results indicated that A/Sichuan/1/2009 strain had significantly higher replication ability and virulence than the other strains, and five unique non-synonymous mutations were identified in important gene-encoding sequences. These mutations led to amino acid substitutions in HA (L32I), PA (A343T), PB1 (K353R and T566A), and PB2 (T471M), and may be critical molecular determinants for replication, virulence, and pathogenicity. Our results suggested that the replication capacity in vitro and virulence in vivo of the 2009 pandemic A (H1N1) viruses were not associated with the clinical phenotypes. This study offers new insights into the transmission and evolution of the 2009 pandemic A (H1N1) virus
Effect of incorporation of 2-tert-butylaminoethyl methacrylate on flexural strength of a denture base acrylic resin
Are Differences in Disability-Free Life Expectancy by Gender, Race, and Education Widening at Older Ages?
To examine change from 1991 to 2001 in disability-free life expectancy in the age range 60-90 by gender, race, and education in the United States. Mortality is estimated over two 10-year follow-up periods for persons in the National Health Interview Surveys of 1986/1987 and 1996/1997. Vital status is ascertained through the National Death Index. Disability prevalence is estimated from the National Health and Nutrition Examination Surveys of 1988-1994 and 1999-2002. Disability is defined as ability to perform four activities of daily living without difficulty. Disability-free life expectancy increased only among white men. Disabled life expectancy increased for all groups-black and white men and women. Racial differences in disability-free life expectancy widened among men; gender differences were reduced among whites. Expansion of socioeconomic differentials in disability-free life at older ages occurred among white men and women and black women. The 1990s was a period where the increased years of life between ages 60 and 90 were concentrated in disabled years for most population groups
Custom-made mouthguards protect football players. Do custom-made mouthguards really prevent injuries?
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