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1,201 result(s) for "Amalgams"
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New science challenges old notion that mercury dental amalgam is safe
Mercury dental amalgam has a long history of ostensibly safe use despite its continuous release of mercury vapor. Two key studies known as the Children’s Amalgam Trials are widely cited as evidence of safety. However, four recent reanalyses of one of these trials now suggest harm, particularly to boys with common genetic variants. These and other studies suggest that susceptibility to mercury toxicity differs among individuals based on multiple genes, not all of which have been identified. These studies further suggest that the levels of exposure to mercury vapor from dental amalgams may be unsafe for certain subpopulations. Moreover, a simple comparison of typical exposures versus regulatory safety standards suggests that many people receive unsafe exposures. Chronic mercury toxicity is especially insidious because symptoms are variable and nonspecific, diagnostic tests are often misunderstood, and treatments are speculative at best. Throughout the world, efforts are underway to phase down or eliminate the use of mercury dental amalgam.
Mercury Concentration in Saliva and the Impact of Chewing: An Inductively Coupled Plasma Mass Spectrometry Study
Mercury, which is found in dental amalgams, is considered to be the most toxic non-radioactive element. However, the health policies of different countries have not reached a consensus on the use and safety of amalgam. This study aims to investigate the effect of amalgam restorations on mercury concentration in saliva, as well as the effect of restoration number, surface number, and chewing on this concentration. A total of 86 participants were included in this study (an equal number for the study and control groups). The number of amalgam restorations and their surfaces were recorded. While both unstimulated and stimulated saliva were collected from the study group, only unstimulated saliva was collected from the control group. The effect of chewing on mercury concentration was examined in the study group with unstimulated and stimulated saliva specimens using inductively coupled plasma mass spectrometry device. Mercury concentration in the unstimulated saliva was found to be higher in the study group compared to the control group ( p = 0.000). As the number of amalgam restorations and the number of amalgam restoration surfaces increased, the mercury concentration in the saliva increased ( p = 0.015 and p = 0.021, respectively). There was no statistically significant difference between mercury levels in the unstimulated saliva and the stimulated saliva ( p =0.316). Chewing presented an insignificant difference in mercury concentration. Given this surprising result, the effect of chewing on mercury concentrations should be explored more extensively in future research.
Evaluating the accuracy of Chat Generative Pre-trained Transformer version 4 frequently asked questions about dental amalgam
The use of artificial intelligence in the field of health sciences is becoming widespread. It is known that patients benefit from artificial intelligence applications on various health issues, especially after the pandemic period. One of the most important issues in this regard is the accuracy of the information provided by artificial intelligence applications. The purpose of this study was to the frequently asked questions about dental amalgam, as determined by the United States Food and Drug Administration (FDA), which is one of these information resources, to Chat Generative Pre-trained Transformer version 4 (ChatGPT-4) and to compare the content of the answers given by the application with the answers of the FDA. The questions were directed to ChatGPT-4 on May 8th and May 16th, 2023, and the responses were recorded and compared at the word and meaning levels using ChatGPT. The answers from the FDA webpage were also recorded. The responses were compared for content similarity in \"Main Idea\", \"Quality Analysis\", \"Common Ideas\", and \"Inconsistent Ideas\" between ChatGPT-4's responses and FDA's responses. ChatGPT-4 provided similar responses at one-week intervals. In comparison with FDA guidance, it provided answers with similar information content to frequently asked questions. However, although there were some similarities in the general aspects of the recommendation regarding amalgam removal in the question, the two texts are not the same, and they offered different perspectives on the replacement of fillings. The findings of this study indicate that ChatGPT-4, an artificial intelligence based application, encompasses current and accurate information regarding dental amalgam and its removal, providing it to individuals seeking access to such information. Nevertheless, we believe that numerous studies are required to assess the validity and reliability of ChatGPT-4 across diverse subjects.
Recent Advancements in Surface Modification, Characterization and Functionalization for Enhancing the Biocompatibility and Corrosion Resistance of Biomedical Implants
Metallic materials are among the most crucial engineering materials widely utilized as biomaterials owing to their significant thermal conductivity, mechanical characteristics, and biocompatibility. Although these metallic biomedical implants, such as stainless steel, gold, silver, dental amalgams, Co-Cr, and Ti alloys, are generally used for bone tissue regeneration and repairing bodily tissue, the need for innovative technologies is required owing to the sensitivity of medical applications and to avoid any potential harmful reactions, thereby improving the implant to bone integration and prohibiting infection lea by corrosion and excessive stress. Taking this into consideration, several research and developments in biomaterial surface modification are geared toward resolving these issues in bone-related medical therapies/implants offering a substantial influence on cell adherence, increasing the longevity of the implant and rejuvenation along with the expansion in cell and molecular biology expertise. The primary objective of this review is to reaffirm the significance of surface modification of biomedical implants by enlightening numerous significant physical surface modifications, including ultrasonic nanocrystal surface modification, thermal spraying, ion implantation, glow discharge plasma, electrophoretic deposition, and physical vapor deposition. Furthermore, we also focused on the characteristics of some commonly used biomedical alloys, such as stainless steel, Co-Cr, and Ti alloys.
Increased mercury emissions from modern dental amalgams
All types of dental amalgams contain mercury, which partly is emitted as mercury vapor. All types of dental amalgams corrode after being placed in the oral cavity. Modern high copper amalgams exhibit two new traits of increased instability. Firstly, when subjected to wear/polishing, droplets rich in mercury are formed on the surface, showing that mercury is not being strongly bonded to the base or alloy metals. Secondly, high copper amalgams emit substantially larger amounts of mercury vapor than the low copper amalgams used before the 1970s. High copper amalgams has been developed with focus on mechanical strength and corrosion resistance, but has been sub-optimized in other aspects, resulting in increased instability and higher emission of mercury vapor. This has not been presented to policy makers and scientists. Both low and high copper amalgams undergo a transformation process for several years after placement, resulting in a substantial reduction in mercury content, but there exist no limit for maximum allowed emission of mercury from dental amalgams. These modern high copper amalgams are nowadays totally dominating the European, US and other markets, resulting in significant emissions of mercury, not considered when judging their suitability for dental restoration.
The Minamata Convention and the phase down of dental amalgam
Oral health is a neglected area of global health, although oral disease is one of the most common public health issues worldwide. Despite advances in modern dentistry, untreated dental caries in permanent teeth was reported as the most prevalent of the 328 conditions assessed in 2016 Global Burden of Disease Study. The restorative model for managing dental caries was developed in the 1900s, alongside dental amalgam as one of the restorative materials commonly used to treat dental caries. Together they still provide the backbone of oral health services in most countries today. A shift away from the restorative model and the widespread use of dental amalgam was perhaps unimaginable even a decade ago, despite the World Health Organization (WHO) calling for oral health to be incorporated into policies for the integrated prevention and treatment of chronic noncommunicable and communicable diseases, and into maternal and child health policies. The Minamata Convention on Mercury (2013) is an international legally binding treaty that aims to protect the human health and the environment from anthropogenic emissions and releases of mercury and mercury compounds. The convention addresses mercury-added products, including dental amalgam, which is made of approximately 50% of elemental mercury by weight, and proposes nine measures to phase down the use of dental amalgam. These measures show the interconnected and interdependent nature of phasing down dental amalgam, and reinforce the need for a multipronged approach as called for by WHO. The implementation of the convention and its provision for dental amalgam can catalyse the shift away from the restorative model of care and the use of mechanically retained filling materials, such as dental amalgam, towards preventive and minimal intervention dentistry that predominantly uses adhesive dental materials. Implementation will also provide an opportunity to strengthen oral health promotion and oral disease prevention within an integrated, people-centred model of health services.
Association between History of Dental Amalgam Fillings and Risk of Parkinson’s Disease: A Population-Based Retrospective Cohort Study in Taiwan
The impact of dental amalgam on the development of Parkinson's disease (PD) is still uncertain, although a positive association between dental amalgam and PD has been found in a few case-control studies. The patients with amalgam fillings restored between 2000 and 2008 were identified by using the National Health Insurance Research Database (NHIRD) in Taiwan. The same number of patients who had no new amalgam filling restored was matched by sex, age, and treatment date. Both cohorts were followed up from the treatment date until the date of diagnosis of PD, death, or the end of the year 2008. The individuals who received amalgam fillings had a significantly higher risk of PD afterward (adjusted hazard ratio [HR]=1.583, 95% confidence interval [CI]=1.122-2.234, p=0.0089) than those who did not. In the individuals who received amalgam fillings, being diagnosed with diabetes or hyperlipidemia demonstrated a significantly lower HR of PD occurrence than in the patients without diabetes or hyperlipidemia (HR=0.449, 95% CI=0.254-0.794, p=0.0059; HR=0.445, 95% CI=0.260-0.763, p=0.0032) after adjusting for comorbidities and Charlson-Deyo Comorbidity Index (CCI) scores. Meanwhile, hypertension increased the hazard risk of PD (HR=1.645, 95% CI=1.098-2.464, p=0.0159). The patients exposed to dental amalgam fillings were 1.583 times more likely to have PD afterward compared to their non-exposed counterparts after adjusting for comorbidities and CCI scores.
Redefining critical illness
Research and practice in critical care medicine have long been defined by syndromes, which, despite being clinically recognizable entities, are, in fact, loose amalgams of heterogeneous states that may respond differently to therapy. Mounting translational evidence—supported by research on respiratory failure due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection—suggests that the current syndrome-based framework of critical illness should be reconsidered. Here we discuss recent findings from basic science and clinical research in critical care and explore how these might inform a new conceptual model of critical illness. De-emphasizing syndromes, we focus on the underlying biological changes that underpin critical illness states and that may be amenable to treatment. We hypothesize that such an approach will accelerate critical care research, leading to a richer understanding of the pathobiology of critical illness and of the key determinants of patient outcomes. This, in turn, will support the design of more effective clinical trials and inform a more precise and more effective practice at the bedside. The authors propose a new conceptual model of critical illness that moves away from the current syndrome-based framework in favor of more precise biological descriptors—spurred by mounting translational evidence and insights from Coronavirus Disease 2019 (COVID-19) research.