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Role of Environmental Toxicants and Inflammation in Parkinson’s Disease
Published in Abhai Kumar, Debasis Bagchi, Antioxidants and Functional Foods for Neurodegenerative Disorders, 2021
Biddut Deb Nath, Dipti Debnath, Rokeya Pervin, Md. Akil Hossain
Mercury, in the form of elements and salts, is found in many domestic and dental amalgam materials. Before the 1970s,219 organic methylmercury was widely used in paints and fungicides. Bioconcentrates of methylmercury have been found in several species of salt water fish as well as in those who ingest these fishes.220 Mercury does not have widely recognized physiological function. Its neurotoxic effects are possibly due to excitotoxicity induced by glutamates,221 degradation of antioxidants such as GSH, and strong oxidative effects.222 Epidemiological findings examined limited information for a PD connection. A SPECT imaging analysis of Taiwanese employees in a lamp factory showed a dose-response association between urinary levels of mercury and decreased striatal bonding of dopamine.223 Correspondingly, Ngim and Devathasan224 observed higher rates of mercury in PD than in study participants but more unfavorable findings from other case-control studies.225
Interactions between Oral Bacteria and Antibacterial Polymer-Based Restorative Materials
Published in Mary Anne S. Melo, Designing Bioactive Polymeric Materials for Restorative Dentistry, 2020
Fernando L. Esteban Florez, Sharukh S. Khajotia
The use of polymer-based materials for direct restorative applications in dentistry was first reported in 1962.[101] Since then, these materials have gone through a constant evolutionary process that resulted in modern resin composites with improved optical, mechanical, physical, and chemical properties. Currently available resin composites can be used either as preventive (e.g., pit and fissure sealants) or restorative materials in virtually all regions of the oral cavity and types of cavity preparation. These materials were previously demonstrated to have comparable annual failure rates when compared to dental amalgams (1% and 3%, Classes I and II)[95,127–129] and indirect restorations,[128] and have also been currently used in minimally invasive cosmetic techniques to improve the esthetic properties of discolored and malpositioned teeth.
Common head and neck viva topics
Published in Joseph Manjaly, Peter Kullar, Advanced ENT Training, 2019
Clinical assessment and cross-sectional imaging (CT/MRI) is the cornerstone of pre-operative assessment to accurately stage the disease according to AJCC/UICC staging system. Both imaging modalities are useful in certain scenarios and often combined; CT provides excellent information on bony invasion and MRI provides improved soft tissue resolution. CT images of the primary tumour can be affected significantly by dental amalgam.
Failure of chelator-provoked urine testing results to predict heavy metal toxicity in a prospective cohort of patients referred for medical toxicology evaluation
Published in Clinical Toxicology, 2022
Stephanie T. Weiss, Sharan Campleman, Paul Wax, William McGill, Jeffrey Brent
Mercury is ubiquitous, and humans are constantly exposed to it in various forms through ambient air, seafood, and in small amounts from mercury-containing dental amalgams [4,13,17]. Some degree of urine mercury excretion is therefore expected in all people who are tested. The administration of a renally cleared mercury chelating agent, such as succimer, dimercaptopropanesulfonate, or edetate calcium disodium, further increases mercury excretion in both mercury-overexposed and non-overexposed subjects [4,6,8]. One study that attempted to establish norms for PUT and unprovoked urine testing in both mercury-overexposed and non-overexposed subjects suggested an upper urine mercury limit of 12 μg/24 h in unprovoked urine testing and 20 μg/24 h after PUT with two doses of the chelator [6]. However, the use of these values has not been studied or validated. Nor is it known whether the addition of a chelator improves diagnostic accuracy using these values [9]. Data from our study indicates that chelator-provoked urine sampling is not of any diagnostic value and, if relied on, leads to inaccurate diagnoses.
Which procedures and materials could be applied for full pulpotomy in permanent mature teeth? A systematic review
Published in Acta Odontologica Scandinavica, 2019
M. Zanini, M. Hennequin, PY. Cousson
Coronal restoration is implicit in the success of the procedure [64]. The results of clinical studies highlight the importance of correctly sealing coronal restorations, with the prosthetic crown and amalgam restorations having the smallest failure rate in comparison to resin composite restorations that increase the risk of full pulpotomy failure [1,3]. Dental amalgams have excellent longevity due to corrosion products that protect against the risk of secondary caries [98]. For environmental reasons, however, many countries decided to limit the use of amalgam in October 2013 [99]. For these reasons, restoration with amalgams can no longer be considered after full pulpotomy. Indirect restoration with crowns or onlays and direct restoration with composite could be indicated for coronal restoration after full pulpotomy. The combination of full pulpotomy with tricalcium silicate cements and CAD/CAM (Computer-aided design and computer-aided manufacturing) coronal restoration crowns could be solutions for a single chairside intervention. The time to place the permanent restoration was shown to be a factor affecting treatment outcome [71]. Indeed, the association between the delayed placement of restoration and unfavourable outcomes has been detected in this clinical study [64]. So, a definitive coronal restoration is recommended as soon as possible after a full pulpotomy.
Biological aspects of modern dental composites
Published in Biomaterial Investigations in Dentistry, 2023
Jan Tore Samuelsen, Jon E. Dahl
Since its introduction in the 1960s [1], dental composites have evolved from a relatively basic silica-filled resin-based material to a wide range of complex, specialized products. When used as intended, modern composites function well clinically and are aesthetically sovereign compared to dental amalgam, the previous first choice for filling therapy. Although the composition of composites has changed over the years, their main components remain a polymer matrix and reinforcing filler particles or short fibers. A coupling agent chemically binds the matrix and filler, further strengthening the composite. In addition to the three main components, composites usually contain small amounts of initiator and stabilizer components.