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Critical Reviews in Toxicology Aug 2021Intraoral fixed appliances remain in the potentially corrosive environment of the mouth for an average of two years. Over time, corrosion causes the release of metal...
Intraoral fixed appliances remain in the potentially corrosive environment of the mouth for an average of two years. Over time, corrosion causes the release of metal ions, such as nickel and chromium. These metals can become allergenic and cytotoxic, causing different conditions in the human body. The aim of this study therefore is to carry out a systematic review of the available scientific evidence on the accumulation of metal ions, and the genotoxic and cytotoxic effects in oral mucosa cells deriving from short- and long-term exposure to them. The systematic review is reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The primary outcome (quantification of metal ion deposits and assessment of their genotoxic and/or cytotoxic effects) and secondary outcome (complementary analysis of cytotoxic and genotoxic effects) were examined. The Cochrane Collaboration tool and Toxicological data Reliability Assessment Tool (ToxRTool) were used for quality assessment. Once the search was performed, a total of seven articles met the inclusion criteria and were included in this study. Two main techniques were used to assess genotoxic effects: alkaline comet assay (6/7) and micronucleus method (1/7). Cytotoxicity was evaluated (4/7) using the trypan blue dye test. Accumulations of nickel (7/7), chromium (5/7), and other metals (zinc, cobalt, iron, manganese, molybdenum, titanium) were also quantified. The results allowed us to conclude that release of metal ions and acute cell and DNA damage in oral mucosa cells takes place in the early stages of treatment. However, more long-term studies are needed to evaluate chronic exposure to metals and DNA damage, as well as cellular capacity to recover DNA integrity.
Topics: Chromium; DNA Damage; Humans; Ions; Mouth Mucosa; Orthodontic Appliances; Reproducibility of Results
PubMed: 34738508
DOI: 10.1080/10408444.2021.1960271 -
The International Journal of... 2021To conduct a systematic review to evaluate the influence of materials and surfaces used for dental implant abutments on the proliferation of human gingival fibroblasts.
PURPOSE
To conduct a systematic review to evaluate the influence of materials and surfaces used for dental implant abutments on the proliferation of human gingival fibroblasts.
MATERIALS AND METHODS
The focus question of this review was: Which material/surface characteristics used for dental implant abutments influence/enhance proliferation of human gingival fibroblasts? The Medline/PubMed, Embase, and Cochrane Library databases were searched using "gingiva," "fibroblasts," "proliferation," and "dental implant abutments" as main keywords with AND/OR as Boolean operators. In vitro studies reporting 3 to 4 or 6 to 7 days of cell proliferation, surface hydrophilicity, and roughness were included. A quality assessment of the selected studies was performed using the web-based Science in Risk Assessment and Policy (SciRAP) tool.
RESULTS
The search identified 1,144 studies, and 44 were eligible for inclusion. The average reporting quality SciRAP score was 82.87 ± 10.68, and the average methodologic quality SciRAP score was 87.35 ± 10.55. Machined, polished, and coated titanium and zirconia surfaces were most commonly investigated. Several studies analyzed aluminum oxide, cobalt-chrome-molybdenum alloy, lithium disilicate, polyether ether ketone, polymer-infiltrated ceramic network, and bioglass. The best cell proliferation was observed on zirconia and on titanium harboring nanotubules or microgrooves. UV treatment, polydopamine, and nitride coatings also improved cell proliferation. Due to the heterogeneity of the data, no correlation could be established between cell profileration and surface hydrophilicity or roughness. However, surface roughness in the range of R = 15 to 145 nm and Sa = 19 to 500 nm on titanium and zirconia proved most suitable.
CONCLUSION
Titanium surfaces with directional guidance patterning and zirconia surfaces best supported cell proliferation during the first week of cell culture. Lack of standardization in surface definitions (machined or polished), methodology, and reporting prevented analytical comparison and should be imposed in future studies.
Topics: Cell Proliferation; Dental Abutments; Dental Implants; Dental Materials; Fibroblasts; Gingiva; Humans; Materials Testing; Surface Properties; Titanium; Zirconium
PubMed: 33616578
DOI: 10.11607/ijp.7388 -
PloS One 2019The number of periprosthetic joint infections (PJI) after total knee arthroplasty (TKA) is increasing annually. Animal models have been used to clarify their clinical... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The number of periprosthetic joint infections (PJI) after total knee arthroplasty (TKA) is increasing annually. Animal models have been used to clarify their clinical characteristics and the infection mechanism of pathogenic bacteria, However, since the prosthesis design of animal models is not uniform, it is difficult to simulate the environment of clinical PJI.
OBJECTIVES
To retrospect the progress on the prosthesis design of animal models of PJI after TKA and to summarize the criteria for evaluating a clinically representative model of PJI.
METHODS
This systematic review was reported on the basis of Systematic Reviews and Meta-Analyzes (PRISMA). Pubmed, EMbase, Cochrane Library, Web of Science, Wanfang Data and China National Knowledge Infrastructure were researched for animal models of PJI after TKA from database establishment to April 2019 according to Chinese and English retrieval words, including "periprosthetic joint infections and total knee arthroplasty," "periprosthetic joint infections and model," "periprosthetic joint infections and biofilm," and "total knee arthroplasty and model."
RESULTS
A total of 12 quantitative studies were enrolled in our study finally: 8 representative studies described prosthesis designs used in PJI animal models, 4 studies described prosthesis designs in non-infected animal models which were suitable for infection models. The major problems need to be dealed with were prosthesis, installation location, material, the function of separating the articular and medullary cavity, fixation manner, and the procedure of preserving the posterior cruciate ligament.
CONCLUSION
A highly representative design of the animal prosthesis of PJI should meet the following criteria: the surface of the prosthesis is smooth with the formation of biofilm, composed of titanium-6Al-4V or cobalt-chromium-molybdenum alloy; prosthesis can bear weight and is highly stable; and it can connect the joint cavity and medullary cavity simultaneously. To reach a more reliable conclusion, further experiments and improvements are required.
Topics: Animals; Arthritis, Infectious; Arthroplasty, Replacement, Knee; Disease Models, Animal; Humans; Printing, Three-Dimensional; Prosthesis Design; Prosthesis-Related Infections; Radiography; Retrospective Studies
PubMed: 31581252
DOI: 10.1371/journal.pone.0223402 -
Environmental Science and Pollution... Apr 2019The aim of this systematic review study was to investigate the causal relationship between environmental factors and gastric cancer (GC) in Iran. In a narrow definition,...
The aim of this systematic review study was to investigate the causal relationship between environmental factors and gastric cancer (GC) in Iran. In a narrow definition, the environment includes water, soil, air, and food. This definition was the main criterion for the inclusion of articles in this study. In addition, exposure to radiation and geographical conditions were considered as less investigated environmental factors in the literatures. International (PubMed, Web of Science, ScienceDirect, Scopus, and Cochran) and national (Scientific Information Database) databases were searched for articles on GC and environmental risk factors in Iran. Twenty-six articles were found to meet the inclusion criteria after title, abstract, and full text review. Risk factors identified for GC include consumption of red meat; high fat, fried, and salted meat; smoked, salted, and fried foods; some dairy products; roasted and fried seeds; strong and hot tea; and un-piped and unchlorinated drinking water, as well as exposure to radiation, loess sediment, soft and grassy soil, soil containing low concentration of molybdenum, and proximity to volcanos. Fresh fruits and vegetable, fresh fish, and honey consumption were recognized as protective agents. Given the risk factors identified, strategies to prevent GC would be educating people to choose a healthy diet and to cook and store food properly, providing access to safe drinking water, taking into account topographical and geographical conditions in choosing a right location to build residential areas, and regulating the use of radiation-emitting devices.
Topics: Animals; Case-Control Studies; Drinking Water; Environmental Pollution; Food Contamination; Humans; Iran; Soil; Stomach Neoplasms
PubMed: 30806933
DOI: 10.1007/s11356-019-04493-8 -
Liver International : Official Journal... Nov 2019Wilson disease (WD) is a rare disorder of copper metabolism. The objective of this systematic review was to determine the comparative effectiveness and safety of common... (Comparative Study)
Comparative Study Meta-Analysis
BACKGROUND & AIMS
Wilson disease (WD) is a rare disorder of copper metabolism. The objective of this systematic review was to determine the comparative effectiveness and safety of common treatments of WD.
METHODS
We included WD patients of any age or stage and the study drugs D-penicillamine, zinc salts, trientine and tetrathiomolybdate. The control could be placebo, no treatment or any other treatment. We included prospective, retrospective, randomized and non-randomized studies. We searched Medline and Embase via Ovid, the Cochrane Central Register of Controlled Trials, and screened reference lists of included articles. Where possible, we applied random-effects meta-analyses.
RESULTS
The 23 included studies reported on 2055 patients and mostly compared D-penicillamine to no treatment, zinc, trientine or succimer. One study compared tetrathiomolybdate and trientine. Post-decoppering maintenance therapy was addressed in one study only. Eleven of 23 studies were of low quality. When compared to no treatment, D-penicillamine was associated with a lower mortality (odds ratio 0.013; 95% CI 0.0010 to 0.17). When compared to zinc, there was no association with mortality (odds ratio 0.73; 95% CI 0.16 to 3.40) and prevention or amelioration of clinical symptoms (odds ratio 0.84; 95% CI 0.48 to 1.48). Conversely, D-penicillamine may have a greater impact on side effects and treatment discontinuations than zinc.
CONCLUSIONS
There are some indications that zinc is safer than D-penicillamine therapy while being similarly effective in preventing or reducing hepatic or neurological WD symptoms. Study quality was low warranting cautious interpretation of our findings.
Topics: Chelating Agents; Copper; Hepatolenticular Degeneration; Humans; Liver; Molybdenum; Penicillamine; Randomized Controlled Trials as Topic; Trientine; Zinc
PubMed: 31206982
DOI: 10.1111/liv.14179 -
International Journal of Molecular... Dec 2020The alterations in serum trace element levels are common phenomena observed in patients with different psychiatric conditions such as schizophrenia, autism spectrum... (Meta-Analysis)
Meta-Analysis
The alterations in serum trace element levels are common phenomena observed in patients with different psychiatric conditions such as schizophrenia, autism spectrum disorder, or major depressive disorder. The fluctuations in the trace element concentrations might act as potential diagnostic and prognostic biomarkers of many psychiatric and neurological disorders. This paper aimed to assess the alterations in serum trace element concentrations in patients with a diagnosed schizophrenia. The authors made a systematic review, extracting papers from the PubMed, Web of Science, and Scopus databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Among 5009 articles identified through database searching, 59 of them were assessed for eligibility. Ultimately, 33 articles were included in the qualitative synthesis. This review includes the analysis of serum levels of the following trace elements: iron, nickel, molybdenum, phosphorus, lead, chromium, antimony, uranium, magnesium, aluminum, zinc, copper, selenium, calcium, and manganese. Currently, there is no consistency regarding serum trace element levels in schizophrenic patients. Thus, it cannot be considered as a reliable prognostic or diagnostic marker of schizophrenia. However, it can be assumed that altered concentrations of those elements are crucial regarding the onset and exaggeration of either psychotic or negative symptoms or cognitive dysfunctions.
Topics: Biomarkers; Case-Control Studies; Female; Humans; Maternal Exposure; Pregnancy; Prenatal Exposure Delayed Effects; Schizophrenia; Schizophrenic Psychology; Trace Elements
PubMed: 33334078
DOI: 10.3390/ijms21249566