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American Journal of Epidemiology Jul 2023Metal exposure has been suggested as a possible environmental risk factor for Parkinson disease (PD). We searched the PubMed, EMBASE, and Cochrane databases to... (Meta-Analysis)
Meta-Analysis
Metal exposure has been suggested as a possible environmental risk factor for Parkinson disease (PD). We searched the PubMed, EMBASE, and Cochrane databases to systematically review the literature on the relationship between metal exposure and PD risk and to examine the overall quality of each study and the exposure assessment method. A total of 83 case-control studies and 5 cohort studies published during the period 1963-July 2021 were included, of which 73 were graded as being of low or moderate overall quality. Investigators in 69 studies adopted self-reported exposure and biomonitoring after disease diagnosis for exposure assessment approaches. The meta-analyses showed that concentrations of copper and iron in serum and concentrations of zinc in either serum or plasma were lower, while concentrations of magnesium in CSF and zinc in hair were higher, among PD cases as compared with controls. Cumulative lead levels in bone were found to be associated with increased risk of PD. We did not find associations between other metals and PD. The current level of evidence for associations between metals and PD risk is limited, as biases from methodological limitations cannot be ruled out. High-quality studies assessing metal levels before disease onset are needed to improve our understanding of the role of metals in the etiology of PD.
Topics: Humans; Cohort Studies; Copper; Lead; Parkinson Disease; Zinc; Metals
PubMed: 37022311
DOI: 10.1093/aje/kwad082 -
International Journal of Paediatric... Jan 2022Preformed metal crowns (PMCs) have been the restoration of choice for paediatric dentistry; however, PMCs have a non-aesthetic appearance, which has become a point of... (Review)
Review
BACKGROUND
Preformed metal crowns (PMCs) have been the restoration of choice for paediatric dentistry; however, PMCs have a non-aesthetic appearance, which has become a point of concern. Recently, prefabricated zirconia crowns (PZCs) have been increasingly used as an aesthetic restorative material for primary teeth, as they have pleasing properties.
AIM
This systematic review summarises the clinical results for PZCs in the primary dentition, including wear on the opposing dentition, retention, fracture resistance, parental satisfaction, gingival health, and cementation materials.
MATERIALS AND METHODS
Electronic database searches were conducted using PubMed, Google Scholar, Web of Science, and the Cochrane Library. Clinical trials, observational studies, and case reports/series were included. The quality of the studies was analysed using the Cochrane tool and the domain-based evaluation for non-randomised studies of interventions.
RESULTS
The search retrieved 166 references, of which 14 studies were included for qualitative analyses. The risk of bias varied from low to unclear. The included studies indicated that prefabricated zirconia crowns are retentive and are not associated with accelerated wear on the opposing dentition. They also exhibit a high fracture resistance, satisfy the parents and are compatible with gingival health. There is, however, inconclusive evidence with regard to cementation materials.
CONCLUSION
Prefabricated Zirconia Crowns appear to be a good alternative to preformed metal crowns in term of esthetics, retention, resistance to fracture, parent satisfaction, and gingival health.
Topics: Child; Crowns; Dental Materials; Humans; Tooth, Deciduous; Zirconium
PubMed: 33772904
DOI: 10.1111/ipd.12793 -
The Science of the Total Environment Jan 2024Prenatal exposure to metal mixtures is associated with adverse pregnancy and birth outcomes like low birth weight, preterm birth, and small for gestational age. However,... (Review)
Review
BACKGROUND
Prenatal exposure to metal mixtures is associated with adverse pregnancy and birth outcomes like low birth weight, preterm birth, and small for gestational age. However, prior studies have used individual metal analysis, lacking real-life exposure scenarios.
OBJECTIVES
This systematic review aims to evaluate the strength and consistency of the association between metal mixtures and pregnancy and birth outcomes, identify research gaps, and inform future studies and policies in this area.
METHODS
The review adhered to the updated Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) checklist, along with the guidelines for conducting systematic reviews and meta-analyses of observational studies of etiology (COSMOS-E). Our data collection involved searching the PubMed, MEDLINE, and SCOPUS databases. We utilized inclusion criteria to identify relevant studies. These chosen studies underwent thorough screening and data extraction procedures. Methodological quality evaluations were conducted using the NOS framework for cohort and case-control studies, and the AXIS tool for cross-sectional studies.
RESULTS
The review included 34 epidemiological studies, half of which focused on birth weight, and the others investigated neonate size, preterm birth, small for gestational age, miscarriage, and placental characteristics. The findings revealed significant associations between metal mixtures (including mercury (Hg), nickel (Ni), arsenic (As), cadmium (Cd), manganese (Mn), cobalt (Co), lead (Pb), zinc (Zn), barium (Ba), cesium (Cs), copper (Cu), selenium (Se), and chromium (Cr)) and adverse pregnancy and birth outcomes, demonstrating diverse effects and potential interactions.
CONCLUSION
In conclusion, this review consistently establishes connections between metal exposure during pregnancy and adverse consequences for birth weight, gestational age, and other vital birth-related metrics. This review further demonstrates the need to apply mixture methods with caution but also shows that they can be superior to traditional approaches. Further research is warranted to deeper understand the underlying mechanisms and to develop effective strategies for mitigating the potential risks associated with metal mixture exposure during pregnancy.
Topics: Female; Humans; Infant, Newborn; Pregnancy; Abortion, Spontaneous; Birth Weight; Cross-Sectional Studies; Fetal Growth Retardation; Mercury; Metals; Placenta; Premature Birth
PubMed: 37963536
DOI: 10.1016/j.scitotenv.2023.168380 -
The Journal of Prosthetic Dentistry Jun 2019There is insufficient evidence to recommend the restorative material for implant-supported prostheses. (Meta-Analysis)
Meta-Analysis Review
STATEMENT OF PROBLEM
There is insufficient evidence to recommend the restorative material for implant-supported prostheses.
PURPOSE
The purpose of this systematic review and meta-analysis was to evaluate studies that compared ceramic and metal-ceramic restorations for implant-supported prostheses (within the same study to avoid indirect comparison) in terms of the mechanical and biological complication rates, prosthesis survival rate, and marginal bone loss.
MATERIAL AND METHODS
Two independent reviewers performed a comprehensive search in databases (PubMed/MEDLINE, Web of Science, and Cochrane Library) for articles indexed until March 31, 2018. The search was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and methods were registered in the International Prospective Register of Systematic Reviews (PROSPERO). The focused question was "Do ceramic restorations have mechanical/biological complication rates, prosthesis survival rates, and marginal bone loss similar to those of metal-ceramic restorations?"
RESULTS
The search identified 949 references. The interinvestigator agreement using kappa values was 0.87 for PubMed/MEDLINE, 0.93 for Scopus, and 1.0 for the Cochrane Library. After analysis, 12 studies were selected for qualitative and quantitative analysis. The mechanical complication rate did not differ between ceramic and metal-ceramic restorations (P=.89), independent of the type of prostheses (single crown: P=.63; fixed partial denture: P=.65). The biological complication rate was also not significantly different between ceramic and metal-ceramic restorations (P=.21). The prosthesis survival rate showed no significant differences between the 2 types of restorations (P=.56). Marginal bone loss was also similar for both types of restorations (P=.12).
CONCLUSIONS
This systematic review indicated that ceramic and metal-ceramic implant-supported prostheses have similar mechanical and biological complication rates, prosthesis survival rates, and marginal bone loss. Thus, both treatments are appropriate options for long-term rehabilitation treatment.
Topics: Ceramics; Dental Prosthesis Design; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Denture, Partial, Fixed; Metal Ceramic Alloys
PubMed: 30661882
DOI: 10.1016/j.prosdent.2018.09.016 -
Frontiers in Endocrinology 2023This study aimed to evaluate the association between blood heavy metal (zinc (Zn), copper (Cu), lead (Pb), and cadmium (Cd)) concentrations and spontaneous abortion (SA)... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
This study aimed to evaluate the association between blood heavy metal (zinc (Zn), copper (Cu), lead (Pb), and cadmium (Cd)) concentrations and spontaneous abortion (SA) and recurrent pregnancy loss (RPL) and explore the possible endocrine dysfunction associated with it.
METHODS
A literature search was performed in the PubMed, Embase, Cochrane Library, and Web of Science databases up to April 2023. The overall effects were expressed as the standard mean difference (SMD). Subgroup analysis was performed according to the type of abortion (SA or RPL). Stata 16.0 was utilized for data analysis.
RESULTS
Based on the integrated findings, abortion women showed significantly lower Zn (SMD = -1.05, 95% CI: -1.74 to -0.36, = 0.003) and Cu concentrations (SMD = -1.42, 95% CI: -1.97 to -0.87, 0.001) and higher Pb (SMD = 1.47, 95% CI: 0.89-2.05, 0.001) and Cd concentrations (SMD = 1.15, 95% CI: 0.45-1.85, = 0.001) than normal pregnant women. Subgroup analysis showed that Zn and Cu deficiency and Cd and Pb exposure were significantly (0.05) associated with RPL, whereas Cu deficiency and Cd and Pb exposure were significantly (0.05) associated with SA.
CONCLUSION
Zn and Cu deficiencies and Pb and Cd exposure were associated with abortion. Endocrine dysfunction, such as insulin resistance, vitamin D insufficiency, and abnormal thyroid and sex hormone concentrations, is thought to be involved in heavy metal-related abortion.
Topics: Pregnancy; Female; Humans; Abortion, Spontaneous; Cadmium; Lead; Metals, Heavy; Zinc
PubMed: 37711903
DOI: 10.3389/fendo.2023.1216507 -
Biological Trace Element Research Feb 2022Metals, many of which are potentially toxic, are present in the aquatic environment originated from both natural and anthropogenic sources. In these ecosystems, these... (Review)
Review
Metals, many of which are potentially toxic, are present in the aquatic environment originated from both natural and anthropogenic sources. In these ecosystems, these elements are mostly deposited in the sediment, followed by water dissolution, potentially contaminating resident biota. Among several aquatic animals, crustaceans are considered excellent bioindicators, as they live in close contact with contaminated sediment. The accumulation of metal, whether they are classified as essential, when in excessive quantities or nonessential, not only cause damage to the health of these animals, but also to the man who consumes seafood. Among the main toxic elements to animal and human health are aluminum, arsenic, cadmium, chromium, copper, lead, mercury, nickel and silver. In this context, this systematic review aimed to investigate the dynamics of these metals in water, the main bioaccumulative tissues in crustaceans, the effects of these contaminants on animal and human health, and the regulatory limits for these metals worldwide. A total of 91 articles were selected for this review, and an additional 68 articles not found in the three assessed databases were considered essential and included, totaling 159 articles published between 2010 and 2020. Our results indicate that both chemical speciation and abiotic factors such as pH, oxygen and salinity in aquatic environments affect element bioavailability, dynamics, and toxicity. Among crustaceans, crabs are considered the main bioindicator biological system, with the hepatopancreas appearing as the main bioaccumulator organ. Studies indicate that exposure to these elements may result in nervous, respiratory, and reproductive system effects in both animals and humans. Finally, many studies indicate that the concentrations of these elements in crustaceans intended for human consumption exceed limits established by international organizations, both with regard to seafood metal contents and well as daily, weekly, or monthly intake limits set for humans, indicating consumer health risks.
Topics: Animals; Ecosystem; Environmental Biomarkers; Environmental Monitoring; Humans; Metals; Risk Assessment; Seafood; Water Pollutants, Chemical
PubMed: 33788164
DOI: 10.1007/s12011-021-02685-3 -
Dental Materials : Official Publication... Oct 2022The goal of this systemic review and meta-analysis was to evaluate the longevity of indirect adhesively-luted ceramic compared to conventionally cemented metal single... (Meta-Analysis)
Meta-Analysis
OBJECTIVES
The goal of this systemic review and meta-analysis was to evaluate the longevity of indirect adhesively-luted ceramic compared to conventionally cemented metal single tooth restorations.
DATA
Randomized controlled trials (RCT) investigating indirect adhesively-luted ceramic restorations compared to metal or metal-based cemented restorations in permanent posterior teeth.
SOURCES
Three electronic databases (PubMed, CENTRAL (Cochrane) and Embase) were screened. No language or time restrictions were applied. Study selection, data extraction and quality assessment were done in duplicate. Risk of Bias and level of evidence was graded using Risk of Bias 2.0 tool and Grade Profiler 3.6.
RESULTS
A total of 3056 articles were found by electronic databases. Finally, four RCTs were selected. Overall, 443 restorations of which 212 were adhesively-luted ceramic restorations and 231 conventionally cemented metal restorations have been placed in 314 patients (age: 22-72 years). The highest annual failure rates were found for ceramic restorations ranging from 2.1% to 5.6%. Lower annual failure rates were found for metal (gold) restorations ranging from 0% to 2.1%. Meta-analysis could be performed for adhesively-luted ceramic vs. conventionally cemented metal restorations. Conventionally cemented metal restoration showed a significantly lower failure rate than adhesively-luted ceramic ones (visual-tactile assessment: Risk Ratio (RR)[95%CI]=0.31[0.16,0.57], low level of evidence). Furthermore, all studies showed a high risk of bias.
CONCLUSION
Conventionally cemented metal restorations revealed significantly lower failure rates compared to adhesively-luted ceramic ones, although the selected sample was small and with medium follow-up periods with high risks of bias.
Topics: Adult; Aged; Ceramics; Dental Restoration Failure; Gold; Humans; Middle Aged; Young Adult
PubMed: 36038401
DOI: 10.1016/j.dental.2022.08.002 -
Association Between Non-alcoholic Fatty Liver Disease and Heavy Metal Exposure: a Systematic Review.Biological Trace Element Research Dec 2023Non-alcoholic fatty liver disease (NAFLD) is a debilitating disease with adverse effects including cirrhosis and hepatocellular carcinoma. Heavy metals can cause severe... (Review)
Review
Non-alcoholic fatty liver disease (NAFLD) is a debilitating disease with adverse effects including cirrhosis and hepatocellular carcinoma. Heavy metals can cause severe dysfunction in different body organs including the liver. This review offers the study regarding the positive or negative association between heavy metals exposure and non-alcoholic fatty liver disease. The method used in this study is a systematic review based on searching in the PubMed, Scopus, and Science direct databases with the keywords of fatty liver, non-alcohol fatty liver, heavy metal, mercury, cadmium, arsenic, chromium, thallium, lead, iron, zinc, and nickel. There were 2200 articles searched in databases, and after assessment, 28 articles were selected. Positive association is established between arsenic, cadmium, iron, lead, mercury, and fatty liver disease. A negative relationship is found between zinc, copper, and progressive fatty liver disease. Furthermore, laboratory methods for NAFLD diagnosis were examined according to the obtained manuscripts. Among the different diagnostic methods, magnetic resonance imaging (MRI) is a sensitive method.
Topics: Humans; Non-alcoholic Fatty Liver Disease; Cadmium; Arsenic; Metals, Heavy; Mercury; Iron; Zinc
PubMed: 36929113
DOI: 10.1007/s12011-023-03629-9 -
Environmental Science and Pollution... May 2022The relationship between toxic metals in the environment and clinical stroke risk remains unclear, although their role as immunotoxicants and carcinogens has been well... (Meta-Analysis)
Meta-Analysis Review
The relationship between toxic metals in the environment and clinical stroke risk remains unclear, although their role as immunotoxicants and carcinogens has been well established. We conducted a systematic review of the relationship between five metals (arsenic, mercury, copper, cadmium, and lead) and stroke. First, we comprehensively searched 3 databases (Pubmed, EMBASE, and Cochrane) from inception until June 2021. Random-effects meta-analyses, pooled relative risks (RR) and 95% confidence intervals (CI) were applied to evaluate the effect value. We finally identified 38 studies involving 642,014 non-overlapping participants. Comparing the highest vs. lowest baseline levels, chronic exposure to lead (RR = 1.07; 95%CI,1.00-1.14), cadmium (RR = 1.30; 95%CI,1.13-1.48), and copper (RR = 1.19; 95%CI,1.04-1.36) were significantly associated with stroke risks. However, the other two metals (arsenic and mercury) had less effect on stroke risk. Further analysis indicated that the association was likely in a metal dose-dependent manner. The results may further support the possibility that environmental toxic metal contaminants in recent years are associated with the increased risk of stroke.
Topics: Arsenic; Cadmium; Copper; Heavy Metal Poisoning; Humans; Lead; Mercury; Stroke
PubMed: 35190994
DOI: 10.1007/s11356-022-18866-z -
Clinical Rheumatology Dec 2022The relationship between exposure to certain metals and the risk of hyperuricemia (HUA) has biological plausibility, yet prior studies have presented inconsistent... (Meta-Analysis)
Meta-Analysis Review
The relationship between exposure to certain metals and the risk of hyperuricemia (HUA) has biological plausibility, yet prior studies have presented inconsistent findings. We aim to clarify the relationship between exposure to certain metals and HUA using a systematic review and meta-analysis approach. We searched the Web of Science, Embase, MEDLINE, Pubmed, Corchrane and China National Knowledge Infrastructure databases from inception through December, 2021 in order to identify studies that assessed the relationships between metals and the risk of HUA. Data were pooled by random-effects models and expressed as pooled odds ratios (OR) and 95% confidence intervals (CIs). The risk of bias was assessed using a tool from Agency for Healthcare Research and Quality (AHRQ). Twenty eligible articles (nineteen cross-sectional studies and one cohort) were included in our analysis, involving 63,283 participants in total. The studies showed that arsenic (pooled OR = 1.702, 95% CI: 1.44, 2.011; n = 6, I = 29.5%), calcium (pooled OR = 1.765, 1.111, 2.804; 4, 82.3%), cadmium (pooled OR = 1.199,1.020, 1.410; 11, 38.5%) and lead (pooled OR = 1.564,1.205, 2.030; 11, 72.9%) exposure were, all linked to an increased risk of HUA. Exposure to molybdenum (pooled OR = 0.804, 0.724, 0.975, 3, 0%) was linked to a decreased risk of HUA, however. Exposure to arsenic, calcium, cadmium and lead is associated with an increased risk of HUA. Molybdenum exposure was associated with a decreased prevalence of HUA; however, aluminum, cobalt, copper, iron, magnesium, manganese, mercury, selenium, thallium and zinc are not associated with HUA risk. Further experimental studies are warranted to decipher the mechanisms by which exposure to the above metals affect HUA risk. The findings reinforced the importance of metals in the HUA risk, and provided a reference for legislation to prevent HUA and protect people's health.
Topics: United States; Humans; Cadmium; Arsenic; Molybdenum; Calcium; Hyperuricemia; Cross-Sectional Studies
PubMed: 36109472
DOI: 10.1007/s10067-022-06362-1