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The Journal of Prosthetic Dentistry Nov 2022Evidence comparing the marginal and internal fit of single metal copings fabricated via selective laser sintering and conventional lost-wax casting is inadequate. (Meta-Analysis)
Meta-Analysis Review
STATEMENT OF PROBLEM
Evidence comparing the marginal and internal fit of single metal copings fabricated via selective laser sintering and conventional lost-wax casting is inadequate.
PURPOSE
The purpose of this systematic review was to compare the fit of single metal copings fabricated via selective laser sintering and lost-wax casting. Moreover, the effects of different variables on fit accuracy were determined.
MATERIAL AND METHODS
Google Scholar, ScienceDirect, SpringerLink, and Wiley databases were searched electronically as well as manually. The mean absolute marginal gap, marginal gap, internal gap, axial gap, and occlusal gap values of single metal copings fabricated via selective laser sintering and lost-wax casting were statistically analyzed to determine and evaluate the factors affecting the fit accuracy (α=.05).
RESULTS
Single metal copings fabricated via selective laser sintering had mean absolute marginal gaps and occlusal gaps similar to those of copings fabricated via lost-wax casting, based on a subgroup meta-analysis of gaps evaluated using stereomicroscopy (P>.05). The fit of single metal copings was not affected by the type of tooth (P>.05). The conventional impression, the indirect digital scan, and the direct digital scan led to similar values of mean axial gap, internal gap, and marginal gap for the copings fabricated via lost-wax casting (P>.05). The indirect and direct digital scans led to similar values of mean axial gap, internal gap, and marginal gap for the copings fabricated via selective laser sintering (P>.05). Printed wax patterns provided significantly smaller mean axial gap values than milled plastic or milled wax patterns for the copings fabricated via lost-wax casting (P<.05). Printed, milled, and conventional wax patterns had similar mean marginal gaps and internal gaps for the copings fabricated via lost-wax casting (P>.05). For single copings fabricated via lost-wax casting, Ni-Cr and Co-Cr had similar mean internal gaps (P>.05).
CONCLUSIONS
No statistically significant differences were found between single metal copings fabricated via selective laser sintering and lost-wax casting. Selective laser sintering can satisfy the clinical requirement for single metal copings.
Topics: Dental Marginal Adaptation; Dental Casting Technique; Dental Prosthesis Design; Computer-Aided Design; Chromium Alloys; Lasers; Crowns
PubMed: 33789799
DOI: 10.1016/j.prosdent.2021.02.011 -
International Journal of Environmental... Sep 2022Electronic waste (e-waste) recycling releases mercury (Hg) into the environment, though to our knowledge Hg levels at such sites have yet to be examined on a worldwide... (Meta-Analysis)
Meta-Analysis Review
Electronic waste (e-waste) recycling releases mercury (Hg) into the environment, though to our knowledge Hg levels at such sites have yet to be examined on a worldwide basis. A systematic review of scientific studies was conducted to extract, analyze, and synthesize data on Hg levels in e-waste products, environments near recycling sites, and in people. Data were extracted from 78 studies from 20 countries, and these included Hg levels in 1103 electrical and electronic products, 2072 environmental samples (soil, air, plant, food, water, dust), and 2330 human biomarkers (blood, hair, urine). The average Hg level in products was 0.65 μg/g, with the highest levels found in lamps (578 μg/g). Average soil and sediment Hg levels (1.86 μg/g) at e-waste sites were at least eight times higher than at control sites. Average urinary Hg levels (0.93 μg/g creatinine) were approximately two-fold higher among e-waste workers versus control groups. Collectively, these findings demonstrate that e-waste recycling may lead to Hg contamination in environments and human populations in close proximity to processing sites. These findings contribute to a growing knowledge base of mercury exposure through diverse source-exposure pathways, and the work has potential policy implications in the context of the Minamata Convention.
Topics: Biomarkers; Creatinine; Dust; Electronic Waste; Environmental Monitoring; Humans; Mercury; Soil; Waste Products; Water Pollutants, Chemical
PubMed: 36231146
DOI: 10.3390/ijerph191911843 -
International Journal of Surgery... Apr 2022The objective of this study was to compare cup survival and the incidence of adverse events associated with the use of trabecular metal (TM) and non-TM cups for... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The objective of this study was to compare cup survival and the incidence of adverse events associated with the use of trabecular metal (TM) and non-TM cups for acetabular revision surgery.
METHODS
The MEDLINE, EMBASE, and Cochrane Library databases were searched for comparative studies that reported cup survival and the incidence of adverse events associated with the use of TM and non-TM cups for acetabular revision surgery. Primary outcomes included cup survival, aseptic loosening, dislocation, and infection.
RESULTS
The meta-analysis included 6 studies that involved 13,864 total hip arthroplasty (THA) revisions who underwent acetabular revision surgery with TM (n = 5,619) or non-TM (n = 8,245) cups. The meta-analysis demonstrated no significant difference in cup survival using re-revision for any reason or aseptic loosening as the endpoint following acetabular revision surgery with TM or non-TM cups (HR = 0.96; [95% CI, 0.84-1.09]; HR = 1.29; [95% CI, 0.70-2.38]). Pooled data indicated that the overall incidence of adverse events for TM or non-TM cups was 6.8% (382/5,289) and 9.0% (725/8,083), respectively, and not significantly different (OR = 0.91; [95% CI, 0.80-1.04]). The incidence of aseptic loosening and infection were significantly lower (OR = 0.75; [95% CI, 0.58-0.96]; OR = 0.70; [95% CI, 0.54-0.90]) and the incidence of dislocation was significantly higher (OR = 1.53; [95% CI, 1.22-1.91]) for TM compared to non-TM cups.
CONCLUSION
This review was the first to use reconstructed time-to-event data to find that there was no difference in survival of TM and non-TM cups in acetabular revision surgery. Overall, fewer adverse events were associated with the use of TM compared to non-TM cups, but the difference was not significant. The incidence of aseptic loosening and infection were significantly lower and the incidence of dislocation was significantly higher for TM compared to non-TM cups. This information is expected to guide orthopedic surgeons in the selection of appropriate acetabular components for THA revision.
Topics: Arthroplasty, Replacement, Hip; Follow-Up Studies; Hip Prosthesis; Humans; Joint Dislocations; Metals; Prosthesis Design; Prosthesis Failure; Registries; Reoperation; Retrospective Studies
PubMed: 35288338
DOI: 10.1016/j.ijsu.2022.106597 -
Reviews on Environmental Health Sep 2021Heavy metals in drinking water can threat human health and may induce several diseases. The association between heavy metals exposure and chronic kidney disease (CKD)...
Heavy metals in drinking water can threat human health and may induce several diseases. The association between heavy metals exposure and chronic kidney disease (CKD) has been indicated by few epidemiological studies. We conducted a systematic review of the epidemiologic publications of the association between exposure to heavy metals through drinking water and CKD. Keywords related to heavy metals and kidney diseases on MeSH were identified and searched in PubMed, Google Scholar, Scopus, Ovid-Medline and Web of Science until July 2020. 14 publications met our inclusion criteria and included in the current review. The included articles were conducted on the association between arsenic, cadmium, lead and chromium in drinking water and CKD. Our study could not find strong evidence between heavy exposure to through drinking water and CKD, except for arsenic. The negative association was found between arsenic and lead and glomerular filtration rate (eGFR). The positive correlation was observed between cadmium exposure and urinary N-acetyl--d-glucosaminidase (NAG) concentrations, and also arsenic and chromium exposure and kidney injury molecule (KIM-1). Assessment of studies showed an association between arsenic, cadmium, lead and chromium and albuminuria and proteinuria, without CKD outcomes. Current systematic study showed few evidence for exposure to arsenic, cadmium, lead and chromium through drinking water and incidence of kidney problems. However, more epidemiological studies are required to confirm this association.
Topics: Arsenic; Biomarkers; Drinking Water; Humans; Kidney; Metals, Heavy; Renal Insufficiency, Chronic; Water Pollutants, Chemical
PubMed: 33128529
DOI: 10.1515/reveh-2020-0110 -
Food and Chemical Toxicology : An... Mar 2018The ingestion of heavy metals through contaminated seafood can causes significant outcomes on human health. In recent years, consume fishes and shrimps has increased in... (Meta-Analysis)
Meta-Analysis Review
The ingestion of heavy metals through contaminated seafood can causes significant outcomes on human health. In recent years, consume fishes and shrimps has increased in Iran, and several study about heavy metals content in fishes and shrimps from Persian Gulf were carried out to check their food safety. The aims of these systematic reviews and meta-analysis was to summarize the evidence on the relation of the intakes of Arsenic (As) and lead (Pb) levels, based on the origin and sub-groups of shrimp species consumed, Hence that we can estimate the risk of oral cancer induced by Pb and As in these groups of shrimp from the persian gulf. We carried out a search of all suitable studies published between 1995 and 2017 in Scopus, Science Direct, PubMed and Web of Science databases. Since the heterogeneity among studied was significant, we used the random effect model (REM) to perform meta-analysis of data. Data were obtained from 9 articles (14 studies), with 511 samples, and it was reported that pooled levels of As and Pb in the muscle shrimps were 1.37 (95% CI: 0.66-2.08 mg/kg d.w.) and 0.58 (95% CI: 0.33-0.82 mg/kg d.w.), respectively. This pooled levels in muscle shrimps were higher than safe dose reported on Food and Agriculture Organization/World Health Organization guidelines (FAO/WHO). The rank order of shrimps species based on As was Panulirus homarus > Penaeus semisulcatus and for the Pb levels was Litopenaeus vannamei > Panulirus homarus > Fenneropenaeus indicus > Metapenaeus affinis. The lowest and highest risk levels of oral cancer, divided by consumers age groups, were respectively 45-54 (6.94E-04) and 15-24 (8.42E-04) for the Pb, and 45-54 (2.87E-01) and 15-24 (3.51E-01) for arsenic. Incremental Lifetime Cancer Risk (ILCR) of Pb and As was higher than 10-4 and 10-3, respectively. All groups (age) of consumers are subject to the cancer risk of due to the consumption of shrimps contaminated by Pb and As, therefore, should be started a control plan for the reduction of the heavy metal bioaccumulation levels in shrimps of the Persian Gulf coupled to a capillary food safety communication.
Topics: Adolescent; Adult; Animals; Arsenic; Carcinogens; Crustacea; Female; Humans; Indian Ocean; Lead; Male; Middle Aged; Mouth Neoplasms; Muscles; Population Health; Risk Assessment; Seafood; Species Specificity; Young Adult
PubMed: 29407475
DOI: 10.1016/j.fct.2018.01.046 -
Contact Dermatitis Jan 2023Occupational hand eczema is frequent in metalworkers. The contribution of metal allergies is poorly elucidated even though such exposures are common at the workplace. To... (Meta-Analysis)
Meta-Analysis Review
Occupational hand eczema is frequent in metalworkers. The contribution of metal allergies is poorly elucidated even though such exposures are common at the workplace. To estimate the prevalence of metal allergy to cobalt (Co), chromium (Cr) and nickel (Ni) in metalworkers and compare these to estimates from the European Surveillance System on Contact Allergies (ESSCA). Two authors independently searched PubMed for studies reporting on the prevalence of metal allergy in metalworkers. Proportion meta-analyses were performed to calculate the pooled proportions of metal allergy in metalworkers. In total, 29 studies (22 from Europe) were included yielding 5691 subjects for quantitative analysis. The pooled proportion (95% confidence interval) of Co, Cr and Ni in European metalworkers with dermatitis referred to patch test clinics was 8.2% (5.3%-11.7%), 8.0% (5.1%-11.4%), and 11.0% (7.3%-15.4%), respectively. The corresponding estimates for unselected metalworkers from workplace studies were 4.9% (2.4%-8.1%), 5.2% (1.0%-12.6%), and 7.6% (3.8%-12.6%), respectively. In comparison, the prevalence of metal allergy in 13 382 consecutive European males with dermatitis was 3.9% (3.6%-4.2%), 4.4% (4.1%-4.8%) and 6.7% (6.3%-7.0%) for Co, Cr and Ni, respectively. Data on sex, age, body piercings and atopic dermatitis in metalworkers with metal allergy was mostly lacking. Metal allergy to all three metals was significantly more common in European metalworkers with dermatitis attending patch test clinics as compared to ESSCA data, indicating a relationship to occupational exposures, however, confounders could not be accounted for.
Topics: Male; Humans; Dermatitis, Allergic Contact; Patch Tests; Dermatitis, Occupational; Metals; Nickel; Cobalt; Chromium; Prevalence
PubMed: 36208426
DOI: 10.1111/cod.14232 -
Environmental Health Perspectives Mar 2020Electronic cigarettes (e-cigarettes) have become popular, in part because they are perceived as a safer alternative to tobacco cigarettes. An increasing number of...
BACKGROUND
Electronic cigarettes (e-cigarettes) have become popular, in part because they are perceived as a safer alternative to tobacco cigarettes. An increasing number of studies, however, have found toxic metals/metalloids in e-cigarette emissions.
OBJECTIVE
We summarized the evidence on metal/metalloid levels in e-cigarette liquid (e-liquid), aerosols, and biosamples of e-cigarette users across e-cigarette device systems to evaluate metal/metalloid exposure levels for e-cigarette users and the potential implications on health outcomes.
METHODS
We searched PubMed/TOXLINE, Embase®, and Web of Science for studies on metals/metalloids in e-liquid, e-cigarette aerosols, and biosamples of e-cigarette users. For metal/metalloid levels in e-liquid and aerosol samples, we collected the mean and standard deviation (SD) if these values were reported, derived mean and SD by using automated software to infer them if data were reported in a figure, or calculated the overall mean (mean ± SD) if data were reported only for separate groups. Metal/metalloid levels in e-liquids and aerosols were converted and reported in micrograms per kilogram and nanograms per puff, respectively, for easy comparison.
RESULTS
We identified 24 studies on metals/metalloids in e-liquid, e-cigarette aerosols, and human biosamples of e-cigarette users. Metal/metalloid levels, including aluminum, antimony, arsenic, cadmium, cobalt, chromium, copper, iron, lead, manganese, nickel, selenium, tin, and zinc, were present in e-cigarette samples in the studies reviewed. Twelve studies reported metal/metalloid levels in e-liquids (bottles, cartridges, open wick, and tank), 12 studies reported metal/metalloid levels in e-cigarette aerosols (from cig-a-like and tank devices), and 4 studies reported metal/metalloid levels in human biosamples (urine, saliva, serum, and blood) of e-cigarette users. Metal/metalloid levels showed substantial heterogeneity depending on sample type, source of e-liquid, and device type. Metal/metalloid levels in e-liquid from cartridges or tank/open wicks were higher than those from bottles, possibly due to coil contact. Most metal/metalloid levels found in biosamples of e-cigarette users were similar or higher than levels found in biosamples of conventional cigarette users, and even higher than those found in biosamples of cigar users.
CONCLUSION
E-cigarettes are a potential source of exposure to metals/metalloids. Differences in collection methods and puffing regimes likely contribute to the variability in metal/metalloid levels across studies, making comparison across studies difficult. Standardized protocols for the quantification of metal/metalloid levels from e-cigarette samples are needed. https://doi.org/10.1289/EHP5686.
Topics: Aerosols; Electronic Nicotine Delivery Systems; Humans; Metalloids; Metals; Saliva
PubMed: 32186411
DOI: 10.1289/EHP5686 -
Brazilian Oral Research Jul 2017The aim of this systematic review was to compare the clinical performance and failure modes of teeth restored with intra-radicular retainers. A search was performed on... (Review)
Review
The aim of this systematic review was to compare the clinical performance and failure modes of teeth restored with intra-radicular retainers. A search was performed on PubMed/Medline, Central and ClinicalTrials databases for randomized clinical trials comparing clinical behavior and failures of at least two types of retainers. From 341 detected papers, 16 were selected for full-text analysis, of which 9 met the eligibility criteria. A manual search added 2 more studies, totalizing 11 studies that were included in this review. Evaluated retainers were fiber (prefabricated and customized) and metal (prefabricated and cast) posts, and follow-up ranged from 6 months to 10 years. Most studies showed good clinical behavior for evaluated intra-radicular retainers. Reported survival rates varied from 71 to 100% for fiber posts and 50 to 97.1% for metal posts. Studies found no difference in the survival among different metal posts and most studies found no difference between fiber and metal posts. Two studies also showed that remaining dentine height, number of walls and ferrule increased the longevity of the restored teeth. Failures of fiber posts were mainly due to post loss of retention, while metal post failures were mostly related to root fracture, post fracture and crown and/or post loss of retention. In conclusion, metal and fiber posts present similar clinical behavior at short to medium term follow-up. Remaining dental structure and ferrule increase the survival of restored pulpless teeth. Studies with longer follow-up are needed.
Topics: Bias; Dental Restoration Failure; Dental Restoration, Permanent; Glass; Gold; Humans; Post and Core Technique; Randomized Controlled Trials as Topic; Titanium; Tooth, Nonvital; Treatment Outcome
PubMed: 28678974
DOI: 10.1590/1807-3107BOR-2017.vol31.0064 -
Environmental Research May 2024Metalloestrogens are metals and metalloid elements with estrogenic activity found everywhere. Their impact on human health is becoming more apparent as human activities... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Metalloestrogens are metals and metalloid elements with estrogenic activity found everywhere. Their impact on human health is becoming more apparent as human activities increase.
OBJECTIVE
Our aim is to conduct a comprehensive systematic review and meta-analysis of observational studies exploring the correlation between metalloestrogens (specifically As, Sb, Cr, Cd, Cu, Se, Hg) and Gestational Diabetes Mellitus (GDM).
METHODS
PubMed, Web of Science, and Embase were searched to examine the link between metalloestrogens (As, Sb, Cr, Cd, Cu, Se, and Hg) and GDM until December 2023. Risk estimates were derived using random effects models. Subgroup analyses were conducted based on study countries, exposure sample, exposure assessment method, and detection methods. Sensitivity analyses and adjustments for publication bias were carried out to assess the strength of the findings.
RESULTS
Out of the 389 articles identified initially, 350 met our criteria and 33 were included in the meta-analysis, involving 141,175 subjects (9450 cases, 131,725 controls). Arsenic, antimony, and copper exposure exhibited a potential increase in GDM risk to some extent (As: OR = 1.28, 95 % CI [1.08, 1.52]; Sb: OR = 1.73, 95 % CI [1.13, 2.65]; Cu: OR = 1.29, 95 % CI [1.02, 1.63]), although there is a high degree of heterogeneity (As: Q = 52.93, p < 0.05, I = 64.1 %; Sb: Q = 31.40, p < 0.05, I = 80.9 %; Cu: Q = 21.14, p < 0.05, I = 71.6 %). Conversely, selenium, cadmium, chromium, and mercury exposure did not exhibit any association with the risk of GDM in our study.
DISCUSSION
Our research indicates that the existence of harmful metalloestrogens in the surroundings has a notable effect on the likelihood of GDM. Hence, we stress the significance of environmental elements in the development of GDM and the pressing need for relevant policies and measures.
Topics: Pregnancy; Female; Humans; Diabetes, Gestational; Cadmium; Copper; Arsenic; Mercury; Observational Studies as Topic
PubMed: 38307186
DOI: 10.1016/j.envres.2024.118321 -
Journal of Neurosurgery. Spine Oct 2023By minimizing imaging artifact and particle scatter, carbon fiber-reinforced polyetheretherketone (CF-PEEK) spinal implants are hypothesized to enhance radiotherapy (RT)...
OBJECTIVE
By minimizing imaging artifact and particle scatter, carbon fiber-reinforced polyetheretherketone (CF-PEEK) spinal implants are hypothesized to enhance radiotherapy (RT) planning/dosing and improve oncological outcomes. However, robust clinical studies comparing tumor surgery outcomes between CF-PEEK and traditional metallic implants are lacking. In this paper, the authors performed a systematic review of the literature with the aim to describe clinical outcomes in patients with spine tumors who received CF-PEEK implants, focusing on implant-related complications and oncological outcomes.
METHODS
A systematic review of the literature published between database inception and May 2022 was performed in accordance with the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The PubMed database was queried using the terms "carbon fiber" and "spine" or "spinal." The inclusion criteria were articles that described patients with CF-PEEK pedicle screw fixation and had a minimum of 5 patients. Case reports and phantom studies were excluded.
RESULTS
This review included 11 articles with 326 patients (237 with CF-PEEK-based implants and 89 with titanium-based implants). The mean follow-up period was 13.5 months, and most tumors were metastatic (67.1%). The rates of implant-related complications in the CF-PEEK and titanium groups were 7.8% and 4.7%, respectively. The rate of pedicle screw fracture was 1.7% in the CF-PEEK group and 2.4% in the titanium group. The rates of reoperation were 5.7% (with 60.0% because of implant failure or junctional kyphosis) and 4.8% (all because of implant failure or junctional kyphosis) in the CF-PEEK and titanium groups, respectively. When reported, 72.5% of patients received postoperative RT (41.0% stereotactic body RT, 30.8% fractionated RT, 25.6% proton, 2.6% carbon ion). Four articles suggested that implant artifact was reduced in the CF-PEEK group. Local recurrence occurred in 14.4% of CF-PEEK and 10.7% of titanium-implanted patients.
CONCLUSIONS
While CF-PEEK harbors similar implant failure rates to traditional metallic implants with reduced imaging artifact, it remains unclear whether CF-PEEK implants improve oncological outcomes. This study highlights the need for prospective, direct comparative clinical studies.
Topics: Humans; Carbon Fiber; Titanium; Prospective Studies; Polyethylene Glycols; Ketones; Carbon; Pedicle Screws; Postoperative Complications; Neoplasms; Kyphosis
PubMed: 37382293
DOI: 10.3171/2023.5.SPINE23106