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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 -
BMC Gastroenterology Jul 2023This study was performed to compare a metal stent (MS) and plastic stent (PS) in terms of efficacy and complications during neoadjuvant therapy (NAT) and the... (Meta-Analysis)
Meta-Analysis
Comparison of metal versus plastic stent for preoperative biliary drainage in patients with pancreatic cancer undergoing neoadjuvant therapy: a meta-analysis and systematic review.
BACKGROUND
This study was performed to compare a metal stent (MS) and plastic stent (PS) in terms of efficacy and complications during neoadjuvant therapy (NAT) and the perioperative period.
METHODS
We performed an electronic search of the following databases until 1 June 2022: PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov. Studies comparing an MS versus PS for PBD in patients with pancreatic cancer undergoing NAT were included.
RESULTS
The meta-analysis showed that use of an MS was associated with lower rates of reintervention (p < 0.00001), delay of NAT (p = 0.007), recurrent biliary obstruction (RBO) (p = 0.003), and cholangitis (p = 0.03). There were no significant differences between the two groups in terms of stent migration (p = 0.31), postoperative complications (p = 0.20), leakage (p = 0.90), and R0 resection (p = 0.50).
CONCLUSIONS
Use of an MS for PBD in patients with pancreatic cancer undergoing NAT followed by surgery was associated with lower rates of reintervention, delay of NAT, RBO, and cholangitis compared with use of a PS. However, the postoperative outcomes were comparable between the MS and PS. Further studies on this topic are recommended.
Topics: Humans; Neoadjuvant Therapy; Drainage; Pancreatic Neoplasms; Metals; Stents; Cholangitis; Cholestasis; Plastics
PubMed: 37438761
DOI: 10.1186/s12876-023-02874-5 -
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 -
International Journal of Environmental... Feb 2022Kapok fiber () belongs to a group of natural fibers that are mainly composed of cellulose, lignin, pectin, and small traces of inorganic compounds. These fibers are... (Review)
Review
Kapok fiber () belongs to a group of natural fibers that are mainly composed of cellulose, lignin, pectin, and small traces of inorganic compounds. These fibers are lightweight with hollow tubular structure that is easy to process and abundant in nature. Currently, kapok fibers are used in industry as filling material for beddings, upholstery, soft toys, and nonwoven materials. However, kapok fiber has also a potential application in the adsorptive removal of heavy metal ions and dyes from aqueous systems. This study aims to provide a comprehensive review about the recent developments on kapok fiber composites including its chemical properties, wettability, and surface morphology. Effective and innovative kapok fiber composites are analyzed with the help of characterization tools such as scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and Brunauer-Emmett-Teller analysis. Different pre-treatment methods such as alkali and acid pre-treatment, oxidation pre-treatment, and Fenton reaction are discussed. These techniques are applied to enhance the hydrophilicity and to generate rougher fiber surfaces. Moreover, surface modification and synthesis of kapok fiber-based composites and its environmental applications are examined. There are various methods in the fabrication of kapok fiber composites that include chemical modification and polymerization. These procedures allow the kapok fiber composites to have higher adsorption capacities for selective heavy metal and dye removal.
Topics: Adsorption; Ceiba; Coloring Agents; Ions; Metals, Heavy; Spectroscopy, Fourier Transform Infrared; Water; Water Pollutants, Chemical
PubMed: 35270400
DOI: 10.3390/ijerph19052703 -
Spine Deformity Nov 2022To assess surgical and safety outcomes associated with different rod materials and diameters in adolescent idiopathic scoliosis (AIS) surgery. (Meta-Analysis)
Meta-Analysis Review
PURPOSE
To assess surgical and safety outcomes associated with different rod materials and diameters in adolescent idiopathic scoliosis (AIS) surgery.
METHODS
A systematic literature review and meta-analysis evaluated the surgical management of AIS patients using pedicle screw fixation systems (i.e., posterior rods and pedicle screws) with rods of different materials and sizes. Postoperative surgical outcomes (e.g., kyphosis and coronal correction) and complications (i.e., hyper/hypo-lumbar lordosis, proximal junctional kyphosis, revisions, reoperations, and infections) were assessed. Random-effects models (REMs) pooled data for outcomes reported in ≥ 2 studies.
RESULTS
Among 75 studies evaluating AIS surgery using pedicle screw fixation systems, 46 described rod materials and/or diameters. Two studies directly comparing titanium (Ti) and cobalt-chromium (CoCr) rods found that CoCr rods provided significantly better postoperative kyphosis angle correction vs. Ti rods during a shorter follow-up (0-3 months, MD = - 2.98°, 95% CI - 5.79 to - 0.17°, p = 0.04), and longer follow-up (≥ 24 months, MD = - 3.99°, 95% CI - 6.98 to - 1.00, p = 0.009). Surgical infection varied from 2% (95% CI 1.0-3.0%) for 5.5 mm rods to 4% (95% CI 2.0-7.0%) for 6 mm rods. Reoperation rates were lower with 5.5 mm rods 1% (95% CI 0.0-3.0%) vs. 6 mm rods [6% (95% CI 2.0-9.0%); p = 0.04]. Differences in coronal angle, lumbar lordosis, proximal junctional kyphosis, revisions, and infections did not differ significantly (p > 0.05) among rods of different materials or diameters.
CONCLUSION
For AIS, CoCr rods provided better correction of thoracic kyphosis compared to Ti rods. Patients with 5.5 mm rods had fewer reoperations vs. 6.0 and 6.35 mm diameter rods.
LEVEL OF EVIDENCE
III.
Topics: Humans; Adolescent; Scoliosis; Lordosis; Titanium; Spinal Fusion; Kyphosis; Cobalt; Chromium
PubMed: 35737287
DOI: 10.1007/s43390-022-00537-1 -
Environmental Health Perspectives Aug 2023Neural tube defects (NTDs) affect pregnancies worldwide annually. Few nongenetic factors, other than folate deficiency, have been identified that may provide... (Review)
Review
BACKGROUND
Neural tube defects (NTDs) affect pregnancies worldwide annually. Few nongenetic factors, other than folate deficiency, have been identified that may provide intervenable solutions to reduce the burden of NTDs. Prenatal exposure to toxic metals [arsenic (As), cadmium (Cd), mercury (Hg), manganese (Mn) and lead (Pb)] may increase the risk of NTDs. Although a growing epidemiologic literature has examined associations, to our knowledge no systematic review has been conducted to date.
OBJECTIVE
Through adaptation of the Navigation Guide systematic review methodology, we aimed to answer the question "does exposure to As, Cd, Hg, Mn, or Pb during gestation increase the risk of NTDs?" and to assess challenges to evaluating this question given the current evidence.
METHODS
We selected available evidence on prenatal As, Cd, Hg, Mn, or Pb exposure and risk of specific NTDs (e.g., spina bifida, anencephaly) or all NTDs via a comprehensive search across MEDLINE, Embase, Web of Science, and TOXLINE databases and applied inclusion/exclusion criteria. We rated the quality and strength of the evidence for each metal. We applied a customized risk of bias protocol and evaluated the sufficiency of evidence of an effect of each metal on NTDs.
RESULTS
We identified 30 studies that met our criteria. Risk of bias for confounding and selection was high in most studies, but low for missing data. We determined that, although the evidence was limited, the literature supported an association between prenatal exposure to Hg or Mn and increased risk of NTDs. For the remaining metals, the evidence was inadequate to establish or rule out an effect.
CONCLUSION
The role of gestational As, Cd, or Pb exposure in the etiology of NTDs remains unclear and warrants further investigation in high-quality studies, with a particular focus on controlling confounding, mitigating selection bias, and improving exposure assessment. https://doi.org/10.1289/EHP11872.
Topics: Female; Pregnancy; Humans; Cadmium; Lead; Prenatal Exposure Delayed Effects; Neural Tube Defects; Mercury; Manganese; Arsenic
PubMed: 37647124
DOI: 10.1289/EHP11872 -
Spine Deformity Nov 2022To assess clinical and safety outcomes associated with different rod materials and diameters in adult spinal deformity (ASD) surgery. (Meta-Analysis)
Meta-Analysis Review
PURPOSE
To assess clinical and safety outcomes associated with different rod materials and diameters in adult spinal deformity (ASD) surgery.
METHODS
A systematic literature review and meta-analysis evaluated ASD surgery using pedicle screw fixation systems with rods of different materials and sizes. Postoperative outcomes (i.e., Cobb, sagittal vertical axis, and pelvic tilt angle) and complications (i.e., pseudarthrosis and rod breakage) were assessed. Random effects models (REMs) pooled data for outcomes reported in ≥ 2 studies.
RESULTS
Among 50 studies evaluating ASD surgery using pedicle screw fixation systems, 17 described rod material/diameter. Postoperative outcomes did not statistically differ between cobalt-chromium (CoCr) vs. titanium (Ti) rods (n = 2 studies; mean [95% confidence interval (CI)] sagittal vertical axis angle: CoCr 37.00° [18.58°-55.42°] and Ti 32.58° [24.62°-40.54°]; mean [95% CI] pelvic tilt angle: CoCr 26.20° [22.87°-29.53°] and Ti 20.15° [18.0°-22.31°]). The pooled proportion (95% CI) of pseudarthrosis was 15% (7-22%) for CoCr and 12% (- 8-32%) for stainless steel (SS) (n = 2 studies each; Chi = 0.07, p = 0.79). The pooled proportion (95% CI) of broken rods was 12% (1-22%) for Ti (n = 3 studies) and 10% (2-19) for CoCr (n = 1 study). Among 6.0-6.35 mm rods, the pooled (95% CI) postoperative Cobb angle (n = 2) was 12.01° (9.75°-14.28°), sagittal vertical axis angle (n = 4) was 35.32° (30.02°-40.62°), and pelvic tilt angle was 21.11° (18.35°-23.86°).
CONCLUSIONS
For ASD patients undergoing posterior fixation and fusion, there are no statistically significant differences in postoperative outcomes or complications among rods of varying materials and diameters. Benchmark postsurgical outcomes and complication rates by rod material and diameter are provided.
LEVEL OF EVIDENCE
III.
Topics: Adult; Humans; Spinal Fusion; Stainless Steel; Titanium; Chromium Alloys; Pseudarthrosis; Cobalt; Chromium
PubMed: 35904725
DOI: 10.1007/s43390-022-00556-y -
Chemosphere Oct 2023Metal contamination associated with mining activities has been considered one of the main environmental pollution problems in the Amazon region. Understanding the levels...
Metal contamination associated with mining activities has been considered one of the main environmental pollution problems in the Amazon region. Understanding the levels of metal contamination from mining activities requires a good understanding of background metal concentrations, which may vary notably according to the geology/lithology characteristics of the region, soil type, and predominant biogeochemical processes. This review assessed 50 papers and reports published between 1989 and 2020 describing environmental concentrations of different metals and metalloids (As, Hg, Mn, Fe, Cd, Cu, Cr, Pb, Ni, and Zn) in water and sediments of mining and non-mining areas in five geographic regions of the Amazon basin. Metal enrichment caused by mining activities was calculated and exposure concentrations were compared with sediment and water quality standards set for the protection of aquatic life. Significant enrichments of Cd, Cu, Cr, Fe, Hg, Mn, Ni and Zn were observed in mining areas in both sediment and water. Regarding background levels in the different geographic regions, the highest prevalence of metal enrichment (i.e., concentrations 10 to 100-fold higher than mean background values) in sediment samples was found for Fe (100% of samples), Ni (90%), and Mn (69%). For water, high prevalence of metal enrichment occurred for Zn, Mn, and Fe (100% of samples), and for Hg (86%). Hg, Fe, Pb, Cu, Cd, Ni and Zn exceeded water and/or sediment quality standards in a significant number of samples in the proximity of mining areas. This study indicates that mining activities significantly contribute to water and sediment contamination across the Amazon basin, posing hazards for freshwater ecosystems and potentially having human health implications.
Topics: Humans; Metals, Heavy; Ecosystem; Cadmium; Lead; Geologic Sediments; Environmental Monitoring; Water Pollutants, Chemical; Mercury; Risk Assessment
PubMed: 37532203
DOI: 10.1016/j.chemosphere.2023.139700 -
Journal of Hepato-biliary-pancreatic... Feb 2022Peripancreatic fluid collections (PFCs) result from acute or chronic pancreatic inflammation that suffers a rupture of its ducts. Currently, there exists three options... (Meta-Analysis)
Meta-Analysis Review
Head-to-head comparison between endoscopic ultrasound guided lumen apposing metal stent and plastic stents for the treatment of pancreatic fluid collections: A systematic review and meta-analysis.
BACKGROUND/AIMS
Peripancreatic fluid collections (PFCs) result from acute or chronic pancreatic inflammation that suffers a rupture of its ducts. Currently, there exists three options for drainage or debridement of pancreatic pseudocysts and walled-off necrosis (WON). The traditional procedure is drainage by placing double pigtail plastic stents (DPPS); lumen-apposing metal stent (LAMS) has a biflanged design with a wide lumen that avoids occlusion with necrotic tissue, which is more common with DPPS and reduces the possibility of migration. We performed a systematic review and meta-analyses head-to-head, including only studies that compare the two main techniques to drainage of PFCs: LAMS vs DPPS.
METHODS
We conducted a systematic review in different databases, such as PubMed, OVID, Medline, and Cochrane Databases. This meta-analysis considers studies published from 2014 to 2020, including only studies that compare the two main techniques to drainage of PFCs: LAMS vs DPPS.
RESULTS
Thirteen studies were included in the meta-analyses. Only one of all studies was a randomized controlled trial. These studies comprise 1584 patients; 68.2% were male, and 31.8% were female. Six hundred sixty-three patients (41.9%) were treated with LAMS, and 921 (58.1%) were treated with DPPS. Six studies included only WON in their analysis, two included only pancreatic pseudocysts, and five studies included both pancreatic pseudocysts and WON. The technical success was similar in patients treated with LAMS and DPPS (97.6% vs 97.5%, respectively, P = .986, RR = 1.00 [95% CI 0.93-1.08]). The clinical success was similar in both groups (LAMS: 90.1% vs DPPS: 84.2%, P = .139, RR = 1.063 [95% CI 0.98-1.15]). Patients treated with LAMS had a lower complication rate than the DPPS groups, with a significant statistical difference (LAMS: 16.0% vs DPPS: 20.2%, P = .009, RR = 0.746 [95% CI 0.60-0.93]). Bleeding was the most common complication in the LAMS group (33 patients, [5.0%]), whereas infection was the most common complication in the DPPS group (56 patients, [6.1%]). The LAMS migration rate was lower than in the DPPS (0.9% vs 2.2%, respectively, P = .05). The mortality rate was similar in both groups, 0.6% in the LAMS group (four patients) and 0.4% in the DPPS group (four patients; P = .640).
CONCLUSION
The PFCs drainage is an indication when persistent symptoms or PFCs-related complications exist. EUS guided drainage with LAMS has similar technical and clinical success to DPPS drainage for the management of PFCs. The technical and clinical success rates are high in both groups. However, LAMS drainage has a lower adverse events rate than DPPS drainage. More randomized controlled trials are needed to confirm the real advantage of LAMS drainage over DPPS drainage.
Topics: Drainage; Endosonography; Female; Humans; Male; Metals; Pancreatic Pseudocyst; Plastics; Randomized Controlled Trials as Topic; Stents; Treatment Outcome; Ultrasonography, Interventional
PubMed: 34107170
DOI: 10.1002/jhbp.1008 -
Clinical Oral Investigations Dec 2023To assess the clinical outcomes of zirconia dental implants based on an updated systematic literature review. (Meta-Analysis)
Meta-Analysis Review
PURPOSE
To assess the clinical outcomes of zirconia dental implants based on an updated systematic literature review.
METHODS
An electronic search was performed in three databases, last updated in June 2023, supplemented by hand searching. The eligibility criteria were clinical studies reporting patients rehabilitated with zirconia implants. The cumulative survival rate (CSR) of implants was calculated. A meta-analysis for marginal bone loss (MBL) under different follow-up times and a meta-regression assessing the relationship between mean MBL and follow-up were done.
RESULTS
Twenty-five studies were included (4017 implants, 2083 patients). Seven studies had follow-up longer than 60 months. 172 implants failed, after a mean of 12.0 ± 16.1 months (min-max 0.3-86.0), of which 47 early failures, and 26 due to implant fracture, the majority in narrow-diameter implants. The 10-year CSR was 95.1%. Implants with coronal part prepared by drills presented statistically significant lower survival than non-prepared implants (p < 0.001). Two-piece implants presented lower survival than one-piece implants (p = 0.017). Implants discontinued from the market presented lower survival than the commercially available ones (p < 0.001). The difference in survival was not significant between implants in maxilla and mandible (p = 0.637). The mean MBL fluctuated between 0.632 and 2.060 mm over long periods of observation (up until 132 months). There was an estimated MBL increase of 0.005 mm per additional month of follow-up.
CONCLUSION
Zirconia implants present high 10-year CSR and short-term low MBL. The review was registered in PROSPERO (CRD42022342055).
CLINICAL RELEVANCE
The clinical outcomes observed for zirconia dental implants are very promising, although these have not yet been extensively studied as titanium alloy implants.
Topics: Humans; Dental Implants; Treatment Outcome; Dental Restoration Failure; Zirconium; Titanium; Dental Prosthesis Design
PubMed: 38135804
DOI: 10.1007/s00784-023-05401-8