-
The Journal of Prosthetic Dentistry Feb 2021Removable partial dentures (RPDs) are traditionally made by casting, a complex, error-prone, and time-consuming process. Computer-aided design and computer-aided... (Review)
Review
STATEMENT OF PROBLEM
Removable partial dentures (RPDs) are traditionally made by casting, a complex, error-prone, and time-consuming process. Computer-aided design and computer-aided manufacturing (CAD-CAM) RPD systems may simplify the clinical steps and minimize errors; however, the accuracy of CAD-CAM RPD systems is unclear.
PURPOSE
The purpose of this systematic review was to determine whether CAD-CAM systems are accurate for the manufacturing of RPD frameworks.
MATERIAL AND METHODS
A literature search was conducted through Medline-PubMed, Scopus, Lilacs, Web of Science, and Cochrane Library databases using specific keywords for articles published up to November 2019. Three reviewers obtained data and compared the results. All studies evaluated the framework accuracy or fit of prostheses fabricated with conventional and digital techniques.
RESULTS
A total of 7 articles, 2 clinical studies, and 5 in vitro studies that complied with the inclusion criteria were evaluated. One in vitro study compared indirect (extraoral) and direct (intraoral) scanning for partially edentulous ridges and shows that digital scans were better than conventional impressions in terms of trueness. In the other studies included, although the frameworks analyzed had clinically acceptable discrepancies (<311 μm), the material influenced the fit. Polyetheretherketone (PEEK) showed better fit than traditional metal cast RPDs. Co-Cr alloy RPDs produced by rapid prototyping exhibited the highest discrepancies when produced by sintering laser melting.
CONCLUSIONS
The results show that the digital technique for RPD frameworks is accurate. In the studies included, the analyzed frameworks had clinically acceptable gaps, but the results were heterogeneous among studies because the articles used different measurement methods with small sample sizes. Few studies discussed the long-term clinical performance. The digital technique for RPD frameworks was accurate because the misfits and mismatches found in in vitro and clinical studies were within the acceptable clinical limit for RPDs.
Topics: Alloys; Computer-Aided Design; Denture, Partial, Removable; Humans; Lasers; Mouth, Edentulous
PubMed: 32147252
DOI: 10.1016/j.prosdent.2020.01.003 -
Toxicology and Industrial Health Jul 2022Today, tattooing has become very popular among people all over the world. Tattooists, with the help of tiny needles, place tattoo ink inside the skin surface and...
Tattoo inks are toxicological risks to human health: A systematic review of their ingredients, fate inside skin, toxicity due to polycyclic aromatic hydrocarbons, primary aromatic amines, metals, and overview of regulatory frameworks.
Today, tattooing has become very popular among people all over the world. Tattooists, with the help of tiny needles, place tattoo ink inside the skin surface and unintentionally introduce a large number of unknown ingredients. These ingredients include polycyclic aromatic hydrocarbons (PAHs), heavy metals, and primary aromatic amines (PAAs), which are either unintentionally introduced along with the ink or produced inside the skin by different types of processes for example cleavage, metabolism and photodecomposition. These could pose toxicological risks to human health, if present beyond permissible limits. PAH such as Benzo(a)pyrene is present in carbon black ink. PAAs could be formed inside the skin as a result of reductive cleavage of organic azo dyes. They are reported to be highly carcinogenic by environmental protection agencies. Heavy metals, namely, cadmium, lead, mercury, antimony, beryllium, and arsenic are responsible for cancer, neurodegenerative diseases, cardiovascular, gastrointestinal, lungs, kidneys, liver, endocrine, and bone diseases. Mercury, cobalt sulphate, other soluble cobalt salts, and carbon black are in Group 2B, which means they may cause cancer in humans. Cadmium and compounds of cadmium, on the other hand, are in Group 1 (carcinogenic to humans). The present article addresses the various ingredients of tattoo inks, their metabolic fate inside human skin and unintentionally added impurities that could pose toxicological risk to human health. Public awareness and regulations that are warranted to be implemented globally for improving the safety of tattooing.
Topics: Amines; Cadmium; Carcinogens; Humans; Ink; Mercury; Metals; Polycyclic Aromatic Hydrocarbons; Soot; Tattooing
PubMed: 35592919
DOI: 10.1177/07482337221100870 -
Quintessence International (Berlin,... 2019This review was undertaken to answer a controversial clinical question with high-quality evidence: When severely damaged teeth are restored, which type of post (metal or... (Meta-Analysis)
Meta-Analysis
OBJECTIVES
This review was undertaken to answer a controversial clinical question with high-quality evidence: When severely damaged teeth are restored, which type of post (metal or fiber) demonstrates superior clinical performance?
DATA SOURCES
The meta-analysis was conducted according to the guidelines in the Cochrane handbook. Electronic databases (MEDLINE, EMBASE, CENTRAL) and gray literatures were screened up to January 2018. Only randomized controlled trials (RCTs) with follow-up of at least 3 years were included. The quality of included studies was assessed by the Cochrane Collaboration's tool. Meta-analysis compared survival, success, post debonding, and root fracture incidence of teeth restored with fiber and metal posts. The GRADE system (Grading of Recommendations, Assessment, Development and Evaluations) was used to assess the strength of the evidence. Of 1,511 records, 14 full texts were obtained. Only four RCTs with follow-up times of 3 to 7 years met the selection criteria. The methodologic quality of included RCTs was low risk of bias. Fiber posts presented significantly higher survival rates than did metal posts (RR 0.57, 95% CI: 0.33 to 0.97, P = .04), while no difference was observed in success rates, post debonding rates, or root fracture rates. The GRADE assessment indicated a high quality of evidence for survival rates and a moderate quality for success rates.
CONCLUSION
It was concluded that fiber posts displayed higher medium-term (3 to 7 years) overall survival rates than did metal posts when used in the restoration of endodontically treated teeth with no more than two coronal walls remaining.
Topics: Dental Restoration Failure; Glass; Humans; Metals; Post and Core Technique; Randomized Controlled Trials as Topic; Tooth, Nonvital
PubMed: 30600326
DOI: 10.3290/j.qi.a41499 -
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 -
Journal of the Science of Food and... Aug 2022Sodium chloride (NaCl) is an enjoyable condiment. However, evidence is accumulating to indicate that an excessive intake of Na in food may lead to an increased risk of... (Review)
Review
Sodium chloride (NaCl) is an enjoyable condiment. However, evidence is accumulating to indicate that an excessive intake of Na in food may lead to an increased risk of cardiovascular and cerebrovascular diseases. Previous systematic reviews have focused on replacing NaCl with other metal salts (e.g. KCl). However, new salty flavor enhancers (yeast extract, taste peptides, and odor compounds) have yet to be reviewed. This systematic review evaluates the methods for, and feasibility, of NaCl reduction. It defines NaCl reduction and considers the methods used for this purpose, especially the use of flavor enhancers (yeast extract, taste peptides, and odor compounds). © 2022 Society of Chemical Industry.
Topics: Flavoring Agents; Odorants; Potassium Chloride; Sodium; Sodium Chloride; Sodium Chloride, Dietary; Taste
PubMed: 35266156
DOI: 10.1002/jsfa.11859 -
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 -
International Breastfeeding Journal Jun 2023Global estimates of calcium, zinc and vitamin D content in breastmilk are lacking. The objective of this systematic review was to determine the calcium, zinc, and... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Global estimates of calcium, zinc and vitamin D content in breastmilk are lacking. The objective of this systematic review was to determine the calcium, zinc, and vitamin D content in breast milk.
METHODS
A systematic search of the online databases Embase, MEDLINE, and CENTRAL was conducted in November 2022 and complemented by searches of the African Journals Online database and the LILACS database, and reference lists. Studies reporting the calcium, zinc and vitamin D content in breast milk of apparently healthy mothers and infants were included. Random effects meta-analyses were conducted. The effect of influencing factors were investigated with sub-group analyses and meta-regressions.
RESULTS
A total of 154 studies reporting on breast milk calcium were identified, with a mean calcium concentration in breast milk of 261 mg/L (95% CI: 238, 284). Calcium concentration was influenced by maternal health and decreased linearly over the duration of lactation. Calcium concentration at a specific time during lactation could be estimated with the equation: calcium concentration [mg/L] = 282 - 0.2331 ✕ number of days since birth. A total of 242 studies reporting on breast milk zinc were identified, with a mean zinc concentration of 2.57 mg/L (95% CI: 2.50, 2.65). Zinc concentration was influenced by several factors, such as maternal age, gestational age, and maternal diet. Zinc concentration started high in the first weeks post-partum followed by a rapid decrease over the first months. Zinc concentration at a specific time during lactation could be estimated with the equation: zinc concentration [mg/L] = 6 + 0.0005 ✕ days - 2.0266 ✕ log(days). A total of 43 studies reporting on breast milk vitamin D were identified, with a mean total antirachitic activity of breast milk of 58 IU/L (95% CI: 45, 70), which consisted mostly of 25OHD3, and smaller amounts of vitamin D3, 25OHD2 and vitamin D2. Vitamin D concentration showed wide variations between studies and was influenced by vitamin D supplementation, continent and season.
CONCLUSIONS
This review provides global estimates of calcium, zinc and vitamin D content in breast milk, as well as indications on changes over time and depending on influencing factors.
Topics: Infant; Female; Humans; Milk, Human; Calcium; Breast Feeding; Zinc; Vitamin D; Vitamins; Dietary Supplements
PubMed: 37264448
DOI: 10.1186/s13006-023-00564-2 -
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 -
Acta Biomaterialia Oct 2023Titanium (Ti) and Ti alloys are commonly used in dental implants, which have good biocompatibility, mechanical strength, processability, and corrosion resistance.... (Review)
Review
Titanium (Ti) and Ti alloys are commonly used in dental implants, which have good biocompatibility, mechanical strength, processability, and corrosion resistance. However, the surface inertia of Ti implants leads to delayed integration of Ti and new bone, as well as problems such as aseptic loosening and inadequate osseointegration. Magnesium (Mg) ions can promote bone regeneration, and many studies have used Mg-containing materials to modify the Ti implant surface. This systematic review summarizes the methods, effects, and clinical applications of surface modification of Ti implants with Mg-containing coatings. Database collection was completed on Janury 1, 2023, and a total of 29 relevant studies were ultimately included. Mg can be compounded with different materials and coated to the surface of Ti implants using different methods. In vitro and in vivo experiments have shown that Mg-containing coatings promote cell adhesion and osteogenic differentiation. On the one hand, the surface roughness of implants increases with the addition of Mg-containing coatings, which is thought to have an impact on the osseointegration of the implant. On the other hand, Mg ions promote cell attachment through binding interactions between the integrin family and FAK-related signaling pathways. And Mg ions could induce osseointegration by activating PI3K, Notch, ERK/c-Fos, BMP-4-related signaling pathways and TRPM7 protein channels. Overall, Mg-based coatings show great potential for the surface modification of Ti implants to promote osseointegration. STATEMENT OF SIGNIFICANCE: The inertia surface of titanium (Ti) implants leads to delayed osseointegration. Magnesium (Mg) ions, known for promoting bone regeneration, have been extensively studied to modify the surface of Ti implants. However, no consensus has been reached on the appropriate processing methods, surface roughness and effective concentration of Mg-containing coatings for osseointegration. This systematic review focus on the surface modification of Ti implants with Mg-containing compounds, highlighting the effects of Mg-containing coatings on the surface properties of Ti implants and its associated mechanisms. Besides, we also provide an outlook on future directions to promote the clinical application of Mg-modified implants.
Topics: Coated Materials, Biocompatible; Ions; Magnesium; Osseointegration; Osteogenesis; Surface Properties; Titanium
PubMed: 37517617
DOI: 10.1016/j.actbio.2023.07.048 -
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