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Journal of Esthetic and Restorative... Jan 2022Several systematic literature reviews have assessed the scientific evidence on resin bonding protocols to conventional 3 mol% ytrria-stabilized zirconia (3Y-TZP)... (Review)
Review
OBJECTIVES
Several systematic literature reviews have assessed the scientific evidence on resin bonding protocols to conventional 3 mol% ytrria-stabilized zirconia (3Y-TZP) ceramics. It has been widely discussed, however, that the differing composition and physical properties of new high-translucent zirconia generations (4Y-TZP and 5Y-TZP) may require alternative bonding materials and procedures. This paper reviewed in vitro studies on the success and durability of bonding protocols to high-translucent zirconia.
MATERIAL AND METHODS
A systematic search of PubMed and Cochrane Library for in vitro studies on bonding to new zirconia generations published until November 2020 was conducted and complemented by a manual search. Studies selected for review fulfilled the applied inclusion and exclusion criteria. The quality of the included studies was assessed with the Cochrane risk-of-bias tool for randomized trials.
RESULTS
Of 629 screened articles, 18 were included in this review. They investigated different surface pretreatment methods, primers, resin cements, aging procedures, and bond strength test protocols. The limited number of the identified studies and the heterogeneity of the extracted data did not allow to conduct a meta-analysis.
CONCLUSIONS
The available evidence suggests that resin bonding protocols successfully applied to conventional zirconia are also the most successful for high-translucent zirconia. Airborne particle abrasion and special phosphate monomer-containing primers or composite resin cements provide long-term durable resin bonds.
CLINICAL SIGNIFICANCE
Durable bonds can be established between high-translucent zirconia and resin cements. The bonding materials and procedures applied do not compromise their physical properties.
Topics: Ceramics; Dental Bonding; Dental Stress Analysis; Materials Testing; Resin Cements; Surface Properties; Zirconium
PubMed: 35072329
DOI: 10.1111/jerd.12876 -
Dental Research Journal 2023An ever-increasing demand is seen for clear aligners and transparent vacuum-formed retainers. They are esthetic and convenient. However, the biomaterials used in these... (Review)
Review
A systematic review of biocompatibility and safety of orthodontic clear aligners and transparent vacuum-formed thermoplastic retainers: Bisphenol-A release, adverse effects, cytotoxicity, and estrogenic effects.
BACKGROUND
An ever-increasing demand is seen for clear aligners and transparent vacuum-formed retainers. They are esthetic and convenient. However, the biomaterials used in these appliances might pose biological safety and biocompatibility threats in terms of their bisphenol-A (BPA) release, cytotoxicity, adverse effects, and estrogenic effects. Due to the controversial results and the lack of any systematic reviews in this regard, we conducted this systematic review.
MATERIALS AND METHODS
Web of Science, PubMed, Cochrane, Scopus, and Google Scholar as well as references of the found articles were searched (independently by 3 researchers) up to December 22, 2021, to find studies relevant to the biocompatibility of clear aligners and thermoplastic retainers. The search keywords were a combination of the following (and more): Essix, vacuum-formed aligner, thermoplastic aligner, clear aligner, Invisalign, vacuum-formed retainer, BPA release, monomer release, cytotoxicity, estrogenicity, biocompatibility, chemical properties, and oral epithelial cell. As eligibility criteria, articles in all languages would be included as long as their text could be translated clearly using online translators or by professional translators; all types of publications (article, book, and thesis) would be included if containing relevant studies and information; they should have been on clear liners or thermoplastic retainers; and they should have been on biocompatibility, safety, cytotoxicity, or estrogenicity of clear aligners or thermoplastic retainers. There were no restrictions on the type of study (randomized clinical trials, experimental studies). Studies focusing merely on the mechanical properties of clear aligners or thermoplastic retainers (without examining their chemical properties) would be excluded. The risk of bias was assessed.
RESULTS
The risk of bias was rather low. However, the methodologies of the studies were quite different. Overall, 16 articles (1 randomized clinical trial and 15 studies) were identified. The data for BPA release were reported in four articles (1 clinical trial and 3 studies). Quantitatively speaking, the amount of released BPA reported by studies was very low, if not zero. However, the BPA level was very high in the only randomized clinical trial. Many adverse effects were linked to using clear aligners or transparent retainers, including pain and soft-tissue issues such as burning, tingling, sore tongue, lip swelling, blisters, ulceration, dry mouth, periodontal problems, and even systemic problems such as difficulty in breathing. Besides these biological adverse effects, oral dysfunctions and speech difficulties and tooth damage may be associated with clear aligners and should as well be taken into consideration.
CONCLUSION
Given the very high levels of BPA leach observed in the only clinical trial and considering other possible dangers of small traces of BPA (even at low doses) and also given the numerous adverse events linked to clear aligners or transparent retainers, it seems that safety of these appliances might be questionable and more clinical studies of biocompatibility are needed in this regard.
PubMed: 37180685
DOI: No ID Found -
Dental Materials : Official Publication... Oct 2021The purpose of this systematic review and meta-analysis was to analyze the literature on the bond strength of self-etching (SE) adhesives containing 10-MDP or other... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
The purpose of this systematic review and meta-analysis was to analyze the literature on the bond strength of self-etching (SE) adhesives containing 10-MDP or other acidic functional monomers, comparing the bonding performance of both compositions.
METHODS
This study is registered in PROSPERO (CRD42020175715) and it followed the PRISMA Statement. The literature search was performed in PubMed, Web of Science, SciELO, Scopus, LILACS, IBECS, and BBO from the starting coverage date through 30 June 2021. Study eligibility criteria consisted of in vitro studies that evaluated the bond strength (microtensile, microshear, tensile or shear testing) to sound dentin/enamel of a minimum of two distinct SE systems, with at least one material containing 10-MDP and one other being comprised of a distinct acidic composition. Statistical analyses were carried out with RevMan 5.3.5 and using random-effects models with the significance level at p < 0.05. Also, Bayesian network meta-analysis (NMA) was conducted using MetaInsight V3 tool.
RESULTS
From 740 relevant studies evaluated in full-text analysis, 210 were incorporated to the systematic review and 206 in meta-analysis. The majority of studies was classified as having medium risk of bias (56.7%), followed by low (35.2%) and high (8.1%) risk of bias. Data from a total of 64 adhesive systems were collected, which favored the 10-MDP-based group at both dentin (overall effect: 6.98; 95% CI: 5.61, 8.36; p < 0.00001) and enamel (overall effect: 2.79; 95% CI: 1.62, 3.96; p < 0.00001) substrates. Microtensile testing was more frequently used (73.4%) in the included studies. Adhesives based on 10-MDP showed greater bonding performance than adhesives comprised of monomers such as PENTA, 6-MHP, 4-META, 4-MET, pyrophosphate esters, mixed composition or monomers derived from sulfonic acid (p ≤ 0.01); whereas similar bond strength values were verified between 10-MDP-based materials and those containing PEM-F, acrylamide phosphates, 4-AET, MAC-10, or monomers derived from polyacrylic and phosphonic acids (p ≥ 0.05). Adhesives based on GPDM were the only ones that resulted in greater bonding potential than the 10-MDP-based group (p = 0.03). Dental bonds in dentin were favored with the application of 2-step 10-MDP-based adhesives; whereas in enamel the dental bonds were favored for both 2-steps versions of adhesives, regardless of the presence of 10-MDP. Indirect evidence from NMA revealed that 1-step 10-MDP-free and universal 10-MDP-free adhesives seemed to perform worst in dentin and enamel, respectively.
SIGNIFICANCE
Adhesives containing 10-MDP showed higher bonding performance than materials formulated with other acidic ingredients, although this result relied on the type of mechanical testing, type of the substrate, acidic composition of the adhesive, and the application category of the SE system. This review summarized the effects of the foregoing factors on the adhesion to dental substrates.
Topics: Bayes Theorem; Dental Bonding; Dental Cements; Dentin; Dentin-Bonding Agents; Materials Testing; Methacrylates; Resin Cements; Tensile Strength
PubMed: 34456050
DOI: 10.1016/j.dental.2021.08.014 -
The Journal of Prosthetic Dentistry Feb 2021The polycrystalline nature of zirconia hinders its ability to bond to tooth structure. Consequently, durable bonding to zirconia has been challenging. In vitro studies... (Review)
Review
STATEMENT OF PROBLEM
The polycrystalline nature of zirconia hinders its ability to bond to tooth structure. Consequently, durable bonding to zirconia has been challenging. In vitro studies have evaluated various methods of bonding to zirconia, but clinical data are sparse.
PURPOSE
The purpose of this systematic review was to critically appraise clinical studies investigating the survival rate of resin-bonded zirconia fixed partial dentures (FPDs), inlay-retained zirconia FPDs, and zirconia veneers.
MATERIAL AND METHODS
Searches were performed in MEDLINE, EMBASE, PubMed, Web of Science, Scopus, Cochrane Library, and Google Scholar. Clinical studies of over 12 months duration involving bonded zirconia restorations between 1990 and July 2018 were reviewed. All suitable studies were assessed for quality by using a "Questionnaire for selecting articles on Dental Prostheses".
RESULTS
Eight studies were ultimately included. Three studies examined posterior inlay-retained FPDs with estimated survival rates of 12.1% at 10 years, 95.8% at 5 years, and 100% at 20 months. Five studies reviewed anterior, resin-bonded FPDs, all of which had a 3- to 10-year survival rate of 100%. Debonds occurred in all studies, but the prostheses could usually be rebonded.
CONCLUSIONS
With correctly designed buccal and lingual coverage retainers and minimal if any veneering porcelain, zirconia-based, posterior, inlay-retained FPDs seem to have a high clinical survival rate. The role of bonding efficacy in this survival rate is unknown. Anterior, cantilevered, resin-bonded zirconia FPDs seem to have a high clinical survival rate. While these prostheses can debond, fracture of the entire prosthesis is unlikely, so they may be rebonded. To bond zirconia, the use of airborne-particle abrasion with 50-μm alumina (AlO) at 0.1 to 0.25 MPa in combination with a phosphate monomer-containing adhesive resin is recommended until further studies become available. Dental dam isolation is also recommended during zirconia bonding.
Topics: Dental Bonding; Dental Materials; Dental Porcelain; Denture Design; Denture, Partial, Fixed; Treatment Outcome; Zirconium
PubMed: 32115220
DOI: 10.1016/j.prosdent.2019.12.017 -
Materials (Basel, Switzerland) Mar 2019The incorporation of functional monomers in dental adhesive systems promotes chemical interaction with dental substrates, resulting in higher adhesion forces when... (Review)
Review
The incorporation of functional monomers in dental adhesive systems promotes chemical interaction with dental substrates, resulting in higher adhesion forces when compared to micromechanical adhesion only. The 10-MDP monomer, whose chemical structure allows for a polar behavior which is favorable to adhesion, also promotes the protection of collagen fibers through the formation of MDP-calcium salts. This systematic review aimed to characterize the interface created by 10-MDP containing adhesive systems through an evaluation of the following parameters: Formation of nano-layered structures, capacity to produce an acid-base resistant zone, and adhesion stability. The research was conducted using PubMed, Cochrane Library, Web of Science and Embase, limited to English, Spanish, and Portuguese articles. The research was done according to the PICO strategy. The 10-MDP monomer has the capacity to produce an acid-base resistant zone on the adhesive interface, which increases the response to acid-base challenges. The adhesion established by these systems is stable over time. To have the best of these adhesive solutions, a scrubbing technique must be used to apply the adhesive system on dental substrates, in order to improve monomers infiltration and to create a stable bond. Time must be given for the solution to infiltrate, hybridize and form the MDP-Ca, improving adhesive stability.
PubMed: 30866488
DOI: 10.3390/ma12050790 -
Acta Neurologica Scandinavica Feb 2019Hereditary transthyretin(TTR)-related amyloidosis (ATTRm amyloidosis) is an endemic/non-endemic, autosomal-dominant, early- and late-onset, rare, progressive disorder,...
Hereditary transthyretin(TTR)-related amyloidosis (ATTRm amyloidosis) is an endemic/non-endemic, autosomal-dominant, early- and late-onset, rare, progressive disorder, predominantly manifesting as length-dependent, small fiber dominant, axonal polyneuropathy and frequently associated with cardiac disorders and other multisystem diseases. ATTRm amyloidosis is due to variants in the TTR gene, with the substitution Val30Met as the most frequent mutation. TTR mutations lead to destabilization and dissociation of TTR tetramers into variant TTR monomers, and formation of amyloid fibrils, which are consecutively deposited extracellularly in various tissues, such as nerves, heart, brain, eyes, intestines, kidneys, or the skin. Neuropathy may not only include large nerve fibers but also small fibers, and not only sensory and motor fibers but also autonomic fibers. Types of TTR variants, age at onset, penetrance, and clinical presentation vary between geographical areas. Suggestive of a ATTRm amyloidosis are a sensorimotor polyneuropathy, positive family history, autonomic dysfunction, cardiomyopathy, carpal tunnel syndrome, unexplained weight loss, and resistance to immunotherapy. If only sensory A-delta or C fibers are affected, small fiber neuropathy ensues. Diagnostic tests for small fiber neuropathy include determination of intraepidermal nerve fiber density, laser-evoked potentials, heat- and cold-detection thresholds, and measurement of the electrochemical skin conductance. Therapy currently relies on liver transplantation and TTR-stabilizers (tafamidis, diflunisal).
Topics: Amyloid Neuropathies, Familial; Humans; Mutation; Prealbumin
PubMed: 30295933
DOI: 10.1111/ane.13035 -
Journal of Pharmacy & Bioallied Sciences May 2019Methyl methacrylate monomer of denture base resins was modified with several monomers to achieve better physico-mechanical properties without compromising the... (Review)
Review
BACKGROUND
Methyl methacrylate monomer of denture base resins was modified with several monomers to achieve better physico-mechanical properties without compromising the biocompatibility. However, there are no consensuses on the best strategy to achieve best modified monomer.
PURPOSE
To identify and evaluate the differences in the properties between conventional and modified monomers and to verify the influence of several variables on the properties of denture base acrylic resin.
MATERIALS AND METHODS
This study was executed by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. In-vitro studies that investigated the properties of conventional and modified monomers were selected. Searches were carried out in the Ebscohost, PubMed, Semantic scholar and J-stage databases. The search commenced from the year 1995 and the last search was done till November 2018. A comparison was performed between modified and unmodified monomers. The analyses were carried out using fixed-effect models.
RESULTS
The meta-analysis results showed high heterogeneity in all aspects, and higher flexural strength for monomers modified with 20% methacrylic acid.
CONCLUSION
Although the articles included in this meta-analysis showed high heterogeneity and high risk of bias, the in-vitro literature seems to suggest that use of modified monomers could improve the properties of denture base resins. Other variants of monomer modifications and their tested parameters were discussed in this systematic review as well. Dimensional accuracy is an unexplored variable to be evaluated extensively in the future researches.
PubMed: 31198322
DOI: 10.4103/JPBS.JPBS_34_19 -
Systematic Reviews Aug 2021Sarcomas are a rare and heterogeneous group of tumors originating from mesenchymal or connective tissue. They represent less than 1% of all adult cancers. The etiology... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Sarcomas are a rare and heterogeneous group of tumors originating from mesenchymal or connective tissue. They represent less than 1% of all adult cancers. The etiology and epidemiology of sarcomas remain understudied and poorly understood. The main objective of our study was to systematically assess the association between various occupational exposures and risk of sarcomas.
METHODS
We performed a systematic literature search using the PubMed, Scopus, EMBASE and Cochrane databases to identify relevant cohort and case-control studies. A meta-analysis method was applied on the incidence and mortality outcomes where the estimate with 95% confidence interval (CI) was obtained.
RESULTS
We included a total of 50 publications in our systematic review and 35 in meta-analysis. For exposures to phenoxy herbicides and chlorophenols, the pooled odds ratio (OR) for sarcoma was 1.85 (95% CI: 1.22, 2.82), based on 16 studies with 2254 participants, while the pooled standardized mortality ratio was 40.93 (95% CI 2.19, 765.90), based on 4 cohort studies with 59,289 participants. For exposure to vinyl chloride monomers the pooled risk ratios for angiosarcoma of the liver and other STS were 19.23 (95% CI 2.03, 182.46) and 2.23 (95 CI 1.55, 3.22) respectively based on 3 cohort studies with 12,816 participants. Exposure to dioxins was associated with an increased STS mortality; the pooled standardized mortality ratio was 2.56 (95% CI 1.60, 4.10) based on 4 cohort studies with 30,797 participants. Finally, woodworking occupation was associated with an increased risk of STS with the pooled OR of 2.16 (95% CI 1.39, 3.36).
CONCLUSIONS
Our findings suggest a positive association between higher exposure to dioxins and increased mortality from STS, between cumulative exposure to vinyl chloride monomers and increased mortality from angiosarcoma of the liver and STS, and between woodworking occupation and STS incidence. These findings were all statistically significant.
Topics: Adult; Cohort Studies; Humans; Incidence; Occupational Diseases; Occupational Exposure; Sarcoma
PubMed: 34389054
DOI: 10.1186/s13643-021-01769-4 -
Phytotherapy Research : PTR Nov 2023Cardiovascular diseases are currently the primary cause of mortality in the whole world. Growing evidence indicated that the disturbances in cardiac fatty acid... (Review)
Review
Cardiovascular diseases are currently the primary cause of mortality in the whole world. Growing evidence indicated that the disturbances in cardiac fatty acid metabolism are crucial contributors in the development of cardiovascular diseases. The abnormal cardiac fatty acid metabolism usually leads to energy deficit, oxidative stress, excessive apoptosis, and inflammation. Targeting fatty acid metabolism has been regarded as a novel approach to the treatment of cardiovascular diseases. However, there are currently no specific drugs that regulate fatty acid metabolism to treat cardiovascular diseases. Many traditional Chinese medicines have been widely used to treat cardiovascular diseases in clinics. And modern studies have shown that they exert a cardioprotective effect by regulating the expression of key proteins involved in fatty acid metabolism, such as peroxisome proliferator-activated receptor α and carnitine palmitoyl transferase 1. Hence, we systematically reviewed the relationship between fatty acid metabolism disorders and four types of cardiovascular diseases including heart failure, coronary artery disease, cardiac hypertrophy, and diabetic cardiomyopathy. In addition, 18 extracts and eight monomer components from traditional Chinese medicines showed cardioprotective effects by restoring cardiac fatty acid metabolism. This work aims to provide a reference for the finding of novel cardioprotective agents targeting fatty acid metabolism.
Topics: Humans; Cardiovascular Diseases; Heart; Medicine, Chinese Traditional; PPAR alpha; Fatty Acids; Energy Metabolism
PubMed: 37533230
DOI: 10.1002/ptr.7965 -
Thrombosis Research Sep 2022Ranging from bleeding to thrombosis, the clinical features of congenital fibrinogen qualitative disorders, including dysfibrinogenemia and hypodysfibrinogenemia, are... (Review)
Review
Ranging from bleeding to thrombosis, the clinical features of congenital fibrinogen qualitative disorders, including dysfibrinogenemia and hypodysfibrinogenemia, are highly heterogeneous. Although the associations between some specific fibrinogen mutations and the thrombotic phenotypes have been well elucidated, the underlying mechanism between fibrinogen variants and bleeding events remains underestimated. After systematically reviewing the literature of (hypo-)dysfibrinogenemia patients with bleeding phenotypes, we identified several well-characterized bleeding-related fibrinogen variants in those patients. Several possible pathomechanisms are proposed to explain the genotype-phenotype associations: 1, mutations in the NH-terminal portion of the Aα chain hamper fibrinogen fitting into the active site cleft of thrombin and drastically slow the conversion of fibrinogen into monomeric fibrin; 2, mutations adding new N-linked glycosylation sites introduce bulky and negatively charged carbohydrate side chains and undermine the alignment of fibrin monomers during polymerization; 3, mutations generating unpaired cysteine form extra disulfide bonds between the abnormal fibrinogen chains and produce highly branched and fragile fibrin networks; 4, truncation mutations in the fibrinogen αC regions impair the lateral fibril aggregation, as well as factor XIII crosslinking, endothelial cell and platelet binding. These established relationships between specific variants and the bleeding tendency will help manage (hypo-)dysfibrinogenemia patients to avoid adverse bleeding outcomes.
Topics: Afibrinogenemia; Blood Coagulation Tests; Fibrin; Fibrinogen; Fibrinogens, Abnormal; Hemorrhage; Humans; Thrombosis
PubMed: 35853369
DOI: 10.1016/j.thromres.2022.07.005