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Journal of International Society of... 2020Dental implants are considered the best treatment option for replacement of missing teeth due to high survival rates and diverse applications. However, not all dental... (Review)
Review
BACKGROUND
Dental implants are considered the best treatment option for replacement of missing teeth due to high survival rates and diverse applications. However, not all dental implant therapies are successful and some fail due to various biological and or/mechanical factors. The objective of this study was to systematically review primary studies that focus on the biomechanical properties of dental implants in order to determine which biomechanical properties are most important for success of dental implant therapy.
MATERIALS AND METHODS
An electronic database search was performed using MEDLINE (PubMed), EMBASE, Google Scholar, and CAB Abstracts. Six principal biomechanical properties were considered to prepare the search strategy for each database using key words and Boolean operators. Human and animal studies (observational studies, trials, and studies) were included in this review. Human studies that were considered eligible needed to have subjects above 18 years who received permanent restorations after implant surgery and followed up for at least 6 months after receiving permanent restorations. Studies with subjects who had absolute contraindications at the time of dental implant surgery were excluded.
RESULTS
In total, 28 studies were included in the review after application of the eligibility criteria; 18 studies, 5 cohort clinical studies, 3 animal studies, and 2 nonrandomized trials. Six studies assessed loss of preload, five studies assessed fatigue strength, four assessed implant abutment connection design, and one assessed implant diameter. Two nonrandomized trials assessed torque and six observational studies assessed the effect of cantilevers. Gold alloy coating of abutment screws resulted in higher preload values followed by titanium alloy coating and gold coating; there was a difference in preload values between coated and uncoated screws when tightened repeatedly. Preload values decreased as a function of time with majority of preload loss occurred within 10s of tightening. The 8-degree internal conical implant performed better than the internal hex design. Higher rate of complications (porcelain chipping, de-cementation) was observed in the cantilever groups in studies.
CONCLUSION
Biomechanical properties of implants like preload, torque, cantilever design, implant abutment design have profound effects on the survival rates of dental implants. With limiations, this review provides some important parameters to consider for successful implant therapy.
PubMed: 33437702
DOI: 10.4103/jispcd.JISPCD_138_20 -
Journal of the Mechanical Behavior of... Sep 2023The purpose of this systematic review and meta-analysis was to compare the results of tribocorrosion in titanium alloys of dental implants submitted to surface treatment... (Meta-Analysis)
Meta-Analysis Review
The purpose of this systematic review and meta-analysis was to compare the results of tribocorrosion in titanium alloys of dental implants submitted to surface treatment with those whose treatment was not performed. An electronic search was carried out on the MEDLINE (PubMed), Web of Science, Virtual Health Library and Scopus databases. The search strategy used was PECO: Participants (P): titanium alloys; Exposure (E): surface treatment; Comparison (C): absence of surface treatment; and Result/Outcome (O): tribocorrosion. The search found a total of 336 articles, where 27 was selected by title or abstract, resulted to 10 after reading in full. The treatments that formed the rutile layer had better tribological results and therefore better protected the material from mechanical and chemical degradation, contrary to the technique with the addition of nanotubes. It was concluded that the surface treatment proves to be efficient to protect metals from mechanical and chemical wear.
Topics: Humans; Alloys; Titanium; Corrosion; Dental Implants; Surface Properties
PubMed: 37423010
DOI: 10.1016/j.jmbbm.2023.106008 -
Neuroscience and Biobehavioral Reviews Jul 2023Elevated inflammation is a risk factor for many psychiatric (e.g., depression) and somatic conditions (e.g., rheumatoid arthritis). Inflammation is influenced by... (Review)
Review
Elevated inflammation is a risk factor for many psychiatric (e.g., depression) and somatic conditions (e.g., rheumatoid arthritis). Inflammation is influenced by psychosocial processes such as emotion regulation. Characterization of which emotion regulation characteristics impact inflammation could help refine psychosocial interventions aimed at normalizing health-harming inflammatory activity for individuals with psychiatric and somatic illnesses. To investigate this issue, we systematically reviewed the literature on associations between a variety of emotion regulation traits and inflammation. Out of 2816 articles identified, 38 were included in the final review. 28 (74%) found that (a) poor emotion regulation is associated with higher inflammation and/or (b) strong emotion regulation skills are associated with lower inflammation. Consistency of results differed as a function of the emotion regulation construct investigated and methodological characteristics. Results were most consistent for studies testing positive coping/social support seeking or broadly defined emotion regulation/dysregulation. Methodologically, studies testing reactivity to a stressor, adopting a vulnerability-stress framework, or using longitudinal data were most consistent. Implications for integrated, transdiagnostic psychoimmunological theories are discussed, as well as recommendations for clinical research.
Topics: Humans; Emotions; Emotional Regulation; Inflammation; Risk Factors; Phenotype
PubMed: 37028579
DOI: 10.1016/j.neubiorev.2023.105162 -
Frontiers in Bioscience (Landmark... Dec 2021The fracture of endodontic instruments inside the canal represents a problem that is not always easy to solve. The reutilization of endodontic instruments after... (Meta-Analysis)
Meta-Analysis Review
The fracture of endodontic instruments inside the canal represents a problem that is not always easy to solve. The reutilization of endodontic instruments after sterilization procedures raises the question of how these processes affect their physical and mechanical properties. Alterations can involve the surface of the instruments, as well as their cutting effectiveness, shape and resistance to torsional and cyclic fatigue. The methodology adopted for this systematic review followed the PRISMA guidelines for systematic reviews. The following search terms were used in PubMed and Scopus: "endodontic sterilization", "endodontic autoclave", "cyclic fatigue", "torsional", "cutting efficiency", "sterilization", "surface characteristics" and "corrosion". After the screening phase, the application of exclusion criteria and the removal of duplicates, 51 studies were identified and divided into four outcomes: cyclic fatigue; deformation and torsional fatigue; corrosion or surface alterations; and cutting efficiency. Our study of the scientific literature highlights disagreements between studies on these effects. After autoclaving, instruments exhibit a reduction in the cutting efficiency, but NiTi alloy instruments have an improved resistance to cyclic and torsional fatigue.
Topics: Equipment Failure; Materials Testing; Network Meta-Analysis; Root Canal Preparation; Sterilization; Stress, Mechanical
PubMed: 34994183
DOI: 10.52586/5062 -
International Journal of Molecular... Dec 2023There is increasing interest in using magnesium (Mg) alloy orthopedic devices because of their mechanical properties and bioresorption potential. Concerns related to... (Review)
Review
Magnesium Alloys in Orthopedics: A Systematic Review on Approaches, Coatings and Strategies to Improve Biocompatibility, Osteogenic Properties and Osteointegration Capabilities.
There is increasing interest in using magnesium (Mg) alloy orthopedic devices because of their mechanical properties and bioresorption potential. Concerns related to their rapid degradation have been issued by developing biodegradable micro- and nanostructured coatings to enhance corrosion resistance and limit the release of hydrogen during degradation. This systematic review based on four databases (PubMed, Embase, Web of Science™ and ScienceDirect) aims to present state-of-the-art strategies, approaches and materials used to address the critical factors currently impeding the utilization of Mg alloy devices. Forty studies were selected according to PRISMA guidelines and specific PECO criteria. Risk of bias assessment was conducted using OHAT and SYRCLE tools for in vitro and in vivo studies, respectively. Despite limitations associated with identified bias, the review provides a comprehensive analysis of preclinical in vitro and in vivo studies focused on manufacturing and application of Mg alloys in orthopedics. This attests to the continuous evolution of research related to Mg alloy modifications (e.g., AZ91, LAE442 and WE43) and micro- and nanocoatings (e.g., MAO and MgF2), which are developed to improve the degradation rate required for long-term mechanical resistance to loading and excellent osseointegration with bone tissue, thereby promoting functional bone regeneration. Further research is required to deeply verify the safety and efficacy of Mg alloys.
Topics: Magnesium; Orthopedic Procedures; Orthopedics; Osteogenesis; Alloys
PubMed: 38203453
DOI: 10.3390/ijms25010282 -
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 -
Bioactive Materials Nov 2021Biodegradable metals are promising candidates for bone defect repair. With an evidence-based approach, this study investigated and analyzed the performance and... (Review)
Review
Biodegradable metals are promising candidates for bone defect repair. With an evidence-based approach, this study investigated and analyzed the performance and degradation properties of biodegradable metals in animal models for bone defect repair to explore their potential clinical translation. Animal studies on bone defect repair with biodegradable metals in comparison with other traditional biomaterials were reviewed. Data was carefully collected after identification of population, intervention, comparison, outcome, and study design (PICOS), and following the inclusion criteria of biodegradable metals in animal studies. 30 publications on pure Mg, Mg alloys, pure Zn and Zn alloys were finally included after extraction from a collected database of 2543 publications. A qualitative systematic review and a quantitative meta-analysis were performed. Given the heterogeneity in animal model, anatomical site and critical size defect (CSD), biodegradable metals exhibited mixed effects on bone defect repair and degradation in animal studies in comparison with traditional non-degradable metals, biodegradable polymers, bioceramics, and autogenous bone grafts. The results indicated that there were limitations in the experimental design of the included studies, and quality of the evidence presented by the studies was very low. To enhance clinical translation of biodegradable metals, evidence-based research with data validity is needed. Future studies should adopt standardized experimental protocols in investigating the effects of biodegradable metals on bone defect repair with animal models.
PubMed: 33997491
DOI: 10.1016/j.bioactmat.2021.03.035 -
Molecular Psychiatry Jul 2021The innate immune system is dysregulated in depression; however, less is known about the longitudinal associations of depression and inflammatory biomarkers. We... (Meta-Analysis)
Meta-Analysis
The innate immune system is dysregulated in depression; however, less is known about the longitudinal associations of depression and inflammatory biomarkers. We investigated the prospective associations of depression and inflammatory biomarkers [interleukin-6 (IL-6), Tumor Necrosis Factor-Alpha (TNF-α), and C-reactive protein (CRP)] in community samples, both unadjusted and adjusted for covariates. The review, registered with PROSPERO, searched for published and unpublished studies via MEDLINE/PsycINFO/PsycARTICLES/EMBASE/Proquest Dissertation. Standardized Fisher transformations of the correlation/beta coefficients, both unadjusted and adjusted for covariates, were extracted from studies examining the prospective associations of depression and inflammatory biomarkers. Systematic review conducted in January, 2019 included 38 studies representing 58,256 participants, with up to 27 studies included in random-effects meta-analysis. Higher CRP/IL-6 were associated with future depressive symptoms, and higher depressive symptoms were associated with higher future CRP/IL-6 in both unadjusted and adjusted analyses - this is the first meta-analysis reporting an adjusted association of IL-6 with future depression. The adjusted prospective associations of depression with CRP/CRP with depression were substantially attenuated and small in magnitude. No significant associations were observed for TNF-α. No conclusive results were observed in studies of clinical depression. Meta-regression indicated that the association of CRP and future depression was larger in older samples and in studies not controlling for possible infection. Small, prospective associations of depression and inflammatory biomarkers are observed in both directions, particularly for IL-6; however, the strength and importance of this relationship is likely obscured by the heterogeneity in depression and profound study/methodological differences. Implications for future studies are discussed.
Topics: Aged; Biomarkers; C-Reactive Protein; Depression; Humans; Inflammation; Interleukin-6; Tumor Necrosis Factor-alpha
PubMed: 32807846
DOI: 10.1038/s41380-020-00867-4 -
The Journal of Prosthetic Dentistry Jul 2022Information comparing the marginal and internal adaptation of single metal copings fabricated via computer-aided design and computer-aided manufacturing (CAD-CAM)... (Review)
Review
STATEMENT OF PROBLEM
Information comparing the marginal and internal adaptation of single metal copings fabricated via computer-aided design and computer-aided manufacturing (CAD-CAM) milling and lost-wax casting is insufficient.
PURPOSE
The purpose of this systematic review and meta-analysis was to compare the adaptation of single metal copings fabricated via CAD-CAM milling to that of copings fabricated via lost-wax casting and to identify factors that influenced their accuracy.
MATERIAL AND METHODS
Following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, Elsevier ScienceDirect, PubMed, Cochrane Library, SpringerLink, and Wiley online databases were searched to select qualified articles, which were assessed by the methodological items for nonrandomized studies (MINORS) criteria. The data on the mean absolute marginal gap, marginal gap, axial gap, occlusal gap, and internal gap values of single metal copings fabricated via CAD-CAM milling and lost-wax casting were extracted, and meta-analysis and meta-regression were used with R software (α=.05) and random-effects models to estimate differences and homogeneity between the 2 methods.
RESULTS
For the single metal copings, lost-wax casting and CAD-CAM milling led to similar marginal and internal accuracies, but lost-wax casting led to better absolute marginal gap values. For the cast copings, Ni-Cr alloy (92.8 μm) and noble alloy (51.5 μm) led to the largest and smallest marginal gaps, respectively, (P=.005). For milled copings, the noble alloy led to the smallest marginal gap (19.1 μm), and Co-Cr alloy to the largest (76.2 μm) (P=.012). Soft milling led to a more accurate marginal gap (41.4 μm) than hard milling (66.1 μm) (P=.04).
CONCLUSIONS
When CAD-CAM milling was used to fabricate single metal copings, no advantage in precision was found compared with lost-wax casting, and single metal copings cast from handmade conventional wax patterns had better marginal adaptation than those fabricated via CAD-CAM milling. Noble metal copings had improved marginal accuracy than base metal copings for both the casting and milling methods. Single copings fabricated via soft milling from unsintered metal blocks had more accurate marginal adaption than copings fabricated via hard milling.
PubMed: 35788274
DOI: 10.1016/j.prosdent.2022.05.018 -
Materials Today. Bio Apr 2023The biological functions of rare-earth elements (REEs) have become a focus of intense research. Recent studies have demonstrated that ion doping or alloying of some REEs... (Review)
Review
The biological functions of rare-earth elements (REEs) have become a focus of intense research. Recent studies have demonstrated that ion doping or alloying of some REEs can optimize the properties of traditional biomaterials. Europium (Eu), which is an REE with low toxicity and good biocompatibility, has promising applications in biomedicine. This article systematically reviews the osteogenic, angiogenic, neuritogenic, antibacterial, and anti-tumor properties of Eu-containing biomaterials, thereby paving the way for biomedical applications of Eu. Data collection for this review was completed in October 2022, and 30 relevant articles were finally included. Most articles indicated that doping of Eu ions or Eu-compound nanoparticles in biomaterials can improve their osteogenic, angiogenic, neuritogenic, antibacterial, and anti-tumor properties. The angiogenic, antibacterial, and potential neuritogenic effects of Eu(OH) nanoparticles have also been demonstrated.
PubMed: 36910271
DOI: 10.1016/j.mtbio.2023.100595