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Frontiers in Bioengineering and... 2021Systematic review assessing the association between oral microorganisms and corrosion of intra-oral metallic alloy-based dental appliances. PubMed, Scopus, and Web of...
Systematic review assessing the association between oral microorganisms and corrosion of intra-oral metallic alloy-based dental appliances. PubMed, Scopus, and Web of Science were searched using keyword combinations such as microbes and oral and corrosion; microbes and dental and corrosion; microorganisms and oral and corrosion; microorganisms and dental and corrosion. Out of 141 articles, only 25 satisfied the selection criteria. s, sulfate-reducing bacteria, sulfate oxidizing bacteria, Veilonella, Actinomyces, were found to have a potential association with corrosion of intraoral metallic alloys such as stainless steel, titanium, nickel, cobalt-chromium, neodymium-iron-boron magnets, zirconia, amalgam, copper aluminum, and precious metal alloys. The included studies inferred an association between oral microorganisms and intra-oral metallic alloys-based dental appliances, although, it is vital to acknowledge that most studies in the review employed an simulation of the intra-oral condition.
PubMed: 33791285
DOI: 10.3389/fbioe.2021.631103 -
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 -
The International Journal of... 2021To conduct a systematic review to evaluate the influence of materials and surfaces used for dental implant abutments on the proliferation of human gingival fibroblasts.
PURPOSE
To conduct a systematic review to evaluate the influence of materials and surfaces used for dental implant abutments on the proliferation of human gingival fibroblasts.
MATERIALS AND METHODS
The focus question of this review was: Which material/surface characteristics used for dental implant abutments influence/enhance proliferation of human gingival fibroblasts? The Medline/PubMed, Embase, and Cochrane Library databases were searched using "gingiva," "fibroblasts," "proliferation," and "dental implant abutments" as main keywords with AND/OR as Boolean operators. In vitro studies reporting 3 to 4 or 6 to 7 days of cell proliferation, surface hydrophilicity, and roughness were included. A quality assessment of the selected studies was performed using the web-based Science in Risk Assessment and Policy (SciRAP) tool.
RESULTS
The search identified 1,144 studies, and 44 were eligible for inclusion. The average reporting quality SciRAP score was 82.87 ± 10.68, and the average methodologic quality SciRAP score was 87.35 ± 10.55. Machined, polished, and coated titanium and zirconia surfaces were most commonly investigated. Several studies analyzed aluminum oxide, cobalt-chrome-molybdenum alloy, lithium disilicate, polyether ether ketone, polymer-infiltrated ceramic network, and bioglass. The best cell proliferation was observed on zirconia and on titanium harboring nanotubules or microgrooves. UV treatment, polydopamine, and nitride coatings also improved cell proliferation. Due to the heterogeneity of the data, no correlation could be established between cell profileration and surface hydrophilicity or roughness. However, surface roughness in the range of R = 15 to 145 nm and Sa = 19 to 500 nm on titanium and zirconia proved most suitable.
CONCLUSION
Titanium surfaces with directional guidance patterning and zirconia surfaces best supported cell proliferation during the first week of cell culture. Lack of standardization in surface definitions (machined or polished), methodology, and reporting prevented analytical comparison and should be imposed in future studies.
Topics: Cell Proliferation; Dental Abutments; Dental Implants; Dental Materials; Fibroblasts; Gingiva; Humans; Materials Testing; Surface Properties; Titanium; Zirconium
PubMed: 33616578
DOI: 10.11607/ijp.7388 -
Journal of Prosthodontic Research Jan 2022This study comprehensively reviewed the current status of the digital workflow of removable partial dentures (RPDs) and summarized information about the fabrication...
PURPOSE
This study comprehensively reviewed the current status of the digital workflow of removable partial dentures (RPDs) and summarized information about the fabrication methods and material properties of the dental framework, artificial teeth, and denture base.
STUDY SELECTION
We performed a systematic review of the literature published in online databases from January 1980 to April 2020 regarding RPD fabrication and materials used in the related digital technology. We selected eligible articles, retrieved information regarding digital RPDs, and conducted qualitative/quantitative analyses. In this paper, the computer-aided design/computer-aided manufacturing (CAD/CAM) framework, artificial teeth, and denture base materials are reported.
RESULTS
A variety of materials, such as cobalt-chromium alloy, titanium, zirconia, and polyether ether ketone, are used for dental CAD/CAM frameworks. The mechanical strength of the metal materials used for the CAD/CAM framework was superior to that of the cast framework. However, the fitness and surface roughness of the framework and clasp fabricated using a selective laser melting (SLM) method were not superior to those obtained via cast fabrication. Most material properties and the surface roughness of poly methyl methacrylate (PMMA) discs used for digital RPDs were superior to those of heat-cured PMMA.
CONCLUSION
The use of a CAD/CAM framework and PMMA disc for digital RPDs offers numerous advantages over conventional RPDs. However, technical challenges regarding the accuracy and durability of adhesion between the framework and denture base remain to be solved. In digital fabrication, human technical factors influence the quality of the framework.
Topics: Computer-Aided Design; Denture Bases; Denture, Partial, Removable; Humans; Tooth, Artificial; Workflow
PubMed: 33504722
DOI: 10.2186/jpr.JPR_D_20_00117 -
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 -
Australian Endodontic Journal : the... Aug 2021This systematic review was registered in PROSPERO (CRD42017075917) and aimed to investigate whether the available clinical evidence supports the hypothesis that... (Review)
Review
This systematic review was registered in PROSPERO (CRD42017075917) and aimed to investigate whether the available clinical evidence supports the hypothesis that reciprocating motion results in a lower incidence of nickel-titanium files fracture compared to continuous rotation. Clinical studies that reported the incidence of fracture of engine-driven nickel-titanium files were included. The main exposure was the kinematics, and the primary outcome was the incidence of files fracture. The overall incidence of files fracture was 2.27%, with a trend for higher incidence with rotary motion (2.43%) than with reciprocating (1.0%), though without significant differences. Multiple meta-regression models revealed that the use of nickel-titanium files in more than four teeth and less proficient operators were associated with a higher incidence of file fracture. There was no difference in the clinical incidence of fracture of nickel-titanium instruments between reciprocating and rotary motions; however, other factors were identified.
Topics: Dental Alloys; Equipment Design; Incidence; Nickel; Root Canal Preparation; Rotation; Titanium
PubMed: 33410578
DOI: 10.1111/aej.12484 -
Dermatitis : Contact, Atopic,...This systematic review summarizes characteristics and treatment outcomes of dental amalgam-associated oral lichenoid lesions (OLLs) and oral lichen planus (OLP). Embase...
This systematic review summarizes characteristics and treatment outcomes of dental amalgam-associated oral lichenoid lesions (OLLs) and oral lichen planus (OLP). Embase and MEDLINE were searched for original studies on OLLs or OLP associated with dental amalgam. Data extraction was completed from 44 studies representing 1855 patients. Removal of amalgam restorations led to complete resolution in 54.2% (n = 423/781), partial resolution in 34.8% (n = 272/781), and no resolution in 11.0% (n = 86/781) of the patients with OLLs, whereas complete resolution occurred in 37.1% (n = 72/194), partial resolution in 26.3% (n = 51/194), and no resolution in 36.6% (n = 71/194) of the patients with OLP. For patients with OLLs, 91.6% of the patients with positive patch tests and 82.9% with negative patch tests had improvement with removal of amalgam, whereas for patients with OLP, 89.2% of the patients with positive patch tests and 78.9% with negative patch tests had improvement with removal of amalgam. Our results suggest improvement occurs, regardless of patch testing status.
Topics: Dental Amalgam; Dental Restoration, Permanent; Dermatitis, Allergic Contact; Humans; Lichen Planus, Oral; Mercury; Mouth Mucosa; Patch Tests; Treatment Outcome
PubMed: 33273245
DOI: 10.1097/DER.0000000000000703 -
Iranian Journal of Pharmaceutical... 2019An important field of bone tissue engineering (BTE) concerns the design and fabrication of smart scaffolds capable of inducing cellular interactions and differentiation... (Review)
Review
An important field of bone tissue engineering (BTE) concerns the design and fabrication of smart scaffolds capable of inducing cellular interactions and differentiation of osteo-progenitor cells. One of these additives that has gained growing attention is metallic ions as therapeutic agents (MITAs). The specific biological advantage that these ions bring to scaffolds as well as other potential mechanical, and antimicrobial enhancements may vary depending on the ion entity, fabrication method, and biomaterials used. Therefore, this article provides an overview on current status of application of MITAs in BTE and the remaining challenges in the field. Electronic databases, including PubMed, Scopus, Science direct and Cochrane library were searched for studies on MITAs treatments for BTE. We searched for articles in English from January-2000 to October-2019. Abstracts, letters, conference papers and reviews, studies, studies on alloys and studies investigating effects other than enhancement of new bone formation (NBF) were excluded. A detailed summary of relevant metallic ions with specific scaffold material and design, cell type, animal model and defect type, the implantation period, measured parameters and obtained qualitative and quantitative results is presented. No ideal material or fabrication method suited to deliver MITAs can yet be agreed upon, but an investigation into various systems and their drawbacks or potential advantages can lead the future research. A tendency to enhance NBF with MITAs can be observed in the studies. However, this needs to be validated with further studies comparing various ions with each other in the same animal model using critical-sized defects.
PubMed: 32802092
DOI: 10.22037/ijpr.2020.112641.13894 -
Materials (Basel, Switzerland) Aug 2020Complex dental components which are individually tailored to the patient can be obtained due to new additive manufacturing technology. This paper reviews the metallic... (Review)
Review
Complex dental components which are individually tailored to the patient can be obtained due to new additive manufacturing technology. This paper reviews the metallic powders used in dental applications, the fabrication process (build orientation, process parameters) and post-processing processes (stress relieving, surface finishing). A review of the literature was performed using PubMed, ScienceDirect, Mendeley and Google Scholar. Over eighty articles were selected based on relevance to this review. This paper attempts to include the latest research from 2010 until 2020, however, older manuscripts (10 articles) were also selected. Over 1200 records were identified through the search; these were screened for title and/or summary. Over eighty articles were selected based on relevance to this review. In order to obtain a product which can be used in clinical applications, the appropriate manufacturing parameters should be selected. A discussion was made on optimal selective laser melting (SLM) parameters in dentistry. In addition, this paper includes a critical review of applied thermal treatment methods for Co-Cr alloys used in dentistry.
PubMed: 32785055
DOI: 10.3390/ma13163524 -
The Journal of Prosthetic Dentistry Sep 2020Digital methods have been increasingly used to evaluate the fit of prostheses, but the accuracy of digital methodology has not been fully clarified. (Meta-Analysis)
Meta-Analysis
STATEMENT OF PROBLEM
Digital methods have been increasingly used to evaluate the fit of prostheses, but the accuracy of digital methodology has not been fully clarified.
PURPOSE
The purpose of this systematic review and meta-analysis was to assess the reliability of digital measurement methods for evaluating the marginal fit of fixed dental prostheses (FDPs) and to identify the potential factors that can influence the accuracy of the measurement methods.
MATERIAL AND METHODS
The differences between digital and conventional measurement methods were analyzed by searching PubMed, Scopus, Web of Science, and Google Scholar databases for studies reporting the marginal fit of FDPs. The agreement of data collection among the reviewers was confirmed by the Cohen kappa coefficient, and the MINORS scale was used to rate the quality of the included studies. The heterogeneity among the studies was evaluated, and meta-analyses with global and subgroup analyses were performed.
RESULTS
Ten in vitro studies were selected according to the eligibility criteria with substantial interreader concordance (κ=0.88). The standard mean difference of the meta-analysis for marginal discrepancy was 0.12 μm (95% confidence interval: -0.12 to 0.35), indicating that no statistically significant differences were found in the marginal discrepancies observed with digital and conventional methods (P=.343). The subgroup analysis for alloy-based prostheses was not significantly different, nor between the material and measurement methods (P=.060).
CONCLUSIONS
Digital methods appear to be reliable as an alternative to conventional methods for evaluating the marginal fit of FDPs. To confirm the results of this study and to identify the influencing factors on the accuracy of digital measurement methods, further controlled laboratory and clinical studies are needed.
Topics: Computer-Aided Design; Dental Implants; Dental Marginal Adaptation; Dental Prosthesis Design; Reproducibility of Results
PubMed: 32665119
DOI: 10.1016/j.prosdent.2020.04.011