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Dento Maxillo Facial Radiology Sep 2022The purpose of this systematic review was to search in literature in which severity unintended effects are caused by dental materials in magnetic resonance imaging...
OBJECTIVES
The purpose of this systematic review was to search in literature in which severity unintended effects are caused by dental materials in magnetic resonance imaging (MRI), such as to evaluate whether these artifacts hamper the diagnosis in the head and neck region.
MATERIALS AND METHODS
Clinical studies showing the severity of artifacts which dental materials are capable of causing in MRI of head and neck, such as their influence on diagnostic accuracy, were included in this review. The searches were conducted in four electronic databases (PubMed/Medline, Embase, Scopus and Web of Science), and a manual search was made in the reference lists of papers screened for full-text reading. Risk of bias was assessed using "Quality Assessment Tool for Diagnostic Accuracy Studies-2" (QUADAS-2). The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to assess the quality of evidence.
RESULTS
From 151 studies selected for full-reading, 19 were considered eligible for this review. Artifacts caused by orthodontic appliances were well-documented, and stainless steel brackets were the materials most likely to cause artifacts in MR imaging of head and neck. The literature was scarce for dental implants and restorations. Diagnoses within the oral cavity, but also those of the brain and craniofacial structures, were affected.
CONCLUSION
Artifacts caused by orthodontic appliances may affect the diagnosis in oral cavity and craniofacial structures. Data regarding dental implants and prosthodontics restorations were inconclusive. The severity of artifacts in MRI and their influence on diagnosis is dependent on dental material features, location in the oral cavity, and magnetic resonance parameters.
Topics: Artifacts; Dental Implants; Dental Materials; Humans; Magnetic Resonance Imaging; Mouth; Orthodontic Appliances
PubMed: 35348371
DOI: 10.1259/dmfr.20210450 -
Primary Dental Journal Nov 2019With increasing patient expectation for aesthetic dental restorations, there has been a drive towards developing ceramic materials to meet this expectation. Multiple...
With increasing patient expectation for aesthetic dental restorations, there has been a drive towards developing ceramic materials to meet this expectation. Multiple ceramic systems have been introduced over the past four decades with considerable advances in material properties. Survival rates of all-ceramic crowns differ by type of ceramic used, fabrication method and clinical indication. Zirconia and lithium disilicate are the most commonly used contemporary ceramic materials in dentistry. Survival data for these types of restorations appears to be promising; however, there is a lack of high-quality long-term clinical data on the success of these restorations. In the absence of robust longitudinal clinical research, laboratory studies have provided some useful information on the performance of ceramic restorations. Further high quality long-term clinical studies are needed to inform us of modes of failure of these restorations and the range of clinical circumstances in which each type of ceramic restoration may be used.
Topics: Ceramics; Crowns; Dental Materials; Dental Porcelain; Dental Restoration Failure; Humans; Zirconium
PubMed: 31666170
DOI: 10.1308/205016819827601527 -
Dental Materials Journal Jan 2020The purpose of the study was to test new method for in vitro evaluation of dental material wear with 3D digitization procedure. Thirty dental crowns, made of...
The purpose of the study was to test new method for in vitro evaluation of dental material wear with 3D digitization procedure. Thirty dental crowns, made of polyetheretherketone and veneered with composite material, were subjected to wear test. The crown surface was digitized using coordinate measuring machine before and after the performed wear test. Mesh 3D models were reconstructed and average and maximum depth of lost material and volume loss was calculated (GOM Inspect 2016 software). Mean average depth value amounted 12±7 µm, maximum depth value was 42 µm, while mean volume loss was 0.0024 mm. The smallest measured values were 4 µm for depth value and 0.0003 mm for volume loss. Coefficient of variation was very high for all tested parameters (>50%) as a result of data inconsistency. Within the limitations of applied methodology, the possibility of using coordinate measuring machine in measurement of dental material wear was confirmed.
Topics: Crowns; Dental Materials; Dental Restoration Wear; Humans; Materials Testing; Surface Properties; Tooth; Tooth Crown; Tooth Wear
PubMed: 31611495
DOI: 10.4012/dmj.2018-280 -
The Journal of Prosthetic Dentistry Mar 2022How axial displacement may be affected by the mechanical properties and internal discrepancy of a cement-retained implant-supported prosthesis is unclear.
STATEMENT OF PROBLEM
How axial displacement may be affected by the mechanical properties and internal discrepancy of a cement-retained implant-supported prosthesis is unclear.
PURPOSE
The purpose of this in vitro study was to assess the difference in internal discrepancy and axial displacement according to the prosthesis material in cement-retained prostheses splinting nonparallel implants.
MATERIAL AND METHODS
Computer-aided design and computer-aided manufacture (CAD-CAM) titanium abutments were fabricated for a vertically placed implant and a 15-degree tilted implant. Three types of prostheses, in zirconia, cobalt-chromium (Co-Cr) alloy, and polymethylmethacrylate resin (PMMA), were fabricated (n=10). The internal discrepancy between the CAD-CAM titanium abutment and the prosthesis was measured by using the replica technique. After luting with an interim cement, they were mounted in Type IV gypsum. The specimens were cyclic loaded, and axial displacement of the prosthesis was measured after 3, 10, 100, and 10 cycles. The internal discrepancy and cumulative axial displacement were assessed by using a 3-way analysis of variance and repeated measures analysis of variance (α=.05).
RESULTS
The internal discrepancy of the prosthesis did not differ based on the prosthesis material (P=.869); however, it was significantly different based on the measurement location, with the occlusal discrepancy (224 ±29 μm) being greater than the axial discrepancy (21 ±10 μm) (P<.05). Implants with an angled placement exhibited less axial displacement than implants with vertical placement (P<.05). The PMMA prosthesis demonstrated significantly greater axial displacement than the zirconia or Co-Cr prostheses (P<.05), which were similar (P=.623).
CONCLUSIONS
Prostheses made with high-elastic moduli materials exhibited less axial displacement than PMMA prostheses, even though the internal discrepancy was not different. Moreover, vertically placed implants presented a greater axial displacement of the prosthesis than implants with angled placement.
Topics: Chromium Alloys; Computer-Aided Design; Dental Abutments; Dental Cements; Dental Implants; Dental Materials; Dental Prosthesis Design; Dental Prosthesis, Implant-Supported; Zirconium
PubMed: 33309295
DOI: 10.1016/j.prosdent.2020.08.044 -
JDR Clinical and Translational Research Jan 2022A European Union amalgam phase-down has recently been implemented. Publicly funded health care predominates in the United Kingdom with the system favoring amalgam use....
INTRODUCTION
A European Union amalgam phase-down has recently been implemented. Publicly funded health care predominates in the United Kingdom with the system favoring amalgam use. The current use of amalgam and its alternatives has not been fully investigated in the United Kingdom.
OBJECTIVES
The study aimed to identify direct posterior restorative techniques, material use, and reported postoperative complication incidence experienced by primary care clinicians and differences between clinician groups.
METHODS
A cross-sectional survey was distributed to primary care clinicians through British dentist and therapist associations (11,092 invitations). The questionnaire sought information on current provision of direct posterior restorations and perceived issues with the different materials. Descriptive statistical and hypothesis testing was performed.
RESULTS
Dentists' response rate was 14% and therapists' estimated minimum response rate was 6% (total = 1,513). The most commonly used restorative material was amalgam in molar teeth and composite in premolars. When placing a direct posterior mesio-occluso-distal restoration, clinicians booked on average 45% more time and charged 45% more when placing composite compared to amalgam ( < 0.0001). The reported incidences of food packing and sensitivity following the placement of direct restorations were much higher with composite than amalgam ( < 0.0001). Widely recommended techniques, such as sectional metal matrix use for posterior composites, were associated with reduced food packing ( < 0.0001) but increased time booked ( = 0.002).
CONCLUSION
Amalgam use is currently high in the publicly funded sector of UK primary care. Composite is the most used alternative, but it takes longer to place and is more costly. Composite also has a higher reported incidence of postoperative complications than amalgam, but time-consuming techniques, such as sectional matrix use, can mitigate against food packing, but their use is low. Therefore, major changes in health service structure and funding and posterior composite education are required in the United Kingdom and other countries where amalgam use is prevalent, as the amalgam phase-down continues.
KNOWLEDGE TRANSFER STATEMENT
This study presents data on the current provision of amalgam for posterior tooth restoration and its directly placed alternatives by primary care clinicians in the United Kingdom, where publicly funded health care with copayment provision predominates. The information is important to manage and plan the UK phase-down and proposed phase-out of amalgam and will be of interest to other, primarily developing countries where amalgam provision predominates in understanding some of the challenges faced.
Topics: Composite Resins; Cross-Sectional Studies; Dental Amalgam; Dental Materials; Dental Restoration, Permanent
PubMed: 33300416
DOI: 10.1177/2380084420978653 -
Stomatologiia 2018For assessment of the modern situation about the choice of materials for manufacture of dental implants and the processing of their surface the scientific literature for... (Review)
Review
For assessment of the modern situation about the choice of materials for manufacture of dental implants and the processing of their surface the scientific literature for the last 2 years was study. On the basis of a large number of contradictory results of the researches devoted to each of dental implantation problems it is possible to draw a conclusion that any of primal problems of implantology is finally not solved. There is no unique opinion at the choice of optimum material for manufacture of dental implants, at the way of processing and modification of their surface. The problem of improvement of quality of dental implantation and fight against complications of this procedure cannot be solved simple drawing other substances on the implanted material surface, this task more easily and more successfully is solved via changes of product structure and various modification of implant surface. Up to the present the researches of an opportunity to influence on characteristics of the implanted materials, changing their structure and character of a surface, continue. And the publications reporting about the considerable positive effect of artificially created roughnesses on product surfaces, and the articles claiming that there are no big differences between the rough and polished implants are confirmed by objective measurements with statistical processing of the obtained data. It should be noted that among articles there are very many works of the doubtful plan or with insufficiently valid conclusions. This review leads to the conclusion that further clinical and experimental studies and about the choice of materials for manufacture of implants and at the ways of processing of their surface are necessary.
Topics: Dental Implantation; Dental Implantation, Endosseous; Dental Implants; Dental Materials; Dental Prosthesis Design; Surface Properties
PubMed: 30199073
DOI: 10.17116/stomat20189704168 -
The Journal of Prosthetic Dentistry Jul 2022The properties of dental computer-aided design and computer-aided manufacturing (CAD-CAM) materials vary. Studies regarding the effects of aging on the properties of...
STATEMENT OF PROBLEM
The properties of dental computer-aided design and computer-aided manufacturing (CAD-CAM) materials vary. Studies regarding the effects of aging on the properties of these materials are lacking.
PURPOSE
The purpose of this in vitro study was to evaluate the changes in the mechanical and surface properties of different CAD-CAM materials after thermocycling and mechanical loading.
MATERIAL AND METHODS
In total, 150 bar-shaped specimens (17.0×4.0×2.0 mm) were prepared from feldspathic glass-ceramic (VM; Vitablocs Mark II), lithium disilicate glass-ceramic (EX; IPS e.max CAD), zirconia-reinforced lithium silicate glass-ceramic (CD; Celtra Duo), polymer-infiltrated ceramic network (VE; Vita Enamic), and resin-nanoceramic (CS; Cerasmart). Each type was divided into 2 groups (n=15; each). One group was subjected to thermocycling in distilled water at 5 °C to 55 °C for 6000 cycles and 50 N mechanical loading for 1.2×10 cycles. The other group was stored in 37 °C water for 24 hours. Nanoindentation hardness, Young modulus, and 3-point flexural strength were measured for the analyses of the mechanical properties. Surface roughness, surface microstructure, and elemental composition were measured to analyze the surface characteristics. Statistical analyses were performed with 1-way ANOVA with the Tukey HSD post hoc test, independent samples t test, Kruskal-Wallis test with Bonferroni post hoc test, Mann-Whitney U test, and 2-way ANOVA (α=.05).
RESULTS
Before and after aging, CS exhibited the lowest hardness (1.20 to 1.04 GPa) and Young modulus (13.76 to 13.48 GPa) values (P<.05). EX exhibited the highest flexural strengths (393.43 to 391.86 MPa), and VM exhibited the lowest (109.98 to 112.73 MPa) values (P<.05). CS exhibited the highest surface roughness (S and S; 10.60 to 28.82, 14.21 to 38.27 nm) values (P<.05). After aging, the hardness and Young modulus of VM, EX, and VE decreased significantly (P<.001). No significant difference was observed in the flexural strengths of the CAD-CAM materials (P>.05). Significant increases were observed in the surface roughness of all the materials (P<.05), with altered microstructures. Except for the flexural strength, the mechanical properties and surface characteristics of the CAD-CAM materials were significantly affected by the material type after aging.
CONCLUSIONS
Before and after aging, resin-nanoceramic exhibited the lowest hardness and Young modulus, and the highest surface roughness. Lithium disilicate glass-ceramic exhibited the highest flexural strength and feldspathic glass-ceramic exhibited the lowest value. After aging, increased surface roughness and microstructure alterations were observed. Significant interactions between aging process and material type were found for the mechanical properties and surface characteristics except for the flexural strength.
Topics: Ceramics; Computer-Aided Design; Dental Materials; Dental Porcelain; Flexural Strength; Hardness; Materials Testing; Surface Properties; Water
PubMed: 33546857
DOI: 10.1016/j.prosdent.2020.11.014 -
The Journal of Prosthetic Dentistry Apr 2019Electron backscatter radiation from dental materials can contribute to soft tissue injury in patients undergoing head and neck radiation therapy.
STATEMENT OF PROBLEM
Electron backscatter radiation from dental materials can contribute to soft tissue injury in patients undergoing head and neck radiation therapy.
PURPOSE
The dose enhancement from the materials used for prosthodontic restoration of the dentition has not been well quantified. This study reports the magnitude of backscatter dose from the contemporary dental materials lithium disilicate and zirconia as compared with high-noble alloy and investigates the role of a spacer material in mitigating this effect.
MATERIAL AND METHODS
Three flat slabs of dental materials high-noble alloy, lithium disilicate, and zirconia with thicknesses of 1.5 and 3 mm were irradiated with 6-MV photons from a clinical linear accelerator. Measurements were made using a thin-window parallel-plate ionization chamber placed at 0, 1, 3, and 5 mm from the material. One millimeter of poly(methyl methacrylate) or thermoplastic material was used to cover the dental material and measure the effect on the adjacent dose enhancement.
RESULTS
Dose enhancements between 8% and 50% were recorded adjacent to the dental restoration materials. The largest enhancements occurred for the material of the highest density, the high-noble alloy. Dose enhancement was substantially lower for lithium disilicate (8%) and zirconia (30%). The thickness of the restoration material did not significantly affect dose enhancement. The dose enhancement decreased with distance from the material, dropping to <10% for all materials at 3 mm.
CONCLUSIONS
Contemporary dental restorations enhance the backscatter dose. The presence of dental restorations may warrant the use of a stent to create separation from these materials as this can mitigate the effect.
Topics: Dental Alloys; Dental Materials; Dental Porcelain; Dental Prosthesis Design; Humans; Materials Testing; Radiation Dosage; Zirconium
PubMed: 30580980
DOI: 10.1016/j.prosdent.2018.07.012 -
International Journal of Molecular... Mar 2023This research addresses the development of a formalized approach to dental material selection (DMS) in manufacturing removable complete dentures (RDC). Three types of...
This research addresses the development of a formalized approach to dental material selection (DMS) in manufacturing removable complete dentures (RDC). Three types of commercially available polymethyl methacrylate (PMMA) grades, processed by an identical Digital Light Processing (DLP) 3D printer, were compared. In this way, a combination of mechanical, tribological, technological, microbiological, and economic factors was assessed. The material indices were calculated to compare dental materials for a set of functional parameters related to feedstock cost. However, this did not solve the problem of simultaneous consideration of all the material indices, including their significance. The developed DMS procedure employs the extended VIKOR method, based on the analysis of interval quantitative estimations, which allowed the carrying out of a fully fledged analysis of alternatives. The proposed approach has the potential to enhance the efficiency of prosthetic treatment by optimizing the DMS procedure, taking into consideration the prosthesis design and its production route.
Topics: Denture, Complete; Polymethyl Methacrylate; Prosthesis Design; Technology; Dental Materials; Computer-Aided Design
PubMed: 37047405
DOI: 10.3390/ijms24076432 -
Surface characterization of indirect restorative materials submitted to different etching protocols.Journal of Dentistry Dec 2022This in vitro study aimed to evaluate the effect of different times and concentrations of hydrofluoric acid etching on the surface of indirect restorative materials...
OBJECTIVES
This in vitro study aimed to evaluate the effect of different times and concentrations of hydrofluoric acid etching on the surface of indirect restorative materials obtained from blocks used in CAD-CAM technology.
METHODS
Specimens (4 mm × 4 mm × 0.8 mm) were obtained for each indirect restorative material: zirconia-reinforced lithium monosilicate ceramic (Celtra Duo), nanoceramic resin (Lava Ultimate), and polymer-infiltrated ceramic network material (Vita Enamic). The materials were submitted to etching with 5% or 10% hydrofluoric acid for 20, 40, 60, or 90 s. A control group for each material was evaluated without any surface treatment, totaling nine experimental groups for each material (n = 10). The specimens were evaluated for surface roughness (R and R), confocal optical microscopy, the contact angle (θ), surface free energy (γs), total free interaction energy (∆G) using a goniometer, and microshear bond strength to resin cement. Specimen images were obtained using scanning electron microscopy, confocal optical microscopy, and atomic force microscopy. Data on the surface roughness, the contact angle, surface free energy, total free interaction energy, and bond strength were subjected to two-way ANOVA and Tukey´s test (α=0.05).
RESULTS
In general, Celtra Duo showed better results after etching with 10% hydrofluoric acid for 40 or 60 s. Lava Ultimate showed better performance after etching with 10% hydrofluoric acid for 20 or 40 s, whereas Vita Enamic showed better results after etching with 5% hydrofluoric acid for 90 s.
CONCLUSION
Each material showed different characteristics after etching with hydrofluoric acid. Knowledge of the proper protocol for each material is essential to ensure improvements in the adhesion process and durability of indirect restorations. In general, Celtra Duo presented mechanical properties superior to those of Lava Ultimate and Vita Enamic.
CLINICAL SIGNIFICANCE
Specific etching protocols must be recommended for each indirect material because longer exposure to hydrofluoric acid can jeopardize the surface, thus affecting the mechanical and bond strength properties.
Topics: Hydrofluoric Acid; Dental Bonding; Dental Porcelain; Materials Testing; Surface Properties; Dental Materials; Resin Cements; Ceramics; Computer-Aided Design
PubMed: 36280006
DOI: 10.1016/j.jdent.2022.104348