207 research outputs found
COMMENTARY. Treatment Concept with CAD/CAM‐Fabricated High‐Density Polymer Temporary Restorations 1
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93767/1/j.1708-8240.2011.00498.x.pd
Exploring Message Meaning: A Qualitative Media Literacy Study of College Freshmen
Critical media literacy demands understanding of the deeper meanings of media messages. Using a grounded theory approach, this study analyzed responses by first-year college students not currently enrolled in formal media literacy education to three types of video messages: an advertisement, a public relations message, and a news report. Students did not exhibit nuanced understandings of message purpose or sender in any of the three types of messages, and had particular difficulty distinguishing public relations and news messages. These results suggest a media literacy curriculum addressing distinctions between media formats, with emphasis on analysis of message intent and point of view, is needed
The complete digital workflow in fixed prosthodontics: a systematic review
Background The continuous development in dental processing ensures new opportunities in the field of fixed prosthodontics in a complete virtual environment without any physical model situations. The aim was to compare fully digitalized workflows to conventional and/or mixed analog-digital workflows for the treatment with tooth-borne or implant-supported fixed reconstructions. Methods A PICO strategy was executed using an electronic (MEDLINE, EMBASE, Google Scholar) plus manual search up to 2016–09-16 focusing on RCTs investigating complete digital workflows in fixed prosthodontics with regard to economics or esthetics or patient-centered outcomes with or without follow-up or survival/success rate analysis as well as complication assessment of at least 1 year under function. The search strategy was assembled from MeSH-Terms and unspecific free-text words: {((“Dental Prosthesis” [MeSH]) OR (“Crowns” [MeSH]) OR (“Dental Prosthesis, Implant-Supported” [MeSH])) OR ((crown) OR (fixed dental prosthesis) OR (fixed reconstruction) OR (dental bridge) OR (implant crown) OR (implant prosthesis) OR (implant restoration) OR (implant reconstruction))} AND {(“Computer-Aided Design” [MeSH]) OR ((digital workflow) OR (digital technology) OR (computerized dentistry) OR (intraoral scan) OR (digital impression) OR (scanbody) OR (virtual design) OR (digital design) OR (cad/cam) OR (rapid prototyping) OR (monolithic) OR (full-contour))} AND {(“Dental Technology” [MeSH) OR ((conventional workflow) OR (lost-wax-technique) OR (porcelain-fused-to-metal) OR (PFM) OR (implant impression) OR (hand-layering) OR (veneering) OR (framework))} AND {((“Study, Feasibility” [MeSH]) OR (“Survival” [MeSH]) OR (“Success” [MeSH]) OR (“Economics” [MeSH]) OR (“Costs, Cost Analysis” [MeSH]) OR (“Esthetics, Dental” [MeSH]) OR (“Patient Satisfaction” [MeSH])) OR ((feasibility) OR (efficiency) OR (patient-centered outcome))}. Assessment of risk of bias in selected studies was done at a ‘trial level’ including random sequence generation, allocation concealment, blinding, completeness of outcome data, selective reporting, and other bias using the Cochrane Collaboration tool. A judgment of risk of bias was assigned if one or more key domains had a high or unclear risk of bias. An official registration of the systematic review was not performed. Results The systematic search identified 67 titles, 32 abstracts thereof were screened, and subsequently, three full-texts included for data extraction. Analysed RCTs were heterogeneous without follow-up. One study demonstrated that fully digitally produced dental crowns revealed the feasibility of the process itself; however, the marginal precision was lower for lithium disilicate (LS2) restorations (113.8 μm) compared to conventional metal-ceramic (92.4 μm) and zirconium dioxide (ZrO2) crowns (68.5 μm) (p < 0.05). Another study showed that leucite-reinforced glass ceramic crowns were esthetically favoured by the patients (8/2 crowns) and clinicians (7/3 crowns) (p < 0.05). The third study investigated implant crowns. The complete digital workflow was more than twofold faster (75.3 min) in comparison to the mixed analog-digital workflow (156.6 min) (p < 0.05). No RCTs could be found investigating multi-unit fixed dental prostheses (FDP). Conclusions The number of RCTs testing complete digital workflows in fixed prosthodontics is low. Scientifically proven recommendations for clinical routine cannot be given at this time. Research with high-quality trials seems to be slower than the industrial progress of available digital applications. Future research with well-designed RCTs including follow-up observation is compellingly necessary in the field of complete digital processing
Clinical evaluation of chairside Computer Assisted Design/Computer Assisted Machining nano‐ceramic restorations: Five‐year status
ObjectivesThis investigation was a longitudinal, randomized clinical trial to measure the clinical performance of a nano‐ceramic material (Lava Ultimate/3M) for chairside Computer Assisted Design/Computer Assisted Machining (CAD/CAM) fabricated restorations.Materials and MethodsOne hundred and twenty chairside CAD/CAM onlays were restored with a CEREC system randomly assigned to 60 leucite‐reinforced ceramic (IPS EmpressCAD/Ivoclar Vivadent AGBendererstrasse 2FL‐9494 SchaanLiechtenstein) onlays and 60 nano‐ceramic (Lava Ultimate/3M) onlays. Equal groups of onlays were cemented using a self‐etch and a total etch adhesive resin cement. The onlays were recalled for a period of 5 years.ResultsAt 1 week postoperatively, 10% of the onlays cemented with both the self‐etch and total etch adhesive resin cements were reported as slightly sensitive. However, all patients were asymptomatic by the 4th week without treatment. Four leucite‐reinforced onlays and one nano‐ceramic onlay fractured and required replacement.ConclusionsAdhesive retention with a self‐etch or total etch cementation technique resulted in a similar clinical outcome with no reported debonds. The nano‐ceramic onlays had a lower incidence of fracture compared to the leucite‐reinforced ceramic onlays with both having a very low risk of fracture. Nano‐ceramic onlays performed equally as well as glass ceramic onlays over 5 years of clinical service.Clinical SignificanceCeramic materials have been a mainstay for chairside CAD/CAM restorations for the past 30 years and a new category of resilient ceramics with a resin matrix has been introduced reported to offer ceramic‐like durability and esthetics with resin‐like efficiency in handling. There are no long‐term clinical studies on the performance of these materials. This is a 5‐year randomized clinical trial on the performance of nano‐ceramic onlays.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154462/1/jerd12516.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154462/2/jerd12516_am.pd
Three-Dimensional Digital Evaluation of the Fit of Endocrowns Fabricated from Different CAD/CAM Materials
Purpose
A wide variety of CAD/CAM materials are available for single‐tooth restorations. CAD/CAM material characteristics are different and may influence CAM fabrication accuracy. There is no study investigating the influence of different CAD/CAM materials on the final fit of the restoration. The aim of this study was to evaluate the fit of endocrowns fabricated from different CAD/CAM materials using a new 3D evaluation method with an intraoral scanning system. The null hypothesis was that there are no significant differences for the fitting accuracy of different CAD/CAM materials.
Materials and Methods
Preparation for an endocrown was performed on a maxillary right first molar on a typodont, and restorations were fabricated with a chairside CAD/CAM system (CEREC Omnicam, MCXL). Three groups using three different CAD/CAM materials were established (each n = 10): zirconia‐reinforced lithium silicate ceramic (Celtra Duo; CD), leucite‐reinforced silicate ceramic (Empress CAD; EM), resin nanoceramic (Lava Ultimate; LU). A 3D digital measurement technique (OraCheck, Cyfex AG) using an intraoral scanner (CEREC Omnicam) was used to measure the difference in fit between the three materials for a master endocrown preparation. The preparation scan and the endocrown fit scan were matched with special difference analysis software OraCheck. Three areas were selected for fitting accuracy measurements: margin (MA), axial (AX), occlusal (OC). Statistical analysis was performed using 80% percentile, one‐way ANOVA, and post‐hoc Scheffé test. Significance level was set to p = 0.05.
Results
Results varied from best 88.9 ± 7.7 μm for marginal fit of resin nanoceramic restorations (LU_MA) to worst 182.3 ± 24.0 μm for occlusal fit of zirconia‐reinforced lithium silicate restorations (CD_OC). Statistically significant differences were found both within and among the test groups. Group CD performed statistically significantly different from group LU for marginal fit (MA) and axial fit (AX) (p 0.05). Deviation pattern for differences was visually analyzed with a color‐coded scheme for each restoration.
Conclusions
Statistically significant differences were found for different CAD/CAM materials if the CAM procedure was identical. Within the limitations of this study, the choice of CAD/CAM material may influence the fitting accuracy of CAD/CAM‐fabricated restorations
Same-Gender Marriage: Implications for Social Work Practitioners
Notably, in 2013, Maryland, Rhode Island, Delaware, and Minnesota became the 10th, 11th, 12th, and 13th states, respectively, to legalize same-gender marriage. Without legal recognition or social support from the larger society, the majority of same-gender partnerships in the U.S. are denied privileges and rights that are considered basic for heterosexual marriages. This manuscript draws from a national cross section of published survey data from 1996 to 2013 reporting Americans’ attitudes regarding same-gender marriage and civil unions. Social work practitioners have broad opportunity to apply their skills to the critical needs facing same-gender partners. After an overview of the legal status of same-gender marriages and their accompanying social and policy issues, recommendations are provided that include identification of specific needs for premarital counseling of same-gender partners and ensuring sensitivity to the myriad challenges they face
Grand Rounds for Dental Students: An Exploration
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153609/1/jddj002203372015795tb05910x.pd
Building, scaling, and sustaining a learning health system for surgical quality improvement: A toolkit
This article describes how to start, replicate, scale, and sustain a learning health system for quality improvement, based on the experience of the Michigan Surgical Quality Collaborative (MSQC). The key components to operationalize a successful collaborative improvement infrastructure and the features of a learning health system are explained. This information is designed to guide others who desire to implement quality improvement interventions across a regional network of hospitals using a collaborative approach. A toolkit is provided (under Supporting Information) with practical information for implementation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156156/3/lrh210215.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156156/2/lrh210215-sup-0001-supinfo.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156156/1/lrh210215_am.pd
The effect of different storage media on the monomer elution and hardness of CAD/CAM composite blocks
ObjectiveThis study aimed to assess the effect of different storage media on the hardness and monomer elution of CAD/CAM composite blocks.MethodsFive resin-composite blocks (RCB), one polymer-infiltrated ceramic network (PICN) block (Enamic (EN)), one ceramic-filled poly ether ether ketone (PEEK) block (Dentokeep (DK)), and one feldspathic ceramic block. Microhardness was measured using a Vickers indenter tester (FM-700, Future Tech Corp., Japan). In addition 4 conventional resin-composites were investigated for monomer elution using high performance liquid chromatography (HPLC) after storage in different media for 3 months. The data were analysed by three-way ANOVA, two-way ANOVA, one-way ANOVA, Tukey’s post hoc test and the independent t-test (α = 0.05 for all tests).ResultsThe specimens stored in the water had a hardness reduction ranging from 0.9% to 24.4%. In artificial saliva, the specimens had a hardness reduction ranging from 2.8% to 23.2%. The hardness reduction percentage in 75% Ethanol/Water (E/W) ranged between 3.8% and 35.3%. All materials, except GR (resin-composite block) and DK (Polyetheretherketone (PEEK)), showed a variable extent of monomer elution into 75% E/W with significantly higher amounts eluted from conventional composites. GRA and GND (conventional resin-composites) eluted TEGDMA in artificial saliva and GRA eluted TEGDMA in water.SignificanceThe hardness of CAD/CAM composite blocks was affected by different storage media, and they were not as stable as ceramic, with PICN exhibited superior hardness stability to all of the resin-composite blocks in all the storage media and was comparable to ceramic block. The hardness reduction percentage of the CAD/CAM composite blocks was influenced by the filler loading and resin-matrix composition.Minimal or no monomer elution from CAD/CAM blocks was detected.<br/
Effects of air abrasion with alumina or glass beads on surface characteristics of CAD/CAM composite materials and the bond strength of resin cements
ABSTRACT Objective The study aimed to evaluate effects of air abrasion with alumina or glass beads on bond strengths of resin cements to CAD/CAM composite materials. Material and Methods CAD/CAM composite block materials [Cerasmart (CS) and Block HC (BHC)] were pretreated as follows: (a) no treatment (None), (b) application of a ceramic primer (CP), (c) alumina-blasting at 0.2 MPa (AB), (d) AB followed by CP (AB+CP), and (e) glass-beads blasting at 0.4 MPa (GBB) followed by CP (GBB+CP). The composite specimens were bonded to resin composite disks using resin cements [G-CEM Cerasmart (GCCS) and ResiCem (RC)]. The bond strengths after 24 h (TC 0) and after thermal cycling (TC 10,000 at 4–60°C) were measured by shear tests. Three-way ANOVA and the Tukey compromise post hoc tests were used to analyze statistically significant differences between groups (α=0.05). Results For both CAD/CAM composite materials, the None group exhibited a significant decrease in bond strength after TC 10,000 (p0.05). The AB+CP group showed a significantly higher bond strength after TC 10,000 than did the AB group for RC (p<0.05), but not for GCCS. The GBB+CP group showed the highest bond strength for both thermal cyclings (p<0.05). Conclusions Air abrasion with glass beads was more effective in increasing bond durability between the resin cements and CAD/CAM composite materials than was using an alumina powder and a CP
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