1,838 research outputs found
Oral health-related impact profile of patients treated with fixed, removable, and telescopic dental prostheses in student courses â a prospective bicenter clinical trial
Objectives!#!To analyze the oral health-related impact profile in patients treated with three different types of dental prosthesis in student courses.!##!Materials and methods!#!This prospective bicenter clinical trial was conducted with 151 patients being treated with fixed (n = 70), removable (n = 61), or telescopic dental prostheses (n = 20) in clinical student courses of two German universities from October 2018 to October 2019. All patients completed three standardized German versions of the Oral Health Impact Profile (OHIP-G49/53) before prosthetic treatment (T0), at control after 1 week (T1), and after 3 months (T2), divided into five dimensions: (a) appearance, (b) oral function, (c) psychosocial impact, (d) linguistic limitations, and (e) orofacial pain. Data were analyzed with Kolmogorov-Smirnov, Wilcoxon signed-rank, Kruskal-Wallis, Mann-Whitney, and Cronbach's alpha tests.!##!Results!#!Within T0-T1 and T0-T2, greater improvements were determined for removable compared with fixed dental prostheses for the dimensions' oral function (p ⤠0.014), linguistic limitations (p ⤠0.016), and appearance (p ⤠0.003). No significant differences were found between fixed and telescopic dental prostheses (p ⼠0.104) or between removable (partial dental prosthesis with clasps and complete dental prosthesis) and telescopic dental prostheses (p ⼠0.100). Within T1-T2, a significant improvement in orofacial pain could be determined (p = 0.007).!##!Conclusions!#!Restorations presented an improvement in oral health-related quality of life. Removable dental prostheses showed better improvement than fixed ones in various dimensions.!##!Clinical relevance!#!Knowledge about the influence of oral health-related quality of life on the three different types of prosthesis used in student courses can be of decisive help in dental consultations
CAD/CAM Diagnostic Esthetic Functional Splint (DEFS) as a removable prototype to evaluate the final prosthetic rehabilitation: a narrative review.
The main objective of this narrative review was to provide an overview of DEFS (Diagnostic Esthetic Functional Splint), namely CAD/CAM manufactured, âsnap-retainedâ, tooth-colored splints available by materials exhibiting a certain degree of elasticity (like polycarbonates or acetal resins) for restoring function, esthetics and occlusion in several clinical situations, before or as an intermediate alternative to undergoing the final treatment. The search strategy included all papers dealing with snap-retained prosthetic systems and was based on a literature review of papers available in electronic databases (Pubmed/Medline, Evidence-Based Dentistry, BMJ Evidence-Based Medicine, Dynamed, Embase, BMJ Clinical Evidence, Web of Science, Scientific reports); eligible papers were researched on Opengreyand a manual search was performed, as well. From the electronic databases emerged 13,199 records, many of which were duplicates. The grey literature and the manual research did not produce any eligible article. After duplicates removal, 7690 records were obtained. Titles, abstracts and keywords were analyzed. The studies concerning the topic of interest were examined by the reviewers and discussed. Although no evidence-based data were found in the literature, according to the authorsâ clinical experience, the DEFS (Diagnostic Esthetic Functional Splint) is a very promising solution in multiple clinical situations, due to its diagnostic, therapeutical, functional and esthetic versatility
The f_LT Response Function of D(e,e'p)n at Q^2=0.33(GeV/c)^2
The interference response function f_LT (R_LT) of the D(e,e'p)n reaction has
been determined at squared four-momentum transfer Q^2 = 0.33 (GeV/c)^2 and for
missing momenta up to p_miss= 0.29 (GeV/c). The results have been compared to
calculations that reproduce f_LT quite well but overestimate the cross sections
by 10 - 20% for missing momenta between 0.1 (GeV/c) and 0.2 (GeV/c) .Comment: 12 Pages, 10 figure
A measurement of the axial form factor of the nucleon by the p(e,e'pi+)n reaction at W=1125 MeV
The reaction p(e,e'pi+)n was measured at the Mainz Microtron MAMI at an
invariant mass of W=1125 MeV and four-momentum transfers of Q^2=0.117, 0.195
and 0.273 (GeV/c)^2. For each value of Q^2, a Rosenbluth separation of the
transverse and longitudinal cross sections was performed. An effective
Lagrangian model was used to extract the `axial mass' from experimental data.
We find a value of M_A=(1.077+-0.039) GeV which is (0.051+-0.044) GeV larger
than the axial mass known from neutrino scattering experiments. This is
consistent with recent calculations in chiral perturbation theory.Comment: 14 pages, 5 figures, uses elsart.cl
Impact of polishing system on surface roughness of different ceramic surfaces after various pretreatments and bracket debonding
Objective
Evaluating various polishing methods after bracket debonding and excessive attachment material removal for different ceramics and pretreatments.
Material and methods
Zirconia (ZrO2), leucite (LEU) and lithium disilicate (LiSi) specimens were pretreated with a) silica coated alumina particles (CoJet); LEU and LiSi additionally with b) hydrofluoric acid (HF), c) Monobond Etch&Prime (MEP), d) silicium carbide grinder (SiC) before bracket bonding, shearing off, ARI evaluation, excessive attachment material removal and polishing with i) Sof-Lex Discs (Soflex), ii) polishing paste (Paste), iii) polishing set (Set). Before/after polishing surface roughness (Ra) was measured with a profilometer. Martens hardness parameter were also assessed.
Results
Irrespective of pretreatment Ra of LEU increased the most, followed by LiSi and ZrO2 (pâ<â0.001, SiC: pâ=â0.012), in accordance with the measured Martens hardness parameter. CoJet/SiC caused greater roughness as HF/MEP (pâ<â0.001). The ZrO2 surface was rougher after polishing with Paste/Set (pâ<â0.001; pâ=â0.047). Ra improved in the LEU/CoJet, LEU/SiC and LiSi/SiC groups with Soflex/Set (pâ<â0.001), in the LiSi/CoJet and LEU/HF groups by Soflex (pâ=â0.003, pâ<â0.001) and worsened by Paste (pâ=â0.017, pâ<â0.001). Polishing of HF or MEP pretreated LiSi with Set increased Ra (pâ=â0.001, pâ<â0.001), so did Paste in the LEU/MEP group (pâ<â0.001).
Conclusions
Paste couldnât improve the surfaces. Soflex was the only method decreasing Ra on rough surfaces and not causing roughness worsening. Polishing of LEU/LiSi after MEP, LEU after HF pretreatment doesn´t seem to have any benefit.
Clinical Relevance
To avoid long-term damage to ceramic restorations, special attention should be paid to the polishing method after orthodontic treatment
A pattern of care analysis: Prosthetic rehabilitation of head and neck cancer patients after radiotherapy
Background
While some medical associations provide guidelines for the implantâprosthetic rehabilitation of head and neck cancer patients, the circulation and implementation in the everyday routine of practicing dentists remain unknown.
Purpose
To analyze patterns of care for the prosthetic rehabilitation of head and neck cancer patients after radiotherapy in German speaking countries.
Materials and methods
An online survey consisting of 34 questions separated into three sections, (a) general inquiries, (b) treatment concepts, and (c) patient cases, was forwarded to university hospital departments for Prosthetic Dentistry and Oral and Maxillofacial Surgery, and members of different medical associations. Statistical differences between groups were analyzed using chiâsquared test (Pâ<â.05).
Results
From May to October 2019, 118 participants completed the survey. The majority practiced in university hospitals, had more than 5âyears of work experience, and reported to be involved in <10 post radiation prosthetic rehabilitation cases per year. Rehabilitation protocols involving dental implants were implemented by oral/oralâ and maxillofacial surgeons and prosthetic dentists, while general dentists favored implantâfree solutions. Xerostomia was recognized as a common problem for a successful prosthetic rehabilitation. The subsequent treatment choice with either fixed dental prostheses or removable dentures was divided among participants.
Conclusions
As treatment planning differed with regard to the participants' field of expertise and work environment, and most practitioners only handle a low number of cases, patients might benefit from centralization in larger institutes with a multidisciplinary structure. A high agreement between the practitioners' treatment concepts and the current state of research was observed. While the choice between a mucosaâ or toothâsupported, and an implantâsupported restoration depends on numerous individual factors, guidelines derived from longitudinal studies would enhance evidenceâbased treatment in this field
Orthodontic bonding to silicate ceramics: impact of different pretreatment methods on shear bond strength between ceramic restorations and ceramic brackets
Objective
The study aims to investigate the shear bond strength (SBS) between silicate ceramic restorations and ceramic brackets after different pretreatments and aging methods.
Material and methods
Leucite (LEU) and lithium disilicate (LiSi) specimens were pretreated with (i) 4% hydrofluoric acidâ+âsilane (HF), (ii) Monobond Etch&Prime (MEP), (iii) silicatizationâ+âsilane (CoJet), and (iv) SiC grinderâ+âsilane (SiC). Molars etched (phosphoric acid) and conditioned acted as comparison group. SBS was measured after 24 h (distilled water, 37 °C), 500âĂâthermocycling (5/55 °C), and 90 days (distilled water, 37 °C). Data was analyzed using ShapiroâWilk, KruskalâWallis with Dunnâs post hoc test and Bonferroni correction, MannâWhitney U, and Chi2 test (pâ<â0.05). The adhesive remnant index (ARI) was determined.
Results
LEU pretreated with MEP showed lower SBS than pretreated with HF, CoJet, or SiC. LiSi pretreated with MEP resulted in lower initial SBS than pretreated with HF or SiC. After thermocycling, pretreatment using MEP led to lower SBS than with CoJet. Within LiSi group, after 90 days, the pretreatment using SiC resulted in lowest SBS values. After HF and MEP pretreatment, LEU showed lower initial SBS than LiSi. After 90 days of water storage, within specimens pretreated using CoJet or SiC showed LEU higher SBS than LiSi. Enamel presented higher or comparable SBS values to LEU and LiSi. With exception of MEP pretreatment, ARI 3 was predominantly observed, regardless the substrate, pretreatment, and aging level.
Conclusions
MEP pretreatment presented the lowest SBS values, regardless the silicate ceramic and aging level. Further research is necessary.
Clinical relevance
There is no need for intraoral application of HF for orthodontic treatment
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
Search for anomalous t t-bar production in the highly-boosted all-hadronic final state
A search is presented for a massive particle, generically referred to as a
Z', decaying into a t t-bar pair. The search focuses on Z' resonances that are
sufficiently massive to produce highly Lorentz-boosted top quarks, which yield
collimated decay products that are partially or fully merged into single jets.
The analysis uses new methods to analyze jet substructure, providing
suppression of the non-top multijet backgrounds. The analysis is based on a
data sample of proton-proton collisions at a center-of-mass energy of 7 TeV,
corresponding to an integrated luminosity of 5 inverse femtobarns. Upper limits
in the range of 1 pb are set on the product of the production cross section and
branching fraction for a topcolor Z' modeled for several widths, as well as for
a Randall--Sundrum Kaluza--Klein gluon. In addition, the results constrain any
enhancement in t t-bar production beyond expectations of the standard model for
t t-bar invariant masses larger than 1 TeV.Comment: Submitted to the Journal of High Energy Physics; this version
includes a minor typo correction that will be submitted as an erratu
Combined search for the quarks of a sequential fourth generation
Results are presented from a search for a fourth generation of quarks
produced singly or in pairs in a data set corresponding to an integrated
luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in
2011. A novel strategy has been developed for a combined search for quarks of
the up and down type in decay channels with at least one isolated muon or
electron. Limits on the mass of the fourth-generation quarks and the relevant
Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a
simple extension of the standard model with a sequential fourth generation of
fermions. The existence of mass-degenerate fourth-generation quarks with masses
below 685 GeV is excluded at 95% confidence level for minimal off-diagonal
mixing between the third- and the fourth-generation quarks. With a mass
difference of 25 GeV between the quark masses, the obtained limit on the masses
of the fourth-generation quarks shifts by about +/- 20 GeV. These results
significantly reduce the allowed parameter space for a fourth generation of
fermions.Comment: Replaced with published version. Added journal reference and DO
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