52,661 results match your criteria crown


Esthetic Outcomes of Implant-Supported Single Crowns Related to Abutment Type and Material: A Systematic Review.

Int J Prosthodont 2021 Mar-Apr;34(2):229-249

Purpose: To systematically review the influence of abutment material and configuration on the soft tissue esthetic outcomes of implant-supported single crowns (iSCs) after 3 years.

Materials And Methods: An electronic search on MEDLINE (PubMed) from January 2000 to July 2019 was conducted for clinical trials with no language restrictions. The focus question was: In partially edentulous patients with iSCs, does the abutment material (metal vs ceramic) or the configuration (standardized vs customized) have an effect on the soft tissue esthetic outcomes? Randomized controlled trials, controlled clinical trials, and prospective or retrospective case series with at least 10 patients and a minimum of 3 years of follow-up were included. Read More

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Medium- and Long-Term Survival Rates of Implant-Supported Single and Partial Restorations at a Maximum Follow-up of 12 Years: A Retrospective Study.

Int J Prosthodont 2021 Mar-Apr;34(2):183-191

Purpose: To present medium- and long-term biologic outcomes of implant-supported single-tooth restorations and fixed partial dentures and to analyze their correlations with prosthesis and patient characteristics.

Materials And Methods: The records of patients treated with implant-supported fixed restorations between 2004 and 2019 reporting the presence or absence of peri-implantitis and/or implant failure were analyzed. The cumulative survival rate (%) over time was calculated, as well as the cumulative prevalence of units free of peri-implantitis. Read More

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Translucent Zirconium Dioxide and Lithium Disilicate: A 3-Year Follow-up of a Prospective, Practice-Based Randomized Controlled Trial on Posterior Monolithic Crowns.

Int J Prosthodont 2021 Mar-Apr;34(2):163-172

Purpose: To systematically evaluate and compare the clinical performance of lithium disilicate (LDS)- and zirconium dioxide (ZrO)-based ceramic monolithic crowns in the posterior dentition.

Materials And Methods: Treatment was administered by two experienced general dental practitioners in two public dental health care clinics. Forty-four patients received 60 crowns randomized to be either LDS or ZrO and cemented with resin cement. Read More

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The Influence of Dentin Wall Thickness and Adhesive Surface in Post and Core Crown and Endocrown Restorations on Central and Lateral Incisors.

Oper Dent 2021 Jan;46(1):75-86

Clinical Relevance: Post and core crowns and endocrowns perform similarly on fracture strength, but endocrowns have more repairable fractures.

Summary: Read More

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January 2021

Chemical processes involving 18-crown-6-ether in activated noncovalent complexes with protonated peptides.

Chemphyschem 2021 Apr 21. Epub 2021 Apr 21.

CIMAP: Centre de recherche sur les ions les materiaux et la photonique, UMR 6252 CEA/CNRS/Unicaen/Ensicaen, GANIL, Bd Becquerel, 14070, CAEN, FRANCE.

These last decades, it has been widely assumed that 18-crown-6-ether (CE) plays a spectator role during the chemical processes occurring in isolated host-guest complexes between peptides or proteins and CE, after activation in mass spectrometers. Our present experimental and theoretical results challenge this hypothesis by showing that CE can abstract a proton or a protonated molecule from protonated peptides after activation by collisions in argon or electron capture/transfer. Furthermore, thanks to comparison between experimental and calculated values of collision cross-sections, we demonstrate that CE can change binding site after electron transfer. Read More

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Sine Qua Non: Dentigerous Cyst.

Head Neck Pathol 2021 Apr 21. Epub 2021 Apr 21.

Department of Pathology, Naval Medical Center San Diego, 34800 Bob Wilson Drive, San Diego, CA, 92134-5000, USA.

Dentigerous cysts, also known as follicular cysts, are among the most common developmental cysts of the gnathic bones. The majority of cases are clinically asymptomatic and discovered incidentally on panographic radiographs during routine dental care. The cyst appears as a radiolucency, classically unilocular, associated with the crown of an unerupted or impacted tooth. Read More

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Multi-stimuli-responsive aggregation of nanoparticles driven by the manipulation of colloidal stability.

Nanoscale 2021 Apr 21. Epub 2021 Apr 21.

Department of Chemistry, University of Liverpool, Crown Street, Liverpool, UK.

The capacity to control the dispersed or aggregated state of colloidal particles is particularly attractive for facilitating a diverse range of smart applications. For this reason, stimuli-responsive nanoparticles have garnered much attention in recent years. Colloidal systems that exhibit multi-stimuli-responsive behaviour are particularly interesting materials due to the greater spatial and temporal control they display in terms of dispersion/aggregation status; such behaviour can be exploited for implant formation, easy separation of a previously dispersed material or for the blocking of unwanted pores. Read More

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One year clinical success of pulpectomy in primary molars with iodoform-calcium hydroxide paste.

Quintessence Int 2021 Apr 21;0(0). Epub 2021 Apr 21.

Objectives: In order to retain primary molars, eg with irreversible pulpitis or pulp necrosis, pulpectomy can be an alternative to extraction. However, reports on the success of pulpectomies in primary teeth vary widely in the literature. Thus, the objective of this study was not only to analyze the success rate of primary tooth pulpectomy 12 months posttreatment in the setting of a specialized clinic, but also to identify and analyze various factors that modify the outcome. Read More

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[Evaluation of fracture strength of two kinds of zirconia all-ceramic crowns with different edge compensation angles].

Beijing Da Xue Xue Bao Yi Xue Ban 2021 Mar;53(2):402-405

Center for Digital Dentistry, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China.

Objective: To evaluate the effects of different edge compensation angles on the fracture strength of multilayer zirconia all-ceramic crowns and traditional uniform zirconia all-ceramic crowns.

Methods: The resin tooth preparation specimen of the mandibular first molar with a knife-edge was fabricated. A 3D digital model of the specimen was obtained by scanning it with a 3D dental model scanner. Read More

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[Clinical analysis of children and adolescents emergency dental trauma cases].

Beijing Da Xue Xue Bao Yi Xue Ban 2021 Mar;53(2):384-389

Department of Oral Emergency, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China.

Objective: To analyze the etiological and clinical characteristics of oral emergency patients under 18 years with dental trauma, and to provide guidance on the prevention and treatment in children and adolescents.

Methods: A retrospective study on the intact data of the dental trauma patients under 18 years from January 2016 to December 2018 in the Department of Oral Emergency in Peking University School of Stomatology was conducted, and the distribution of the patients' gender, age and visiting time, as well as the number and position of traumatic teeth, diagnostic classification, and multiple injury with dental trauma were analyzed.

Results: During the period, 54. Read More

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Fenestration of the cavernous internal carotid artery associated with a persistent primitive trigeminal artery.

Interv Neuroradiol 2021 Apr 20:15910199211012261. Epub 2021 Apr 20.

Department of Neurosurgery, Kokura Memorial Hospital, Kitakyushu, Japan.

Fenestration of the cavernous segment of the internal carotid artery (ICA) is an extremely rare variant with unknown clinical significance. We present two cases of this variant, both of which were associated with a persistent primitive trigeminal artery (PPTA). Large dual channels of the ICA were seen extending from the part immediately distal to the origin of the PPTA to the C3 segment of the ICA. Read More

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The adaptation and investigation of cone-beam CT reconstruction algorithms for horizontal rotation fixed-gantry scans of rabbits.

Phys Med Biol 2021 Apr 20. Epub 2021 Apr 20.

ACRF Image X Institute, The University of Sydney, Sydney, New South Wales, AUSTRALIA.

Fixed-gantry radiation therapy has been proposed as a low-cost alternative to the conventional rotating-gantry radiation therapy, that may help meet the rising global treatment demand. Fixed-gantry systems require gravitational motion compensated reconstruction algorithms to produce cone-beam CT (CBCT) images of sufficient quality for image guidance. The aim of this work was to adapt and investigate five CBCT reconstruction algorithms for fixed-gantry cone-beam CT images. Read More

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Nanosecond pulsed fiber laser irradiation for enhanced zirconia crown adhesion: Morphological, chemical, thermal and mechanical analysis.

J Photochem Photobiol B 2021 Apr 15;219:112189. Epub 2021 Apr 15.

CNR-IMEM Institute, Parco delle Scienze 37a, I-43100 Parma, Italy.

The increasing demand for aesthetics, together with advancements in technology, have contributed to the rise in popularity of all-ceramic restorations. In the last two decades, the continuous progression in ceramic materials science for dental applications has permitted the fabrication of high-strength materials. Amongst these, zirconia-based ceramics have improved in terms of fracture resistance and long-term viability in comparison with other silica-based materials. Read More

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Thyroid immune-related adverse events following immune checkpoint inhibitor treatment.

J Clin Endocrinol Metab 2021 Apr 20. Epub 2021 Apr 20.

Faculty of Medicine and Health, The University of Sydney, Sydney, Australia.

Background: Thyroid dysfunction occurs commonly following immune checkpoint inhibition. The etiology of thyroid immune-related adverse events (irAEs) remains unclear and clinical presentation can be variable. This study sought to define thyroid irAEs following immune checkpoint inhibitor (ICI) treatment and describe their clinical and biochemical associations. Read More

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Quasilinear 3d-metal(i) complexes [KM(N(Dipp)SiR)] (M = Cr-Co) - structural diversity, solution state behaviour and reactivity.

Dalton Trans 2021 Apr 22;50(14):4890-4903. Epub 2021 Mar 22.

Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Straße 4, D-35032 Marburg, Germany.

The synthesis and characterization of neutral quasilinear 3d-metal(i) complexes of chromium to cobalt of the type [KM(N(Dipp)SiMe)] (Dipp = 2,6-di-iso-propylphenyl) are reported. In solid state these metal(i) complexes either occur as isolated molecules (Co) or are part of a potassium ion linked 1D-coordination polymer (Cr-Fe). In solution the potassium cation is either ligated within the ligand sphere of the metal silylamide or is separated from the complex depending on the solvent. Read More

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Palpable Adenopathy Does Not Indicate High-Volume Axillary Nodal Disease in Hormone Receptor-Positive Breast Cancer.

Ann Surg Oncol 2021 Apr 19. Epub 2021 Apr 19.

Breast Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA.

Background: Axillary metastases in the form of palpable adenopathy indicate the need for neoadjuvant chemotherapy or axillary lymph node dissection (ALND). Patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) disease infrequently have nodal pathologic complete response to neoadjuvant chemotherapy and often require ALND. Sentinel lymph node biopsy is an accepted treatment for patients with two or fewer non-palpable nodal metastases who are undergoing breast conservation. Read More

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ASO Author Reflections: Rethinking Palpable Adenopathy as a Marker of High-Volume Axillary Nodal Disease in Hormone Receptor-Positive Breast Cancer.

Ann Surg Oncol 2021 Apr 19. Epub 2021 Apr 19.

Breast Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA.

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Evaluation of automated pipelines for tree and plot metric estimation from TLS data in tropical forest areas.

Ann Bot 2021 Apr 20. Epub 2021 Apr 20.

AMAP, Univ. Montpellier, IRD, CNRS, CIRAD, INRAE, Montpellier, France.

Background And Aims: Terrestrial LiDAR scanning (TLS) data are of great interest in forest ecology and management because they provide detailed 3D information on tree structure. Automated pipelines are increasingly used to process TLS data and extract various tree- and plot-level metrics. With these developments comes the risk of unknown reliability due to an absence of systematic output control. Read More

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Dynamics of coordination of HO and NH in crown ether cavities.

Phys Chem Chem Phys 2021 Apr 26;23(14):8633-8640. Epub 2021 Mar 26.

LCPM Laboratory, Faculty of Sciences, Chemistry Department, University of Oran 1, Ahmed BenBella, Oran, Algeria.

Crown ethers stand out for their ability to form inclusion complexes with metal cations and positively charged molecular moieties. Hydronium and ammonium interact strongly with crown ethers and potentially modulate their ionophoric activity in protic solvents and physiological environments commonly involved in (bio)technological applications. In this work, Born-Oppenheimer molecular dynamics (BOMD) computations are employed to gain insights into the coordination arrangements of HO and NH in the complexes with the native crown ethers 15-crown-5 (15c5) and 18-crown-6 (18c6). Read More

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Comparative evaluation of displacement and stress distribution pattern during maxillary arch distalization with Infra Zygomatic Screw- A three dimensional finite element study.

Int Orthod 2021 Apr 16. Epub 2021 Apr 16.

Department of Orthodontics and Dentofacial Orthopaedics, Teerthanker Mahaveer Dental College, Moradabad, Uttar Pradesh, India.

Objective: This study aimed to evaluate and compare the distribution of stress and displacement of teeth during maxillary arch distalization with IZC (Infra zygomatic crest) screw with two maxillary positions and different lever arm heights.

Settings And Design: Six three-dimensional finite element models of the maxillary arch were constructed with third molars extracted. Models 1, 2 and 3: IZC 6 (mesial to mesiobuccal root of first molar, 6) with 0mm, 4mm and 8mm lever arm height; Models 4, 5 and 6: IZC 7 (mesial to mesiobuccal root of second molar, 7) with 0mm, 4mm and 8mm, respectively. Read More

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Wear resistance of crowns made from different CAM/CAD materials.

Dent Mater 2021 Apr 16. Epub 2021 Apr 16.

Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University at Kiel, Germany. Electronic address:

Objectives: The aim of this laboratory study was to evaluate the wear resistance of crowns made from current computer-aided design and computer-aided manufacture (CAD/CAM) materials. In addition, the abrasion of the steatite antagonist against these materials was compared.

Methods: Identically shaped crowns of lithium disilicate, zirconia-reinforced lithium disilicate and a polymer-infiltrated ceramic network (PICN) were fabricated with an occlusal thickness of 1. Read More

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Mechanical behavior of nano-hybrid composite in comparison to lithium disilicate as posterior cement-retained implant-supported crowns restoring different abutments.

Dent Mater 2021 Apr 16. Epub 2021 Apr 16.

Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University at Kiel, Germany. Electronic address:

Objective: Resin-based materials are gaining popularity in implant dentistry due to their shock absorption capacity. Therefore, the aim of this study was to evaluate the fracture strength and failure mode of resilient materials for both crowns and abutments and compare them to the most widely used materials in different combinations after subjection to long-term fatigue loading.

Methods: Forty-eight cement-retained implant-restorations were assembled on titanium implants. Read More

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Outcomes of Calcium Hydroxide with Iodoform Pulpectomies in Primary Teeth.

J Dent Child (Chic) 2021 Jan;88(1):46-51

Dr. Moskovitz is a clinical associate professor, Department of Pediatric Dentistry, Hebrew University - Hadassah School of Dental Medicine, Jerusalem, Israel;, Email:

To assess retrospectively the success rate of calcium hydroxide with iodoform as a filling material in pulpectomies of primary molars with irreversible pulpitis or pulp necrosis, and to evaluate factors that affect outcomes.
This study consisted of records of 73 patients with primary molars treated with pulpectomy with high quality radiographs. Treatment was considered successful clinically if the tooth was not extracted and radiographs showed a decrease or no change in preexisting pathologic radiolucent defects. Read More

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January 2021

[Influence of morphological parameters of natural teeth and fixed partial dentures supported by dental implants on the time of occlusion].

Stomatologiia (Mosk) 2021 ;100(2):60-63

Central Research Institute of Dentistry and Maxillofacial Surgery - Ministry of Health of Russia, Moscow, Russia.

Objective: To study the effect of morphological parameters of natural teeth and fixed partial dentures supported by dental implants on the time of occlusion.

Material And Methods: The study of the morphological parameters of the first right upper and lower molars of natural teeth and fixed partial dentures supported by dental implants in the positions of the first molars of the upper and lower jaws, followed by determination of the relationship between the obtained data and the occlusion time using mathematical and statistical analysis.

Results: The study of the morphology of the occlusal surface of natural teeth and fixed partial dentures supported by dental implants did not reveal significant differences in the results of measuring the distances between the cusps of the upper and lower first molars, both natural teeth and fixed partial dentures supported by dental implants. Read More

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Modelling of early infection of cereal roots by the take-all fungus: a detailed mechanistic simulator.

New Phytol 1994 Nov;128(3):515-537

National Institute of Agricultural Botany, Huntingdon Road, Cambridge, CB3 OLE, U.K.

A stochastic model is constructed to simulate the spatial and temporal spread of infection of the take-all fungus, Gaeumannomyces graminis var. tritici (Sacc.) Arx & Olivier var. Read More

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November 1994

Annual carbon balance and nitrogen-use efficiency in tropical C and CAM epiphytes.

New Phytol 1994 Mar;126(3):481-492

Smithsonian Tropical Research Institute, P.O. Box 2072, Balboa, Republic of Panama.

Over the course of 12 months, diel (24 h) measurements of gas exchange were performed on leaves of three epiphytic species growing in the crown of a kapok tree on Barro Colorado Island, Panama: a drought-deciduous orchid with the C , pathway (Catasetum viridiflavum Hook.), an evergreen C fern (Polypodium crassifolium L.), and an evergreen epiphyte with an intermediate C -C -CAM pathway of photosynthesis (Clusia uvitana Pitt. Read More

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A one-year study on carbon, water and nutrient relationships in a tropical C -CAM hemi-epiphyte, Clusia uvitana Pittier.

New Phytol 1994 May;127(1):45-60

Smithsonian Tropical Research Institute, P.O. Box 2072, Balboa, Republic of Panama.

Diel (24 h) courses of CO and water-vapour exchange of leaves of hemi-epiphytic plants of Clusia uvitana Pittier (Clusiaceae) were measured under natural tropical conditions in the semi-evergreen moist forest of Barro Colorado Island, Panama, from January 1991 until January 1992. Plants were studied at two sites, in the crown of a 47-m tall tree (Ceiba pentandra) and on the shore of Lake Gatun, at a height of about 2-4 m. The following results were obtained: (1) Diel carbon gain was mainly a function of photosynthetic photon fluence rate (PPFR) on individual days. Read More

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Ectomycorrhizal formation by micropropagated clones of Eucalyptus marginata inoculated with isolates of Pisolithus tinctorius.

New Phytol 1989 Feb;111(2):209-214

School of Environmental and Life Sciences, Murdoch University, Murdoch, Western Australia 6150.

Eucalyptus marginata Donn ex Sm. and Pisolithus tinctorius (Pers.) Cok and Couch were co-cultured to obtain ectomycorrhizal formation in vitro. Read More

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February 1989

The clones of common lime (Tilia×vulgaris Hayne) planted in England during the seventeenth and eighteenth centuries.

Authors:
Donald Pigott

New Phytol 1992 Jul;121(3):487-493

University Botanic Garden, Cory Lodge, Bateman Street, Cambridge CB2 1JF, UK.

Most avenues of limes planted in England and Wales during the late seventeenth and early eighteenth century contain two distinct clonal types of common lime (Tilia×vulgaris Hayne). They differ in many morphological characters. Clonal group A has a fluted trunk with epicormic bosses or sprouts, a conical crown, scarlet, shining, ellipsoid overwintering buds, bright green leaves with obliquely asymmetric bases, long bracts narrowed to both ends and inflorescences normally of seven flowers. Read More

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Patterns of size and fate relationships of contiguous organs in the apple (Malus domestica) crown.

New Phytol 2004 Sep;163(3):533-546

Université Montpellier 3, UFR IV, Département de Mathématiques & Informatique Appliqués, Route de Mende, 34199 Montpellier Cedex 5, France.

•  In apple (Malus domestica), the size of a shoot and the vegetative or reproductive fate of the terminal bud on that shoot are considered to be related phenomena but with contrasted results depending on studies. Our hypothesis was that these relationships would be partly cultivar-dependent. •  Over a 3-yr period, the size relationships between shoots and fruit on two architecturally contrasted apple cultivars were assessed. Read More

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September 2004