252 results match your criteria indentation statistically


Studies of the early stages of the dynamic setting process of chemically activated restorative glass-ionomer cements.

Biomater Investig Dent 2021 Apr 1;8(1):39-47. Epub 2021 Apr 1.

Department of Physics, State University of Maringa, Maringá, Brazil.

Objective: To evaluate the early stages of the setting process of chemically activated restorative glass-ionomer cements (GICs).

Material And Methods: Five GICs were evaluated ( = 5): Equia Forte (GC), Equia Forte HT (GC), Ketac Universal (3M ESPE), Maxxion R (FGM) and Riva Self Cure (SDI) by Thermography, Fourier Transform Infrared Attenuated Total Reflectance Spectroscopy (FTIR-ATR) and Gillmore needle indentation mechanical testing. The FTIR-ATR spectra showed the formation of metal carboxylates within the cements and enabled the stabilization time (ST) to be determined and the thermographic camera measured the temperature field images in the sample. Read More

View Article and Full-Text PDF

The effect of different confluence confirmation strategies on the obturation of Vertucci type II canal: micro-CT analysis.

Restor Dent Endod 2021 Feb 26;46(1):e12. Epub 2021 Jan 26.

Department of Conservative Dentistry, Wonkwang University Daejeon Dental Hospital, Daejeon, Korea.

Objectives: The present study aims to compare the obturation quality of 2 confluence confirmation techniques in artificial maxillary first premolars showing Vertucci type II root canal configuration.

Materials And Methods: Thirty artificial maxillary premolars having Vertucci type II root canal configuration were made. They were divided into 3 groups according to the confluence confirmation technique as follows. Read More

View Article and Full-Text PDF
February 2021

The Effect of Helium Ion Radiation on the Material Properties of Bone.

Calcif Tissue Int 2021 Jan 30. Epub 2021 Jan 30.

Department of Biomedical Engineering, The College of New Jersey, 2000 Pennington Road, Ewing, NJ, 08628, USA.

Ionizing radiation, from both space and radiation therapy, is known to affect bone health. While there have been studies investigating changes in bone density and microstructure from radiation exposure, the effects of radiation on material properties are unknown. The current study addresses this gap by assessing bone material property changes in rats exposed to helium-4 radiation through spherical micro-indentation. Read More

View Article and Full-Text PDF
January 2021

Macro-, Micro- and Nanomechanical Characterization of Crosslinked Polymers with Very Broad Range of Mechanical Properties.

Polymers (Basel) 2020 Dec 10;12(12). Epub 2020 Dec 10.

Anton Paar TriTec SA, Vernets 6, 2035 Corcelles, Switzerland.

This work is focused on the comparison of macro-, micro- and nanomechanical properties of a series of eleven highly homogeneous and chemically very similar polymer networks, consisting of diglycidyl ether of bisphenol A cured with diamine terminated polypropylene oxide. The main objective was to correlate the mechanical properties at multiple length scales, while using very well-defined polymeric materials. By means of synthesis parameters, the glass transition temperature () of the polymer networks was deliberately varied in a broad range and, as a result, the samples changed their mechanical behavior from very hard and stiff (elastic moduli 4 GPa), through semi-hard and ductile, to very soft and elastic (elastic moduli 0. Read More

View Article and Full-Text PDF
December 2020

Influence of Different Postpolymerization Strategies and Artificial Aging on Hardness of 3D-Printed Resin Materials: An In Vitro Study.

Int J Prosthodont 2020 Nov/Dec;33(6):634-640

Purpose: To investigate the influence of different postpolymerization strategies and artificial aging periods on the Martens hardness parameters of 3D-printed resin materials indicated for temporary use.

Materials And Methods: Disks made of four 3D-printed resin materials (n = 30 each) were additively manufactured and postpolymerized with three different postpolymerization devices (n = 10 specimens of each material per device). Disks cut from a prefabricated milling material served as a control. Read More

View Article and Full-Text PDF
December 2020

A Novel Magnetic Resonance Imaging-based Lumbar Muscle Grade to Predict Health-related Quality of Life Scores Among Patients Requiring Surgery.

Spine (Phila Pa 1976) 2021 Feb;46(4):259-267

Hospital for Special Surgery, New York, NY.

Study Design: Retrospective cross-sectional cohort.

Objective: The aim of this sudy was to determine whether muscle health measurements are associated with health-related quality of life scores (HRQOLs) for patients with lumbar spine pathology.

Summary Of Background Data: Poor muscle health has been implicated as a source of pain/dysfunction for patients with lumbar spine pathology. Read More

View Article and Full-Text PDF
February 2021

Comparison of mechanical properties of different reinforced glass-ceramics.

J Prosthet Dent 2020 Nov 6. Epub 2020 Nov 6.

Head of Dental Material Research, Department of Prosthetic Dentistry, University Hospital, LMU Munich, Munich, Germany.

Statement Of Problem: Data concerning the mechanical properties of the newly developed lithium disilicate ceramic HS10PC are lacking.

Purpose: The purpose of this in vitro study was to investigate the flexural strength (FS), Martens hardness (HM), indentation modulus (E), fracture load (FL), and wear resistance (WR) of HS10PC compared with those of the established glass-ceramics IPS e.max Press and IPS Empress Esthetic. Read More

View Article and Full-Text PDF
November 2020

Effect of home and in-office bleaching systems on the nanomechanical properties of tooth enamel.

Saudi Dent J 2020 Nov 6;32(7):343-348. Epub 2019 Nov 6.

Department of Restorative Dentistry, Riyadh Elm University, Riyadh, Saudi Arabia.

Objectives: The purpose of this in vitro laboratory study was to gauge the nanomechanical properties of the tooth enamel surface using home and in-office bleaching products.

Methods: Thirty-six extracted lower lateral incisor teeth (sound and without caries, cracks or restorations) were selected. A silicone mould was used to affix the samples in resin after cutting away the roots. Read More

View Article and Full-Text PDF
November 2020

Comparison of two ultra-widefield imaging for detecting peripheral retinal breaks requiring treatment.

Graefes Arch Clin Exp Ophthalmol 2020 Sep 24. Epub 2020 Sep 24.

Department of Vitreo-retinal Services, Aravind Eye Hospital and Post Graduate Institute of Ophthalmology, Madurai, Tamil Nadu, India.

Aim: To compare the sensitivity of Optomap Panoramic 200 and Clarus 500 in detecting peripheral retinal breaks that required treatment.

Methods: This prospective study enrolled consecutive patients undergoing laser for treatment-requiring peripheral retinal breaks from May 2019 to July 2019. The patients first underwent indirect ophthalmoscopy examination with scleral indentation by a retinal consultant and then ultra-widefield imaging by a single trained technician on Optomap 200 and Clarus 500 in all nine ocular gazes. Read More

View Article and Full-Text PDF
September 2020

Reduction of Intraocular Pressure Spikes Due to Intravitreal Bevacizumab Injections by Scleral Indentation with Cotton Swab or Digital Ocular Massage: Innovative Techniques Compared.

Clin Ophthalmol 2020 27;14:2533-2541. Epub 2020 Aug 27.

Eye Clinic, Department of Surgical Sciences, University of Turin, AOU Città della Salute e della Scienza, Turin, Italy.

Purpose: This study aims to evaluate the effectiveness of different decompressive injection techniques in reducing intraocular pressure (IOP) spikes, if compared to the injection without pressure applied on the eye, following the intravitreal injection of bevacizumab.

Patients And Methods: Two hundred patients with indication to intravitreal therapy were randomized into five arms: 40 received intravitreal injection without ocular decompression (arm A), 40 with pre-injection scleral indentation with cotton swab (arm B), 40 with pre-injection digital ocular massage (arm C), 40 with post-injection scleral indentation with cotton swab (arm D) and 40 with post-injection digital ocular massage (arm E). All patients underwent measurement of the IOP with Goldamm applanation tonometer 10 minutes before and 10 minutes after the injection. Read More

View Article and Full-Text PDF

In vitro study on the influence of postpolymerization and aging on the Martens parameters of 3D-printed occlusal devices.

J Prosthet Dent 2020 May 19. Epub 2020 May 19.

Professor, Department of Prosthetic Dentistry, University Hospital, LMU Munich, Munich, Germany.

Statement Of Problem: Additive manufacturing has been proposed for the fabrication of occlusal devices. However, information about the mechanical properties of additively manufactured devices is lacking.

Purpose: The purpose of this in vitro study was to evaluate the influence of the postpolymerization unit and artificial aging on the Martens hardness (HM) and indentation modulus (E) of different 3D-printed materials in comparison with a conventionally milled material. Read More

View Article and Full-Text PDF

Difference in biophysical properties of cancer-initiating cells in melanoma mutated zebrafish.

J Mech Behav Biomed Mater 2020 07 8;107:103746. Epub 2020 Apr 8.

Department of Mechanical Engineering, Tufts University, Medford, MA, USA; Department of Biomedical Engineering, Tufts University, Medford, MA, USA; Department of Physics, Tufts University, Medford, MA, USA. Electronic address:

Despite sharing oncogenetic mutations, only a small number of cells within a given tissue will undergo malignant transformation. Biochemical and physical factors responsible for this cancer-initiation process are not well understood. Here we study biophysical differences of pre-melanoma and melanoma cells in a BRAF/P53 zebrafish model. Read More

View Article and Full-Text PDF

Effect of Hygrothermal Treatment on the Porous Structure and Nanomechanics of Moso Bamboo.

Sci Rep 2020 04 16;10(1):6553. Epub 2020 Apr 16.

International Center for Bamboo and Rattan, Beijing, 100102, PR China.

Hygrothermal treatment is an environmentally friendly and efficient modification method. In this study, Moso bamboo was modified with hygrothermal treatments, and the results of nitrogen adsorption, X-ray diffraction (XRD), scanning electron microscopy (SEM) and nano indentation (NI) were then examined. Interestingly, the samples that underwent hygrothermal treatment at 180 °C and 117% RH (relative humidity) had the highest crystallinity (36. Read More

View Article and Full-Text PDF

Effect of build orientation on the manufacturing process and the properties of stereolithographic dental ceramics for crown frameworks.

J Prosthet Dent 2021 Mar 4;125(3):453-461. Epub 2020 Apr 4.

Professor, Department of Prosthodontics, Faculty of Dental Surgery, University of Lille, Lille, France.

Statement Of Problem: Stereolithography (SLA) ceramic crown frameworks are suitable for clinical use, but the impact of SLA build orientation has not been identified.

Purpose: The purpose of this in vitro study was to investigate the effect of 3 build orientations on the physical and mechanical properties and the microstructure of SLA alumina dental ceramics.

Material And Methods: The physical and mechanical properties and microstructures of 3 different oriented SLA alumina ceramics (ZX, ZY, and XY) were evaluated by visual observation, hydrostatic weighing (n=10/group), Weibull analyses (n=30/group), scanning electron microscopy, 3-point flexural strength (n=30/group), fracture toughness (indentation, single-edge-V-notched-beam) (n=4/group), and Vickers hardness (n=15/group) testing. Read More

View Article and Full-Text PDF

Residual polymerization stresses in human premolars generated with Class II composite restorations.

J Mech Behav Biomed Mater 2020 04 20;104:103643. Epub 2020 Jan 20.

Department of Operative Dentistry, Tsurumi University School of Dental Medicine, Yokohama, Kanagawa, Japan.

The objective of this study was to assess the influence of filling techniques on residual polymerization stresses in resin composite restorations of the tooth. Flat planes were ground in buccal enamel surfaces of extracted human premolars, followed by preparing Class II cavities. Indentation cracks were introduced in the planes and crack lengths were measured mesio-distally (x-direction) and cervico-incisally (y-direction). Read More

View Article and Full-Text PDF

Mechanical performance of monolithic materials cemented to a dentin-like substrate.

J Prosthet Dent 2020 May 20;123(5):753.e1-753.e7. Epub 2020 Feb 20.

Professor, Dental Prosthesis, Department of Dentistry, University of Taubate (UNITAU), Taubate, Brazil. Electronic address:

Statement Of Problem: Studies on the mechanical behavior of restorative materials bonded to tooth structure and considering the properties of the material and the bonding between both substrates are lacking.

Purpose: The purpose of this in vitro study was to evaluate the hardness, fracture toughness, load-to-failure, cyclic fatigue, and stress distribution of 4 computer-aided design and computer-aided manufacturing (CAD-CAM) materials when bonded to a substrate similar to dentin (G10).

Material And Methods: Disks (11×1. Read More

View Article and Full-Text PDF

Dimensional analysis of the bicipital groove and its associated pathology in a South African population.

J Orthop 2020 May-Jun;19:128-131. Epub 2019 Nov 18.

Department of Clinical Anatomy, School of Laboratory Medicine and Medical Sciences, University of KwaZulu Natal, Durban, South Africa.

The bicipital groove (BG) forms an indentation between the greater and lesser humeral tubercles and lodges the long head of biceps brachii tendon (LHBBT) along with the ascending branch of the circumflex humeral artery. This study aimed to determine the dimensions (length, width, depth) of the BG in a select South African population. The dimensions of the BG in one hundred and sixty (n = 160; Right: 80; Left: 80, Male: 100; Female: 60) unpaired dry bone humerii were measured with a digital caliper (Linear Tools 2012, 0-150 mm, LIN 86500963) and was analyzed using SPSS (V25). Read More

View Article and Full-Text PDF
November 2019

Magnetic resonance imaging of the quadriceps fat pad oedema pattern in relation to patellofemoral joint pathologies.

Pol J Radiol 2019 27;84:e375-e380. Epub 2019 Sep 27.

Haseki Research and Training Hospital, Turkey.

Purpose: Quadriceps fat pad is located posterior to the quadriceps tendon. Increased signal intensity of this fat pad is seen on routine knee magnetic resonance imaging (MRI) examinations, but the exact mechanism and related pathologies are not clear. In this study we aimed to evaluate the relationship between MRI signal intensity and morphological features of quadriceps fat pad, as well as various pathologies of the patellofemoral joint. Read More

View Article and Full-Text PDF
September 2019

Imaging Features and Clinical Decision Analysis of 110 Cases of Intrapulmonary Lymph Nodes.

Thorac Cardiovasc Surg 2020 10 26;68(7):652-658. Epub 2019 Dec 26.

Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.

Objective: Through the summary and analysis of large samples, the characteristic imaging manifestations of intrapulmonary lymph nodes (IPLNs) were quantified, and two corresponding rating tables were developed. These rating tables could be used to distinguish the IPLNs from primary lung cancer, so as to improve the diagnostic accuracy and help clinicians make correct judgments and decisions.

Methods: A total of 82 patients with 110 IPLNs and 35 patients with primary lung cancer lesions were collected from June 2017 to December 2018. Read More

View Article and Full-Text PDF
October 2020

Morphological changes of the dorsal contour of the corpus callosum during the first two years of life.

Pediatr Radiol 2020 04 16;50(4):543-549. Epub 2019 Dec 16.

Department of Radiology, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., CR 135, Portland, OR, 97239, USA.

Background: In the medicolegal literature, focal concavities or notching of the corpus callosum has been thought to be associated with fetal alcohol spectrum disorders. Recent work suggests corpus callosum notching is a dynamic and normal anatomical feature, although it has not yet been defined in early life or infancy.

Objective: Our purpose was to characterize the dorsal contour of the corpus callosum during the first 2 years of life by defining the prevalence, onset and trajectory of notching on midsagittal T1-weighted images. Read More

View Article and Full-Text PDF

Pop-in behavior and elastic-to-plastic transition of polycrystalline pure iron during sharp nanoindentation.

Authors:
Fabian Pöhl

Sci Rep 2019 Oct 25;9(1):15350. Epub 2019 Oct 25.

Ruhr-Universität Bochum, Chair of Materials Technology, Bochum, 44780, Germany.

This study analyzes the elastic-to-plastic transition during nanoindentation of polycrystalline iron. We conduct nanoindentation (Berkovich indenter) experiments and electron backscatter diffraction analysis to investigate the initiation of plasticity by the appearance of the pop-in phenomenon in the loading curves. Numerous load-displacement curves are statistically analyzed to identify the occurrence of pop-ins. Read More

View Article and Full-Text PDF
October 2019

Surface, Microstructural, and Mechanical Characterization of Prefabricated Pediatric Zirconia Crowns.

Materials (Basel) 2019 Oct 9;12(20). Epub 2019 Oct 9.

Clinic of Orthodontics and Pediatric Dentistry, Centrer of Dental Medicine, University of Zurich, 8032 Zurich, Switzerland.

The purpose of this study was to characterize the surface roughness, the microstructure, and mechanical properties of four prefabricated zirconia pediatric crowns. Ten prefabricated crowns from four different manufacturers (Cheng Crowns Zirconia), (EZCrowns), (NuSmile ZR), and (Zirconia Pediatric Crowns) were included in this study. The surface roughness parameters (Sa, Sq, Sz, Sc, and Sv) of all samples were studied by optical profilometry and then the microstructure was studied by Raman spectroscopy. Read More

View Article and Full-Text PDF
October 2019

Micromechanical heterogeneity of the rat pia-arachnoid complex.

Acta Biomater 2019 12 1;100:29-37. Epub 2019 Oct 1.

Department of Mechanical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030, USA; Translational and Molecular Imaging Institute (TMII), Mount Sinai Hospital, New York, NY 10029, USA. Electronic address: http://www.kurtlab.com.

To better understand the onset of damage occurring in the brain upon traumatic events, it is essential to analyze how external mechanical loads propagate through the skull and meninges and down to the brain cortex. However, despite their crucial role as structural dampers protecting the brain, the mechanical properties and dynamic behavior of the meningeal layers are still poorly understood. Here, we characterized the local mechanical heterogeneity of rat pia-arachnoid complex (PAC) at the microscale via atomic force microscopy (AFM) indentation experiments to understand how microstructural variations at the tissue level can differentially affect load propagation. Read More

View Article and Full-Text PDF
December 2019

The effect of different cooling procedures on mechanical properties of denture base materials measured by instrumented indentation testing.

J Prosthodont Res 2020 Jul 30;64(3):326-331. Epub 2019 Sep 30.

Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, Greece.

Purpose: To evaluate the different cooling procedures on the mechanical properties of five heat-cured polymethyl methacrylate (PMMA) denture materials.

Methods: 250 specimens were made equally from Meliodent (ME), Paladon 65 (PA), Probase Hot (PB), Stellon QC-20 (QC) and Vertex Rapid Simplified (VE) implementing five different cooling procedures (n=10/procedure): A) removal from water bath, bench-cooling (10min) and cooling under water (15min), B) remain in water bath till room temperature, C) removal from water bath and cooling in water for 15min, D) removal from water bath and bench cooling till room temperature and E) removal from water bath, bench cooling for 30min and cooling under water for 15min. The specimens were immersed in distilled water (15 days/37ºC) and then subjected to Instrumented Indentation Testing for Martens Hardness (HM), indentation modulus (E) and elastic index (η). Read More

View Article and Full-Text PDF

Factors affecting interpretation of tissue dielectric constant (TDC) in assessing breast cancer treatment related lymphedema (BCRL).

Lymphology 2019 ;52(2):92-102

College of Medical Sciences, Nova Southeastern University, Davie, Florida USA.

Tissue dielectric constant (TDC) measurements are increasingly used as quantitative adjunctive tools to detect and assess lymphedema. Various factors affect measured TDC values that may impact clinical interpretations. Our goal was to investigate possible impacts of: 1) anterior vs. Read More

View Article and Full-Text PDF

Mechanical properties and metallurgical features of new and ex vivo used Reciproc Blue and Reciproc.

Int Endod J 2020 Feb 27;53(2):250-264. Epub 2019 Sep 27.

Department of General Surgery and Surgical-Medical Specialties, University of Catania, Catania, Italy.

Aim: To compare the mechanical properties and metallurgic features of new and used Reciproc Blue and Reciproc instruments.

Methodology: A total of 120 R25 Reciproc Blue and R25 Reciproc instruments were used. The morphological, chemical, mechanical, thermal and phase composition characteristics of new and ex vivo used files were investigated by scanning electron microscopy (FEG-SEM) with energy dispersive X-ray spectroscopy (EDS), focused ion beam analysis (FIB), micro-Raman spectroscopy, FEG-SEM metallography, X-ray diffraction (XRD), differential scanning calorimetry (DSC) and indentation tests. Read More

View Article and Full-Text PDF
February 2020

Water-induced Effects on the Hardness and Modulus of Contemporary Sealants Derived from Instrumented Indentation Testing (IIT).

J Contemp Dent Pract 2019 Jun 1;20(6):653-656. Epub 2019 Jun 1.

Clinic of Orthodontics and Pediatric Dentistry, Center of Dental Medicine, University of Zurich, Zuirch, Switzerland, Phone: +41 446343210, e-mail:

Aim: To compare the mechanical properties of four different types of contemporary fissure sealants before and after water storage employing a modern instrumented indentation testing (IIT) method.

Materials And Methods: Four different types of materials used in everyday practice were deliberately selected. Fissurit (FIS) is a highly filled resin, Embrace (EMB) is a bisphenol A (BPA)-free unfilled resin, Helioseal (HEL) is an unfilled resin, and Riva Protect (RIV) is a glass-ionomer material. Read More

View Article and Full-Text PDF

Changes in Roughness and Mechanical Properties of Invisalign Appliances after One- and Two-Weeks Use.

Materials (Basel) 2019 Jul 28;12(15). Epub 2019 Jul 28.

Clinic of Orthodontics and Pediatric Dentistry, Center of Dental Medicine, University of Zurich, 8032 Zurich, Switzerland.

The aim of this study was to estimate the possible changes of surface roughness and the mechanical properties of Invisalign appliances over one- and two-week of service. Forty appliances with attachments were retrieved after the end of orthodontic treatment from different patients. Half of them had been used for one week (1W), and the rest for two weeks (2W). Read More

View Article and Full-Text PDF

Argon Laser Iridoplasty For Plateau Iris Syndrome: Long-Term Outcomes of 48 Eyes.

J Glaucoma 2019 09;28(9):767-771

Department of Ophthalmology, Saint Joseph Hospital.

Precis: Argon laser peripheral iridoplasty (ALPI) was performed on 48 eyes with plateau iris syndrome (PIS). Indentation gonioscopy was used to monitor the opening of the iridocorneal angle. Mean intraocular pressure (IOP) at 5 years decreased from 15. Read More

View Article and Full-Text PDF
September 2019

Clinical factors contributing to postoperative aqueous flare intensity after 27-gauge pars plana vitrectomy for the primary rhegmatogenous retinal detachment.

Jpn J Ophthalmol 2019 Jul 18;63(4):317-321. Epub 2019 May 18.

Department of Surgery-Related, Division of Ophthalmology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan.

Purpose: To investigate the perioperative clinical factors, which contribute to the postsurgical aqueous flare intensity (AFI) following 27-gauge pars plana vitrectomy (27GPPV) for primary rhegmatogenous retinal detachment (RRD).

Study Design: Retrospective clinical study.

Methods: We performed retrospective analyses of the medical records of 47 eyes of 47 patients with primary RRD who had undergone 27GPPV with a wide-angle viewing system. Read More

View Article and Full-Text PDF