101 results match your criteria method 50n

Impact of multilevel facetectomy on segmental spinal flexibility in patients with thoracic adolescent idiopathic scoliosis.

Clin Biomech (Bristol, Avon) 2021 Mar 20;83:105296. Epub 2021 Feb 20.

Department of Orthopaedic Surgery, Hokkaido University Hospital, N14W5, Sapporo, Hokkaido 060-8648, Japan. Electronic address:

Background: The aim of this study was to intraoperatively assess the effects of multilevel facetectomy on segmental spinal flexibility in patients with thoracic adolescent idiopathic scoliosis.

Methods: Twenty patients who underwent posterior thoracic adolescent idiopathic scoliosis curve correction were evaluated. Compressive or distractive loaded force of 50N was applied on the handle of a compressor or distractor connected to the necks of pedicle screws inserted at T7 to T11. Read More

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Influence of contemporary CAD-CAM milling systems on the fit and adaptation of partially stabilized Zirconia fixed partial dentures.

Pak J Med Sci 2021 Jan-Feb;37(1):45-51

Tariq Abduljabbar Department of Prosthetic Dental Science, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia. Research Chair for Biological Research in Dental Health, King Saud University, Riyadh, Saudi Arabia.

Objective: To evaluate marginal fit and internal adaptation of three-unit Zr frameworks fabricated from four Zr CAD/CAM milling systems.

Methods: Fixed partial denture models were replicated (40 stone models) using Polyvinyl Siloxane impression material (PVS) and type IV stone for Zr framework fabrication. FPDs were milled with four CAD/CAM systems, Group-II: LAVAL Zirconia milled by LAVA , Group-2: Vita In-Ceram YZ milled by Cerec®, Group-3: Zirconia milled by GM1000 and Group-4: Zirconia milled by DWX-50N. Read More

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January 2021

Two-body wear and fracture behaviour of an experimental paediatric composite crown in comparison to zirconia and stainless steel crowns dependent on the cementation mode.

Dent Mater 2021 Feb 6;37(2):264-271. Epub 2020 Dec 6.

Department of Conservative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians University Munich, Germany.

Objectives: The purpose of this in vitro study was to assess the two-body wear and fracture behaviour of an experimental additive manufactured composite crown in comparison to zirconia and stainless steel crowns and its cementation protocol for primary molars.

Material And Methods: Three different paediatric crowns - experimental composite crowns (CCs, 3M), zirconia crowns (ZCs, NuSmile), and stainless steel crowns (SSCs, 3M)-were cemented with an experimental resin-modified glass ionomer cement (RMGIC, 3M) and two self-adhesive cements (SACs; RelyX Unicem Automix 2, 3M; BioCem, NuSmile). Seven groups, each with eight specimens, were thermally cycled (55 °C/50 °C) and dynamically loaded (50N/ 1. Read More

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February 2021

Ligamentous and Capsular restraints to Anterior Posterior and Superior Inferior laxity of the Acromioclavicular joint - a biomechanical study.

J Shoulder Elbow Surg 2020 Sep 30. Epub 2020 Sep 30.

Biomechanics Group, Department of Mechanical Engineering, Imperial College London, London SW7 2AZ, UK.

Background: Approximately 9% of shoulder girdle injuries involve the acromioclavicular joint (ACJ). There is no clear gold standard or consensus on surgical management of these injuries, in part perpetuated by our incomplete understanding of native ACJ biomechanics. We have therefore conducted a biomechanical study to assess the stabilizing structures of the ACJ in superior-inferior (SI) and anterior-posterior (AP) translation. Read More

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September 2020

Fatigue and wear behaviour of zirconia materials.

J Mech Behav Biomed Mater 2020 10 9;110:103970. Epub 2020 Jul 9.

DDS, Department of Prosthetic Dentistry, UKR University Hospital Regensburg, 93042, Regensburg, Germany.

Objectives: Comparison of in-vitro fatigue and wear performance of 3Y-, 4Y-, 5Y-TZP and lithiumdisilicate ceramic, multilayer/monolayer 4Y-TZP and variation of wall thickness at 5Y-TZP.

Method And Materials: Crowns (n = 96; 6 groups à 16) were made of 3Y-TZP-LA, 4Y-TZP (multilayer and monolayer), 5Y-TZP (0,5mm/1 mm wall thickness) and lithiumdisilicate. 8 per group were stored in water (24hrs), 8 underwent TCML (1. Read More

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October 2020

A pilot biomechanical study comparing a novel, intramedullary Nail/Plate construct to standard Dual-Plate fixation of intra-articular C2.3 distal humerus fractures.

Injury 2020 Oct 23;51(10):2148-2157. Epub 2020 Jun 23.

Department of Orthopaedic Surgery and Rehabilitation Medicine, State University of New York (SUNY) Downstate Medical Center, 450 Clarkson Ave, MSC 30, Brooklyn, NY 11203, USA. Electronic address:

Background: The gold-standard treatment for intra-articular distal humerus fractures (DHFs) is dual-plate/dual-column fixation, though optimal orientation is not yet established. With a superior method not yet identified, we propose a load-sharing construct, combining absolute stability (extramedullary plate fixation) for distal articular fragments and relative stability (load-sharing intramedullary nail) for the metaphyseal segment. The purpose of this pilot study was to evaluate the biomechanical performance of a novel implant compared to orthogonal dual-plating. Read More

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October 2020

Temporary materials: comparison of in vivo and in vitro performance.

Clin Oral Investig 2020 Nov 24;24(11):4061-4068. Epub 2020 Jun 24.

Department of Prosthetic Dentistry, Regensburg University Medical Center, D-93042, Regensburg, Germany.

Objective: The aim of this investigation was to compare clinical performance and in vitro wear of temporary CAD/CAM and cartridge crowns. This study is an approach to estimate the influence of in vivo use and laboratory simulation on temporary crowns.

Materials And Methods: A total of 90 crowns were fabricated from each temporary CAD/CAM or cartridge material. Read More

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November 2020

Evaluation of Film Thickness of Crown Disclosing Agents and Their Comparison with Cement Film Thickness after Final Cementation.

Eur J Dent 2020 Mar 13;14(2):224-232. Epub 2020 Apr 13.

Department of Conservative Dental Sciences and Endodontics, Qassim University College of Dentistry, Buraidah, Saudi Arabia.

Objective:  Verification of the accuracy of crown fit before final cementation is imperative. The aim of this study was to evaluate the film thickness of commonly used dental crown disclosing materials and their comparison with final cement thickness.

Materials: AND METHODS: One hundred fifty provisional crowns (Protemp) were fabricated on standardized resin dies and divided into five groups ( = 150; = 30) based on five disclosing agents: A = Fit-Checker auto-mix; B = Okklu-top; C = Express; D = Fit-Checker hand-mix; E = Coltene PSI, and Final cement = Relyx U200. Read More

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Extraction force and its determinants for minimally invasive vertical tooth extraction.

J Mech Behav Biomed Mater 2020 05 19;105:103711. Epub 2020 Feb 19.

Oral Health Translation Research, School of Dentistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada; Oral, Dental and Craniofacial Research, King's College London, Guy's Hospital, London, UK. Electronic address:

Background: Minimally invasive vertical extraction devices have been developed to minimise the need for flap surgery and trauma to alveolar bone during tooth extraction. The objective of this study was to measure the forces required for vertical tooth extraction and evaluate the determinants of these forces.

Methods: The investigators coupled a precision load cell with a Benex® extractor to record extraction forces for 59 consecutive routine extractions of tooth roots. Read More

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The early failure of the gamma nail and the dynamic hip screw in femurs with a wide medullary canal. A biomechanical study of intertrochanteric fractures.

Clin Biomech (Bristol, Avon) 2020 01 14;71:201-207. Epub 2019 Nov 14.

Department of Orthopedic Surgery, Medical University of Gdańsk, ul. Nowe Ogrody 1-6, 80-803 Gdańsk, Poland.

Background: Intertrochanteric fractures may occur in a bone with a wide medullary canal that may lead to significant mobility of a intramedullary nail, contrary to an extramedullary device. This study evaluates the Dynamic Hip Screw and the gamma nail in AO 31.A2. Read More

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January 2020

Analysis of stress distribution in ceramic and titanium implants in alveolar sockets of the anterior region of the maxilla.

J Clin Exp Dent 2019 Oct 1;11(10):e850-e857. Epub 2019 Oct 1.

Department of Dentistry, São Leopoldo Mandic Dental Research Center, rua Rua Marechal Floriano 600/1009, Centro, Governador Valadares/MG, Campinas - São Paulo -Brazil.

Background: In the routine of dentistry, knowing the biomechanical properties of implant systems and their inherent stress distribution under force loading is an essential step to predict structural damage and biological responses. This study aimed to investigate stress distribution in zirconia and titanium implants and their biomechanical response in alveolar sockets of the anterior region of the maxilla through tridimensional finite element analysis.

Material And Methods: From computed tomography scans of a reference patient, three models of the maxillary dental arch were designed with Rhinoceros 5. Read More

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October 2019

Influence of ultrasound-assisted sodium bicarbonate marination on the curing efficiency of chicken breast meat.

Ultrason Sonochem 2020 Jan 25;60:104808. Epub 2019 Sep 25.

Engineering Laboratory for Agro-products Processing, Anhui Agricultural University, Hefei 230036, China.

Effects of ultrasound combined with sodium bicarbonate assisted curing (USC), sodium bicarbonate assisted curing (SC) and traditional wetting curing (WC) on curing efficiency and tenderization of the chicken breast meat were investigated. Compared with SC and WC treatments, the highest marinade uptake and chloride content were observed in USC treatment (P < 0.05). Read More

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January 2020

Altered shoulder kinematics using a new model for multiple dislocations-induced Bankart lesions.

Clin Biomech (Bristol, Avon) 2019 Dec 28;70:131-136. Epub 2019 Aug 28.

Orthopaedic Robotic Laboratory, University of Pittsburgh, Pittsburgh, USA; Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, USA. Electronic address:

Background: Many active individuals undergo multiple dislocations during the course of a season before surgical treatment without considering the implications of each successive injury. Therefore, the purpose of this study was to develop a multiple dislocation model for the glenohumeral joint and evaluate the resulting changes in joint function.

Methods: Eight cadaveric shoulders were evaluated using a robotic testing system. Read More

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December 2019

Biomechanical comparison of different tendon suturing techniques for three-stranded all-inside anterior cruciate ligament grafts.

Orthop Traumatol Surg Res 2019 10 24;105(6):1101-1106. Epub 2019 Jul 24.

Department of Orthopaedic Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-Daero, Seocho-Gu, Seoul 06591, Republic of Korea. Electronic address:

Objective: In all-inside anterior cruciate ligament (ACL) reconstruction, it is usually difficult to obtain sufficient autologous semitendinosus tendon length for quadruple stranded graft in Asians, females, and those with short stature. The purpose of this study was to compare biomechanical properties of three different types of suture preparations for tripled graft and determine which method could achieve sufficient strength for ACL through in vitro study. The hypothesis of this study was that suturing with a rip-stop (RS) stitch for tripled-strand graft would lead to stronger mechanical properties than suturing with buried-knot four sutures. Read More

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October 2019

Fatigue resistance of ultrathin CAD/CAM ceramic and nanoceramic composite occlusal veneers.

Dent Mater 2019 10 25;35(10):1370-1377. Epub 2019 Jul 25.

Department of Conservative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-University Munich, Goethestr. 70, 80336 Munich, Germany.

Objective: The fracture resistance of different ultrathin occlusal computer-aided design/computer-aided manufacturing (CAD/CAM) veneers was investigated under cyclic mechanical loading to restore combined enamel-dentin defects.

Methods: Eighty-four molars were reduced occlusally until extensive dentin exposure occurred with a remaining enamel ring. Twenty-four molars were ground flat for examination of highly standardized specimens, of which 8 were treated with uniformly flat 0. Read More

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October 2019

Oral mucosa pressure caused by mandibular implant overdenture with different types of attachments.

J Prosthodont Res 2020 Apr 29;64(2):145-151. Epub 2019 Jun 29.

Department of Prosthodontics and Oral Implantology, School of Dentistry, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate 020-8505, Japan. Electronic address:

Purpose: To determine the appropriate attachment and design of a denture base for mandibular implant overdenture (IOD), the oral mucosa pressure caused by mandibular implant overdentures was measured using edentulous jaw models with various attachments.

Methods: An experimental edentulous mandibular model with a 1.5-mm thick artificial oral mucosa was used. Read More

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Influence of additional cement augmentation on endplate stability in circumferential stabilisation of osteoporotic spine fractures.

Clin Biomech (Bristol, Avon) 2019 08 11;68:163-168. Epub 2019 Jun 11.

Department for Trauma and Reconstructive Surgery, RWTH Aachen University Hospital, Pauwelsstraße 30, 52074 Aachen, Germany.

Background: Anterior stabilisation of osteoporotic spine fractures is uncommon but necessary in the case of complex vertebral body comminution. The purpose of this study was to investigate the effect of additional cement-augmentation on the endplate stability.

Methods: Twelve human cadaveric lumbar spines were divided in two groups: (A) posterior cement-augmented pedicle screw/rod-based instrumentation of L3 to L5, posterior decompression of L4/5 and partial corpectomy of L4 and (B) same experimental setup with additional cement-augmentation of the adjacent endplates. Read More

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Biomechanical performance of cranial implants with different thicknesses and material properties: A finite element study.

Comput Biol Med 2019 06 19;109:43-52. Epub 2019 Apr 19.

Department of Oral and Maxillofacial Surgery, Division for Regenerative Orofacial Medicine, University Hospital Hamburg-Eppendorf, Hamburg, Germany; Fraunhofer Research Institution for Additive Manufacturing Technologies IAPT, Hamburg, Germany.

This study investigated the effect of implant thickness and material on deformation and stress distribution within different components of cranial implant assemblies. Using the finite element method, two cranial implants, differing in size and shape, and thicknesses (1, 2, 3 and 4 mm, respectively), were simulated under three loading scenarios. The implant assembly model included the detailed geometries of the mini-plates and micro-screws and was simulated using a sub-modeling approach. Read More

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A Biomechanical Comparison of Six Suture Configurations for Soft Tissue-Based Graft Traction and Fixation.

Arthroscopy 2019 04 11;35(4):1163-1169. Epub 2019 Mar 11.

Rensselaer Polytechnic Institute, Troy, New York, U.S.A.

Purpose: The purpose of this study was to compare 6 different graft fixation techniques to determine the preparation speed, fixation security, biomechanical strength, and resultant tissue trauma.

Methods: Six different techniques (10 samples each): #2 OrthoCord Krackow stitch, #2 FiberWire Krackow stitch, SpeedTrap, WhipKnot, Loop-in-loop stitch were created in the distal 3 cm of 9 cm bovine flexor tendons. The proximal 3 cm tendon segment was clamped in a testing machine and the distal suture ends secured by pneumatic grips. Read More

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Cup-Shaped Tooth Wear Defects: More than Erosive Challenges?

Caries Res 2019 6;53(4):467-474. Epub 2019 Mar 6.

Department of Dentistry, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, The Netherlands.

Background/aim: The underlying mechanism of the development of cups and grooves on occlusal tooth surfaces is still unclear. The aim of this study was to evaluate factors contributing to in vitro cup formation, in order to elucidate the clinical process.

Methods: A total of 48 extracted human molar teeth were exposed to acidic aqueous solutions at pH of 4. Read More

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Ultrasound melted polymer sleeve for improved primary pedicle screw anchorage: A novel augmentation technique.

Clin Biomech (Bristol, Avon) 2019 03 14;63:16-20. Epub 2019 Feb 14.

Department of Trauma Surgery, Medical University of Innsbruck, Innsbruck, Austria. Electronic address:

Background: Cement augmentation of pedicle screws to prevent screw loosening is associated with significant complications, such as cement leakage or bone necrosis. Therefore, an alternative strategy to improve pedicle screw anchorage has been recently developed: Polymer reinforcement of pedicle screws uses an in situ melted polymer sleeve in order to enhance screw anchorage. This biomechanical study evaluated the effect of polymer-reinforcement by comparing polymer-reinforced pedicle screws to non-augmented as well as cement-augmented screws under cyclic loading. Read More

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Fracture Strength of Various Types of Large Direct Composite and Indirect Glass Ceramic Restorations.

Oper Dent 2019 Jul/Aug;44(4):433-442. Epub 2019 Jan 31.

Introduction: The objective of this study was to investigate the mechanical behavior of severely compromised endodontically treated molars restored by means of various types of composite buildups, full-contour lithium disilicate crowns (with or without post) or a lithium disilicate endocrown.

Methods And Materials: One hundred five sound molars were endodontically treated and randomly assigned to 1 control group (endodontic access cavity only) and 6 experimental groups (n=15): glass fiber reinforced composite (GFRC group), direct microhybrid composite (C group), direct microhybrid composite restoration with glass fiber post (CP group), composite buildup and full-contour lithium disilicate crown (LDS group), additional glass fiber post (P-LDS group), and endocrown (EC group). Molar crowns in the treatment groups were removed 1 mm above the cementoenamel junction and restored. Read More

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November 2019

Distal fibula osteotomies improve tibiotalar joint compression: A biomechanical study in a cadaveric model.

Clin Biomech (Bristol, Avon) 2019 02 9;62:23-27. Epub 2019 Jan 9.

Department of Orthopaedics and Rehabilitation, Penn State College of Medicine, Hershey Medical Center, 500 University Drive, Mail Code H089, Hershey, PA 17033, USA. Electronic address:

Background: Successful tibiotalar joint fusion relies on adequate compression. Compression following joint preparation may be affected by the extent to which the fibula holds the joint out to anatomical length. The purpose of this study was to evaluate the effect of various distal fibula osteotomies on tibiotalar joint compression. Read More

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February 2019

Finite element analysis of titanium alloy-graphene based mandible plate.

Comput Methods Biomech Biomed Engin 2019 Feb 9;22(3):324-330. Epub 2019 Jan 9.

b Medical Engineering Design Research Group , Nottingham Trent University , Nottingham , UK.

Titanium alloy based maxillofacial plates and implants are widely used in fracture treatment and reconstructions. Filler materials Graphene Nanoplatlets(GNPs) were used in a Titanium alloy maxillofacial plate and a Finite Element Model (FEM) was designed to reconstruct a fractured human mandible. Both 50N and 500N bite forces were applied on the mandible and stress distribution using Von mises failure theory across the plate sections was analyzed. Read More

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February 2019

Evaluation of Microleakage Between Different Post and Core Systems Under Gradual Loading: an Study.

Acta Stomatol Croat 2018 Sep;52(3):218-226

Prosthodontics Unit, School Of Dental Sciences, Universiti Sains Malaysia, Heath Campus, Kelantan, Malaysia.

Objective: This study aimed to compare the difference in marginal dye penetration between everStick, Parapost XP, Parapost fiber white and control groups under gradual loading.

Materials And Methods: Sixty-eight human maxillary permanent incisors were divided into four groups. Each specimen was endodontically treated with step-back technique and prepared for each post system according to experimental groups, subsequently cemented in the canal. Read More

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September 2018

Restrictive Transfusion Strategy Is More Effective in Massive Burns: Results of the TRIBE Multicenter Prospective Randomized Trial.

Mil Med 2019 03;184(Suppl 1):11-15

Department of Public Health Sciences, University of California Davis, Medical Sciences 1C, Room 104 University of California, Davis One Shields Avenue, Davis, CA.

Objectives: Studies suggest that a restrictive transfusion strategy is safe in burns, yet the efficacy of a restrictive transfusion policy in massive burn injury is uncertain. Our objective: compare outcomes between massive burn (≥60% total body surface area (TBSA) burn) and major (20-59% TBSA) burn using a restrictive or a liberal blood transfusion strategy.

Methods: Patients with burns ≥20% were block randomized by age and TBSA to a restrictive (transfuse hemoglobin <7 g/dL) or liberal (transfuse hemoglobin <10 g/dL) strategy throughout hospitalization. Read More

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Durability and Biological Response of a New Posterior Dynamic Stabilization System Using Polyethylene with Vitamin E.

Biomed Res Int 2018 25;2018:5785708. Epub 2018 Sep 25.

Department of Orthopaedic Surgery, Nihon University Itabashi Hospital, 30-1 Oyaguchikamimati Itabashi-ku, Tokyo 173-8610, Japan.

Objective: The purpose of this study was to evaluate the durability and biological response of a new Posterior Dynamic Stabilization system using polyethylene with vitamin E on the sliding surface.

Summary Of Background Data: The use of polyethylene with vitamin E on the sliding surface in Posterior Dynamic Stabilization has not been reported previously.

Methods: A developed pedicle screw-based Posterior Dynamic system consists of four parts: a set screw, a rod, a ball, and a pedicle screw. Read More

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January 2019

Contribution of minimally invasive bone augmentation to primary stabilization of the osteosynthesis of Schatzker type II tibial plateau fractures: Balloon vs bone tamp.

Clin Biomech (Bristol, Avon) 2018 11 11;59:27-33. Epub 2018 Aug 11.

Institut Pprime UPR 3346, CNRS - Université de Poitiers - ISAE-ENSMA, France; ABS Lab, Université de Poitiers, France.

Background: Schatzker type II tibial plateau fractures necessitate the least invasive treatment possible. Arthroscopic reduction by bone tamp followed by osteosynthesis is the current gold standard for this type of tibial plateau fracture. The objective of this study was to compare this technique to anterior approach tuberoplasty with balloon reduction. Read More

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November 2018

Reliability of wear measurements of CAD-CAM restorative materials after artificial aging in a mastication simulator.

J Mech Behav Biomed Mater 2018 10 25;86:185-190. Epub 2018 Jun 25.

Department of Prosthetic Dentistry, LMU München, Goethestraße 70, 80336 Munich, Germany. Electronic address:

Objectives: The purpose of this in vitro study was to assess the 2-body wear behavior of computer-aided design and computer-aided manufacturing (CAD-CAM) restorative materials and additionally to validate an automatic approach to wear quantification as provided by newly developed software.

Materials And Methods: Two composite resins (Experimental Composite, Shofu Block HC), 1 polymethyl methacrylate- (PMMA)-based material (Telio CAD), and 1 dual-network material (VITA Enamic) were tested (n = 12). The materials were stored in distilled water at 37 °C for 14 days, then aged in a mastication simulator (cycles: 400 000, 50 N, 1. Read More

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October 2018

FE analysis of conceptual hybrid composite endodontic post designs in anterior teeth.

Dent Mater 2018 Jul 24;34(7):1063-1071. Epub 2018 Apr 24.

School of Dentistry - University of Naples Federico II, Italy.

Objectives: To assess conceptual designs of dental posts consisting of polyetherimide (PEI) reinforced with carbon (C) and glass (G) glass fibers in endodontically treated anterior teeth.

Methods: 3D tessellated CAD and geometric models of endodontically treated anterior teeth were generated from Micro-CT scan images. Model C-G/PEI composite posts with different Young's moduli were analyzed by Finite Element (FE) methods post A (57. Read More

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