Cutting Efficiency of Diamond Grinders on Composite and Zirconia.

This in vitro study was carried out to compare the cutting efficiency of diamond grinders on zirconia and resin-based composite materials. Grinders were employed with a special holder for the handpiece to apply a constant load (160 g) for resin-based composite (8 cuts, 40 s each) and zirconia materials (4 cuts, 5 min each; n = 10 for each material and grinder). To assess the efficiency of the grinders, weight measurements of the material were taken before and after the grinding process.

Pull-Off Behavior of Hand-Cast, Thermoformed, Milled, and 3D-Printed Splints.

Purpose: To investigate the insertion/pull-out performance of splints produced by hand casting, thermoforming, milling, and 3D printing.

Materials And Methods: A total of 120 identical mandibular splints (n = 8 specimens per group) were manufactured with hand casting, thermoforming, milling, and 3D printing. The splints were stored in water at 37°C for 10 days and then placed onto cobalt-chromium arches and fixed on one side.

Finite Element Analysis of Occlusal Interferences in Dental Prosthetics Caused by Occlusal Adjustment.

Purpose: To investigate the influence of occlusal interference using finite element analysis (FEA).

Materials And Methods: The FEA model designed for this study centered on an all-ceramic, bilayered, fixed partial denture (FPD) retained on the maxillary first premolar and first molar, with the second premolar replaced by a pontic. The surrounding structures-such as the neighboring teeth, antagonists, and periodontium-were modeled.

Microstructure, composition, and flexural strength of different layers within zirconia materials with strength gradient.

Objectives: The aim of this study was to compare composition, microstructure, and mechanical strength of current multilayer zirconia blanks.

Methods: Bar shaped specimens were made from several layers of multilayer zirconia blanks (Cercon ht ML, Dentsply Sirona, US; Katana Zirconia YML, Kuraray, J;SHOFU Disk ZR Lucent Supra, Shofu, J; priti multidisc ZrO Multi Translucent, Pritidenta, D; IPS e.max ZirCAD Prime, Ivoclar Vivadent, FL).

Survival dependence of 3D-printed temporary materials on the filler content.

Aim: The aim of the present study was the evaluation of the in vitro performance and fracture force of 3D-printed anterior implant-supported temporary partial dentures (TPDs) with different filler content.

Materials And Methods: Identical anterior resin-based TPDs (tooth sites 11 to 13; n = eight per material) were 3D printed from methacrylate resins with different filler content. A cartridge polymethyl methacrylate (PMMA) material was used as a reference.

Inadequate Reporting of Complications in Randomized Controlled Trials Cited as Supporting Evidence Underpinning AAOS CPG Recommendations for Hip and Knee Osteoarthritis: Application of the CONSORT Harms Checklist.

Background: Randomized controlled trials (RCTs) have been shown to influence clinical decision-making and health policy. Therefore, it is essential that trial outcomes-including harms-are completely reported.

Methods: We included all RCTs cited as supporting evidence for the American Academy of Orthopaedic Surgeons Surgical Management of Osteoarthritis of the Knee, Osteoarthritis of the Knee, and Osteoarthritis of theHip Clinical Practice Guideline recommendations.

In Vitro Mastication Simulation and Wear Test of Virgilite and Advanced Lithium Disilicate Ceramics.

Purpose: To compare wear behavior, durability during in vitro mastication simulation, and fracture force of an established and a novel lithium disilicate CAD/CAM material, as well as to examine the impact of cementation and reduced ceramic thickness on durability and fracture force.

Materials And Methods: Specimens (n = 8 per group) were prepared from lithium disilicate (LS; IPS e.max, Ivoclar Vivadent) and advanced lithium disilicate (ALD; Cerec Tessera, Dentsply Sirona).

Effects of storage and toothbrush simulation on color, gloss, and roughness of CAD/CAM, hand-cast, thermoforming, and 3D-printed splint materials.

Objectives: The aim was to investigate color, gloss, or roughness of splint materials after storage in liquids and toothbrush simulation.

Materials And Methods: A total of 58 × 8 (n = 10 per material and group) specimens were fabricated (hand-cast, thermoforming, CAD/CAM-milled, 3D-printed materials); stored in air, water, coffee, red wine, and cleaning tablets; and investigated after fabrication, 24 h, two-, and four-week storage or toothbrushing. Color values (L*, a*, b*; ISO 11664-4:2008; CM-3500d, Konica-Minolta), gloss (ISO 2813:2014), and roughness values were determined (3D laser-scanning-microscope, KJ 3D, Keyence) before and after simulation or storage.

Thermoanalytical Investigations on the Influence of Storage Time in Water of Resin-Based CAD/CAM Materials.

New resin-based composites and resin-infiltrated ceramics are used to fabricate computer-aided design (CAD) and computer-aided manufacturing (CAM)-based restorations, although little information is available on the long-term performance of these materials. The aim of this investigation was to determine the effects of storage time (24 h, 90 days, 180 days) on the thermophysical properties of resin-based CAD/CAM materials. Thermogravimetric Analysis (TGA), differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) were used in the study.

In vitro performance of CAD/CAM and conventional removable dentures.

Aim: Innovations in CAD/CAM technology and materials science offer new methodologies for removable prosthodontics. As clinical data are still rare, in vitro performance of both CAD/CAM and comparable conventional materials may help to estimate the clinical outcome.

Materials And Methods: Specimens (n = 8 per group) from teeth (CediTEC, SR VivodentCAD, Vitapan), base materials (V-Print dentbase, IvoBase CAD, Paladur), adhesives (CediTEC Primer/Adhesive, IvoBase CAD Bond), and a fully printed specimen (Try-In) were created.

The role of medical school prestige and location in neurosurgery residency placement: An analysis of data from 2016 to 2020.

Objective: There remains a gap in the literature analyzing how categorical variables may affect the highly competitive neurosurgery residency application process for MD Seniors in the United States. We aimed to improve understanding of the impact of medical school prestige and geographic location on candidacy for neurosurgery residency.

Methods: Schools were stratified into high and low prestige cohorts based on the U.

Investigating the mechanical and optical properties of novel Urethandimethacrylate (UDMA) and Urethanmethacrylate (UMA) based rapid prototyping materials.

Objective: This study is focused on testing experimental rapid prototyping materials for occlusal splints made from Urethandimethacrylate (UDMA) and Urethanmethacrylate (UMA).

Methods: Materials were mixed from UDMA and UMA in ratios of 1.0:0.

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

A Correction to this paper has been published: https://doi.org/10.1007/s00784-021-04067-4.

Long-term clinical performance and complications of zirconia-based tooth- and implant-supported fixed prosthodontic restorations: A summary of systematic reviews.

Objectives: To present an overview on systematic reviews on prosthodontic zirconia restorations and to discuss long-term complications as well as information on anatomical and functional changes to the masticatory system.

Data/sources: MEDLINE, EMBASE, Trip medical, and Cochrane Library databases were searched for systematic reviews up to February 2021. Bias was assessed and clinical survival and complications were analyzed.

Machine-driven simulation of removing luting agent remnants from implant surfaces: An investigator-independent assessment of cleaning protocols.

Introduction: To simulate removing luting agent remnants from crowns fixed onto implant-abutment analogs using a standardized machine-driven protocol including a scaler and air polishing or sonic.

Material And Methods: A motor-driven device was constructed that controlled the rotational speed of the specimens, machining distance, contact pressure, and working time. A standardized layer of cement (Provicol, VOCO; Cuxhaven, G; Ketac Cem, 3MEspe; Seefeld, G; or Rely X Unicem, 3MEspe, Seefeld, G) was placed onto the finishing line of the crowns luted onto titanium-abutment analogs.

Pilot in-vitro study on insertion/removal performance of hand-cast, milled and 3D printed splints.

Objectives: The aim of this in-vitro pilot study was to establish a splint testing method and compare insertion/removal performance of dental splints.

Materials And Methods: 56 identical lower jaw splints (n = 8 per group) were manufactured from 2x methacrylate (MA) hand-cast (reference material), deep-drawn Polyethyleneterephthalate, combined deep-draw MA hand-cast, 2x CAD/CAM-milled MA and 3D-printed MA systems. After 10 days water storage (37 °C), cyclic pull-off and insertion performance on a metal jaw was investigated.

Multilayer zirconia: Influence of positioning within blank and sintering conditions on the in vitro performance of 3-unit fixed partial dentures.

Statement Of Problem: Multilayer zirconia blanks comprise material layers with different optical and mechanical properties. Whether positioning within the blank, as well as variation in the sintering procedure, will lead to restorations with different properties is unclear.

Purpose: The purpose of this in vitro study was to test the influence of sintering procedures and positioning in a multilayer blank on the in vitro performance of 3-unit zirconia fixed partial dentures.

In vitro performance and fracture resistance of interim conventional or CAD-CAM implant-supported screw- or cement-retained anterior fixed partial dentures.

Statement Of Problem: Interim restorations represent an essential clinical treatment step; however, limited information is available concerning the performance of computer-aided design and computer-aided manufacturing (CAD-CAM) interim materials.

Purpose: The purpose of this in vitro study was to evaluate the performance and fracture load of resin anterior implant-supported interim fixed partial dentures (IFPDs).

Material And Methods: Identical anterior resin IFPDs (maxillary central incisor to canine; n=16 per material) were milled from polymethylmethacrylate (PMMA) or di-methacrylate (DMA) systems with different filler content.

Fatigue and wear behaviour of zirconia materials.

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.

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

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.

Laboratory performance and fracture resistance of CAD/CAM implant-supported tooth-coloured anterior FDPs.

Objectives: This study investigated the in-vitro performance and fracture force of anterior implant-supported tooth-coloured fixed dental prosthesis (FDPs). Different material types with varying flexural strength and modulus of elasticity were compared with screw-retained or bonded application.

Materials And Methods: Identical anterior FDPs (tooth 11-13; n = 80) from materials (flexural strength 240-1150 MPa, modulus 7.

Fracture force of CAD/CAM resin composite crowns after in vitro aging.

Objectives: The aim of this in vitro study was to investigate the influence of material, preparation, and pre-treatment on the aging and fracture force of CAD/CAM resin composite molar crowns.

Materials And Methods: CAD/CAM molar crowns (n = 80) were milled from four resin composites (Block HC, Shofu; Lava Ultimate, 3 M; Grandio Blocs, Voco; and Tetric CAD, Ivoclar Vivadent, with/without sandblasting). Extracted human teeth were prepared with optimal preparation (height 6-8 mm, angle 6-8°) or worst-case preparation (height 3.

Roughness, surface energy, and superficial damages of CAD/CAM materials after surface treatment.

Objectives: The aim of this study was to examine the effects of surface pre-treatment on CAD/CAM materials including ceramics, zirconia, resin-infiltrated ceramic, and resin-based composite.

Materials And Methods: Specimens were made of ten CAD/CAM materials (Celtra Duo, Degudent, D; Vita Suprinity, Vita, D; E.max CAD, Ivoclar-Vivadent, FL; E.

Local variance for multi-scale analysis in geomorphometry.

Increasing availability of high resolution Digital Elevation Models (DEMs) is leading to a paradigm shift regarding scale issues in geomorphometry, prompting new solutions to cope with multi-scale analysis and detection of characteristic scales. We tested the suitability of the local variance (LV) method, originally developed for image analysis, for multi-scale analysis in geomorphometry. The method consists of: 1) up-scaling land-surface parameters derived from a DEM; 2) calculating LV as the average standard deviation (SD) within a 3 × 3 moving window for each scale level; 3) calculating the rate of change of LV (ROC-LV) from one level to another, and 4) plotting values so obtained against scale levels.