Fatigue lifetime of reduced-diameter implants placed in different bone models.

Objectives: This study assessed the fatigue lifetime of reduced-diameter implants placed in either bovine rib or polymer-based bone model.

Methods: Bovine ribs were classified according to the criteria proposed by Lekholm and Zarb and were analyzed for bone fraction. Fourteen dental implants (3.

Influence of connection design and material properties on stress distribution and fatigue lifetime of zygomatic implants: A finite element analysis.

Zygomatic implants (ZIs) were developed as a graftless alternative to rehabilitate severely reabsorbed maxillae. This study aims to employ three-dimensional finite element analysis (FEA) to simulate the impact of external hexagonal implant connection (EHC) and internal hexagonal implant connection (IHC) on the stress distribution and fatigue lifetime within the ZI systems using parameters defined in ISO 14801:2016. Two ZI assemblies (Nobel Biocare and Noris Medical) were scanned in a micro-CT scanner and reconstructed using Nrecon software.

Determination of elastic moduli of polymeric materials using microhardness indentation.

Young's modulus of elasticity (or stiffness, E) is an important material property for many applications of polymers and polymer-matrix composites. The common methods of measuring E are by measuring the velocity of ultrasonic pulses through the material or by resistance to flexure, but it is difficult for ultrasound to penetrate polymers that contain filler particles, and flexural measurements require large specimens that may not mimic the clinical case. Thus, it may be difficult to determine E using conventional techniques.

Are we approaching the development of a novel calcium phosphate-based bioceramic dental material?

Objectives: Develop a sustainable bovine hydroxyapatite dental ceramic with the addition of titanium dioxide (TiO) nanoparticles (5 % and 8 % by weight), analyzing the outcome of this addition to the microstructure, as well as its mechanical and chemical properties, in order to evaluate whether they satisfy the International Organization for Standardization (ISO) 6872:2015 for dental ceramics or not.

Methods: Disks were obtained through uniaxial followed by isostatic pressing from bovine hydroxyapatite powder and TiO nanoparticles and sintered at 1300ºC for 2 h. Three experimental groups were developed (HA, HA+5 %TiO and HA+8 %TiO) and subjected to X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), indentation fracture (IF), biaxial flexural strength (BFS) and chemical solubility test.

Silver-Doped Titanium Oxide Layers for Improved Photocatalytic Activity and Antibacterial Properties of Titanium Implants.

Titanium has a long history of clinical use, but the naturally forming oxide is not ideal for bacterial resistance. Anodization processes can modify the crystallinity, surface topography, and surface chemistry of titanium oxides. Anatase, rutile, and mixed phase oxides are known to exhibit photocatalytic activity (PCA)-driven bacterial resistance under UVA irradiation.

Longevity of different abutments placed on narrow diameter implants: Assessment of structural damage and loosening.

Objectives: To evaluate structural damage and loosening of abutments placed on narrow diameter implants after cyclic fatigue.

Methods: Sixty Morse taper narrow diameter implants (Neodent, Brazil) received two types of abutments (1PA- one-piece abutment or 2PA- two-piece abutment), which were randomly divided into 3 fatigue experiments (n = 10). The implants were placed into a customized supporting holder and a software-assisted digital torque wrench secured the manufacturer recommended torque for each abutment.

Comparison of subcritical growth parameters of a Y-TZP obtained via cyclic or dynamic fatigue tests.

Objective: The objective of this study was to 1) compare the stress corrosion coefficient (n) of a Y-TZP obtained by two fatigue tests: cyclic and dynamic and 2) evaluate the effect of frequency in the characteristic lifetime and the existence of interaction between the cyclic fatigue and slow crack growth.

Methods: A total of 145 Y-TZP specimens were produced in accordance with the manufacturer's instructions. These specimens, measuring 4.

Preparation and optimization of an eggshell membrane-based biomaterial for GTR applications.

Objectives: Guided Tissue Regeneration (GTR) is a popular clinical procedure for periodontal tissue regeneration. However, its key component, the barrier membrane, is largely collagen-based and is still quite expensive, posing a financial burden to the patients as well as healthcare systems and negatively impacting the patient's decision-making. Thus, our aim is to prepare a novel biomimetic GTR membrane utilizing a natural biomaterial, soluble eggshell membrane protein (SEP), which is economical as it comes from an abundant industrial waste from food and poultry industries, unlike collagen.

Structural and torque changes in implant components of different diameters subjected to mechanical fatigue.

Objectives: To evaluate torque maintenance and structural damage in implant components of different diameters subjected to a fatigue challenge.

Methods: Thirty 10-mm-long, morse taper connection, titanium dental implants and their corresponding one-piece abutments were divided into three groups (n = 10) according to implant diameter: 4.3 mm (I4.

Influence of Different Surface Finishing Protocols on the Wear Behavior of Lithium Disilicate Glass-Ceramics.

Purpose: To evaluate the effect of different finishing protocols on the wear behavior of lithium disilicate glass-ceramics (LD).

Materials And Methods: Specimens were produced from LD prefabricated CAD/CAM blocks and divided into three groups according to the surface treatment (n = 8): control, polishing, and glaze. Ceramic specimens were subjected to wear testing using a dual-axis chewing simulator.

Role of gender and age in influencing dentist perceptions of effective leadership capabilities.

Statement Of The Problem: The characteristics of effective leaders in dentistry are unknown, especially as they relate to the perceptions of attributes associated with emotional intelligence.

Purpose: The purpose of this study was to survey dentists about their perceptions of the relative importance of emotional intelligence domains in effective leadership and in effective leaders with whom they have worked and to determine whether the differences were based on gender and age.

Material And Methods: A survey was sent to a list of over 50 000 dentists.

Effects of abutment screw preload and preload simulation techniques on dental implant lifetime.

Background: This study aimed to investigate how the predicted implant fatigue lifetime is affected by the loss of connector screw preload and the finite element analysis method used to simulate preload.

Methods: A dental implant assembly (DI1, Biomet-3i external hex; Zimmer Biomet) was scanned using microcomputed tomography and measured using Mimics software (Materialise) and an optical microscope. Digital replicas were constructed using SolidWorks software (Dassault Systèmes).

Antibacterial and biocompatible polyaniline-doped titanium oxide layers.

Titanium anodization has been shown to produce crystalline oxides exhibiting photocatalytic reactions that form reactive oxygen species (ROS) when exposed to UV light. The ROS subsequently attack bacteria cells, and thus reduce bacteria attachment on titanium implant surfaces. Polyaniline (PANI) is a conductive polymer that has shown antibacterial properties when electropolymerized onto titanium.

Optimization of Lithium Disilicate Glass-Ceramic Crowns: Finish Line, Scanning, and Processing Methods.

Purpose: To investigate the optimal combination of factors (finish line, scanning, and ceramic processing) to achieve the best values of both adaptation and fracture load for lithium disilicate crowns (LD).

Materials And Methods: Two abutment preparations, chamfer (C) and rounded shoulder (S), were produced with a dentin analog material and scanned with either extraoral (E) or intraoral (I) scanners. Images were processed using CAD software to design a premolar.

Relationship between fracture toughness and fractal dimensional increment in two types of dental glass-ceramics with different fracture surface roughness.

Objectives: Previous studies have reported the fractal dimensional increment of glass-ceramic fracture surfaces. The objective of this study was to determine the relationship between fracture toughness and fractal dimensional increment of two dental glass-ceramics with different volume fraction of crystals and different fracture surface roughness.

Methods: Bar-shaped specimens were prepared from lithium disilicate (LDS) and nanofluorapatite (NFA) glass-ceramics.

A novel single-step anodization approach for PANI-doping oxide surfaces to improve the photocatalytic activity of titanium implants.

Crystalline titanium oxides have shown photocatalytic activity (PCA) and the formation of antibacterial reactive oxygen species (ROS) when stimulated with UV light. Polyaniline (PANI) is a conductive polymer that has shown antibacterial effects. Previously, titanium oxides have been PANI-doped using a multi-step approach.

CAD/CAM versus 3D-printing/pressed lithium disilicate monolithic crowns: Adaptation and fatigue behavior.

Objectives: this study aimed to evaluate the adaptation and fatigue behavior of lithium disilicate glass-ceramic (LD) monolithic crowns produced by press (combined with 3D-printing) and CAD/CAM milling (control) techniques.

Methods: thirty abutment preparations with a chamfer finish line were produced with a dentin analogue material and scanned with extraoral scanner. Captured images were processed using CAD software to design a premolar.

Effect of Bone Remodeling on Dental Implant Fatigue Limit Predicted Using 3D Finite Element Analysis.

Background: To evaluate the effect of bone remodelling around a reduced-diameter dental implant on its fatigue limit using finite element analysis (FEA).

Methods: A dental implant assembly, which included a reduced-diameter dental implant (Biomet-3i external hex), an abutment (GingiHue) and a connector screw (Gold-Tite Square screw), was scanned using micro-computed tomography (Skyscan 1172). Its dimensions were measured using Mimics (Materialise) and an optical microscope (Keyence).

Influence of piston material on the fatigue behavior of a glass-ceramic.

Statement Of Problem: The lack of standardization regarding the loading piston material used in fatigue tests could limit the interpretation of study findings.

Purpose: The purpose of this in vitro study was to evaluate the effect of the piston material on the fatigue behavior of a lithium disilicate glass-ceramic.

Material And Methods: Plate-shaped, 1.

Mechanical behavior and adhesive potential of glass fiber-reinforced resin-based composites for use as dentin analogues.

Purpose: To characterize experimental glass fiber-reinforced resin-based composites (GFIR-isophthalic; and GFOR-orthophthalic), evaluating their mechanical behavior and adhesive potential to ceramic in comparison to human dentin and a traditional glass fiber-reinforced epoxy resin (G10).

Methods: Density (ρ), elastic modulus (E), and Poisson's ratio (ν) were evaluated using 2 mm thick specimens from GFIR, GFOR, human dentin and G10. Biaxial flexural strength (δf), Knoop hardness and surface topography under scanning electron microscopy (SEM) were assessed for GFIR and GFOR specimens.

Fractal analysis at varying locations of clinically failed zirconia dental implants.

Objectives: Previous studies have shown that the fracture toughness of ceramics can be determined from the fractal dimensions (D) of their fracture surfaces and that the surface should be leveled to obtain an accurate D measurement. This study was to determine the effects of leveling operations and distance from the failure origin on the D values.

Methods: Twelve clinically failed zirconia implants from four different manufacturers: Axis Biodental (n=7), Z-Systems (n=3), Straumann (n=1), and Swiss Dental Solutions (n=1) were obtained from one of the authors and thoroughly cleaned.

OPTIMIZATION OF COLLAGEN-ELASTIN-LIKE POLYPEPTIDE-BIOGLASS SCAFFOLD COMPOSITION FOR OSTEOGENIC DIFFERENTIATION OF ADIPOSE-DERIVED STEM CELLS.

We have developed a multicomponent hydrogel scaffold that can mimic the bone extracellular matrix by incorporating collagen, elastin-like polypeptide (ELP), and Bioglass. We examined the effects of Bioglass addition to collagen-ELP scaffolds on mechanical properties, physical characteristics, and osteogenic differentiation, by varying the Bioglass amount and particle size. Response surface methodology with a central composite design predicted 5 mg (6.

Low pressure dependent elasticity of porous ceramics.

The primary goal of this study was to characterize the influence of the pore-saturated gas media and their physical properties on the elasticity of porous ceramic materials. Resonant ultrasound spectroscopic measurements were performed on test specimens of alumina with ~40% porosity, zirconia with ~48% porosity, and sintered fully dense zirconia to determine the hydrostatic pressure-dependent macroscopic elasticity. Here, we report the variation of elasticity of porous and full dense samples over approximately five orders of magnitude (800-0.

Effects of ZnO/TiO nanoparticle and TiO nanotube additions to dense polycrystalline hydroxyapatite bioceramic from bovine bones.

Objectives: A bovine dense hydroxyapatite ceramic (HA) was produced as new biomaterial, however, the production of a material with consistently high flexural strength remains challenging. The objective of this study was to evaluate the effects of ZnO nanoparticles, TiO nanoparticles, and TiO nanotubes (1%, 2%, and 5% by weight) on the microstructure and flexural strength of a bovine dense hydroxyapatite ceramic (HA).

Methods: Discs (Ø=12.