Comparison of Low and High Temperature Sintering for Processing of Bovine Bone as Block Grafts for Oral Use: A Biological and Mechanical In Vitro Study.

Large oral bone defects require grafting of bone blocks rather than granules to give physically robust, biocompatible and osteoconductive regeneration. Bovine bone is widely accepted as a source of clinically appropriate xenograft material. However, the manufacturing process often results in both reduced mechanical strength and biological compatibility.

Effect of thermocycling on the mechanical properties, inorganic particle release and low temperature degradation of glazed high translucent monolithic 3Y-TZP dental restorations.

The influence of thermocycling on the surface deterioration of glazed monolithic high translucent 3Y-TZP dental restorations is still unclear. The purpose of this study therefore was to evaluate low temperature degradation (LTD), elemental release and surface degradation pattern after five years of simulated clinical time. A total of 123 specimens were prepared from second-generation high translucent 3Y-TZP as per ISO 6872:2015 standards (3 mm × 4 mm × 30 mm).

Fatigue behavior of removable partial denture cast and laser-sintered cobalt-chromium (CoCr) and polyetheretherketone (PEEK) clasp materials.

Objective: To investigate the fatigue behavior of cast and laser-sintered cobalt-chromium (CoCr) and polyetheretherketone (PEEK) material for a removable partial denture (RPD) clasps.

Methods: Dumbbell-shaped specimens were digitally designed with the center part of the dumbbell being a half-round shape at the cross-sectional dimension of 1.25 mm to simulate a typical clasp design and dimensions.

The Effect of Low-Processing Temperature on the Physicochemical and Mechanical Properties of Bovine Hydroxyapatite Bone Substitutes.

Bovine bone grafts (BBX) require protein removal as part of the manufacturing process to reduce antigenicity and, in consequence, to be safely used in humans. Deproteinisation may have direct effects on the characteristics of the bone material and on in vivo material performance. This research aimed to comprehensively study the physicochemical and mechanical properties of BBX processed at low deproteinisation processing temperatures.

Different Undercut Depths Influence on Fatigue Behavior and Retentive Force of Removable Partial Denture Clasp Materials: A Systematic Review.

Purpose: To perform a systematic review that provides an overview of the current literature on fatigue behavior of removable partial denture (RPD) clasp materials based on different retentive areas.

Materials And Methods: The review followed the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Electronic searches were done via PubMed, Scopus, and OVID for studies reporting on RPD clasps and the fatigue failure of clasp materials.

Evaluation of wear behaviour of various occlusal splint materials and manufacturing processes.

Objectives: To investigate the volumetric and vertical loss of occlusal splints manufactured by conventional (heat-cure), subtractive (CAD/CAM) and additive (3D-printing) methods.

Methods: Six occlusal splint materials were investigated (n = 126), using three manufacturing methods: heat-cured, CAD/CAM and 3D-printed built-in three different printing angles (0°,45°and 90°). Block-on-ring wear testing was performed with extracted human molars as the antagonist.

Optical and mechanical properties of conventional, milled and 3D-printed denture teeth.

Objectives: Investigate the effect of various liquids on the optical properties and Vickers hardness of conventional, milled and 3D-printed denture teeth.

Methods: Six different types of denture teeth (Maxillary anteriors of three different conventional teeth, Vivodent DCL, SR Phonares II, Vita Physiodens; milled teeth, IvotionDent; and two different 3D-printed teeth, Asiga DentaTooth and NextDent C&B MFH) were investigated (total n = 336). The labial surface of each specimen was prepared to a dimension of 10 × 5 × 3mm.

Effect of Two Brands of Glaze Material on the Flexural Strength and Probability of Failure of High Translucent Monolithic Zirconia.

(1) Background: The effect of glazing on the mechanical properties of monolithic high translucent zirconia is not well reported. Therefore, the purpose of this study was to evaluate the effect of glazing on the flexural strength of high translucent zirconia; (2) Methods: Ninety specimens were prepared from second-generation 3Y-TZP high translucent blocks and divided into three groups. Glaze materials were applied on one surface of the specimen and subjected to a four-point bending test and flexural stress and flexural displacement values were derived.

Is titanium-zirconium alloy a better alternative to pure titanium for oral implant? Composition, mechanical properties, and microstructure analysis.

Introduction: Titanium (Ti) is widely accepted as a biomaterial for orthopaedic and dental implants, primarily due to its capacity to integrate directly into the bone and its superior corrosion resistance. It has been suggested that titanium-zirconium alloy (TiZr), with 13-17% of zirconium, has better mechanical properties than pure Ti, but there are very few published studies assessing the suitability of TiZr for high-load- bearing implants. This study aimed to compare the mechanical properties and microstructures of TiZr and commercially pure titanium (Ti).

The effect of light curing intensity on bulk-fill composite resins: heat generation and chemomechanical properties.

Objectives: The aim of this study was to assess the effect of light curing intensity and wavelength spectrum on heat generation and chemomechanical properties of bulk-fill composites.

Methods: Four bulk-fill restorative materials (Filtek bulk-fill, Tetric PowerFill bulk-fill, Beautifil Bulk restorative and Admira Fusion X-tra were used in this study. A total of 100 cylindrical specimens of each composite ( = 25/group) were prepared, then cured using monowave light curing unit (LCU) with a single light intensity of 1470 mW/cm, and polywave LCU with three different light intensities (1200,2100, 3050mW/cm).

Fibre-reinforced and repaired PMMA denture base resin: Effect of placement on the flexural strength and load-bearing capacity.

Objectives: To measure the effect of placement of glass fibre mesh on the flexural strength and load bearing capacity of repaired polymethylmethacrylate (PMMA) denture base resin.

Materials And Methods: A total of 150 heat-polymerised acrylic resin specimens were fabricated with dimensions of 5 × 30 × 50 mm for flexural strength testing. Specimens were divided into 5 groups according to repair width and placement of the fibre mesh.

Optical Properties and Color Stability of Denture Teeth-A Systematic Review.

Purpose: To systematically review past studies to determine the effect of various solutions on the color of denture teeth, thus answering the question in regards to which type of denture teeth has the best optical properties after exposure to various solutions. The method of measuring the color of artificial teeth was also evaluated as a secondary outcome.

Materials And Methods: A search of studies that quantitatively investigated the influence of immersion solutions on the color change of denture teeth was conducted.

Real-time in vitro measurement of denture-mucosa pressure distribution in a typical edentulous patient with and without implants: Development of a methodology.

Purpose: To measure the pressure distribution on the oral mucosa in vitro by comparing the pressure distributions under a complete denture and that of an implant overdenture.

Materials And Method: Anatomically accurate models and conventional Class I complete denture (CD) were produced and subjected to cyclic loading using a 100 N vertical centric and unilateral masticatory load with the universal testing machine (Instron 3369). Four miniature pressure sensors were positioned at four different locations in the intaglio surface of the denture and recorded pressure at 100 Hz frequency measured during a 10-cycle load at 1 Hz.

Topographical mapping of the mechanical characteristics of the human neurocranium considering the role of individual layers.

The site-dependent load-deformation behavior of the human neurocranium and the load dissipation within the three-layered composite is not well understood. This study mechanically investigated 257 human frontal, temporal, parietal and occipital neurocranial bone samples at an age range of 2 to 94 years, using three-point bending tests. Samples were tested as full-thickness three-layered composites, as well as separated with both diploë attached and removed.

Investigation of dental elastomers as oral mucosa simulant materials.

Objective: To measure mechanical properties of dental soft liners in tensional stress to identify their suitability as human oral mucosa simulant materials.

Methods: Eleven different dental elastomers were subjected to tensile testing to obtain their tensile strength and elastic moduli (n = 15/group) according to the ISO-527 method. Fractured surfaces of one specimen per sample group were examined under the light microscope and scanning electron microscope (SEM).

Comparison of hardness and polishability of various occlusal splint materials.

Objectives: To measure polishability of occlusal splint materials manufactured by various methods.

Methods: Seven occlusal splint materials manufactured by four different methods - Heat cured (Vertex Rapid simplified Clear), CAD-milled (Ceramill a-splint), Vacuum-formed (Proform splint) and 3D-printed (Freeprint Ortho, KeySplint Soft, DentaClear and FreePrint Splint 2.0) were tested for gloss, roughness, and surface hardness and elastic modulus.

Adhesion of Denture Characterizing Composites to Heat-Cured, CAD/CAM and 3D Printed Denture Base Resins.

Purpose: To measure the adhesion of the denture characterizing composite to heat-cured, CAD/CAM and 3D printed denture base resins.

Methods And Materials: Two different denture characterizing composites with different viscosities (SR Nexco; high viscosity (SR) and Kulzer Cre-active; low viscosity (K)) and three denture base resins (Heat cure, CAD-milled and 3D printed) were investigated. 60 beams (25 × 4 × 3 mm) were fabricated for each denture base resin; 30 were bonded to SR and 30 to K to form a beam 50 × 4 × 3 mm.

Mechanical properties of human oral mucosa tissues are site dependent: A combined biomechanical, histological and ultrastructural approach.

Aim: To investigate load-deformation properties of Thiel-embalmed human oral mucosa tissues and to compare three different anatomical regions in terms of mechanical, histological and ultrastructural characteristic with focus on the extracellular matrix.

Materials And Methods: Thirty specimens from three different regions of the oral cavity: attached gingiva, buccal mucosa and the hard palate were harvested from two Thiel-embalmed cadavers. Mechanical properties were obtained, combining strain evaluation and digital image correlation in a standardised approach.

Evaluation of surface roughness, hardness and elastic modulus of nanoparticle containing light-polymerized denture glaze materials.

Statement Of Problem: The surface hardness and roughness of different glaze materials for denture base acrylic resins have not been well reported.

Purpose: The purpose of the study was to measure the surfaces hardness, elastic modulus and surface roughness of 5 different light-polymerized glaze materials for poly methyl methacrylate (PMMA) denture base materials.

Material And Methods: A total of 210 PMMA resin specimens (10 × 5 × 2 mm) were prepared (30 per group); control group was untreated, group 1 was surface treated with conventional pumice and high shine paste; group 2 to 6 specimens were glaze coated with different commercially available denture glaze materials.

Real-time pulp temperature change at different tooth sites during fabrication of temporary resin crowns.

Aim: To record the pulp temperature at different tooth sites during fabrication of two different temporary crown systems.

Methodology: Two temporary crown systems were investigated; a conventional direct fabricated and a preformed thermoplastic resin system. Extracted caries-free human teeth (incisor, premolar and molar) were prepared for full coverage ceramic restoration with roots sectioned below the cemento-enamel junction.

Mechanical Properties of Human Dura Mater in Tension - An Analysis at an Age Range of 2 to 94 Years.

Realistic human head models are of great interest in traumatic brain injury research and in the forensic pathology courtroom and teaching. Due to a lack of biomechanical data, the human dura mater is underrepresented in head models. This study provides tensile data of 73 fresh human cranial dura mater samples retrieved from an area between the anterior middle and the posterior middle meningeal artery.

Bond Strength of Denture Teeth to Heat-Cured, CAD/CAM and 3D Printed Denture Acrylics.

Purpose: To establish the fracture toughness (K ) and flexural bond strength of commercially available denture teeth to heat cured, CAD/CAM and 3D printed denture-based resins (DBRs).

Materials And Methods: Three types of DBRs (Heat cure, CAD-milled and 3D printed) and four different types of commercial denture teeth (Unfilled PMMA, double cross-linked PMMA, PMMA with nanofillers and 3D printed resin teeth) were investigated. DBR and epoxy embedded denture teeth (n = 30 per group) specimen beams (25 × 4 × 3 mm) were fabricated.

The cooling efficiency of different dental high-speed handpiece coolant port designs.

The study investigated the cooling efficiency of different numbers of water coolant ports on high-speed handpieces (HSH) under cooling conditions used in clinical practice. Twenty-four groove cuts with water on and nine cuts without water were made on extracted human premolars using three HSHs with different port configurations. Thermocouples were placed in the pulp chambers and temperature changes were recorded with 1-, 3- and 4-coolant port handpieces.

An Investigation on the Correlation between the Mechanical Properties of Human Skull Bone, Its Geometry, Microarchitectural Properties, and Water Content.

With increasingly detailed imaging and mechanical analysis, modalities need arises to update methodology and assessment criteria for skull bone analysis to understand how bone microarchitecture and the presence of attached tissues may affect the response to mechanical load. The main aim was to analyze the effect of macroscopic and microstructural features, as well as periosteal attachment, on the mechanical properties of human skull bone. Fifty-six skull specimens from ethanol-phenoxyethanol-embalmed cadavers were prepared from two human cadavers.