Microstructures and Mechanical Properties of Co-Cr Dental Alloys Fabricated by Three CAD/CAM-Based Processing Techniques.

The microstructures and mechanical properties of cobalt-chromium (Co-Cr) alloys produced by three CAD/CAM-based processing techniques were investigated in comparison with those produced by the traditional casting technique. Four groups of disc- (microstructures) or dumbbell- (mechanical properties) specimens made of Co-Cr alloys were prepared using casting (CS), milling (ML), selective laser melting (SLM), and milling/post-sintering (ML/PS). For each technique, the corresponding commercial alloy material was used.

Nano- and Micro-Scale Oxidative Patterning of Titanium Implant Surfaces for Improved Surface Wettability.

A simple and scalable surface modification treatment is demonstrated, in which nano- and microscale features are introduced into the surface of titanium (Ti) substrates by means of a novel and eco-friendly oxidative aqueous solution composed of hydrogen peroxide (H202) and sodium bicarbonate (NaHCO3). By immersing mirror-polished Ti discs in an aqueous mixture of 30 wt% H2O2/5 wt% NaHCO3 at 23 +/- 3 degrees C for 4 h, it was confirmed that this mixture is capable of generating microscale topographies on Ti surfaces. It also simultaneously formed nanochannels that were regularly arranged in a comb-like pattern on the Ti surface, thus forming a hierarchical surface structure.

Antimicrobial Activity of Glass lonomer Cement Incorporated with Chlorhexidine-Loaded Zeolite Nanoparticles.

A functional dental restorative system with antimicrobial properties was developed using zeolite (ZE) nanoparticles (NPs) as a drug delivery carrier. ZE NPs loaded with chlorhexidine (CHX) were prepared using the ionic immobilization method. The resulting CHX-loaded ZE NPs were then incorporated into commercial dental glass ionomer cement (GIC).

A simple, sensitive and non-destructive technique for characterizing bovine dental enamel erosion: attenuated total reflection Fourier transform infrared spectroscopy.

Although many techniques are available to assess enamel erosion in vitro, a simple, non-destructive method with sufficient sensitivity for quantifying dental erosion is required. This study characterized the bovine dental enamel erosion induced by various acidic beverages in vitro using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Deionized water (control) and 10 acidic beverages were selected to study erosion, and the pH and neutralizable acidity were measured.

The Effect of Novel Mercapto Silane Systems on Resin Bond Strength to Dental Noble Metal Alloys.

Self-assembled monolayers of thiols (RSH), which are key elements in nanoscience and nanotechnology, have been used to link a range of materials to planar gold surfaces or gold nanoparticles. In this study, the adhesive performance of mercapto silane systems to dental noble metal alloys was evaluated in vitro and compared with that of commercial dental primers. Dental gold-palladium-platinum (Au-Pd-Pt), gold-palladium-silver (Au-Pd-Ag), and palladium-silver (Pd-Ag) alloys were used as the bonding substrates after air-abrasion (sandblasting).

In Vitro Evaluation of Hydroxyapatite-Coated Titanium Implant with Atmospheric Plasma Treatment.

Plasma treatments are becoming a popular method for modifying the characteristics of a range of substrate surfaces. Atmospheric pressure plasma (APP) is cost-efficient, safe and simple compared to high-pressure plasma. This study examined the effects of a low-temperature APP treatment of a hydroxyapatite (HA)-coated Ti (HA-Ti) surface.

Simple Heat Treatment of Zirconia Ceramic Pre-Treated with Silane Primer to Improve Resin Bonding.

Establishing a strong resin bond to dental zirconia ceramic remains difficult. Previous studies have shown that the conventional application of silane does not work well with zirconia. This paper reports that a silane pre-treatment of dental zirconia ceramic combined with subsequent heat treatment has potential as an adhesive cementation protocol for improving zirconia-resin bonding.

Effect of Atmospheric Plasma Treatment to Titanium Surface on Initial Osteoblast-Like Cell Spreading.

Plasma treatments are becoming a popular method for modifying the characteristics of a range of substrate surfaces. Atmospheric pressure plasma is cost-efficient, safe and simple compared to high-pressure plasma. This study examined the effects of atmospheric pressure plasma to a titanium (Ti) surface on osteoblast-like cell (osteoblast) spreading and cellular networks.

Osteogenic Evaluation of Porous Calcium Phosphate Granules with Drug Delivery System Using Nanoparticle Carriers.

Novel porous biphasic calcium phosphate (BCP) granules incorporated with drug-releasing poly(lactic-co-glycolic acid) (PLGA) nanoparticles were developed as a drug delivery platform for bone regeneration. The charge interaction between the BCP and PLGA nanoparticle surfaces was manipulated to create this combination system. Spherical BCP granules with open micro-channels and PLGA nanoparticles loaded with dexamethasone (DEX) as a model drug were fabricated using a liquid nitrogen method and standard emulsion method, respectively.

Preliminary Evaluation of Mechanical Properties of Co-Cr Alloys Fabricated by Three New Manufacturing Processes.

A preliminary tensile test was performed to evaluate the mechanical properties of cobalt-chromium (Co-Cr) alloys fabricated by three new manufacturing processes: metal milling, milling for soft metal, and rapid prototyping (n=6). For comparison, the three alloy materials were also used to fabricate specimens by a casting procedure. In all groups tested, the proof strength and elongation were over 500 MPa and 2%, respectively.

Antibacterial releasing titanium surface using albumin nanoparticle carriers.

We developed a simple and highly efficient method for delivery from titanium (Ti) surfaces using albumin nanoparticle carriers. A Ti disc with a resorbable blasting media surface was used as a metal implant with a localized drug delivery structure. Human serum albumin (HSA) nanoparticles loaded with chlorhexidine (CHX) diacetate salt hydrate as the model drug were fabricated using a desolvation technique.

Efficacy of various cleaning solutions on saliva-contaminated zirconia for improved resin bonding.

Purpose: This study aimed to investigate the efficacy of cleaning solutions on saliva-contaminated zirconia in comparison to air-abrasion in terms of resin bonding.

Materials And Methods: For saliva-contaminated airabraded zirconia, seven cleaning methods)-no contamination (NC), water-spray rinsing (WS), additional airabrasion (AA), and cleaning with four solutions (Ivoclean [IC]; 1.0 wt% sodium dodecyl sulfate [SDS], 1.

Combined Effect of a Microporous Layer and Type I Collagen Coating on a Biphasic Calcium Phosphate Scaffold for Bone Tissue Engineering.

In this study, type I collagen was coated onto unmodified and modified microporous biphasic calcium phosphate (BCP) scaffolds. Surface characterization using a scanning electron microscope (SEM) and a surface goniometer confirmed the modification of the BCP coating. The quantity of the collagen coating was investigated using Sirius Red staining, and quantitative assessment of the collagen coating showed no significant differences between the two groups.

Improved Resin-Zirconia Bonding by Room Temperature Hydrofluoric Acid Etching.

This study was conducted to evaluate the shear bond strength of "non-self-adhesive" resin to dental zirconia etched with hydrofluoric acid (HF) at room temperature and to compare it to that of air-abraded zirconia. Sintered zirconia plates were air-abraded (control) or etched with 10%, 20%, or 30% HF for either 5 or 30 min. After cleaning, the surfaces were characterized using various analytical techniques.

Effect of adhesive resin flexibility on enamel fracture during metal bracket debonding: an ex vivo study.

Objective: To test the null hypothesis that neither the flexural properties of orthodontic adhesive resins nor the enamel pre-treatment methods would affect metal bracket debonding behaviours, including enamel fracture.

Materials And Methods: A dimethacrylate-based resin (Transbond XT, TX) and two methyl methacrylate (MMA)-based resins (Super-Bond C&B, SB; an experimental light-cured resin, EXP) were tested. Flexural strength and flexural modulus for each resin were measured by a three-point-bending test.

Synthesis, characterization, biocompatibility of hydroxyapatite-natural polymers nanocomposites for dentistry applications.

Hydroxyapatite (HA), the main mineral component of bones and teeth, was synthesized by using the reaction between calcium nitrate tetrahydrate Ca(NO3)2∙4H2O and diammonium hydrogen phosphate (NH4)2HPO4 (DAHP) with a chemical precipitation method. The objective of this study is to utilize novel inorganic-organic nanocomposites for biomedical applications. HA is an inorganic component (75% w) and chitosan, alginate and albumin (Egg white) are organic components of nanocomposites (25% w).

Influence of different drying methods on microtensile bond strength of self-adhesive resin cements to dentin.

Objective: This study investigated the effect of different drying methods of dentin surface on the bonding efficacy of self-adhesive resin cements (SRCs).

Materials And Methods: Three SRCs (RelyX U200, RU; Maxcem Elite, ME; and BisCem, BC) and one resin-modified glass ionomer cement (RelyX Luting 2, RL) were used. The characteristics of the materials were evaluated using thermogravimetric analysis and surface roughness and contact angle measurements.

Effects of prepolymerized particle size and polymerization kinetics on volumetric shrinkage of dental modeling resins.

Dental modeling resins have been developed for use in areas where highly precise resin structures are needed. The manufacturers claim that these polymethyl methacrylate/methyl methacrylate (PMMA/MMA) resins show little or no shrinkage after polymerization. This study examined the polymerization shrinkage of five dental modeling resins as well as one temporary PMMA/MMA resin (control).

Soybean extracts facilitate bacterial agglutination and prevent biofilm formation on orthodontic wire.

Soybean is an essential food ingredient that contains a class of organic compounds known as isoflavones. It is also well known that several plant agglutinins interfere with bacterial adherence to smooth surfaces. However, little is known about the effects of soybean extracts or genistein (a purified isoflavone from soybean) on bacterial biofilm formation.

Degree of conversion of two dual-cured resin cements light-irradiated through zirconia ceramic disks.

Purpose: The aim of this Fourier transform infrared (FTIR) spectroscopic study was to measure the degree of conversion (DC) of dual-cured resin cements light-irradiated through zirconia ceramic disks with different thicknesses using various light-curing methods.

Materials And Methods: Zirconia ceramic disks (KT12) with three different thicknesses (1.0, 2.

Comparative short-term in vitro analysis of mutans streptococci adhesion on esthetic, nickel-titanium, and stainless-steel arch wires.

Objective: To test the hypothesis that there are no differences in mutans streptococci (MS) adhesion between esthetic and metallic orthodontic arch wires based on their surface characteristics.

Materials And Methods: Surface roughness (Ra) and apparent surface free energy (SFE) were measured for six wires-four esthetic, one nickel-titanium (NiTi), and one stainless-steel (SS)-using profilometry and dynamic contact angle analysis, respectively. The amount of MS (Streptococcus mutans and Streptococcus sobrinus) adhering to the wires was quantified using the colony-counting method.

A simple 2-step silane treatment for improved bonding durability of resin cement to quartz fiber post.

Introduction: This study examined a clinically feasible protocol for improving hydrolytic stability using a 2-step silanization including a nonorganofunctional silane.

Methods: The surfaces of 24 D.T.

Polymerization kinetics of dual-curing adhesive systems when used solely or in conjunction with chemically-cured resin cement.

Purpose: To investigate the chemical polymerization kinetics of commercial dual-curing adhesive systems when used solely or in conjunction with chemically-curing resin cement.

Materials And Methods: Four adhesive systems comprising simplified-step adhesives and activators (Prime&Bond NT with Self Cure Activator, Excite DSC, AQ Bond Plus, All-Bond SE) were used. The pH values of the adhesives and adhesive/activator blends were measured.

Drug delivery from hydroxyapatite-coated titanium surfaces using biodegradable particle carriers.

The goal of this study was to develop a functional titanium (Ti) implant loaded with bioactive molecules using biodegradable polymeric particles as drug delivery carrier for dental applications. In this study, dexamethasone (DEX)-loaded poly(lactic-co-glycolic acid) (PLGA) particles were electrostatically immobilized on a Ti disc surface coated with hydroxyapatite (HA) nanocrystals using a low temperature high speed collision (LTHSC) method. Resorbable blasting media (RBM) Ti discs (S1), HA-Ti discs (S2), and HA-Ti discs treated with DEX-loaded PLGA particles (S3) were fabricated in this study as sample discs.

Porous zirconia/hydroxyapatite scaffolds for bone reconstruction.

Objective: Highly porous apatite-based bioceramic scaffolds have been widely investigated as three-dimensional (3D) templates for cell adhesion, proliferation, and differentiation promoting the bone regeneration. Their fragility, however, limits their clinical application especially for a large bone defect.

Methods: To address the hypothesis that using a ZrO(2)/hydroxyapatite (HAp) composite might improve both the mechanical properties and cellular compatibility of the porous material, we fabricated ZrO(2)/HAp composite scaffolds with different ZrO(2)/HAp ratios, and evaluated their characteristics.