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Clinical Oral Investigations Sep 2023Ceramic-sintering affects bond strength and longevity of metal-ceramic. This study investigated the effect of sintering temperatures and times on metal-ceramic bond...
OBJECTIVES
Ceramic-sintering affects bond strength and longevity of metal-ceramic. This study investigated the effect of sintering temperatures and times on metal-ceramic bond strength vis-a-vis interfacial fracture toughness.
MATERIALS AND METHODS
One hundred eighty rectangular-shaped (25 × 8 × 1 mm) casting (Auriloy® (CA)) and CAD-milling (Ceramill Sintron® (MA)) alloys were prepared and randomly veneered with ceramic at normal (930 °C; (TN)), increased (940 °C; (TI)), and extremely increased (950 °C; (TE)) sintering temperatures and normal (1 min; (HN)), increased (2 min; (HI)), and extremely increased (3 min; (HE)) sintering time (n = 10/group). Pre-cracked was subjected to four loading-unloading cycles at 0.05 mm/min speed to determine interfacial fracture toughness from strain energy release rate (G). Microstructures were examined with a scanning electron microscope (SEM), energy-dispersive X-ray (EDX), and atomic force microscopy (AFM). ANOVA and Tukey comparisons were determined for significant differences (α = 0.05).
RESULTS
Significant differences in G due to the effect of alloy, sintering temperature, and time (p < 0.05) were indicated. MA revealed higher G than CA. Raising temperatures enabled increasing G for CA, not for MA. Extended sintering permitted increasing G for both alloys. Rougher surface of MA than CA was observed. Interfacial ion exchange was differently indicated between CA and MA.
CONCLUSIONS
Bond strength was influenced by alloy, sintering temperature, and time. Ceramic has better adhesion to MA than CA. Enhancing bond for CA was succeeded through increasing sintering temperature and time, whereas through extended sintering for MA.
CLINICAL RELEVANCE
MA offers stronger bond than CA. Enhancing bond is suggested by extended sintering. Raising temperature can enhance bond for CA, not for MA.
Topics: Dental Porcelain; Metal Ceramic Alloys; Dental Bonding; Surface Properties; Ceramics; Chromium Alloys; Materials Testing
PubMed: 37462729
DOI: 10.1007/s00784-023-05157-1 -
Frontiers in Bioengineering and... 2023is the most common species that causes peri-implantitis. It forms an irreversible dense biofilm and causes inflammation. A novel 3D-printed porous TC4-6Cu alloy was...
is the most common species that causes peri-implantitis. It forms an irreversible dense biofilm and causes inflammation. A novel 3D-printed porous TC4-6Cu alloy was fabricated using selective laser melting (SLM) technology for the dental implant, which is anticipated to inhibit biofilm formation. We attempted to investigate the antibacterial ability and antibacterial mechanism of the 3D-printed porous TC4-6Cu alloy against . This work used scanning electron microscopy (SEM) and laser confocal microscopy (CLSM) to detect the antimicrobial ability of the alloy against sessile . The results indicated that the 3D-printed porous TC4-6Cu alloy could cause bacterial fragmentation and deformation. Plate antimicrobial counting experiments showed that the antibacterial rates of the alloy against adherent bacteria and planktonic bacteria after 24 h were 98.05% and 73.92%, respectively. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Cu were tested to appraise the antibacterial property of the alloy against planktonic The relationship between the antibacterial mechanism of the alloy with oxidative stress was evaluated through ROS fluorescence intensity and protein leakage concentration. The results revealed that the alloy significantly eliminated adherent bacteria and inhibited biofilm formation. Moreover, 3D-printed porous TC4-6Cu alloy demonstrated significant bactericidal ability by inducing the production of reactive oxygen species (ROS), which could result in protein leakage from the bacterial cell membrane. This research may open a new perspective on the development and biomedical applications for dental implantation.
PubMed: 37600307
DOI: 10.3389/fbioe.2023.1226745 -
Materials (Basel, Switzerland) Nov 2023β-Ti alloys have long been investigated and applied in the biomedical field due to their exceptional mechanical properties, ductility, and corrosion resistance.... (Review)
Review
β-Ti alloys have long been investigated and applied in the biomedical field due to their exceptional mechanical properties, ductility, and corrosion resistance. Metastable β-Ti alloys have garnered interest in the realm of biomaterials owing to their notably low elastic modulus. Nevertheless, the inherent correlation between a low elastic modulus and relatively reduced strength persists, even in the case of metastable β-Ti alloys. Enhancing the strength of alloys contributes to improving their fatigue resistance, thereby preventing an implant material from failure in clinical usage. Recently, a series of biomedical high-entropy and medium-entropy alloys, composed of biocompatible elements such as Ti, Zr, Nb, Ta, and Mo, have been developed. Leveraging the contributions of the four core effects of high-entropy alloys, both biomedical high-entropy and medium-entropy alloys exhibit excellent mechanical strength, corrosion resistance, and biocompatibility, albeit accompanied by an elevated elastic modulus. To satisfy the demands of biomedical implants, researchers have sought to synthesize the strengths of high-entropy alloys and metastable β-Ti alloys, culminating in the development of metastable high-entropy/medium-entropy alloys that manifest both high strength and a low elastic modulus. Consequently, the design principles for new-generation biomedical medium-entropy alloys and conventional metastable β-Ti alloys can be converged. This review focuses on the design from β-Ti alloys to the novel metastable medium-entropy alloys for biomedical applications.
PubMed: 37959643
DOI: 10.3390/ma16217046 -
ACS Applied Bio Materials Nov 2023The utilization of guided tissue regeneration membranes is a significant approach for enhancing bone tissue growth in areas with bone defects. Biodegradable magnesium...
The utilization of guided tissue regeneration membranes is a significant approach for enhancing bone tissue growth in areas with bone defects. Biodegradable magnesium alloys are increasingly being used as guided tissue regeneration membranes due to their outstanding osteogenic properties. However, the degradation rates of magnesium alloy bone implants documented in the literature tend to be rapid. Moreover, many studies focus only on the initial 3-month period post-implantation, limiting their applicability and impeding clinical adoption. Furthermore, scant attention has been given to the interplay between the degradation of magnesium alloy implants and the adjacent tissues. To address these gaps, this study employs a well-studied magnesium-aluminum (Mg-Al) alloy membrane with a slow degradation rate. This membrane is implanted into rat skull bone defects and monitored over an extended period of up to 48 weeks. Observations are conducted at various intervals (2, 4, 8, 12, 24, and 48 weeks) following the implantation. Assessment of degradation behavior and tissue regeneration response is carried out using histological sections, micro-CT scans, and scanning electron microscopy (SEM). The findings reveal that the magnesium alloy membranes demonstrate remarkable biocompatibility and osteogenic capability over the entire observation duration. Specifically, the Mg-Al alloy membranes sustain their structural integrity for 8 weeks. Notably, their osteogenic ability is further enhanced as a corrosion product layer forms during the later stages of implantation. Additionally, our in vitro experiments employing extracts from the magnesium alloy display a significant osteogenic effect, accompanied by a notable increase in the expression of osteogenic-related genes. Collectively, these results strongly indicate the substantial potential of Mg-Al alloy membranes in the context of guided tissue regeneration.
Topics: Rats; Animals; Alloys; Magnesium; Aluminum; Bone Regeneration; Osteogenesis
PubMed: 37865928
DOI: 10.1021/acsabm.3c00488 -
Journal of Visualized Experiments : JoVE Mar 2024This protocol describes the synthesis of Au nanoparticle seeds and the subsequent formation of Au-Sn bimetallic nanoparticles. These nanoparticles have potential...
This protocol describes the synthesis of Au nanoparticle seeds and the subsequent formation of Au-Sn bimetallic nanoparticles. These nanoparticles have potential applications in catalysis, optoelectronics, imaging, and drug delivery. Previously, methods for producing alloy nanoparticles have been time-consuming, require complex reaction conditions, and can have inconsistent results. The outlined protocol first describes the synthesis of approximately 13 nm Au nanoparticle seeds using the Turkevich method. The protocol next describes the reduction of Sn and its incorporation into the Au seeds to generate Au-Sn alloy nanoparticles. The optical and structural characterization of these nanoparticles is described. Optically, prominent localized surface plasmon resonances (LSPRs) are apparent using UV-visible spectroscopy. Structurally, powder X-ray diffraction (XRD) reflects all particles to be less than 20 nm and shows patterns for Au, Sn, and multiple Au-Sn intermetallic phases. Spherical morphology and size distribution are obtained from transmission electron microscopy (TEM) imaging. TEM reveals that after Sn incorporation, the nanoparticles grow to approximately 15 nm in diameter.
Topics: Gold Alloys; Silver; Gold; Tin; Metal Nanoparticles; Alloys
PubMed: 38557764
DOI: 10.3791/66628 -
International Journal of Molecular... Jul 2023The creation of buffer (hybrid) layers that provide improved adhesion to two heterogeneous materials is a promising and high-priority research area in the field of...
A Study of the Peculiarities of the Formation of a Hybrid Interface Based on Polydopamine between Dental Tissues and Dental Composites, Using IR and Raman Microspectroscopy, at the Submicron Level.
The creation of buffer (hybrid) layers that provide improved adhesion to two heterogeneous materials is a promising and high-priority research area in the field of dental materials science. In our work, using FTIR and Raman microspectroscopy at the submicron level in a system of dental composites/intact dental enamel, we assessed the molecular features of formation and chemically visualized the hybrid interface formed on the basis of a nature-like adhesive, polydopamine (PDA). It is shown that a homogeneous bioinspired PDA-hybrid interface with an increased content of O-Ca-O bonds can be created using traditional methods of dental tissue pretreatment (diamond micro drilling, acid etching), as well as the subsequent alkalinization procedure and the developed synthesis technology. The development of the proposed technology for accelerated deposition of PDA-hybrid layers, as well as the creation of self-assembled biomimetic nanocomposites with antibacterial properties, may in the future find clinical application for minimally invasive dental restoration procedures.
Topics: Composite Resins; Resin Cements; Surface Properties; Indoles; Dental Bonding; Materials Testing
PubMed: 37511394
DOI: 10.3390/ijms241411636 -
Computer Methods in Biomechanics and... May 2024At present, selective laser melting (SLM) 3D printing technology can accurately control the internal pore structure and complex cell shape. Three types of reticulated...
At present, selective laser melting (SLM) 3D printing technology can accurately control the internal pore structure and complex cell shape. Three types of reticulated meshes with cubic, G7 and composite structure cell shapes were fabricated by the SLM 3D printing technology using Ti-6Al-4V alloy powders. The bone stresses around the implant and the stresses in the implant were analyzed by ANSYS finite element software, which comprehensively evaluated the effect of porous dental implants with different spatial porosity characteristics on osseointegration. The results show that porous dental implants with composite structure of pore characteristics have improved mechanical and biological properties and can better promote the growth and integration of bone tissue.
Topics: Porosity; Dental Implants; Materials Testing; Alloys; Titanium; Bone and Bones; Osseointegration; Surface Properties
PubMed: 37053006
DOI: 10.1080/10255842.2023.2199901 -
Materials (Basel, Switzerland) Oct 2023Titanium-based alloys are used in orthopedic applications as fixation elements, hard tissue replacements in artificial bones, and dental implants. Despite their wide...
Titanium-based alloys are used in orthopedic applications as fixation elements, hard tissue replacements in artificial bones, and dental implants. Despite their wide range of applications, metallic implant defects and failures arise due to inadequate mechanical bonding, postoperative clotting problems, aseptic loosening, and infections. To improve the surface bioactivity and reduce the corrosion rate of the Ti6Al4V alloy, multi-layered coatings (HAp, BG, Cs, and Hep) were applied via electrophoretic deposition (EPD). XRD images showed the presence of HAp within the coating. In vitro investigation: cell line NIH-3T3 fibroblasts were seeded on the non-coated and coated Ti6Al4V substrates, and their cellular behavior was evaluated. The results indicated that the HApBGCsHep coating could enhance the adhesion and proliferation of NIH 3T3 cells. In addition, the potentiodynamic polarization results are compatible with the in vitro outcome.
PubMed: 37834746
DOI: 10.3390/ma16196608 -
BDJ Open Dec 2023Evaluation of the Shear bond strength over zirconia and titanium alloy and degree of conversion of extraoral compared to intraoral self-adhesive resin cements.
OBJECTIVE
Evaluation of the Shear bond strength over zirconia and titanium alloy and degree of conversion of extraoral compared to intraoral self-adhesive resin cements.
MATERIALS AND METHODS
Nine bonding protocols were carried out on zirconia 4Y-TZP and titanium alloy (Ti-6Al-4V). Seven resin cement (one extraoral and six intraoral) were tested in the shear bond strength test and the degree of conversion measurements.
RESULTS
The significantly highest value was obtained for Monobond Plus + Multilink Hybrid Abutment, the extraoral resin cement for both titanium alloy (35.1 MPa) and zirconia (32.9 MPa). For each resin, significantly higher DC values were obtained for the dual-cure mode compared with the self-cure mode. Regardless of the cure mode, Nexus Universal reached the highest DC (78.4%).
DISCUSSION/CONCLUSIONS
In this study, the extraoral self-curing resin cement showed the higher bond strength values on zirconia and titanium alloy when associated with a universal primer. Some intraoral dual-cure resin cements showed closed performances when used with universal primers. There is no direct correlation between the degree of conversion of the resin cement and the shear bond strength obtained on the prosthetic materials tested.
PubMed: 38071342
DOI: 10.1038/s41405-023-00178-0 -
American Journal of Orthodontics and... Nov 2023The objective of this study was to determine and compare the moment-to-force (Mc/F) ratio and the type of tooth movement generated in the anterior and posterior segments...
INTRODUCTION
The objective of this study was to determine and compare the moment-to-force (Mc/F) ratio and the type of tooth movement generated in the anterior and posterior segments in orthodontic space closure with stainless steel and titanium-molybdenum alloy loop archwires.
METHODS
Three-dimensional model of the maxilla from which the first premolar was extracted, 18 × 25-mil slot stainless steel brackets, and 16 × 22-mil stainless steel and β titanium-molybdenum alloy (TMA) closing loop archwires with anterior gable bend of 15° and posterior gable bend of 25° were constructed. The archwires were engaged in the brackets, and 1-mm activations were carried out, which were repeated 5 times. The anterior and posterior segment Mc/F ratio and the type of tooth movement generated by the 2 wires were compared.
RESULTS
It was found that the Mc/F ratio for the anterior segment was approximately 5 mm, and for posterior teeth was approximately 10 mm for both stainless steel and TMA closing loop archwire. The anterior teeth exhibited controlled tipping, whereas the posterior teeth showed bodily tooth movement, which was in accordance with the Mc/F ratio that was obtained.
CONCLUSIONS
The Mc/F ratio and the type of tooth movement exhibited by stainless steel and TMA closing loop archwires were similar in both anterior and posterior segments.
Topics: Humans; Stainless Steel; Molybdenum; Titanium; Finite Element Analysis; Friction; Orthodontic Brackets; Orthodontic Wires; Dental Stress Analysis; Alloys; Dental Alloys; Materials Testing; Orthodontic Appliance Design
PubMed: 37656072
DOI: 10.1016/j.ajodo.2023.06.010