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Novel laser textured surface designs for improved zirconia implants performance
摘要： The development of new surface designs to enhance the integration process between surgically placed implants and biological tissues remains a challenge for the scientific community. In this way and trying to overcome this issue, in this work, laser technology was explored to produce novel textures on the surface of green zirconia compacts produced by cold pressing technique. Two strategies regarding line design (8 and 16 lines design) and different laser parameters (laser power and number of laser passages) were explored to assess their influence on geometry and depth of created textures. The produced textures were evaluated with Scanning Electron Microscopy (SEM) and it was observed that well-defined textured surfaces with regular geometric features (cavities or pillars) were obtained by laser combining different strategies lines design and parameters. The potential of proposed textures was also evaluated regarding surface wettability, friction performance (static and dynamic coefficient of friction evolution) against bone, aging resistance and flexural strength. Results demonstrated that all the produced textures display a super hydrophilic or hydrophilic behavior. Regarding the friction behavior, it was experimentally observed a high initial static coefficient of friction (COF) for all produced textures. Concerning the aging resistance, all the textured surfaces revealed a low monoclinic content, less than 25% after 5?h of hydrothermal aging. The flexural strength results showed that the mechanical resistance of zirconia was not significantly compromised with the laser action. Based on the obtained results, it is possible to prove that the processing route used for manufacturing the new and different surface designs (cold pressing technique followed by laser texturing) showed to be particularly effective for the production of zirconia implants with customized surface designs according to the properties required in a specific application. These new surface designs besides to enhance the surface wettability and also to improve the fixation at the initial moment of the implantation, do not significantly compromise the resistance to aging and the mechanical performance of zirconia. Hence, a positive impact on the long-term performance of the zirconia implants may be expected with the proposed novel laser textured surface designs.
关键词： Flexural strength,Aging resistance,Zirconia,Surface wettability,Coefficient of friction,Laser surface texturing
更新于2025-09-12 10:27:22
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Q-switching Zirconia-Erbium-doped Pulsed Fiber Laser with MWCNTs-PEO as Saturable Absorber
摘要： Q-switched pulses provide a significant contribution to recent biomedical applications such as laser treatment, medical imaging, biomedical diagnoses and spectroscopy due to high efficiency, compact device, less footprint, flexibility and cost effective. A successful generation of Q-switching pulsed fiber laser by using a homemade fiber of zirconia-based erbium-doped fiber (Zr-EDF) with the utilization multi-walled carbon nanotubes-polyethylene oxide (MWCNTs-PEO) as saturable absorber is reported. The active medium is 1 meter length of Zr-EDF with -0.6 ps2 group delay dispersion (GDD) for overall setup arrangement. At maximum pump power 126 mW, the repetition rate, pulse duration, output power and pulse energy are 17.3 kHz, 7.57 μs, 1.13 mW and 65.03 nJ, respectively.
关键词： MWCNTs-PEO,Saturable Absorber,Pulsed Fiber Laser,Q-switching,Zirconia-Erbium-doped fiber
更新于2025-09-12 10:27:22
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Solution Combustion Synthesis of ZrO 2 :Tb 3+ Nanophosphors Viable for WLEDs
摘要： Tb3+ doped Zirconium oxide (ZrO2) nanopowders were synthesized by solution combustion method using oxalyl di-hydrazide (ODH). The effect of dopant concentration on the crystal structure and photoluminescence properties of the nano phosphors were investigated. Band gap of the samples were obtained from Wood and Tauc plot. Scanning electron microscopy analysis reveals the formation of porous powders with large amount of voids. Room temperature photoluminescence shows visible luminescence of the phosphors under near UV excitation. The colour index of phosphors were calculated using CIE co-ordinates. These phosphors show bright green emission centered at 550 nm. The emission intensity increased with Tb3+ concentration up-to 5 mol% and decreased thereon. All these samples were emitting green colour having colour coordinates at (0.25,0.65). The colour purity of the samples reveals that these phosphors are promising candidates as green emitting phosphors in the tricolor GaN based white light emitting diodes.
关键词： Phosphors,Zirconia,Terbium,WLEDs,Photoluminescence
更新于2025-09-12 10:27:22
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Effects of laser-assisted grinding on surface integrity of zirconia ceramic
摘要： Zirconia ceramics has an important position in the field of biomaterials because of excellent mechanical properties. Because of abrasive resistance and hardness, conventional machining of zirconia ceramic is difficult and time-consuming. A nontraditional hybrid laser-assisted grinding (LAG) system combining laser and cubic boron nitride (CBN) grinding wheel was developed for machining zirconia ceramic. This hybrid system utilizes the outstanding thermostability of zirconia ceramic: The material present on the cutting path is rapidly removed by local laser heating and grinding wheel. A combined theoretical and experimental study was performed to evaluate different modes of machining of zirconia ceramic. The machining parameters were predicted by numerical analysis. The surface quality, surface morphology, and subsurface damage of zirconia ceramic specimens were analyzed and compared. The results show that LAG can easily achieve ductile regime grinding in the same machine tool. Compared with conventional grinding, the surface integrity of zirconia ceramic was significantly improved by the LAG process. LAG could achieve ductile regime grinding with a large depth-of-cut. It changes the machinability of zirconia ceramic.
关键词： Surface quality,Surface morphology,Laser-assisted grinding,Zirconia ceramic,Subsurface damage
更新于2025-09-11 14:15:04
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Surface roughness alterations of zirconia implants after Er:YAG laser irradiation: a preliminary study
摘要： Objective This study aimed to investigate the surface roughness parameters (Rp in μm) of zirconia implants (TAVDental) after erbium YAG (LiteTouchTM) laser irradiation. Material and methods Implants were randomized into two groups according to the laser irradiation parameters (1.5 W/10 Hz and 1.5 W/30 Hz). The surface topography of each implant was analyzed before and after laser irradiation using laser-scanning microscopy. The roughness values from three different areas (cervical, middle, and apical) of each implant were registered. Result Irrespective of the different laser settings and implant surface areas, both groups showed a significant reduced mean and peak surface roughness values after laser irradiation. However, no signs of thermal defects were observed. Conclusion Based on the conditions of this preliminary study, it can be concluded that the use of the Er, YAG (1.5 W, 10 and 30 Hz) is a safe tool for zirconia implant surface decontamination.
关键词： Er:YAG laser,Implant surface decontamination,Implant surface roughness alterations,Zirconia implants
更新于2025-09-11 14:15:04
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Using Er:YAG laser to remove lithium disilicate crowns from zirconia implant abutments: An in vitro study
摘要： When implants are restored with cement-retained restorations, prosthetic retrievability can be difficult and often requires sectioning using rotary instruments. Sometimes repeated removals of a cement-retained implant crown are needed such as for treatment of peri-implantitis or immediate implant provisionalization. The purpose of this study was to evaluate the effect of erbium-doped yttrium aluminum garnet (Er:YAG) laser as a non-invasive treatment modality to remove lithium disilicate crowns from zirconia implant abutments following long-term cementation, repetitive debonding and re-cementation, and short-term retrieval.
关键词： cement-retained restorations,zirconia implant abutments,lithium disilicate crowns,Er:YAG laser,prosthetic retrievability
更新于2025-09-11 14:15:04
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Femtosecond laser microstructuring of alumina toughened zirconia for surface functionalization of dental implants
摘要： The continuous need for high-performance implants that can withstand mechanical loads while promoting implant integration into bone has focused recent research on the surface modification of hard ceramics. Their properties of biocompatibility, high mechanical and fatigue resistance and aesthetic color have contributed to its successful applications in dentistry. Alumina toughened Zirconia (ATZ) has been gaining attention as a material for dental implants applications due to its advanced mechanical properties and minimal degradation at body temperature. Still, in order to improve tissue response to this bioinert material, additional modifications are desirable. Improving the surface functionality of this ceramic could lead to enhanced implant-tissue interaction and subsequently, a successful implant integration. In this work, microtopographies were developed on the surface of Alumina toughened Zirconia using an ultrafast laser methodology, aiming at improving the cellular response to this ceramic. Microscale grooves and grid-like geometries were produced on ATZ ceramics by femtosecond laser ablation, with a pulse width of 150 fs, wavelength of 800 nm and repetition rate of 1 kHz. The variation of surface topography, roughness, chemistry and wettability with different laser processing parameters was examined. Cell-surface interactions were evaluated for 7 days on both microstructured surfaces and a non-treated control with pre-osteoblasts, MC3T3-E1 cells. Both surface topographies showed to improve cell response, with increased metabolic activity when compared to the untreated control and modulating cell morphology up to 7 days. The obtained results suggest that femtosecond laser texturing may be a suitable non-contact methodology for creating tunable micro-scale surface topography on ATZ ceramics to enhance the biological response.
关键词： Femtosecond laser microtexturing,Dental implants,Hard ceramics,Alumina toughened zirconia,Surface topography,Biological response
更新于2025-09-11 14:15:04
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Stabilization of cubic phase in scandium-doped zirconia nanocrystals synthesized with sol-gel method
摘要： A new room-temperature synthesis of nanocrystals of scandium doped zirconium oxide by sol-gel method is reported. The structure of the obtained product is checked with standard structural analysis methods. The crystal phase of ZrO2-Sc2O3 nanocrystals changes from monoclinic to tetragonal and cubic with the increase in scandium concentration. The importance of the cubic phase, which appears at 10 mol% and refines at 16 mol% of Sc2O3 concentration, is emphasized. The UV-Vis absorption spectra of the product are measured, and its bandgap is evaluated from the fundamental absorption edge. The value of the bandgap was calculated as 5.65 eV for the cubic phase.
关键词： scandium-doped zirconia nanocrystals,UV-Vis spectra,sol-gel synthesis,stabilization of cubic phase
更新于2025-09-11 14:15:04
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Effect of the Calcination Temperature on the Properties of Y-TZP Powders Prepared by Co-Precipitation
摘要： Yttria-stabilized tetragonal zirconia (Y-TZP) powders were prepared by co-precipitation, and the effect of the calcination temperature on the powder characteristics and sintering of Y-TZP ceramics was examined. Amorphous zirconium and yttrium hydroxide particles were precipitated starting from ZrOCl2·8H2O and Y(NO3)3·6H2O. After microwave drying and attrition milling, the co-precipitated gel was calcined for 1 h at different temperatures ranging from 550°C to 1050°C to obtain the tetragonal phase and remove chloride ions followed by additional milling by attrition milling for 12 h to control the size of the particles and agglomerates. The agglomeration behavior and the phase composition of the Y-TZP powders synthesized depend significantly on the calcination temperature. Powders calcined below 650°C exhibited hard agglomerates with small primary particles, which resulted in large primary and secondary agglomerates. Powders calcined above 950°C showed hard agglomerates with large primary particles and agglomerates. On the contrary, powder calcined at 850°C had soft agglomeration with small primary and secondary agglomerates; these powders had the maximum specific surface area and a good powder activity.
关键词： Co-Precipitation Method,Agglomerates,Yttria-Stabilized Zirconia,Calcined Temperature
更新于2025-09-11 14:15:04
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Ultrathin Yttria-Stabilized Zirconia as a Flexible and Stable Substrate for Infrared Nano-Optics
摘要： Infrared (IR) technologies have become increasingly relevant as they offer a wide range of applications, from thermal imaging to chemical and biological vibrational spectroscopy. Substrate materials, such as calcium fluoride and zinc selenide, are commonly used for IR optics. Unfortunately, they are typically fragile or hygroscopic, thus potentially producing problems during device fabrication and in the long-term functional operation. Here, yttria-stabilized zirconia (YSZ) ceramic is introduced as a flexible and stable platform for IR nano-optics. In particular, the YSZ substrate is combined with metallic nanostructures and graphene to demonstrate new plasmonic, polarizing, and transparent heating devices, which, at the same time, enable high-temperature processing and withstand harsh environments thanks to the high YSZ thermal and chemical stability. In addition, it is shown that the YSZ substrate is mechanically flexible, ideally suited for making foldable or bendable devices, and for low-cost large-scale roll-to-roll fabrication processes. The combination of all the aforesaid features, which are not available from other alternative materials, and this work offers compelling evidence that ultrathin YSZ is a unique substrate for IR applications.
关键词： zirconia,transparent,graphene,midinfrared,flexible plasmonics
更新于2025-09-10 09:29:36