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Purpose: To evaluate the response of human peri-implant soft tissue (PIST) to different healing abutment materials 24 hours after positioning by assessing the expression of genes related to the early connective tissue wound healing response. Materials and Methods: The following four materials were used to create experimental abutments that were mounted on implants placed in five patients (four different abutments in each patient): group A--grade 4 titanium (Ti), group B--grade 5 Ti, group C--zirconia (Zr), and group D--polyetheretherketone (PEEK). Before implant placement, a gingival biopsy (control, CT) sample was obtained using a 2-mm-diameter punch (T0). After 24 hours, PIST biopsy samples were collected using a specifically designed custom-made cutting device. Real-time polymerase chain reaction (PCR) was performed to analyze the expression of the following genes: COL-I, COL-III, MMP-1, TIMP-1, TGF-^1, FN, ITGA4, ITGA5, ITGB1, RAC-1, COL-IV, aSMA, IL-6, and CXCL-1. Results: Gene expression analysis showed some differences between CT and the experimental groups; however, no significant differences were detected when comparing the experimental groups. COL-I was significantly downregulated in groups A and C compared to CT. Expression of MMP-1 and TIMP-1 increased in all the experimental groups but to a lesser extent in group A. FN, RAC-1, COL-IV, and aSMA were downregulated, especially in group A, in which CXCL-1 and IL-6 showed the lowest expression. Conclusions:The results of grade 4 Ti and Zr abutments seem to be promising, because a lower expression of genes related to inflammation, myofibroblast activation, and extracellular matrix remodeling was observed when compared with grade 5 Ti and PEEK, without triggering a profibrotic response in the early phases of PIST repair. [ABSTRACT FROM AUTHOR]

Purpose: To investigate whether the wettability of two zirconia (Zr) implant disk surfaces is affected by glycine and erythritol air polishing using the following wetting solutions as test mediums: saline, bovine serum albumin (BSA), bovine thrombin, and bovine artificial blood. Materials and Methods: The two types of Zr disks used were SDS (Swiss Dental Solutions; n = 6) and Patent (Zircon Medical AG; n = 6). Surface parameters (Sa, Sz, Sdr, Ssk, Sku, and Spd) were measured to determine their initial surface roughness. Air polishing was completed using glycine or erythritol powders using the AIRFLOW PERIO device (EMS Dental). The wettability of the disk surfaces was evaluated by the contact angle analysis applied to the treated and untreated disks using four wetting solutions, including saline, BSA, bovine thrombin, and bovine artificial blood. In total, 720 contact angle measurements were completed with n = 30 per group. Statistical analysis was performed using one-way ANOVA and the post-hoc Tukey HSD test. Results: The results indicate that SDS has a greater wettability than Patent before and after air polishing. The wettability of surfaces treated with glycine was hydrophobic in some cases. Erythritol increased the surface wettability of Zr disks more than glycine. BSA and bovine artificial blood had lower contact angles than saline and bovine thrombin for both types of untreated disks. Conclusions: The initial wettability of Zr disks differs between manufacturers, and air polishing with erythritol powder increases the wettability of Zr implant disks for saline, bovine serum, bovine thrombin, and bovine artificial blood. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the esthetic outcomes based on the color differences in zirconia (Zr) of varying thickness, resin cement color, and types of titanium (Ti) implant surface treatments. Materials and Methods: Overall, 28 high-translucency monolithic zirconia (HTMZ) specimens were arranged into four groups based on Zr thickness: 1.0, 1.5, 2.0, and 2.5 mm (n = 7 per thickness). Each group was tested using two resin cement colors (clear and opaque) in combination with six surface-treated Ti groups (n = 7), including untreated titanium (UT), anodization (AN), 50-µm alumina airborne-particle abrasion followed by AN (SBAN), AN followed by 50-µm alumina airborne-particle abrasion (ANSB), 9.5% hydrofluoric acid followed by AN (HFAN), and AN followed by 9.5% hydrofluoric acid (ANHF). This created a total of 48 experimental groups, including the use of composite resin (n = 7, shade A2D) for four control groups. All specimens were measured using a spectrophotometer and subsequently compared with composite resin (control) with the corresponding Zr thickness to establish color differences. A color difference of < 2.7 was considered clinically acceptable. The data obtained were statistically analyzed using ANOVA and post hoc test (P = .05). Results: Zr thickness, resin cement color, and type of Ti implant surface treatment significantly affected the observed color differences (P < .05). When using 2.5-mm HTMZ with clear resin cement on AN, UT, SBAN, HFAN, and ANSB, the mean color differences were below the clinically acceptable values, and the 95% CIs of color differences were below the clinically acceptable values for AN, UT, and SBAN groups. Conclusions: HTMZ with a minimum thickness of 2.5 mm and clear resin cement on AN, UT, and SBAN groups potentially result in acceptable color matching with 95% CIs. [ABSTRACT FROM AUTHOR]

Purpose: To measure zirconia-to-zirconia microtensile bond strength (µTBS) using composite cements with and without primer. Materials and Methods: Two Initial Zirconia UHT (GC) sticks (1.8x1.8x5.0 mm) were bonded using four cements with and without their respective manufacturer's primer/adhesive (G-CEM ONE [GOne] and G-Multi Primer, GC; Panavia V5 [Pv5]), and Panavia SA Cement Universal [PSAu], and Clearfil Ceramic Plus, Kuraray Noritake; RelyX Universal (RXu) and Scotchbond Universal Plus [SBUp], 3M Oral Care). Specimens were trimmed to an hour-glass shaped specimen whose isthmus is circular in cross-section. After 1-week water storage, the specimens were either tested immediately (1-week µTBS) or first subjected to 50,000 thermocycles (50kTC-aged µTBS). The fracture mode was categorized as either adhesive interfacial failure, cohesive failure in composite cement, or mixed failure, followed by SEM fracture analysis of selected specimens. Data were analyzed using linear mixed-effects statistics (α = 0.05; variables: composite cement, primer/adhesive application, aging). Results: The statistical analysis revealed no significant differences with aging (p = 0.3662). No significant difference in µTBS with/without primer and aging was recorded for GOne and PSAu. A significantly higher µTBS was recorded for Pv5 and RXu when applied with their respective primer/adhesive. Comparing the four composite cements when they were applied in the manner that resulted in their best performance, a significant difference in 50kTC-aged µTBS was found for PSAu compared to Pv5 and RXu. A significant decrease in µTBS upon 50kTC aging was only recorded for RXu in combination with SBUp. Conclusion: Adequate bonding to zirconia requires the functional monomer 10-MDP either contained in the composite cement, in which case a separate 10-MDP primer is no longer needed, or in the separately applied primer/adhesive. [ABSTRACT FROM AUTHOR]

Purpose: This investigation aimed to assess the impact of additive manufacturing-generated surface textures on zirconia bond strength. Materials and Methods: Zirconia samples (n = 144) fabricated using digital light-processing (DLP) technology were categorized into 6 groups according to the type of surface conditioning (group NN: no designs, no air abrasion; group NY: no designs, with air abrasion; group GN: groove designs, no air abrasion; group GY: groove designs with air abrasion; group HN: hexagon grid, no air abrasion; group HY: hexagon grid, with air abrasion). Composite resin cylinders were cemented to the treated zirconia surfaces with dual-curing, self-adhesive resin cement (Clearfil SA Luting). The shear bond strength (SBS) was tested after water storage for 3 days or 3 days with an additional 10,000 thermocycles. Results: The zirconia samples fabricated using DLP technology have high accuracy. The SBS of the NY, GY, and HY groups did not significantly differ after 3 days, and neither did the SBS of the NN, GN, and HN groups. The NN, NY, and HY groups exhibited reduced SBS compared to their initial values following artificial aging, while the SBS of the remaining three groups were not diminished. The GY group obtained the highest SBS value after aging. Conclusion: Printing grooves with air abrasion can improve the bond strength. [ABSTRACT FROM AUTHOR]

The barium titanate derivative Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 O 3 (BCZT) offers high dielectric and piezoelectric performance but has poor mechanical properties. Ceramic composite materials combining BCZT with tougher Al 2 O 3 or ZrO 2 could be the solution to the inherent brittleness of electroceramics. This work focuses on BCZT with 1–5 vol% addition of reinforcing phase dispersed in the microstructure. While hardness was improved in all composites, especially in ZrO 2 -reinforced BCZT, toughness was positively affected only by Al 2 O 3. The chemical reactivity of BCZT during sintering resulted in the formation of new barium aluminate phases at the grain boundaries and possibly also within the grains, which affected the electrical properties of the composites. The addition of zirconia resulted in the formation of BaZrO 3 or Ba(Zr,Ti)O 3 , which is a natural part of the BCZT solid solution and shifts the phase composition towards relaxor behaviour. ZrO 2 -reinforced composites exhibited higher permittivity but lower ferroelectric properties, accompanied by a substantial Curie temperature decrease. [ABSTRACT FROM AUTHOR]

The functionalization of zirconia surfaces by accurate and fast printing of periodical patterns embedding sub‐micrometric features is of great interest to many engineering fields and is yet to be explored. This study aims to assess the influence of the Direct Laser Interference Patterning processing parameters on the morphology and microstructure of zirconia surfaces using a 532 nm 10 ps‐pulsed laser source. Well‐defined linear structures with a period of 3 µm are successfully produced. Depending on the laser parameters, the structures are developed at or below the surface level, with higher depths (≈1 µm) being seen for increasing values of laser fluence and pulse overlap. Line‐like hierarchical structures with smaller interference spatial structures (3 µm period) and higher secondary structures with different periods (18, 15, and 12 µm) and heights (7, 5, and 3 µm, respectively) are also obtained on zirconia surface. Ablated regions presented few traces of molten material, nano‐droplets, and sub‐micrometric (<1 µm) pores, while no (sub) micrometric cracks are detected. A slight amount of tetragonal to monoclinic phase transformation (≈5%) is detected by X‐ray diffractometry. A processability map for ps‐laser processing of zirconia is proposed based on the experimental data. [ABSTRACT FROM AUTHOR]

Objectives: To compare marginal bone levels, biological, and technical outcomes of screw‐retained versus cemented all‐ceramic implant‐supported zirconia‐based single crowns after an observation period of 7.5 years. Methods: Forty‐four single implants in the esthetic zone in 44 patients (22 females, 22 males) were randomly assigned to two types of restorations: SR (screw‐retained); veneered one‐piece zirconia abutment and CR (cement‐retained); veneered lithium disilicate crown intraorally cemented on a one‐piece zirconia abutment. Patients were recalled annually up to 7.5 years and survival rates, biological, and technical parameters assessed. Results: A total of 31 patients attended the 7.5‐year follow‐up visit (17 SR group, 14 CR group). The survival rate on the restorative level was 77.5% (74.0% CR, 81.0% SR, p =.6399). Median marginal bone loss (MBL) values yielded −0.073 mm (−0.305; 0.238) in the CR and −0.215 mm (−0.500; 0.555) in the SR group (intergroup p =.6194). Mean bleeding on probing (BoP) values were significantly in favor of group SR with 20 ± 17% compared to 40 ± 22% in group CR (p =.011). The overall biological complication rate amounted to 27.5% (42.1% CR, 14.3% SR, p =.0775), whereas the technical complication rate was 32.5% (42.1% CR, 23.8% SR, p =.314). In total, CR restorations showed significantly more complications (84.2% for CR, 38.1% for SR, p =.0041). Conclusion: One‐piece zirconia‐based single crowns on two‐piece dental implants exhibited a high rate of technical and biological complications at 7.5 years of follow‐up. Cemented restorations revealed significant higher rates of bleeding on probing and total complications compared to screw‐retained restorations. [ABSTRACT FROM AUTHOR]

Objectives: To assess the influence of different primer compositions—silane (S), 10-methacryloyloxydecyl dihydrogen phosphate (MDP), and the combination of silane and MDP (S + MDP)—on the bonding performance of MDP-free and MDP-containing resin cements to highly translucent zirconia. Materials and methods: Tribochemical silica-coated zirconia plates were pretreated with one of three experimental primers, S, MDP, or S + MDP, with untreated specimens serving as controls. Subsequently, these plates were bonded to stainless-steel rods using either two MDP-free or two MDP-containing resin cements. Tensile bond strength was measured after 24 h (TC0) and following thermal cycling (4–60 °C for 10,000 cycles; TC10,000). Data were analyzed using a three-way analysis of variance (ANOVA), followed by one-way ANOVA and Tukey-Kramer post hoc tests (α = 0.05). X-ray photoelectron spectroscopy (XPS) assessed the elemental mass concentrations on the zirconia surfaces. Results: For MDP-free resin cements, MDP-treated specimens exhibited significantly greater bond strengths than controls, regardless of the aging conditions. However, a significant reduction in bond strength was observed between TC0 and TC10,000 in most of the MDP-free resin cement groups, except for one S + MDP group. Conversely, for MDP-containing resin cements, the S + MDP group exhibited no statistically significant differences between aging conditions. Notably, XPS analysis detected silicon, zirconium, and aluminum on the zirconia surfaces. Conclusions: No significant difference in tensile bond strength was observed between aging conditions for MDP-containing resin cements bonded to tribochemical silica-coated zirconia primed with S + MDP. Clinical relevance: The combination of MDP-containing primers and resin cements demonstrated superior bonding performance to tribochemical silica-coated zirconia. [ABSTRACT FROM AUTHOR]

Introduction: In every prosthetic treatment, the final purpose of the restoration is to restore function and esthetics for the patient, respecting biology and anatomical parameters. Regarding full coverage restorations, there are some factors to take into consideration: like the finish line (chamfer, shoulder, featheredge, etc.), the management of the provisional restoration and tissue healing, the material for the final restoration, and the impression technique. All these aspects will determine the treatment process and its possible results. In recent years, vertical preparation and more specifically biologically oriented preparation technique has generated great interest since its introduction in prosthodontics, changing the periodontal tissues, and providing long‐term stability. Materials and Methods: With this technique, the objective is to change the position of the gingival margin, moving it more apically or coronally, depending on the modifications of the provisional. The relining of the provisional is a fundamental step of this technique: the intrasulcular part of the provisional is modified giving a new emergence profile and providing an augmentation of the tissue in the healing process. Discussion: In vertical preparation, there is no predetermined margin. The dental technician should position the finish line more apically or coronally, depending on the depth of the sulcus and on the esthetic needs. Ceramic restorations should not invade the epithelial attachment, otherwise it may cause biological and mechanical problems, repetition of the impression, and of the crown restoration, which lead to increased clinical and laboratory time usage as well as expenses. One challenge is communicating the shape and contour of the temporary restoration to the dental lab to ensure accurate information for the final restoration. Conclusion: Finally, the objective of this article is to describe a technique for transferring all necessary information of the provisional and obtaining a predictable result for the final restoration by using an intraoral scanner system and the fabrication of two 3D printed prototypes. One for the final volume of the crowns and the other for the finish line position. Clinical Significance: The fabrication of 3D printed prototypes allows for a more predictable final restoration, reducing possible communication errors between clinician and technician when restoring with biologically oriented preparation technique. In any esthetic treatment where the restoration does not have a predetermined margin, it is possible with this additional clinical step to provide a more esthetic outcome. [ABSTRACT FROM AUTHOR]

Digital technologies represent new alternatives in prosthetic rehabilitation of all kinds of maxillary or mandibular spans. This article is composed of two parts, in which different technological aspects will be presented regarding the prosthetic restoration of frontal maxillary areas using the CAD-CAM technology, but using different material for resistance framework, both veneered with ceramic materials to restore the aesthetics. The main materials that will be used are: Co-Cr dental alloy and zirconium dioxide (zirconia). [ABSTRACT FROM AUTHOR]

Present work reports on the synthesis of NiO-incorporated nanotorous ZrO2 synthesized by facile co-precipitation method for supercapacitor application. The as-synthesized composite was characterised using FTIR and XRD confirming the successful synthesis of ZrO2-NiO composite (ZNC). FESEM analysis also revealed morphology transition from nanoclusters of tiny ZrO2 particles and stacked flakes of NiO to self-assembled nanotorus ZNC. Electrochemical analyses (like CV, GCD, EIS) also revealed improved electrochemical behaviour of ZrO2 whose specific capacitance increased from 87.77 F/g to 251 F/g in ZNC at 1 A/g. This could be attributed to the synergistic effect of nanotorous morphology in the presence of NiO. These observations were well complemented by a reduced band gap (~ 2.96 eV) and lower charge transfer and solution resistance. A mechanistic insight was also proposed for a deeper understanding of the development of torous structured material. This work provides a closer look into how NiO-driven torous morphology of ZrO2-NiO composite has improved the electrochemical performance of ZrO2. [ABSTRACT FROM AUTHOR]

Zirconia/alumina composites are a family of structural ceramics with excellent mechanical properties. In order to improve the engineering reliability of this kind of composites, the uniform spatial distribution of the two phases is necessary. One of the effective methods to achieve this goal is to synthesize uniform zirconia–alumina composite nano powders. Here, we report mechanochemical synthesis of zirconia–alumina composite nano powders, in which dehydration and crystallization of Zr–Y–Al hydroxide can be achieved under milling conditions, leading to the formation of the tetragonal zirconia phase with supersaturated Al3+. The mechanochemically synthesized powders have the uniform element distribution and a fine primary crystallite size of around 11 nm. After sintering at 1400°C, t‐ZrO2/α‐Al2O3 composite with the uniform phase distribution and grain size distribution could be obtained. To uncover the full benefits of these supersaturated composite powders in ceramic processing, future work could be done to break up the deagglomerations and improve the sinterability of the mechanochemically synthesized zirconia/alumina powders. [ABSTRACT FROM AUTHOR]

Oxide ceramic matrix composites (Ox‐CMCs) are composed of porous matrices reinforced by dense fibers to achieve high damage tolerance. It is generally assumed that their mechanical properties are fiber dominant. However, fiber strength can also be influenced by the surrounding matrix as it can affect fiber grain growth. Fiber–matrix interactions are studied in this work regarding fiber microstructural evolution and composite strength. Minicomposites containing Nextel 610 fibers and different matrix compositions (alumina, alumina–zirconia, and mullite–alumina) are evaluated after sintering and after additional heat treatment at 1200°C for 100 h. Fiber grain growth during sintering is faster in alumina matrix and slower in mullite–alumina matrix. Scanning transmission electron microscope–energy‐dispersive X‐ray spectroscopy (STEM–EDX) measurements show that Si diffuses between fiber and matrix grain boundaries. This outward or inward diffusion of SiO2 leads to the respectively different grain growth kinetics. Grain growth inhibition in alumina–zirconia matrix is only observed after the longer heat treatment, suggesting that ZrO2 diffusion is slower than SiO2. The resultant composite strength depends not only on fiber properties, but also on matrix densification. Minicomposite with alumina–zirconia matrix showed higher strength, while mullite–alumina composites showed higher thermal stability. In summary, the properties of Ox‐CMCs can be tailored by adjusting the matrix composition with the used fibers. [ABSTRACT FROM AUTHOR]

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Zirconium dioxide nanoparticles (ZrO2 NPs) were synthesized using simple, lucrative and easily scalable flame pyrolysis method by directly burning the precursor solution in air. ZrO2 NPs were collected in the form of white soot one from cold surface of conical Flask (F-ZrO2 NPs) and another from direct crucible (C-ZrO2 NPs). The synthesized ZrO2 NPs were characterized by various techniques viz., Fourier Transform Infrared (FT-IR) spectroscopy, X-ray Diffraction (XRD), UV–vis absorption spectroscopy, Energy Dispersive X-ray Spectroscopy (EDS), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Field Emission Scanning Electron Microscopy (FE-SEM), High Resolution Transmission Electron Microscopy (HR-TEM). The synthesised ZrO2 NPs demonstrated the monoclinic (m-ZrO2) and tetragonal (t-ZrO2) mixed phases with an average crystalline size of 16.96 nm. The morphological analysis elucidated the uniform distribution of spherically shaped ZrO2 NPs. The dye degradation performance of synthesized nanoparticles was experienced for the complexed structured Methylene Blue (MB) azo dye meant for environmental applications. The synthesized nanoparticles demonstrated excellent dye removal efficiency of 97.90% along with successful reusability up to six cycles for removal of aqueous Methylene Blue (MB) hazardous colorant dye. So, the synthesised ZrO2 NPs designated as finest contender for the wastewater treatment and various environmental applications. [ABSTRACT FROM AUTHOR]

Despite the significant recent advances in manufacturing materials supporting advanced dental therapies, peri‐implantitis still represents a severe complication in dental implantology. Herein, a sol–gel process is proposed to easily deposit antibacterial zirconia coatings onto bulk zirconia, material, which is becoming very popular for the manufacturing of abutments. The coatings' physicochemical properties were analyzed through x‐ray diffraction and scanning electron microscopy‐energy‐dispersive x‐ray spectroscopy investigations, while their stability and wettability were assessed by microscratch testing and static contact angle measurements. Uniform gallium‐doped tetragonal zirconia coatings were obtained, featuring optimal mechanical stability and a hydrophilic behavior. The biological investigations pointed out that gallium‐doped zirconia coatings: (i) displayed full cytocompatibility toward human gingival fibroblasts; (ii) exhibited significant antimicrobial activity against the Aggregatibacter actinomycetemcomitans pathogen; (iii) were able to preserve the commensal Streptococcus salivarius. Furthermore, the proteomic analyses revealed that the presence of Ga did not impair the normal oral microbiota. Still, interestingly, it decreased by 17% the presence of Fusobacterium nucleatum, a gram‐negative, strictly anaerobic bacteria that is naturally present in the gastrointestinal tract. Therefore, this work can provide a valuable starting point for the development of coatings aimed at easily improving zirconia dental implants' performance. [ABSTRACT FROM AUTHOR]

Finishing and polishing dental ceramics after chairside adjustments is necessary to regain the original surface topography. Though highly subjective, visual and tactile assessment are the most practical ways to assess surface roughness clinically. Several manufacturers recommend polishing kits for specific ceramic materials that differ in efficacy. Proper polishing protocols require the use of sequential polishing instruments that reduce the size of the adjustment abrasions, improve aesthetics and reduce plaque accumulation. If polishing systems are interchanged, stepwise use of a zirconia polishing system may have a "universal" effect on different ceramic substrates. Adjusting zirconia restorations could result in phase transformation and potentially compromise flexural strength. The extent of this degradation is dependent on the yttria content of the zirconia. This may be reduced by appropriate finishing and polishing. [ABSTRACT FROM AUTHOR]

To assess the fracture resistance of computer‐aided design and computer‐aided manufacturing (CAD/CAM) ultratranslucent multilayered zirconia (5Y‐YZP) veneers with varying facial thickness. Sixty translucent zirconia veneers were designed and milled using a chairside CAD/CAM system for maxillary central incisors. The butt joint incisal veneer tooth preparations consisted of 1.00 mm incisal reduction, 0.40 mm chamfer margin, and three different facial reductions; 0.50, 0.75, and 1 mm, respectively. The ceramic veneers were cemented to printed resin dies and subjected to thermal cycling. Subsequently, the restorations were loaded with compressive loading force, and fracture occurrences were recorded. Scanning electron microscope (SEM) images of the fractured specimens were captured. The fracture resistance varied among the veneers with different facial thicknesses. Ultratranslucent zirconia veneers with a facial thickness of 1.00 mm exhibited the highest fracture resistance values (742.15 N), followed by those with 0.75 mm facial thickness (673 N). Minimally invasive veneers with 0.50 mm thickness displayed similar fracture resistance as thicker veneers with 0.75 mm. However, veneers with 1.00 mm thickness displayed the highest values. SEM fracture patterns for 0.50 and 0.75 mm display similar and fewer crack lines than 1.00 mm veneers. Research Highlights: Minimally invasive zirconia veneers exhibit similar fracture resistance to thicker veneers. [ABSTRACT FROM AUTHOR]

Zirconia coating has a lot of promise when it comes to enhancing the optical performance and laser-induced damage threshold (LIDT) of the mirror in laser systems. In this work, a high LIDT ZrO2 coating was created using the sol-gel spin coating technique. The anhydrous ethanol solvent was substituted with alcohol ether solvent, and the spin coating technique was employed to achieve a macro homogeneous and flawless ZrO2 coating. Additionally, organic polymer polyethylene glycol (average Mn 200, PEG200) doping was used to achieve the uniform ZrO2 coating with LIDT. ZrO2-PEG composite coatings with consistent LIDT and exceptional optical properties were created. Alcohol ether solvents helped the sol produce a more homogeneous gel coating on the substrate, as demonstrated by the ZrO2 coating microscope pictures. The LIDT with a 0.5 wt.% PEG200 content was the most uniform. PEG200 organic molecules were able to alter the link state of the ZrO2 particles. The macroscopic mechanical characteristics of the coatings revealed that the hardness and elastic modulus of the ZrO2-PEG composite coating were mostly influenced by the PEG200 content. When the PEG200 content was 0.3 wt.%, the hardness and elastic modulus of the ZrO2-PEG composite coating were the lowest with the highest of the LIDT at 39.25 ± 3.13 J/cm2 (@ 1064 nm, 11 ns, 1 mm2). Highlights: Stable ZrO2 sol was prepared by sol-gel technology with Zirconium (IV) n-propoxide solution, Diethylene glycol (DEG), acetic acid (HAc), and water in ethanol solvent. ZrO2 coating was developed on the fused quartz substrates by a spin coating method, and the effect of solvents on the uniformity of use investigated. The macro defect-free and uniform ZrO2 coatings were successfully obtained by changing the ethanol solvent to alcohol ether solvents. PEG200 had improved the LIDT of ZrO2 coating to a certain extent while enhancing the uniformity of the spatial distribution of it. [ABSTRACT FROM AUTHOR]

ABSTRACT Objectives Materials and Methods Results Conclusions To investigate if the fracture load of implant‐supported cantilever fixed dental prostheses (ICFDPs) in the anterior region is affected by the implant type and the aging protocol.Sixty ICFDPs were prepared using multilayer monolithic zirconia for restoring bone‐level (BL) and tissue‐level (TL) titanium‐zirconium implants. Fracture load was measured at baseline (no aging) or after aging in a chewing simulator loading the implant crown or the cantilever in a 30° angle (n = 10 per group). A two‐way ANOVA was applied (α = 0.05) for the effects of implant type and aging protocol.Implant type (p < 0.001) and aging (p < 0.001) had a significant effect on fracture load values. Baseline specimens of both BL (665 ± 62 N) and TL (554 ± 23 N) had significantly higher mean fracture load values than those of aged specimens(BL implant crown 545 ± 46 N, BL cantilever 563 ± 45 N, TL implant crown 455 ± 32 N, TL cantilever 476 ± 24 N) (p < 0.001). The loading position during aging did not affect fracture load values for BL (p = 0.980) nor TL (p = 0.749). BL implants failed by cement fracture and abutment deformation, while for TL the transmucosal part of the implant deformed.The fracture load values of anterior ICFDPs decrease with aging in a chewing simulator. BL implants are preferable over TL implants for anterior ICFDPs as higher fracture load values were achieved, and no implant deformation occurred. [ABSTRACT FROM AUTHOR]

Background: Primary tooth wear is a common phenomenon that affects chewing ability, dental sensitivity, aesthetics, and occlusion. This study was conducted to compare the antagonistic enamel wear of primary molars opposed to four different crown materials. Methods: Forty lower second primary molars of children aged 4–8 years were allocated into 4 groups: Group 1 (n = 10): received stainless steel crowns; Group 2 (n = 10): received prefabricated commercially available zirconia crowns (NuSmile®); Group 3 (n = 10): received locally manufactured zirconia crowns created via the CAD/CAM system; and Group 4 (n = 10): received locally manufactured hybrid ceramic (Vita Enamic®) crowns created via the CAD/CAM system. All the crowns were cemented with resin-modified glass ionomer cement. The upper arch was scanned with a 3D intraoral scanner immediately (baseline), 6 months, and 1 year after crown cementation to evaluate the wear of the natural enamel of the antagonistic primary molar. The resultant scans were compared via Exocad software to measure the amount of linear wear of the mesiopalatal cusp of the primary upper second molar. Results: The analysed data revealed statistically significant differences between the studied groups. The highest mean wear was detected in the CAD/CAM zirconia crown group, followed by the NuSmile zirconia crown group and then the CAD/CAM hybrid crown group, and the lowest mean wear was detected for the stainless-steel crown group. Conclusion: Compared with stainless steel crowns, aesthetic crowns cause more wear in the antagonistic primary molar enamel. CAD/CAM zirconia crowns induce the greatest amount of wear, followed by NuSmile zirconia crowns. The CAD/CAM hybrid crown is an aesthetic tooth-coloured crown that causes less wear of the opposing enamel than zirconia crowns do. Trial registration: The ClinicalTrials.gov Protocol Registration and Results System (PRS) has this RCT registered as (NCT06456879) on 07/06/2024. [ABSTRACT FROM AUTHOR]

CO 2 methanation has emerged as a promising strategy for the greenhouse gas CO 2 utilization and storage of hydrogen. However, achieving low temperature activity and high temperature stability remains challenging due to the sintering of Ni-based catalysts. To address these limitations, this study introduces a Ni–CaZrO 3 catalyst featuring a perovskite phase supported on ZrO 2 , prepared via citrate complexation and impregnation methods. In this approach, a perovskite-type oxide (PTO) of CaZrO 3 forms through a solid reaction on the surface of ZrO 2 with impregnated CaO. The formation of CaZrO 3 on Ni/ZrO 2 restrains the ZrO 2 support aggregation and reduces the particle size of Ni nanoparticles (NPs), thereby enhancing the activity for CO 2 methanation. The interaction between Ni–CaZrO 3 , and ZrO 2 effectively confines the Ni NPs and CaZrO 3 , enhancing the sintering resistance of Ni–CaZrO 3. This leads to excellent stability of the resulting catalyst for CO 2 methanation. The Ni–CaZrO 3 /ZrO 2 catalyst achieves 85% CO 2 conversion and maintains 100% methane selectivity at 300 °C, demonstrating the prolonged stability over 100 h at 550 °C. Notably, the loading of CaZrO 3 in a perovskite phase on ZrO 2 via solid surface reaction represents an interesting and valuable route, which could be extended to loading other PTOs for industrial applications. [Display omitted] • Ni and CaZrO 3 with perovskite phase loaded on ZrO 2 via solid surface reaction. • Perovskite-type CaZrO 3 reduced Ni particle size and enhanced surface area. • Improved interaction between Ni–CaZrO 3 and ZrO 2 compared to Ni and ZrO 2. • High Ni dispersion achieved 85% CO 2 conversion at 300 °C with 100% CH 4 selectivity. • Ni–CaZrO 3 confinement improved stability over 100 h at 550 °C and anti-sintering. [ABSTRACT FROM AUTHOR]

Abrasive jet machining (AJM) process is commonly used for cutting and drilling of brittle materials in which the phenomenon of material removal can be considered as mechanical erosion by the impingement of high-velocity abrasives. The focus of this research is to compare the performance and economic benefits of recently developed hot abrasive jet machining (hot-AJM) with traditional AJM techniques when machining zirconia ceramic using silicon carbide (SiC) grain particles. The modified AJM employed abrasive air jet (combination of hot abrasive and compressed air) to strike on the work surface for material erosion. Briefly, the cutting performance is investigated by comparing the technological characteristics like material removal rate, machining cost, and taper angle of the developed hole. Abrasive grain size, nozzle pressure, and stand-off distance are considered as the variable factors for machining trials in accordance with the design of experiments. The usage of hot abrasives in AJM improved the material erosion owing to the occurrence of plastic deformation followed by deep chipping on the machined surfaces. From the results, it was observed that the hot-AJM outperformed the normal AJM with regard to improved material removal, reduced dimensional deviation of hole and minimal machining cost. According to the findings of the cost assessment, the machining of zirconia ceramic using hot-AJM was more cost-effective than using normal AJM since it resulted 25% reduction in the total cost of production. The overall machining cost expenditure per unit in hot-AJM was lower (INR 123.12) than expenditure in traditional AJM (INR 153.47). Machining with hot-modified AJM, compared to normal AJM, offers a more techno-economically viable solution for enhancing machinability. [ABSTRACT FROM AUTHOR]

The manufacture of products from refractory ceramics requires high temperatures due to the high activation energies of the sintering process of refractory oxides. Processing temperatures for ceramics made of ZrO 2 , Al 2 O 3 , MgO can be reduced if a flux or glass-forming component is selected. Furthermore, in multicomponent ceramics it is possible to create more favorable thermoresistive properties. This study examines the synthesis, structural, phase and mechanical properties of multicomponent porous ZrO 2 -WO 3 -Al 2 O 3 -MgO ceramics with varying weight concentrations of components. Experimental samples were obtained by standard solid state reaction method. The analysis of fabricated samples was carried out using X-ray phase analysis, scanning electron microscopy and the Vickers microhardness test. In this work, a new approach to increasing the microhardness of porous refractory ceramics is presented, in which WO 3 -based flux forms a matrix composed of glass-like formations that "attach" particles of ZrO 2 and MgAl 2 O 4 phases. The obtained ceramics demonstrates high microhardness values HV0.05 for porous materials ranging from 500 to 600. Studies have shown that the selected composition of multicomponent ceramics (x = 0.10–0.25) can be used as a refractory material up to temperatures of ∼1300 °C. The fabricated refractory ceramics potentially possess chemical stability and optimal microhardness properties, which makes these materials promising as a heat insulating lining in the metals, ceramics and glass manufacturing, as well as for components in the chemical industry. [ABSTRACT FROM AUTHOR]

Digital light processing technology has the advantages of high molding accuracy and the ability to prepare complex structures, which is commonly used in the preparation of resin or ceramics. By mixing two particle sizes of zirconia powders, this paper successfully prepared a 60 vol% slurry with a low viscosity of 1.28 Pa s at shear rate was 50 s−1. By systematically studying the rheological properties of the mixed slurry, the curing depth was exceeding 100 μm at exposure time of 3 s. Furthermore, by investigating the debinding process of the printed sample, it is found that the sintering sample after debinding in vacuum has the highest density. This work has a positive significance for the preparation and debinding process of high solid loading ceramic slurry. [ABSTRACT FROM AUTHOR]

ABSTRACT Background Aim Material and Methods Results Conclusion and Clinical Implications Dental implants made of zirconia (ZrO2) are a potential alternative for titanium implants in dentistry because of their good biocompatibility, mechanical properties and excellent aesthetic results. However, solid long‐term scientific data to prove clinical success of ZrO2 implants are scarce.The aim of this study was to describe and to examine the clinical performance of custom‐made two‐piece ZrO2 implants, to identify possible influencing factors: a) manipulation of the implant after placement and b) the occlusal scheme on the survival rate, and to evaluate the performance of the implant‐supported crown. This follow‐up study collected and examined the 5‐year data to answer the main question: What are the survival and the success rates of custom‐made ZrO2 implants in the maxillary premolar region after 5 years?Of the 31 included patients in this prospective 5‐year follow‐up single‐arm clinical trial, 30 received a custom‐made ZrO2 implant to replace a missing single maxillary premolar, which was subsequently restored with a lithium disilicate crown. Parameters regarding clinical performance, marginal bone‐level (MBL) changes, and patient‐related outcome measures (PROMs) were assessed preoperatively, at the baseline, as well as 1 and 5 years after crown placement. Chances of survival and success of the implant were calculated and displayed using Kaplan–Meier statistics. Kaplan–Meier survival analysis was also performed with stratification based on the variables “manipulation of the implant prior to impression taking” and “occlusal scheme” and compared using log‐rank tests. Bone‐level moderation in time was compared using a paired samples t‐test. Patient's expectations and satisfaction after 5 years were compared as a measure of fulfilled expectations, using a Wilcoxon signed‐rank test. Performance of the implant‐supported crowns was evaluated using validated criteria.Survival and success probabilities after 5 years were, respectively, 75.8% (95% CI [60.0%; 91.0%]) and 71.0% (95% CI [54.0%; 88.0%]) for the custom‐made ZV3 implants. No significant differences in survival rate were found after stratification on “manipulation of the implant” and on “occlusal scheme.” Mean bone‐level alteration between baseline and the first follow‐up was +0.06 mm (95% CI [−0.23 mm; 0.12 mm]; SD = 0.42 mm) and between baseline and the second follow‐up was +0.04 mm (95% CI [−0.35 mm; 0.26 mm]; SD = 0.54 mm). Patients' satisfaction for patients with implants still in function after 5 years was 91.7% (IQR = [90.5%–97.3%]), indicating satisfaction with the treatment. Pooled satisfaction in patients with successful implants after 5 years was significantly higher than patients' expressed expectations before treatment. None of the crowns failed, and no interventions were required.Survival rate of these particular ZV3 implants in our study was lower than expected and clinically not acceptable. Hence, ZV3 implant placement as applied in this study cannot be recommended for clinical practice. Further research on the different appearances of mechanical failure in ZrO2 implants would be highly recommended before a larger prospective randomized clinical trial is conducted to evaluate treatment with custom‐made ZrO2 dental implants. [ABSTRACT FROM AUTHOR]

Low‐shrinkage porous mullite–zirconia ceramics were prepared using Al and ZrSi2 as raw materials and AlF3 as the whisker catalyst through foam‐gelcasting and freeze‐drying methods. The oxidation of Al and ZrSi2 combined with the Kirkendall effect and volume expansion was employed to reduce the sintering shrinkage, while the mullitization was promoted by the reaction between AlF3 and extra ZrSi2, and ZrO2 were generated to enhance the compressive strength as the reinforcing phase. The effect of AlF3 and ZrSi2 content on the microstructure and properties of porous mullite‐zirconia were explored. These ceramics exhibited high porosity (73.75%–85.02%) and compressive strength (2.98–17.71 MPa), low shrinkage (0.47%–10.89%) and thermal conductivity (0.228–0.462 W/(m·K)). In particular, the porous mullite–zirconia ceramics with great compressive strength (4.01 MPa) companied with near‐zero shrinkage (0.47%) at the AlF3 content of 15 wt% and extra ZrSi2 content of 20 wt% by introducing the reinforcing phase (ZrO2). Additionally, the temperature difference around 950°C of the porous ceramics during the heating test proved the exceptional application on thermal insulation. [ABSTRACT FROM AUTHOR]

Mask stereolithography 3D printing for zirconia ceramics has attracted increasing attention in the industrial manufacturing due to their advantages of complex shapes, precisely controlled internal structures and fine surface effects. However, high refractive index and expensive equipment cost have always affected its development. Herein, we combine liquid crystal display (LCD) light curing 3D printing with zirconia molding, which is free from environmental and price limitations. In the conventional method of operation, the cured layer is bonded to the bottom and cannot be manufactured. We put forward a strategy for optimizing separation process and investigate the mechanism of the separation process in depth for high-quality zirconia ceramics LCD 3D printing. The results show that the controlled adjustment of the surface free energy can achieve a great reduction in the separation force, which enabled the successful printing of zirconia ceramics based on LCD. The effect of physical properties of the separation membrane on the separation process was studied and the solid content and 3D printing parameters of ceramic paste were optimized. When the solid content is 72.5 wt%, high quality zirconia ceramic parts with flexural strength of 255 MPa and relative density of 98.1 % can be obtained. This work provides new ideas for the convenient customization of zirconia ceramics in many fields. [ABSTRACT FROM AUTHOR]

ZrO2, TiO2, ZrO2-TiO2, and TiO2-ZrO2 were successfully prepared using the sol–gel method and fully characterized to check their physico-chemical features. X-ray diffraction showed the co-existence of monoclinic and tetragonal ZrO2 in addition to the Anatase phase for TiO2. The formation of mixed oxides led to a reduction in the band gap values and a modification of the textural characteristics, while the XPS evidenced an oxygen vacancy-rich surface. The ability of the synthesized materials to eliminate drug contaminants was checked using Sulfamethoxazole (SMX) as a model molecule under UV and BLUE-LED irradiation. The materials' potential to decrease wastewater toxicity was also studied. The best photocatalyst was TiO2-ZrO2 with 76 and 100% conversion under visible and UV irradiation, respectively. [ABSTRACT FROM AUTHOR]

This study was to investigate the effects of optimized microstructured surfaces on bond strength and bond durability of the latest nanoparticle jetting (NPJ)-printed zirconia. Zirconia microstructured surfaces with different geometries and void volume were analyzed through three-dimensional finite element analysis for surface micromorphology optimization. Zirconia disks and cylinders were additively manufactured by an NPJ 3D printer (N = 128). They were randomly divided into four groups based on surface micromorphology optimization and airborne-particle abrasion (APA) treatment before they were bonded using 10-methacryloloxydecyl dihydrogen phosphate (MDP) containing resin cement (Clearfil SA luting cement). The shear bond strengths (SBSs) were tested before and after 10,000 thermocycles and were analyzed by one-way ANOVA analysis. Failure modes were determined by optical microscopy. Zirconia surfaces were analyzed with X-ray diffraction, scanning electron microscopy, and three-dimensional interference microscopy. The optimized microstructured surface was characterized by circular microstructures with 60 % void volume, about 20 µm of depths, about 10 µm of undercuts, and consistent beam widths. The optimized microstructured surface combined with APA treatment and MDP-containing resin cement possessed the highest SBSs both before and after thermocycling aging (P＜0.05). The greater reductions of zirconia bond strengths occurred when the zirconia were not treated with APA (P＜0.05). The optimized microstructured zirconia surface with circular microstructures and 60 % void volume fabricated by the latest NPJ printing technology could greatly enhance the zirconia bond strength and durability in combination with APA treatment and application of MDP-containing resin cement, which might be promising for adhesively bonded indirect restorations of NPJ-printed zirconia. • Nano-particle Jetting (NPJ) technology had high printing accuracy. • The optimized zirconia surface had circular microstructures with 60 % void volume. • APA treatment and MDP application can enhance zirconia bond performance. • The optimized microstructured surface can improve zirconia bond durability. [ABSTRACT FROM AUTHOR]

Objective: We assessed the changes in optical properties and biocompatibility of transition zones in multilayered translucent monolithic zirconia exposed to prolonged hydrothermal aging and compared the results to those with different yttrium oxide contents. Materials and Methods: Four types of zirconia blocks from IPS e.max ZirCAD were used: 3Y-TZP e.max ZirCAD LT (ZL), 4Y-TZP e.max ZirCAD MT (ZM), 5Y-TZP e.max ZirCAD MT Multi (ZT), and 3Y/5Y-TZP e.max ZirCAD Prime (ZP). A total of 120 specimens (15.0 mm diameter and 1.5 mm height) were fabricated and divided into three groups (n = 10). The aging process for the specimens was conducted in an autoclave set to 134 °C and 0.2 MPa, with durations of 0 h (control), 5 h (first aged), and 10 h (second aged). The optical properties and biocompatibility were analyzed, followed by a statistical analysis of the data (α = 0.05). Results: Before and after aging, ZL and ZP exhibited the lowest color changes. ZT exhibited the highest average transmittance and translucency parameter values, while ZL had the lowest. The water contact angle test showed the highest value in ZM and lowest in ZL across all the aging stages. ZL, ZM, and ZP showed a considerable decrease in the water contact angle; however, ZT did not. A cell counting kit-8 assay showed ZL had the highest value, while ZM had the lowest. A filamentous actin test exhibited the highest value in ZL and lowest in ZM. In the vinculin analysis, ZL and ZT exhibited the lowest values, whereas ZM and ZP had the highest. Conclusion: 3Y/5Y-TZP exhibited a balanced performance across critical parameters, such as color stability, translucency, and biocompatibility, aligning with 3Y-TZP. While 5Y-TZP demonstrated superior translucency, it confirmed the lowest color stability, whereas 3Y-TZP achieved the highest biocompatibility. These properties provide clinicians with a reliable material option that ensures superior esthetic outcomes and long-term prognosis, ultimately contributing to improved patient satisfaction and clinical longevity. [ABSTRACT FROM AUTHOR]

Optical characteristics and microstructure of multilayered zirconia with different yttria contents in each layer can be influenced differently with a layer after speed sintering. The layer-wise translucency and opalescence of dental zirconia (E.max, E.max ZirCAD prime; Cercon, Cercon ht ML) after conventional (control) and speed sintering were analyzed using a spectrophotometer (n = 5). Specimens were subjected to microstructural analyses (n = 2) using field-emission scanning electron microscopy (FE-SEM) and phase analyses (n = 1) using high-resolution X-ray diffraction (HRXRD) and Rietveld refinement. The translucency parameter (TP) and opalescence parameter (OP) were analyzed using a 3-way ANOVA, followed by Scheffé's post hoc test (α = 0.05). The average grain size was analyzed using the Welch's t-test and Kruskal–Wallis test, followed by the Bonferroni–Dunn post hoc test (α = 0.05). Changes to the TP and OP after speed sintering were only observed in the dentin layers. Although the TP of E.max increased (p < 0.05), the difference was below the 50:50% perceptibility threshold (ΔE00 = 0.8). The OP of E.max decreased slightly, whereas that of Cercon increased slightly (p < 0.05). The microstructure and phase fraction of both zirconia barely changed. Therefore, speed sintering is considered to have a negligible clinical impact on the optical characteristics and microstructure. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the influence of simplified ceramic surface treatments on the microshear bond strength (µSBS) of 2 resin cements to a zirconia-reinforced lithium silicate (ZLS) material. Blocks of ZLS were sectioned to obtain a total of 90 specimens (1.5 mm thick), which were assigned to 9 different surface treatment protocols (n = 10). Either hydrofluoric acid (HF) surface conditioner or ammonium polyfluoride self-etching ceramic primer (Monobond Etch & Prime [MEP]) was used for surface treatment and then combined with different bonding strategies (Monobond N silane-based universal primer, Prosil sllane coupling agent, Ambar Universal APS self-etching adhesive, and/or Signum Zirconia Bond methyl methacrylate-based bonding system [SZB]) and luting agents (Allcem or Multilink Automix dual-curing resin cement). Composite resin cylinders were bonded to ZLS with each of the cementation protocols, and the specimens were subjected to 6000 thermal cycles from 5°C to 55°C prior to the µSBS evaluation. The failure mode was analyzed with the aid of a stereoscopic loupe. Statistical analyses were performed with 1-way analysis of variance and Tu key HSD test (α = 0.05). The HF and MEP protocols resulted in significantly higher µSBS values (P< 0.001), while conditioning with SZB resulted in the lowest µSBS. Multilink Automix groups presented higher µSBS values than Allcem groups (P < 0.01). There was no statistically significant difference in the µSBS values of the MEP + Allcem groups based on whether or not an adhesive layer was applied. The failure mode was predominantly adhesive for all specimens. The results indicate that the ammonium polyfluoride-based material MEP may be used as a substitute for surface treatment with HF and silane, but the use of a zirconia primer alone is not advised for bonding to a ZLS ceramic material. [ABSTRACT FROM AUTHOR]

Zirconia implants are recognized for their excellent biocompatibility, aesthetics, and favorable mechanical properties. However, the effects of zirconia surfaces on osteogenesis, particularly in the presence of macrophages, are still not well understood. This study compares two types of zirconia surfaces—ceria-stabilized zirconia/alumina nanocomposite (NANO-Zr) and 3 mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP)—with titanium (Ti) substrates. Both zirconia surfaces promoted macrophage adhesion and proliferation, facilitated a shift from M1 to M2 polarization, and created an immune microenvironment conducive to osteogenesis by downregulating IL-6 and TNF-α and upregulating IL-10 and TGF-β gene expression. In macrophage co-cultures, both zirconia surfaces also supported osteoblast adhesion and proliferation, with NANO-Zr notably enhancing osteogenic differentiation and mineralization. These results highlight NANO-Zr as a promising candidate for future dental and orthopedic implant applications. [ABSTRACT FROM AUTHOR]

Commercially available magnesium aluminate spinel powder (AR-78) was taken as the starting raw material and then the effect of incremental addition of zirconia (ZrO2), in the concentration range of 1-8 wt.% (in steps of 1 wt.%) on the property development of magnesium aluminate spinel, sintered in the temperature range of 1550-1650 °C, was investigated. The study showed that the combined effect of ZrO2 addition and increased sintering temperature aided in the densification of spinel with maximum density shown by the 6 wt.% ZrO2 containing batches. All ZrO2 containing batches revealed the presence of spinel as major phase; unreacted monoclinic zirconia, and aluminum zirconium oxide or Al0.52Zr0.48O1.74 with a tetragonal structure as minor phases. Owing to the similar crystal structure of the secondary phase-Al0.52Zr0.48O1.74 with that of the parent spinel, the densification of spinel was improved. Further, the ZrO2 phases served as grain-growth inhibitors by serving as pinning agents along the spinel grain boundaries and helped in restrict the growth of spinel grains. This resulted in a controlled grain structure and led to improvement in strength values (cold crushing strength and flexural strength) in comparison with additive-free spinel batch. Improvement in thermal shock behavior in terms of strength retainment capacity was also observed with the addition of ZrO2. [ABSTRACT FROM AUTHOR]

Our study examined how different titanium alloy Ti6Al4V (Ti64) and zirconia (ZrO2) surfaces, ranging from rough to very smooth, affect the expression of elastase (NE), matrix metalloproteinase (MMP)-8, MMP-9, and extracellular traps (NETs) by neutrophils. Discs of Ti64 and ZrO2, 10 mm in diameter and 1.5 mm thick, were created using diamond-impregnated polishing burs and paste to produce rough (Ra > 3 µm), smooth (Ra ≥ 1 to 1.5 µm), and very smooth (Ra < 0.1 µm) surfaces. Neutrophils from Wistar rats were cultured on these surfaces, and the culture supernatants were then examined for NE, MMP-8, and MMP-9 using ELISA. At the same time, NET formation was demonstrated immunohistochemically by staining neutrophils with CD16b and DNA with DAPI. Overall, the expressions of NE and MMP-8 were significantly higher from neutrophil culture on Ti64 and ZrO2 rough surfaces compared to the very smooth surface (R > S > VS) after 2 h and 4 h of culture. The expression of MMP-9 also increased with culture time; however, no significant surface effects on expression were observed. Similarly, rough Ti64 and ZrO2 surfaces (R & S) also showed significantly larger NET formation compared to the very smooth surface (VS) after 4 h and 8 h cultures. Our findings suggest that increasing surface roughness on Ti64 and ZrO2 triggers higher NE, MMP-8, and NET formation secretion. [ABSTRACT FROM AUTHOR]

This study investigated the effect of various storage media on the physicochemical properties of plasma-treated 3-mol% yttria-stabilized tetragonal zirconia: air, vacuum, deionized water (DIW), and plasma-activated water (PAW). Each group was divided into five subgroups based on storage periods: immediately after NTP irradiation (T0), and after 1 week (T1), 2 weeks (T2), 3 weeks (T3), and 4 weeks (T4). The control group (C) received no treatment. The storage groups were monitored weekly using various analytical techniques, including contact angle measurements, scanning electron microscopy (SEM), focused ion beam (FIB)-SEM, confocal laser scanning microscopy (CLSM), x-ray photoelectron spectroscopy (XPS), and x-ray diffraction (XRD). Our results demonstrate that plasma-treated zirconia surfaces stored in DIW retained or even increased their hydrophilicity due to the formation of hydrogen bonds and preservation of nitrogen functionalities. In contrast, surfaces stored in air exhibited significant hydrophobic recovery. FIB-SEM analysis showed no adverse internal structural changes regardless of storage medium. The roughness of the zirconia surface slightly increased after plasma treatment and was generally retained across all storage groups for 4 weeks, except for the air storage group. This study concludes that storage in DIW effectively preserves the enhanced surface properties of plasma-activated zirconia for up to 4 weeks. [ABSTRACT FROM AUTHOR]

The TiO 2 substrate coatings containing varied ZnO or ZrO 2 nanoparticles were made using the polymeric and microwave combustion methods and then thermally treated at various temperatures. Furthermore, before coating on the substrate, the produced nanoparticles undergo characterization and calcination to optimize the conditions for developing ZnO and ZrO 2 phases and track their composition. The X-ray diffraction method (XRD), transmission electron microscopy (TEM), and infrared analysis (IR) are used to characterize the calcined produced nanoparticles. After heat treatment at 1000 °C, the TiO 2 substrate is prepared. The produced coated substrate is studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared (IR), apparent porosity, bulk density, chemical corrosive properties and electrochemical measurement in 3.5 % NaCl and 1 M HCl solutions. The corrosion resistance of ZnO or ZrO 2 -covered TiO 2 substrate is ascertained by anticorrosive behaviors, which include weight loss, apparent porosity, corrosion rate, and SEM. The findings showed that 800 °C is the ideal temperature for preparing ZrO 2 -coated substrate, whereas 1000 °C is the perfect temperature for preparing ZnO-coated substrate. The microstructure reveals surface micro-cracks on the ZrO 2 -coated TiO 2 substrate. Good dispersion, homogeneity, and compaction were noted for the ZnO-coated substrate. Between 14 and 17 % of the ZnO-coated substrate and 20–21 % of the ZrO 2 -coated substrate, made via polymeric and microwave combustion techniques, had visible porosity when ZnO-coated samples exhibited greater corrosion resistance against NaCl media. In contrast, ZrO 2 -coated samples had much stronger anticorrosive qualities in HCl media than uncoated and Zn-coated samples. According to the electrochemical results, the ZnO-coated TiO 2 synthesized by polymeric technique at 1000 °C showed 99.86 % inhibitory efficiency against NaCl. An inhibitory efficiency of 94.4 % was observed in a ZrO 2 -coated TiO 2 substrate that was produced at 800 °C using a polymeric technique. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective Materials and Methods Results Conclusions Clinical Significance To investigate whether nonthermal atmospheric plasma (NTAP) can promote bonding between commonly used adhesive monomers and zirconia.The zirconia surface and monomers (HEMA, BisGMA, TEGDMA, and MDP) were treated with different NTAP approaches (10 w, 30 s), and the surface characteristics and chemical structures between the zirconia surface and monomers were verified by the contact angle, scanning electron microscopy (SEM), attenuated total reflectance Fourier transform infrared (ATR/FT‐IR) spectroscopy, and x‐ray photoelectron spectroscopy (XPS). Scotchbond Universal adhesive with two different resin cements, RelyX Ultimate and RelyX Unicem 2, was applied, followed by NTAP‐aided clinical procedures, and then microtensile bond strength test (μTBS) and failure mode evaluation were tested for preliminary mechanical properties assessment. One‐way ANOVA was employed for the statistical analysis.The contact angle analysis, SEM, and ATR‐FTIR confirmed that NTAP can promote the polymerization of BisGMA, TEGDMA, and MDP on the zirconia surface, while XPS confirmed that NTAP can induce a chemical reaction between MDP and zirconia.Nonthermal atmospheric plasma can increase the affinity between selected monomers and zirconia and promote the chemical bonding strength between phosphate monomers and zirconia; besides, it can enhance the bonding strength of two different adhesive systems.The mechanism of how NTAP improved common adhesive monomers interacting with zirconia surfaces was revealed in this study. NTAP, as a relatively high energy‐boosting method, could not only improve the surface affinity of zirconia and chemical bonding in‐between monomers and zirconia but also enhance the polymerization of different monomers onto zirconia, resulting in improved bonding properties. Thus, further exploration of versatile bonding materials and/or onto different dental substrates could take this into account. [ABSTRACT FROM AUTHOR]

Microstructural evolution during the sintering of tetragonal ZrO 2 nanoparticles was investigated using stress-free sintering and sinter forging. The green body prepared via gel casting had a densely packed structure with a narrow pore size distribution. Special attention was paid to the evolution of pore structures in the initial and intermediate stages of sintering. Pore coarsening, which is considered an important issue in the nanoceramics densification, was not remarkable in sinter forging. The accelerated densification rate, coupled with the retention of finer pore size than that in stress-free sintering throughout densification, lowered the sintering temperature requirement. This temperature reduction effectively inhibited grain growth, allowing samples prepared via pressure-assisted sintering to maintain a nanometric structure. [ABSTRACT FROM AUTHOR]

Flash healing is a technique that uses power spikes to rapidly repair microcracks on ceramic surfaces. In this study, the microstructures of flash-healed Vickers-indented microcracks near the positive/negative electrodes under a DC electric field were examined by scanning transmission electron microscopy. The microstructural morphology near the positive electrode was almost identical to that of the microcracks located between both electrodes, as previously reported. However, a decrease in the degree of healing was observed near the negative electrode. This was attributed to the insufficient recovery of dislocations generated at the indentation state, which should have occurred in the initial stage of healing. The delay in dislocation recovery prevented contact between the inner surfaces of the microcracks and is possibly related to the increase in oxygen vacancies near the negative electrode. [ABSTRACT FROM AUTHOR]

The mutual influence of interface processes during simultaneous contact of zirconia ceramic plate with adhesion-active Cu–Ga–Ti melt (on one side of the plate) and inert to oxides liquid copper (on other side of the plate) was studied. Wetting of ceramic with metal melts was studied by sessile drop method, the structure of the interfaces was determined using SEM. Due to the dissolution of ceramic oxygen in Cu–Ga–Ti, non-stoichiometric zirconia (ZrO2-x) is formed, then ‘surplus’ zirconium from the ZrO2-x structure dissolves in the copper melt, the stoichiometry of zirconia is restored and an additional amount of oxygen dissolves in the Cu–Ga–Ti melt. It leads to a decrease in the adhesion of Cu–Ga–Ti to ceramics, while improving the wetting of ZrO2 ceramics with copper. The ZrO2–Cu–Ga–Ti interface contains copper–titanium–oxygen intermetallides with zirconia inclusions, which does not provide adhesion of metals with solid oxides. If the contact of Cu–Ga–Ti with ZrO2 is formed before contact with liquid copper, then the interface layer contains oxidized titanium, which promotes adhesion of metal to ceramic. Thus, the design of the sample affects the processes in the studied systems in the same way as the heating mode and the amount of the active component. [ABSTRACT FROM AUTHOR]

Martensitic phase transformation of zirconia (ZrO2), when realized from the superelastic effect, has immense potential in energy applications, such as micro‐actuation and high‐energy dissipation/damping. In this study, martensitic transformation in ZrO2 is studied using a newly developed microscale phase field model, which is scale‐independent and contains an averaged gradient term. The model is implemented using the FEniCS package in Python. With a thorough explanation of the model construction, the mechanics of phase transformation are detailed, and the material behaviors under different stress conditions are discussed. Mesh sensitivity, multivariant evolution, and the effect of particle size are analyzed to understand the martensite evolution in superelastic ZrO2. This work provides new insight into the martensitic phase transformation behaviors of micron‐sized spherical ZrO2 particles. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the fracture resistance of veneered incisor crowns made from highly translucent zirconia frameworks. Materials and Methods: Ninety‐six all‐ceramic single crowns were based on either a coping with minimum wall thickness or a cutback framework fabricated from highly translucent zirconia (5Y‐PSZ). Each one‐third of the specimens was finalized with different veneering ceramics using standardizations and glaze firing. Crowns were luted to cobalt–chromium dies with MDP‐containing composite cement. Half of the entire sample underwent artificial aging (chewing simulation and thermocycling) before fracture load tests were conducted using a 6 mm steel sphere applied in a 90° angle to the oral aspect of the crowns with 1.3 mm distance to the incisal edge. Besides descriptive presentation of recorded forces at first damage (F1d) and fracture (Fu), Kruskal Wallis and Mann–Whitney U tests were used to analyze data at α = 0.05. Results: Directly after manufacturing, incisor crowns of all test groups showed sufficient mean fracture resistances. After artificial aging, crack formation was observed in a high percentage for fully veneered crowns of all test groups, but only for one veneering ceramics with cutback crowns. Mean test forces of unaged crowns were F1d,mean ≥ 422 N | Fu,mean ≥ 749 N (fully veneered) and F1d,mean ≥ 644 N | Fu,mean ≥ 706 N (cutback) dropped significantly to F1d,mean ≥ 131 N | Fu,mean ≥ 223 N (fully veneered) and F1d,mean ≥ 324 N | Fu,mean ≥ 524 N (cutback). Conclusions: Within the limitations of this laboratory study, 5Y‐PSZ based anterior crowns can be a viable treatment option. Framework design, choice of the veneering ceramics and artificial aging show relevant effects on the fracture resistances. Concerted veneering ceramics should be used and partially veneering of the zirconia frameworks should be favored over full veneers. [ABSTRACT FROM AUTHOR]

ZnO/ZrO2 catalysts have shown better activity in the CO2 hydrogenation to methanol compared with single component counterparts, but the interaction between ZnO and ZrO2 is still poorly understood. In particular, the effect of the ZrO2 support phase (tetragonal vs. monoclinic) was not systematically explored. Here, we have synthesized ZnO/ZrO2 catalysts supported on tetragonal ZrO2 (ZnO/ZrO2‐t) and monoclinic ZrO2 (ZnO/ZrO2‐m), which resulted in the formation of different ZnOx species, consisting of sub‐nanometer ZnO moieties and large‐sized ZnO particles, respectively. ZnO/ZrO2‐t exhibited a higher methanol selectivity (81 vs. 39 %) and methanol yield (1.25 vs. 0.67 mmol g−1 h−1) compared with ZnO/ZrO2‐m. The difference in performance was attributed to the redox state and degree of dispersion of Zn, based on spectroscopy and microscopy results. ZnO/ZrO2‐t had a high density of ZnOx‐ZrOy sites, which favored the formation of active HCOO* species and enhanced the yield and selectivity of methanol along the formate pathway. Such ZnO clusters were further dispersed on ZrO2‐t during catalysis, while larger ZnO particles on ZnO/ZrO2‐m remained stable throughout the reaction. This study shows that the phase of ZrO2 supports can be used to control the dispersion of ZnO and the catalyst surface chemistry, and lead to enhanced catalytic performance. [ABSTRACT FROM AUTHOR]

Key Clinical Message: The principles of tissue preservation, minimally invasiveness and approaching different clinical situations biologically rather than surgically govern today's dentistry. Thus, different clinical scenarios require procedures that offer the dentist and the patient the possibility to choose the more invasive treatment options later in life. Subsequently, the case reported refers to a minimally invasive technique that treats single tooth edentulism using single partial retainer FDPs fabricated from monolithic zirconia. This approach is conservative, biocompatible, aesthetic, strong, rapidly obtained through CAD/CAM techniques and cost‐effective. [ABSTRACT FROM AUTHOR]

Objectives Optimum flexural strength and viscosity are essential for longevity while efficiently handling dental luting composite. This study aims to investigate the effects of zirconia and alumina on the flexural strength (FS)and viscosity of dental cement made of silica rice husk. Materials and Methods Study groups with different percentages of weight (wt.): Group 1 (3 wt.% zirconia), Group 2 (3 wt.% alumina), and Group 3 (3 wt.% zirconia and 2 wt.% alumina), negative control specimen (0 wt.% zirconia/alumina) and Rely-X U200 (3M ESPE). A universal testing machine and a rheometer were used to test FS and viscosity, respectively. One-way ANOVA and post-hoc Bonferonni test were used for data analyses. Results and Discussion FS and viscosity for Group 3 (3 wt.% zirconia and 2 wt.% alumina) were significantly higher compared to the negative control (p<0.05). Conclusion: Adding zirconia and alumina improved flexural strength without compromising the viscosity of dental luting composite. This experimental dental luting cement using hybrid fillers could be an alternative to resin luting cement. [ABSTRACT FROM AUTHOR]

Objectives: The objective of this review was to assess clinical trials that have examined the materials, design, and bonding of ceramic cantilevered resin‐bonded fixed dental prostheses (RBFDPs) as a potential option for replacing missing anterior teeth. The evaluation primarily focuses on the rate of restoration failure and clinical complications. Materials and Methods: A thorough search of databases including PubMed/MEDLINE, Scopus, and the Cochrane Library, was conducted. The most recent search was performed in October 2023. Clinical studies that compared ceramic cantilevered RBFDPs with double retainers or cantilevered RBFDPs using different ceramic materials or bonding systems were included. The outcome measures considered were restoration failure and complication rates. Results: Twelve studies met the eligibility criteria. The pooled data showed a statistically significant decrease in complication events when using cantilever designs compared with double retainer designs (p < 0.05); however, there were no differences found between the two designs in terms of restoration failure. The complication and failure rate of cantilever RBFDPs did not show a statistically significant difference with or without ceramic primer application before luting with phosphate monomer‐containing luting resin (p > 0.05). Conclusions: Ceramic cantilevered RBFDPs have lower complication rates compared with those with double retainers. The use of a ceramic primer prior to luting composite resin for ceramic cantilevered RBFDPs decreases the occurrence of complications and failures, although this effect was not statistically significant. Additional research is required to confirm these findings. Glass ceramic cantilever RBFDPs showed a decrease in success after 6 years, requiring ongoing monitoring, but both zirconia and glass‐infiltrated alumina cantilever RBFDPs have demonstrated durability with excellent long‐term success and survival rates for up to 10 and 15 years. Clinical Significance: Cantilever ceramic RBFDPs in the anterior region are a less invasive and valuable treatment option, providing good esthetic results. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the effect of different cement types on the incidence of failure and loss of retention of zirconia and metal‐ceramic single crowns (SCs) cemented on implant abutments. Methods: We placed 567 implant‐supported SCs in 358 patients and retrospectively evaluated long‐term retention for up to 12.8 years. The frameworks were made from metal alloy (n = 307) or zirconia (n = 260). SCs were cemented with permanent (glass‐ionomer cement; n = 376) or semipermanent cement (zinc oxide non‐eugenol cement; n = 191) on standardized (n = 446) or customized (n = 121) abutments. Kaplan–Meier curves were used to calculate the incidence of decementation. Differences between survival curves were assessed with log‐rank tests. Cox‐regression analysis was performed to evaluate multiple risk factors. Results: Of the 567 SCs, 22 failed because of technical complications and four because of implant loss. Loss of retention was observed in 50 SCs. Analysis revealed a 7% probability of loss of retention for zirconia and 16% for metal‐ceramic SCs after 10 years (p =.011). After 5 years, loss of retention was higher for standardized abutments than for customized abutments (p =.014). The probability of loss of retention was higher with semipermanent than with permanent cement (p =.001). Cox‐regression analysis revealed semipermanent cement as the only significant risk factor for SC failure (p =.026). Conclusions: In contrast to semipermanent cement, permanent cement provides acceptable long‐term retention of cemented implant‐supported SCs. These possible positive effects of customized abutments have to be controlled with larger sample sizes. [ABSTRACT FROM AUTHOR]