• Novel gas-based joining method eliminates the need for fillers and fluxes. • Melting point depression gases react and enrich the metal surface. • Exposed surface enables diffusion-driven bonding with the following heat treatment. • Proof of concept with bulk stainless steel samples shows successful metal joining. • Gas Actuated Bonding offers a new and fundamentally different joining strategy. Metal joining remains an essential yet challenging process in manufacturing, particularly for components with small dimensions, multiplex, delicate geometries, or dissimilar metals, where conventional joining methods can be insufficient. Here, we introduce Gas Actuated Bonding (GAB), a novel joining method that employs gaseous melting-point-depressant (MPD) agents to induce a diffusion-active state at temperatures below the bulk melting point of the substrate metal. Using phosphine (PH 3 ) as an MPD agent on stainless steel (316 L), we demonstrate that controlled MPD gas exposure followed by uniform heat treatment results in a metallurgical joint without the need for fillers, fluxes, or localized heat input. Microstructural and compositional analyses confirm phosphorus incorporation and diffusion at the interface, consistent with a joining mechanism driven by an interfacial layer capable of high mobility. This approach establishes a new framework for controllable, flexible metal joining.

Nucleases are a class of enzymes that specifically cleave nucleic acids in all living organisms. They play crucial roles in essential biological processes, including the regulation of gene expression, DNA damage repair, and RNA processing and degradation. MYG1 (melanocyte proliferating gene 1) is a highly conserved eukaryotic protein that exhibits 3'→5' exonuclease activity. This study systematically characterizes the enzymatic properties of MYG1 and determines its structures in complexes with metal ions and various mono- and poly-(deoxy)nucleotides. The functional roles of key residues involved in metal ion binding and substrate binding in the catalytic reaction are examined through site-directed mutagenesis, enzymatic activity assay, and structure determination. Our biochemical and structural data together demonstrate that MYG1 is a Mn 2 +- or Mg 2 +-dependent 3'→5' exonuclease capable of cleaving a variety of nucleic acids with different structures. It exhibits the highest activity for single-stranded RNA and a nucleotide preference for U in single-stranded RNA and dT in single-stranded DNA. Mechanistically, MYG1 functions as a dimer, with the active site formed by the catalytic domain of monomer 1 and the substrate-binding domain of monomer 2, and cleaves nucleic acids through a two-metal ion-mediated catalytic mechanism. These findings establish a molecular basis for further investigations into the biological functions and molecular mechanisms of MYG1 within cells and its potential roles in human diseases.

ABSTRACT As a fundamental phenomenon in nature, chirality has been extensively studied in molecular structures; however, it remains underexplored at the electronic level. Understanding how structural chirality transfers into electronic states is crucial for uncovering the essence of many chiral effects. In this study, we report the engineering and direct visualization of chiral electronic states within an otherwise planar, achiral hexa‐ peri ‐hexabenzocoronene (HBC) framework. By employing atomically precise asymmetric nitrogen doping of HBC through on‐surface synthesis, we fabricate a C 3 ‐symmetric triaza‐HBC on Au(111). Utilizing high‐resolution scanning tunneling microscopy and non‐contact atomic force microscopy, we resolve the chiral molecular structure of triaza‐HBC confined to the surface, as well as the chiral texture of the resulting interfacial electronic states and its evolution at different energies. Density functional theory calculations reveal that these electronic chiral features arise from the molecule's intrinsic chiral orbitals, which hybridize strongly with the metal substrate while still retaining their chiral character. This study not only demonstrates a clear transfer of chirality from molecular structure to the electronic landscape but also provides a versatile platform for the rational design of chiral electronic molecules and materials.

Abstract Thin inorganic films, such as metal oxides, are frequently employed as functional materials for decoupling or optimisation of the interaction between molecular magnetic layers and metallic surfaces. In the case of single-molecule magnet (SMM) deposits, an effective decoupling layer can reduce the hybridisation with the metallic substrate, which would otherwise suppress their intrinsic magnetic bistability. In this work, we investigate the potential of an ultra-thin Fe oxide layer as a substrate for the terbium(III) bis-phthalocyaninato (TbPc 2 ) SMM in technological platforms. A multi-technique approach was employed to evaluate the integrity of a TbPc 2 sub-monolayer deposit and to determine the molecular adsorption geometry at the surface. Furthermore, large-scale facilities experiments were performed, and X-ray magnetic circular dichroism was used to probe the magnetic properties of the TbPc 2 sub-monolayer. Similar to what is observed on metallic surfaces, a suppression of the slow relaxation mechanisms in TbPc 2 is detected. The central finding is that while the magnetic moments and electronic configuration of the molecule are preserved, the characteristic slow magnetic relaxation is suppressed. This highlights the critical role of substrate phonon stiffness and tunnel barrier thickness in stabilizing the SMM behavior.

Photoluminescence blinking is a major drawback of semiconductor nanoparticle-based single-photon emitters. Here, we present a novel work on the theoretical analysis of the blinking mechanism in zinc oxide nanoparticles (ZnO NPs) and demonstrate that blinking can be suppressed by allowing photoinduced charge to quickly exchange with a metallic reservoir. Further, we show that ZnO NPs coated on a metallic substrate exhibit single-photon emission with high brightness, comparable to fluorescent nanodiamonds and that they exhibit high stability against photo-degradation. Furthermore, polarization-resolved photoluminescence measurements indicate that the emission dipole in ZnO NPs is well aligned with the axis of the excitation dipole, thereby providing a single-photon source with controllable polarization states of single-photon emission.

Purpose The interfacial performance of epoxy coatings strongly influences their long-term corrosion protection on metallic substrates. This study aims to elucidate how cerium-based conversion coatings affect epoxy/metal interfacial interactions and adhesion mechanisms. Design/methodology/approach Electrochemical impedance spectroscopy (EIS) and pull-off tests were used to assess interfacial stability and adhesion on differently pretreated substrates. A surface-energy-based thermodynamic model was implemented to predict interfacial bonding strength. In addition, density functional theory (DFT) calculations and molecular dynamics (MD) simulations were conducted to probe atomic-scale interactions and dynamic adsorption behavior at the epoxy/CeO2 interface. Findings Cerium conversion coated substrates exhibited superior interfacial stability and adhesion compared to other pretreatments, as indicated by higher impedance values and cohesive failure within the coating. Thermodynamic predictions of interfacial bonding strength were consistent with EIS and adhesion results. DFT results revealed enhanced electronic interactions and charge transfer at the epoxy/CeO2 interface, while MD simulations demonstrated stable adsorption and resistance to interfacial disruption under realistic conditions. Originality/value This work integrates experimental electrochemical and adhesion characterization with thermodynamic and atomistic simulations to provide a predictive understanding of corrosion-resistant coating interfaces, offering a rational basis for interface design beyond conventional trial-and-error approaches.

For their incorporation in molecular spintronic devices, it is mandatory to understand how the properties of spin-crossover molecules are modified when they are in direct contact with metallic substrates and how the growth of molecular films is governed by the substrate. In this context, we investigate in detail the structure of [FeII(HB(3,5-(CH3)2Pz)3)2] (Pz = pyrazolyl) ultrathin films adsorbed on Cu(110) using grazing incidence X-ray diffraction measurements, along with their spin-crossover properties measured by X-ray absorption spectroscopy. For submonolayer coverage, the molecules self-assemble into two equivalent domains that are in a perfect epitaxial relationship with the Cu(110) substrate at room temperature. In parallel, the molecules are fully locked in a high spin (HS) state at low temperature. Density functional theory calculations show that there is a complex interplay between the epitaxial strain effect and the binding to the substrate that governs the orientation growth and the spin-crossover properties of the molecular films. For thicker thicknesses, a layer-by-layer growth of the (100) planes of the molecular bulk crystal with the release of the epitaxial constraint is observed, while the spin-crossover properties of the films are partially recovered with the opening of a hysteresis. The results obtained are very different from those observed on thin films adsorbed on Cu(111), indicating that not only the nature of the substrate but also its symmetry influences the spin-crossover properties of molecules.

Molecular catalysts offer atomically defined active sites with tunable catalytic performance, which is strongly substrate-dependent. Nevertheless, a mechanistic understanding of how substrate effects govern activity remains lacking, particularly under electrochemical conditions where the applied potential can dynamically reshape interfacial electronic structure. Here, using density functional theory and constant-potential calculations, we systematically investigate how metal substrates regulate the CO2 reduction activity of transition-metal phthalocyanines (TMPcs). Across FePc, CoPc, and NiPc supported on Au, Ag, and Pt surfaces with different facets, we revealed that metal substrates regulate the activity through two coupled mechanisms: (i) tuning the static charge state of the metal center, which controls *CO binding strength under vacuum, and (ii) enabling potential-driven dynamic charge transfer that reshapes reaction energetics under working conditions. Accordingly, electron transfer at the transition-metal center emerges as an effective electronic descriptor for *CO adsorption and the support-dependent activity trend. More importantly, metallic substrates exhibit a pronounced electronic response to applied potential, acting as charge reservoirs that dynamically modulate the active site. As a result, CoPc/Pt(111) becomes thermodynamically favorable for CO2 reduction at -0.6 V versus RHE, whereas graphene-supported CoPc remains limited under the same conditions. These findings show that both substrate nature and applied potential are critical for determining the activity of molecular electrocatalysts and provide design principles for supported molecular catalysts for CO2 reduction.

Ice adhesion on exposed structures remains a major operational challenge, motivating the search for passive, material-based anti-icing strategies. Molecular dynamics offers a controlled way to investigate ice–surface interactions beyond the limits of experimental setups. In this work, we develop a simulation framework to model the impact of solid hexagonal ice droplets on metallic substrates. Ice impacts are simulated across a range of velocities (10–120 m/s), temperatures (120–250 K), and face-centred cubic surface materials (gold, copper, silver, aluminum, and nickel). Using LAMMPS, mW water force-field, EAM/Alloy metal potentials, and Lennard-Jones water–surface interactions, we quantify phase evolution through angular order parameter and quasi-liquid layer measurements, complemented by the CHILL+ algorithm in OVITO. By isolating all external factors, we show that melting increases with velocity and temperature and correlates with substrate properties: metals with high thermal diffusivity and low Young’s modulus tend to decrease post-collision ice melting. The ratio of the former to the latter, a derived index of merit Υ, significantly correlates with melting percentage and identifies silver as the most effective anti-ice material examined. Statistical analyses strongly suggest that these surface properties influence interfacial melting, supporting the use of this modelling framework for screening and designing anti-icing materials.

The integration of metal-organic framework (MOF) thin films into functional devices is currently hindered by high temperatures, prolonged processing times, and complex additives required by conventional fabrication methods. We demonstrated a plasma-assisted strategy to directly synthesize crystalline MOF films on metal substrates under ambient conditions and overcome these kinetic and processing limitations. We used a HKUST-1 on a copper substrate as a model system and demonstrated that continuous crystalline films are formed within minutes in an ethylene glycol solution without the need for thermal annealing or external metal precursors. The mechanistic investigation revealed that the plasma-liquid-solid interface functions as a unique reaction field providing a dual driving force. The plasma treatment induced a reaction by functioning as an electrochemical driver for anodic metal dissolution while simultaneously assisting in ligand deprotonation through the generation of reactive species such as hydroxyl and superoxide ions. This process is governed by a kinetic balance, where a specific processing window defined by the metal electrode potential and the ligand acidity distinguishes copper from other metals. These results indicate that atmospheric pressure plasma serves as a potent tool for interfacial coordination chemistry, provided that the electrochemical ion supply and acid-base kinetics are synchronized. This work establishes a design principle for the rapid and additive-free fabrication of MOF films, thus offering a foundation for the streamlined integration of functional porous layers into next-generation devices.

Pterin deaminase and sepiapterin deaminase are key members of the amidohydrolase superfamily and play essential roles in pteridine metabolism across a wide range of biological systems. Pterin deaminase catalyzes the deamination of pterins, contributing to the regulation of purine and pyrimidine metabolism, whereas sepiapterin deaminase is specifically involved in the degradation of sepiapterin, a critical intermediate in the tetrahydrobiopterin (BH4) biosynthetic pathway. These enzymes are distributed throughout prokaryotic and eukaryotic organisms and display diverse substrate specificity, metal dependency, and enzymatic stability. Pterin deaminase has been identified in bacterial and fungal species, as well as in mammalian liver tissues, where it plays a role in folate metabolism and cellular signalling. In contrast, sepiapterin deaminase is predominantly found in vertebrate tissues with a high BH4 demand, particularly in the neurological and vascular systems. Structural analyses reveal that both enzymes share the conserved metal-binding characteristics of the amidohydrolase superfamily, with pterin deaminase being a zinc-dependent metalloenzyme. Despite sharing the (β/α)₈-barrel fold and metal-binding catalytic core, subtle variations in active-site residues, such as the substitution of histidine with cysteine, determines their catalytic behavior, metal preference, and redox sensitivity. Comparative kinetic and structural analyses revealed that pterin deaminase displayed broader catalytic flexibility and higher metal tolerance, whereas sepiapterin deaminase maintained strict substrate selectivity and redox regulation. These adaptive differences reflect an evolutionary transition from general pterin degradation to specialized cofactor maintenance and pigment biosynthesis. Beyond their biochemical distinctiveness, both enzymes exhibit emerging biomedical and biotechnological significance. Pterin deaminase in folate catabolism and potential antitumor applications and sepiapterin deaminase in neurotransmitter regulation and pigment-associated disorders. This review provides a detailed structural, catalytic, and physiological perspectives to highlight the evolutionary divergence of pterin deaminase and sepiapterin deaminase within the amidohydrolase fold, and their growing relevance in metabolic and biomedical research. KEY POINTS: • Pterin deaminase and Sepiapterin deaminase play important but different roles in the pteridine metabolic network. • Pterin Deaminase's thermostability and substrate versatility make it a promising biocatalyst for green chemistry, pharmaceutical synthesis, and diagnostic biosensors. • Sepiapterin deaminase -like enzymes in bacteria appear stress-inducible, with expression modulated by oxidative response factors such as SoxRS and fumarate-nitrate reductase (FNR), an adaptive role in redox regulation and biofilm formation.

Controlling whether a molecular radical retains its spin on a metal surface is a key prerequisite for building switchable, atomically precise carbon-based spin architectures. Here, we use 3,6-bis(4-bromophenyl)-9H-fluorene to synthesize covalently linked fluorene trimers and oligomeric chains on Au(111) via Ullmann coupling and then generate strongly localized fluorenyl-type radical centers by site-selective tip-induced dehydrogenation. Combining the bond-resolved nc-AFM with scanning tunneling spectroscopy, we identify two interconvertible adsorption configurations: a non-bonded radical state that displays a pronounced zero-bias Kondo resonance and a chemisorbed state in which a local C-Au bond is formed at the radical site, accompanied by a characteristic geometric relaxation of the five-membered ring and complete quenching of the Kondo resonance. In both the macrocycles and chains, the distribution of the Kondo-active sites depends on metastable global adsorption geometries and can be reversibly reconfigured by tip perturbation. These results establish a structure-resolved chemisorption versus physisorption switch as a practical design rule for stabilizing and toggling spins in multi-radical rings and chains directly on metallic substrates, opening opportunities for programmable quantum spin functionalities in surface-supported π-systems.

Metal substrates were preprocessed via picosecond laser surface texturing (PLST, 532 nm) to fabricate interfacial microgrooves for tribological performance optimization prior to deposition of a magnesium silicate hydroxide (MSH)/graphite/MoS2–PI solid lubricant coating. By tuning the PLST parameters (average laser power: 0.2–0.5 W, scan passes: 3–5, hatch spacing: 0.005–0.1 mm), three representative texture geometries (linear, circular, and square) were produced, and the resulting coating performance was compared with conventional mechanical polishing and sandblasting pretreatments. Among the three laser textures, the linear texture exhibited the most excellent tribological performance and interfacial adhesion, outperforming the circular and square counterparts. Ball-on-disk tests in a kerosene-contaminated environment (10 N, 800 rpm) showed that the linear-textured sample reached the lowest steady-state friction coefficient (0.038), lower than polished (0.048) and sandblasted (0.052) controls, together with reduced wear scar dimensions. Progressive-load scratch tests indicated a pronounced adhesion enhancement, with the critical failure load increasing from 7.05 N (polished) to 26.05 N for the linear-textured interface, which is higher than 21.21 N (circular) and 23.78 N (square) textures. Cross-sectional microscopy and EDS mapping reveal that the laser-defined microgrooves (~15 μm depth, ~120 μm width, ~500 μm spacing) act as a parameter-controlled interfacial architecture that promotes mechanical interlocking and provides lubricant-rich reservoirs. This laser-enabled interfacial design suppresses delamination, supports transfer film stability, and ultimately enhances the coating’s tribological performance by reducing friction and wear.

Surface lattice resonances (SLRs) in metasurfaces have become a transformative platform for subwavelength optical devices. However, current high quality-factor (high-Q) SLR implementations are fundamentally limited by their dependence on homogeneous dielectric environments. To overcome this limitation, we introduce guided-surface lattice resonances (gSLRs) by integrating nanoparticle arrays within slab waveguides. This configuration facilitates efficient coupling between scattered light and Bloch modes, enabling high-Q multimodal resonances even in index-discontinuous environments, realizing a quality-factor (Q-factor) of 1489. The coupling strength and resonance intensity of these multimodal gSLRs can be continuously modulated by adjusting the vertical displacement of the nanoparticle arrays within the slab layers. To augment the sensitivity to local dielectric variations, we investigate gSLRs in metasurfaces integrated with metallic substrates, demonstrating suitability for biosensors. A mathematical sensing model, incorporating biochemical reaction kinetics and optical responses, is established and validated through bovine serum albumin (BSA) sensing, achieving a limit-of-detection as low as 0.65 pM.

Zinc-rich coatings provide cathodic protection for metal substrates through the sacrificial anode action of zinc powder, which is widely used in marine equipment. However, zinc powder is easily covered by nonconductive corrosion products during service, resulting in low actual utilization rate of zinc powder and the failure of cathodic protection, which seriously restricts the long-term protective life of the coating. In this study, we designed a zinc-rich epoxy coating modified with 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), successfully builting an intelligent coating with a multilevel protection mechanism. The experimental results show that adding 2 wt·% HEDP (70Zn-HEDP) to a coating with a zinc powder content of 70 wt·% can increase the duration of its cathodic protection to twice that of the unmodified coating with a zinc powder content of 70 wt·% (70Zn), improve the utilization rate of zinc powder in the coating, and significantly slow down the zinc corrosion products, generate and enhance the physical blocking performance of the coating. With integrated electrochemical testing, morphological characterization, and DFT theoretical simulation, we reveal the multilevel protection mechanism of HEDP's multifunctionality: it preferentially chelates Zn2+ to sustain zinc reactivity and prolong cathodic protection, deposits insoluble complexes to seal coating defects. It ultimately generates a protective Zn/Fe-HEDP passivation layer upon exposure to steel. The multifunctional protection mechanism of organophosphates provides ideas for the design of the next generation of zinc-based anticorrosion coatings with both intelligent response and long service life.

Optimal experimental conditions of indium tin oxide (ITO) as a thin-film supporting substrate for spectroscopically reliable infrared reflection-absorption (IR-RA) measurements are studied experimentally by the use of ITO substrates having a wide range of thickness from 50 to 500 nm. When the thickness is 300 nm or more, the reflectivity of ITO is close to that of a metallic substrate, but this is not solely due to the dielectric properties of ITO. This is an apparent reflectivity partly due to the RA-specific large angle-of-incidence. In fact, the observed RA spectra are quantitatively out of expectations significantly at 2000 cm-1 or higher, which means that the surface selection rules (SSRs) of RA spectrometry in the high wavenumber region are lost. With the optimized experimental conditions, an ITO substrate is employed for an actual application study of hole-collecting layer deposited on ITO. The IR-RA spectrum is beautifully obtained as if it were on a metallic substrate, and the SSR is also recognized properly.

Understanding and engineering atomic defects in hexagonal boron nitride (hBN) provides a powerful platform for realizing solid-state quantum emitters and spin qubits, advancing the field of quantum information science and technologies. However, the full potential of such quantum defects remains locked by the critical lack of a deterministic structure-property relationship at the atomic scale. Here, we demonstrate a strategy to atomically engineer and decipher quantum defects in hBN by integrating scanning tunneling microscopy/spectroscopy (STM/STS) and noncontact atomic force-microscopy with a CO-functionalized tip. We implemented controllable argon ion bombardment to create both boron vacancies (VB) and nitrogen vacancies (VN) in submonolayer hBN grown on Cu(111). Simultaneously, encapsulated Ar species trapped between hBN and Cu(111) locally lift the hBN to form nanobubbles, thereby decoupling atomic vacancies from the metal substrate and enabling direct probing of their electronic states. For the on-bubble VN, STS measurement reveals a prominent in-gap state with a phonon replica. Furthermore, with aid of STM tip-assisted manipulation, we demonstrate that the tuning of nanobubble sizes modulates their strain profile, thereby modulating the energetic positions of electronic states in on-bubble defects, corroborated by density functional calculations. Our studies offer insight into the intrinsic defect structures in hBN and quantum defect engineering via local strain engineering.

ConspectusThe growing demand for nanoscale temperature measurement capabilities is motivated by diverse applications such as thermal management of microelectronics and batteries, design of plasmonic systems, mechanistic studies of catalysis, and unraveling intracellular processes. Upconverting nanoparticles (UCNPs) are lanthanide-doped inorganic probes that are popular luminescent thermometers, with advantages including well-understood temperature-dependent behavior, broadly tunable excitation and emission wavelengths, and exceptional thermal and chemical stability. Like other optical thermometry techniques, luminescence thermometry provides the desirable capability of remotely collecting the temperature-dependent signal from the far field. Conventional implementations of luminescence thermometry also share a major limitation of other optical thermometry techniques, namely, their diffraction limited spatial resolution. However, in contrast with other optical thermometry techniques, luminescence thermometry also creates an opportunity to leverage certain unique strategies for circumventing the diffraction limit.In this Account, we discuss our contributions to initiating or building on three major strategies for achieving UCNP thermometry beyond the diffraction limit. Some of these concepts originate from or have direct parallels in the realm of biological imaging, where optical imaging with spatial resolution below the diffraction limit has been a longstanding goal; conversely, others have no direct bioimaging analogy. Exciting an isolated single UCNP with a diffraction limited laser beam enables thermometry with subdiffraction limited spatial resolution governed by the UCNP size, although this approach is inherently restricted to measurements at a single spatial point. We begin by describing our efforts to extend single-UCNP measurements to smaller UCNP sizes and understand how their temperature-dependent emission can be influenced by external factors such as the excitation laser intensity or the surrounding optical environment, the latter of which is exemplified by an investigation of how single-UCNP emission is altered when the UCNPs are placed on various metallic substrates. Next, we show how the principles underlying single-UCNP thermometry can be expanded to sample multiple temperature points within a subdiffraction region by combining different UCNP compositions with spectrally orthogonal temperature-dependent luminescence. As a practical demonstration, we resolve a nearly 20 K temperature difference over a sub-110 nm distance originating from the steep temperature gradient near a laser-heated Ag nanodisk. Finally, we discuss our adaptation of UCNP-based stimulated emission depletion (STED) super-resolution imaging for super-resolution nanothermometry, combining temperature-dependent STED spectroscopy, self-assembled UCNP monolayer formation, and a detection scheme that enables practical scan times. STED nanothermometry can reveal a temperature gradient on a Joule-heated microstructure that is undetectable with analogous diffraction limited measurements, showcasing the power of this approach. We conclude with our perspective on the outlook for UCNP thermometry methods that circumvent the diffraction limit, highlighting both current research needs to further improve the measurement capabilities and strategies that could facilitate broader adoption of these emerging techniques.

The aim of this study was to evaluate the influence of prosthetic substrate type, resin cement shade, and opaquer liner application on the translucency and color matching of translucent zirconia- and lithium-based ceramics. Four A2-shade zirconia materials (Katana HTML Plus, STML, UTML, and YML), with and without an opaquer liner, lithium disilicate ceramics (Amber Mill LT and HT), and zirconia-reinforced lithium silicate (Celtra Duo) were investigated. Monolithic crowns and standardized rectangular specimens were fabricated using CAD/CAM technology and cemented with neutral, warm-shade, and opaque try-in pastes onto A2-shade composite resin and cobalt-chromium substrates. Color measurements were performed using a digital colorimeter based on the CIE L*a*b* system. Translucency parameters (TPs) and color differences (ΔE) relative to the A2 reference shade were calculated. Lithium-based ceramics exhibited significantly higher translucency than zirconia materials. Application of the opaquer liner on intaglio surface of crowns reduced their translucency. On A2-shade substrates, translucent zirconia luted with neutral or warm-shade paste demonstrated the most favorable color compatibility. In contrast, opaque try-in paste resulted in clinically unacceptable color deviations and loss of optical depth. On metallic substrates, most materials exhibited pronounced gray discoloration and substantial color mismatch, particularly lithium disilicate ceramics. These findings indicate that ceramic type, substrate color, opaquer liner application, and resin cement shade significantly influence the optical performance and final color outcome of all-ceramic restorations.

Cathodic disbondment of epoxy-glass flake coatings on different metal substrates in simulated seawater