Ceramic Discs Research Articles

Nanodentistry aspects explored towards nanostructured ZrO2: Immobilizing zirconium-oxide nanotube coatings onto zirconia ceramic implant surfaces

We report on a facile strategy to impart nanostructured morphology to commercially available ceramic-preforms used for biomedical applications in the field of dentistry. This process involves the deposition of nanotubular zirconium-oxide (ZrNT) membranes onto zirconia (ZrO2) ceramic discs at ambient conditions. ZrNTs are fabricated via electrochemical anodization of zirconium foil in a one-pot synthesis. The ZrNT film is detached from the metal-foil using office-adhesive tape and freestanding ZrNT films were obtained via dissolution of adhesives in a solvent bath, which also facilitate the transfer of ZrNT film onto the ceramic. This simple technique allows to impart a robust micro-nanoscale structure to bulk-ceramics that can potentially offer insights into designing ‘smart’ implants in the field of ceramic-biomaterial applications.

Design and operation of a hybrid LED/LD-pumped phosphor-converted white-light lamp.

Illumination sources based on phosphors, pumped by laser diodes (LDs), have seen rapid developments over the past decade. Here, we present a new, to the best of our knowledge, design that features both spectral richness and the capability for high brightness. Complete design details and operational characterization have been described. This basic design can be extended in various ways to customize such lamps for different operational requirements. A hybrid arrangement of both LEDs and an LD is used to excite a mixture of two phosphors. The LEDs, in addition, provide a blue fill-in to enrich output radiation and to tune the chromaticity point inside the white region. The LD power, on the other hand, can be scaled up to generate very high brightness levels that are not achievable with pumping from LEDs alone. This capability is gained using a special transparent ceramic disk that carries the remote phosphor film. We also show that the radiation from our lamp is free from speckle-producing coherence.

Study on Steep Front Impulse Test Voltage Value of Disc Insulators with Variation in the Number of Units of Insulator String

The insulators used in power transmission and distribution networks should withstand abnormal system-generated switching impulses and natural lightning impulses. To avoid the failure of insulators in the field, the impulse puncture strength evaluation of the ceramic insulators is important. IEC 61211 standard stipulates the procedure to evaluate the ceramic disc insulators’ strength to withstand steep front impulses. In this test, the test voltage is determined by using a short standard string of five insulators. This paper presents the variation in the impulse stresses across the disc insulator units in the string due to non-linear voltage distribution under impulse flashover. This paper also correlates the test voltage values defined by the IEC standard with the highest stress on insulator units under impulse flashover of string insulators by using voltage distribution. The correlation study has been carried out with insulator strings having different arcing distances by using a different number of units.

Effect of surface treatment on flexural strength and subcritical crack growth of lithium disilicate: an in vitro study

Alternative surface treatments have been proposed for the cementation of lithium disilicate ceramics aiming to improve adhesive and flexural strength under fatigue. This study aimed to evaluate the slow crack growth (SCG) parameters of the lithium disilicate ceramic after hydrofluoric acid (HF) etching or air abrasion (AB) as surface treatments. Ceramic discs were treated with HF (5%, 20 s) or AB (30 µm silica-modified alumina particles, 2.8 bar, 10 mm distance, 15 s), and received a layer of resin cement. The surface roughness after surface treatment was evaluated (n = 5). Samples were tested in a piston-on-three-ball assembly to evaluate the flexural strength (n = 20), inert strength (n = 25), and to determine SCG parameters n and D (n = 35). The highest roughness (p < 0.01) was observed in the AB group, with the highest reliability according to the Weibull analysis, but the lowest SCG susceptibility. Flexural (p = 0.03) and inert strength (p < 0.01) were the greatest in the HF group. Despite exhibiting lower strength than 5% HF, air abrasion may be an alternative for the surface treatment of lithium disilicate surfaces, indicating the best prognosis over time.

Characterization of high-power mechanical quality factor of piezoelectric ceramic discs under self-heating condition

We have developed a method to characterize high-power mechanical quality factor Qm of a thickness-poled piezoelectric disc under self-heating condition. In order to obtain Qm from temperature and vibration measurements, a heat transfer model for a thin piezoelectric disc vibrating in its fundamental radial mode was built, and a numerical solution method based on the finite difference approach was developed to investigate the temperature rise of the piezoelectric disc as a function of position and time. Numerical simulations were performed to verify the validity of the model and to quantify the influence of different material parameters on the temperature rise. A theoretical formula for characterizing Qm of a piezoelectric disc was deduced according to the definition of the mechanical quality factor, in which the relationship among the self-heating parameters (hg), the sample vibration level (v0) and Qm was established. Furthermore, using a self-designed experimental equipment, we have characterized the high-power mechanical quality factor Qm of a PZT8 disc sample under different vibration levels using a tone-burst excitation, which can increase the operating electric field strength limits. The disc results show that Qm degrades drastically with increasing vibration amplitude. Especially, the Qm values measured under self-heating conditions have lower magnitudes than those measured using transient/burst method, indicating self-heating effects do significantly contribute to Qm characterization.

Effect of Ceramic Thickness on Light Attenuation, Degree of Conversion, Knoop Hardness, and Elastic Modulus of Four Luting Resins.

This study evaluated the influence of the thickness of disilicate ceramic on the light attenuation (mW/cm2), degree of conversion (DC, %), Knoop hardness (KH, N/mm2) and the elastic modulus (E, MPa) of four luting resins. Three resin cements: RelyX Veneer (RV, 3M Oral Care, Monrovia, CA USA); Allcem Veneer APS (AC, FGM); Variolink Esthetic LC (VE, Ivoclar Vivadent, Schaan, Liechtenstein) and one flowable resin composite Tetric N-Flow (TF, Ivoclar Vivadent) were photocured for 20 seconds. The irradiance (mW/cm2) and emission spectrum (mW/cm2/nm) from a broad-spectrum LED light unit (Bluephase G2, Ivoclar Vivadent) were measured over the luting material (control) and through 0.3 mm, 0.7 mm, and 1.0 mm thick ceramic discs (e.max CAD, Ivoclar Vivadent). The LED light delivered 26.1 J/cm2 to the surface and 6.2 J/cm2 through the 1.0 mm thick ceramic. The distribution of violet and blue light across the light tip of the light-curing unit (LCU) was relatively homogeneous, but there was less violet range. The irradiance and spectral radiant power decreased significantly as the ceramic thicknesses increased (p<0.001). The luting material type had significant effect on KH and E values (p<0.001). The RV had the greatest KH and E values, and VE had the lowest. Ceramic thickness had no significant effect on KH (p=0.213) and E (p=0.130). The KH (p=0.265) and E (p=0.165) were also not influenced by the location where these measurements were made across the specimens. No significant reduction of the DC was observed as the ceramic thickness increased (p=0.311). Increasing the ceramic thickness exponentially reduced the irradiance. This reduction was more pronounced at the shorter wavelengths (violet) of light, with an 82% decrease for 1 mm-thick ceramic. Increasing the ceramic thickness did not affect the DC, irrespective of photoinitiators used in the tested resins. The position of the violet and blue LEDs within the body of the LCU did not influence KH or E in any of the resins tested. The KH and E of VE were significantly lower than the other 3 luting materials tested.

Wear Performance of a Novel Silicon Nitride Ceramic for Biomedical Applications

Ceramic materials are sometimes used as bearing surfaces of joint implants due to their high wear resistance and biocompatibility. Silicon nitride (Si3N4) is one of the ceramics under investigation for such use, owing to its bacteriostatic properties and high wear resistance. Traditional Si3N4 is sintered using Al2O3 and Y2O3 as sintering aids. To improve the biocompatibility and bioactivity of Si3N4, new sintering aids (SrO, MgO, and SiO2) were used in this work. This substitution may however have substantial effects on the wear properties of the material. Hence, the aim of this study was to evaluate these effects. Multidirectional pin-on-disc wear tests against ultra-high molecular weight polyethylene pins were used to this end, running in fetal bovine serum solution at 37 °C for 2 million cycles. The surface roughness, phase composition, and surface morphology of the surfaces were investigated, together with the pH of the wear test lubricant and compared to a traditional Si3N4 composition. XRD and SEM results showed that the prepared ceramics were composed of α- and β-phase Si3N4. The surface roughness of the Si3N4 ceramic discs was in accordance with the biomedical standard, and the wear test results demonstrated that the new ceramics had a low wear factor and a comparable coefficient of friction to Si3N4 ceramics reported in previous work. However, the dissolution of the materials over time may be a concern for biotribological applications, such as long-term use or in other wear couples.

Hard Wear-Resistant Ti-Si-C Coatings for Cu-Cr Electrical Contacts.

In this study, hard wear-resistant Ti-Si-C coatings were deposited on Cu-Cr materials to improve their performance as sliding electrical contact materials. A ceramic disk composed of Ti3SiC2 and TiC phases was used as a target for DC magnetron sputtering to deposit the coatings. The influence of the power supplied to the magnetron on the chemical composition, structure, and friction coefficient of the coatings was examined. The coatings demonstrated high hardness (23-25 GPa), low wear rate (1-3 × 10-5 mm3/N/m) and electrical resistance (300 μOhm·cm), and fair resistance to electroerosion. The coating deposited at 450 W for 30 min displayed optimal properties for protecting the Cu-Cr alloy from the arc effect.

Energy harvesting and storage with ceramic piezoelectric transducers coupled with an ionic liquid-based supercapacitor

One of the main issues of wearable electronic devices regards their power supply and autonomy. The exploitation of mechanical energy from body motion and vibrations can be realized by using piezoelectric materials coupled with a proper energy storage device. To this aim, Self-Powered Supercapacitors (SPSCs) have been investigated over the last decades, either as internally integrated SPSC (iSPSC), where the piezoelectric element of the device is used as Super Capacitor (SC) separator, or via an external integration (eSPSC), where the piezoelectric unit and the SC are connected by a bridge rectifier. In this paper, an eSPSC power supply is developed by integrating a stuck of commercial ceramic piezoelectric disks and an ionic liquid-based micro-SC. In detail, a stack of 15 commercial lead zirconate titanate (PZT) disks is used as the energy harvesting unit and mechanically stressed by a compressive force of 85 N at 2 Hz. The piezoelectric output successfully charged the 22 mF supercapacitor up to 3.1 V after 2 h of test, achieving a stored energy value equal to 110 mJ. The proposed integrated system outperforms the state-of-the-art SPSC assembled with micro-SC (both iSPSC and eSPSC). The use of the two different units (piezo-energy harvesting unit and micro-SC energy storage unit) allows an independent sizing and tuning of the supercapacitor according to the output current of the piezoelectric unit.

Color Assessment of Feldspathic Ceramic with Two Different Thicknesses, Using Multiple Polymeric Cements.

The purpose of this study was to evaluate the color changes of feldspathic ceramics CEREC Blocs (Dentsply Sirona, Milford, DE, USA) when cemented with different luting agents, while varying the ceramic thickness. Seventy ceramic discs of feldspathic ceramic (A2 shade) were obtained with 0.5 and 0.8 mm thicknesses. Seventy composite discs (A3 shade) 1 mm in thickness were used as substrates. After being polished and conditioned, the ceramic and composite discs were cemented with different resin cements and a flowable composite: Variolink® Esthetic Light, Neutral and Warm (Ivoclar Vivadent, Schaan, Liechtenstein); RelyXTM Veneer B0.5, Translucent and A3 Opaque/yellow shades (3M Oral Care, St. Paul, MN, USA); G-aenial® Universal Flow A2 (GC Europe, Leuven, Belgium). Color difference (ΔE) was determined using a spectrophotometer. A two-way ANOVA and multiple comparisons were performed using the Bonferroni method with a 95% confidence interval. Variolink® Neutral showed the highest ΔE (15.12 ± 0.71) and RelyXTM Veneer A3 the lowest value (1.59 ± 0.33). There are no statistically significant differences between the two ceramic thicknesses for Variolink® Light (p = 0.230) and RelyXTM Veneer B0.5 (p = 0.318) cements. The feldspathic ceramic final color is influenced by the cement used and the ceramic thickness. The use of different cements in a thin ceramic has a clinically significant impact on the final esthetic result.

Ceramic surface conditioning, resin cement viscosity, and aging relationships affect the load-bearing capacity under fatigue of bonded glass-ceramics

This study aimed to evaluate the influence of ceramic surface treatments, resin cement viscosities, and storage regimens on the fatigue performance of bonded glass-ceramics (lithium disilicate, LD; feldspathic, FEL). Ceramic discs (Ø = 10 mm; thickness = 1.5 mm) were allocated into eight groups per ceramic (n = 15), considering three factors: “ceramic surface treatment” in two levels – 5% hydrofluoric acid etching and silane-based coupling agent application (HF), or self-etching ceramic primer (E&P); “resin cement viscosity” in two levels – in high or low viscosity; and “storage regimen” in two levels – baseline, 24 h to 5 days; or aging, 180 days + 25,000 thermal cycles. Adhesive luting was performed onto glass fiber-reinforced epoxy resin discs (Ø = 10 mm; thickness = 2 mm) and the bonded assemblies were subjected to cyclic fatigue tests: initial load = 200 N; step-size = 25 N (FEL) and 50 N (LD); 10,000 cycles/step; 20 Hz. Scanning electron microscopy (SEM) inspections were performed. Regarding the LD ceramic, the fatigue behavior was reduced after aging for HF_HIGH and E&P_LOW conditions, while stable performance was observed for HF_LOW and E&P_HIGH. Regarding the FEL results, aging negatively affected HF_HIGH, E&P_HIGH, and E&P_LOW, being that only the HF_LOW condition presented a stable behavior. The failure initiated from defects on the etched surface of the ceramics, where the cross-sectional analysis commonly revealed unfilled areas. Long-term aging might induce a decrease in mechanical behavior. The ‘ceramic microstructure/surface conditioning/resin cement viscosity relationships’ modulate the fatigue performance of lithium disilicate and feldspathic glass-ceramics.

Lipopolysaccharide penetration analysis of two different resin cement systems to dentin and ceramic surface

Background/purposeOne of the challenges in adhesive ceramic restorations is deterioration of tooth-cement-ceramic interfaces. This study was to quantitatively investigate lipopolysaccharide (LPS) penetration through adhesive ceramic restorations. Materials and methodsStandardized holes were formed on ceramic (IPS Empress CAD, Ivoclar Vivadent) and human dentin discs. Prepared discs were randomly assigned to experimental groups (n = 6/group): SC, self-adhesive resin cement (SmartCem 2, Dentsply Sirona) bonded to ceramic discs; ST, self-adhesive resin cement bonded to dentin discs; VC, etch-and-rinse resin cement (Variolink II, Ivoclar Vivadent AG) bonded to ceramic discs; VT, etch-and-rinse resin cement bonded to dentin discs. The specimens underwent thermocycling (10,000 cycles; 5–55 °C) then LPS penetration test until 5-weeks. A mixed effect analysis using R statistical language was performed for data analysis. ResultsDentin and ceramic bonded with etch-and-rinse resin cements (groups VT and VC) showed significantly less penetration than those with self-adhesive resin cement (groups ST and SC) (P < 0.05). ST showed significantly lower penetration than SC (P < 0.05), that showed similar penetration with positive control (P > 0.05). VC showed minimal penetration during observed time of period (P < 0.05). Scanning electron microscope observations showed different interfacial characteristics among the groups. ConclusionWithin the limitation of this study, etch-and-rinse resin cement showed less LPS penetration than self-adhesive resin cement on both ceramic and dentin surfaces.

An evaluation of the effect of matric suction on the dynamic strain-dependent parameters of an unsaturated silt

This research investigates the influence of matric suction on the variation of shear modulus and damping ratio of a silty soil in very small to medium shear strain levels. A set of laboratory experiments including three bender elements tests in addition to three resonant column-torsional shear tests have been carried out on unsaturated Firuzkuh silt specimens. In this regard, an unsaturated triaxial cell equipped with a set of bender elements and a resonant column-torsional shear device that can apply and control matric suction have been used. All specimens had an initial void ratio of 0.7 and were tested in various matric suctions under a net mean stress of 50 kPa. For this purpose, the axis translation technique has been implemented for applying matric suction, and High Air Entry Value (HAEV) ceramic discs have been used for air-water control of unsaturated silt specimens. According to the results, a significant variation of shear modulus and damping ratio has been observed with changes in matric suction and shear strain level. The output data indicate that shear modulus increases with increasing matric suction while the damping ratio decreases with an increase in matric suction. In addition, shear modulus and damping ratio decrease and increase with increasing shear strain, respectively.

Çeşitli Kompozit Rezinlere Uygulanan Farklı Yüzey Pürüzlendirme Yöntemlerinin Porselen Bağlanma Dayanımına Etkisi: İn Vitro Çalışma

Objective: This study compares different surface conditioning methods applied to various composite surfaces in order to investigate the possible effects on composite-ceramic bond strength. It was aimed to increase the bond strength between flowable composite which is frequently used in the immediate dentin sealing procedure and ceramic surfaces. Material and Methods: Eighty flowable composite and eighty conventional composite discs were prepared with five different surface conditioning methods applied to the discs. The folllowing treatments were applied to the discs: orthophosphoric acid, air-flow, bur conditioning, Er:YAG laser irradition and an unconditioned control group. The composite disc surface roughness was measured with a profilometer. Composite and ceramic (Glass-ceramic blocks, e.max CAD, Ivoclar Vivadent AG, Liechtenstein) discs were then bonded with an adhesive resin cement. The shear bonding test was performed with an universal tester. Results: There was no statistical difference between the conditioning methods applied to flowable composites in terms of bond strength (p>0.05). However, a statistically significant difference was found between the conditioning methods applied to conventional composites regarding bond strength (p<0.05). The highest mean bond strength value was observed with ER:YAG laser conditioned conventional composites and was significantly higher than laser irradiated flowable composite groups. Conclusion: Our data shows that similar bond strength values are obtained when using either flowable or conventional composite resins. In addition, both conventional and flowable composite resins require surface conditioning to achieve reliable adhesion to porcelain material.

Translucidez e capacidade de mascaramento de uma zircônia translúcida com diferentes espessuras sobre substratos escuros

ABSTRACT Objectives: To evaluate the translucency, contrast ratio and masking ability of a translucent zirconia with different thicknesses. Methods: Disc shaped specimens (n= 3) with 10 mm (Ø) x 1.5 mm, 1 mm and 0.7 mm (thickness) were manufactured simulating all-ceramic simplified restorations. Substrate discs (n= 2; Ø: 10 mm; thickness: 2 mm) were simulated with composite resin shades: A2 (positive control) and C4; and metal alloys: silver (Ni-Cr) and golden (Cu-Al). Optical properties of the 9 translucent zirconia specimens placed on the 3 different substrates were analyzed by a spectrophotometer. The color variation (ΔE00) between each ceramic structure over the positive control substrate (A2) and over the dark backgrounds (C4, silvery, golden) were obtained as to their ceramic masking ability and subjected to non-parametric Kruskal Wallis test (5%). The translucency parameter (TP00) and contrast ratio (CR) of the different thicknesses of the ceramic discs were also collected and analyzed by one-way ANOVA and the Tukey test (5%). Results: The translucent zirconia showed greater opacity in the thickness of 1.5 mm, although it was not statistically different between 0.7 and 1.0 mm. All dark backgrounds significantly affected the final color of the simplified restoration in all evaluated thicknesses. However, the increase in ceramic thickness showed a decrease in ΔE00 values for all substrates. Conclusion: The translucent zirconia was not able to mask the dark substrates, independent of the evaluated thickness.

Soil water retention curve of silty sand – experimental investigation using different laboratory methods

Most of the infrastructure investments and earthworks not requiring deep foundations are usually designed in the vadose zone to avoid excessive groundwater-structure interactions. The mechanical behaviour of soil material, under partially saturated conditions, is greatly influenced by pore-water tension, known as soil suction, and the characteristics of the Soil Water Retention Curve (SWRC). In the present paper, the SWRC of a silty sand was determined using two different experimental methods. In the first method, a modified pore water pressure transducer was used for suction monitoring, while the specimen was allowed to change its moisture content by natural evaporation. For the second method, a modified consolidation cell fitted with a high air entry value ceramic disc on the base pedestal was used. Suction was applied using the axis translation technique by utilising pore air and pore water pressure controllers, while moisture was monitored using a volumetric measurement system. Through the determination of the SWRC for the silty sand, this paper intends to compare the abovementioned testing methods basedon the produced SWRCs and to reveal advantages and limitations.

알루미나계 수도밸브용 세라믹디스크의 가속수명시험 및 수명 모델 개발

Purpose: An accelerated life test (ALT) plan was devised after investigating the potential failure mechanisms of a ceramic disk material for a water valve. Moreover, ALT was implemented to establish a life distribution and acceleration model.BRMethods: The thermal shock behavior of the ceramic disk was predicted using finite element method. To reproduce the disk, a jig was fabricated and then the ALT was performed. After the test, failure analysis was conducted through optical microscopy and surface roughness measurement.BRResults: The life distribution of the ceramic disk for the water valve was confirmed to have a Weibull distribution with a shape parameter of 1.5. Moreover, because the operating condition was thermal shock acceleration, the acceleration model was suitable when the Coffin-Manson model with a material constant of 6.6 was applied.BRConclusion: The analysis of the average values and standard deviations of the surface roughness of failed products using ALT showed that the more severe the environment, the greater the wear of the ceramic disk. This indicated that ALT was well planned and implemented.

Effect of resin cement elastic modulus on the biaxial flexural strength and structural reliability of an ultra-thin lithium disilicate glass–ceramic material

Photo- and dual-polymerized resin-based luting agent was evaluated for elastic moduli effects on ultra-thin lithium disilicate (LD) glass-ceramic strengthening, structural reliability, and stress distribution. One hundred-sixty LD discs (IPS e.max CAD, Ivoclar/Vivadent) were produced in ultra-thin thicknesses (half with 0.3mm and the other half with 0.5mm). The ultra-thin ceramic disks were coated with two different cement types (Variolink Veneer - V and Panavia F 2.0 - P). Two positive control groups were tested following hydrofluoric (HF) acid etching (LDt3, LDt5) and two negative control groups were tested for untreated ceramic (LD 3, LD 5). Biaxial flexural strength (BFS), characteristic strength (σ0) and Weibull modulus (m) were the response variables (n = 20) at the ceramic/resin cement interface (z = 0). Finite element analysis (FEA) was used to calculate maximum principal stress. Data were analyzed using two-way ANOVA, and Tukey's test. Scanning electron microscopy (SEM) was used to analyze the failed specimens using fractography and surface morphology. The BFS of LD at either thickness was not affected by cement types, as also demonstrated by FEA. Structural reliability significantly improved in the positive control group (LDt5). The cementation of ultra-thin LD with a resin-cement of varying elastic moduli did not influence BFS. LD surface modification by HF acid-etching increased the reliability. Ultra-thin anterior veneer designs made from lithium disilicate have been widely proposed and the apparent success of LD ultra-thin veneers was not influenced by the cement choice in the current studies albeit the elastic moduli luting agents used were of similar values.

Degree of conversion and bond strength of resin cements through different thicknesses of lithium disilicate ceramic using different curing modes

Objectives: The aim of this in vitro study was to assess the physical and mechanical properties of resin cements to ceramic substrate using different curing modes by evaluating the degree of conversion and bond strength of these cements. &#x0D; Methods: Hundred twenty square lithium disilicate ceramic discs specimens of three thicknesses (0.5, 1 and 1.5 mm) and 10x10mm diameter were bonded to 120 bovine teeth using two resin cements (one light cure and one dual cure) and using two curing modes (ramp and continuous). As a result, 12 experimental groups were established for bond strength testing. degree of conversion of luting cements was evaluated using Fourier transform infrared spectroscopy (FTIR).&#x0D; Results: using the continuous mode compared to the ramp after controlling the type of resin and material thickness showed no significant difference(P&gt;0.001) in SBS and DC. the effect of changing the material thickness between 0.5mm, 1mm and 1.5mm after controlling the resin type and mode of light curing, showed significant difference (p&lt;0.001) from 1mm to 1.5mm using light-cured resin and continuous curing mode for SBS. while for the DC these correlations between different material thicknesses and both light cure type of resin and continuous light-curing mode was significant (p&lt;0.001), it was also significant with dual cure cement. This study also evaluated the effect of using dual-cured resin cement compared to the light-cured resin cement on the SBS and DC, for the SBS the effect was significant with higher thicknesses (p&lt;0.001 for the thickness of 1.5 mm) but not significant with thicknesses less than this such as 0.5mm and 1mm (P&gt;0.05).&#x0D; Conclusion: There is no change on the effect of changing light curing mode on the DC and SBS increasing the thickness decrease SBS and DC, dual-cured resin performed better when used for thickness of 1.5mm.

Comparison of Color Accuracy between Natural Dentin Substrate and Three Dentin Porcelain Brands of Glass-Matrix Ceramic System (Digital Image Analysis)

Purpose: The purpose of this laboratory study was to differentiate the color of natural dentin (ND) and dentin porcelain (DP) by using three brands of Glass-Matrix Ceramic System (GMCS) by parametric CIE L*, a*, b* system. Materials and methods: An extracted human upper central incisor was prepared as a control group. Uniformly thick dentin specimen was taken from the middle coronal third of the labial half longitudinally. Twelve disks of GMCS dentin porcelain were fabricated according to manufactures' instructions by using conventional powder/slurry technique, 4 disks for each group; Feldspathic ceramic VITA VMK 95 (VMK), Leucite-based ceramic VITA VM9 (VM9), and Fluorapatite-based ceramic IPS e.max Ceram IVOCLAR (IEC). ND and DP specimens' thickness were (8×1 mm, shade A3) and (n=4). A digital camera was used to take samples' photos while the color readings were obtained by graphic software. The specimens' colors were measured, and the data were statistically evaluated using Levene's test, One-way ANOVA, and Post Hoc Multiple Comparisons. Results: Parametric CIE L*, a*, b*, and ΔE values of all ceramic disks compared to ND were significantly different even within ceramic brands (P&lt;.05), ΔE were ND &gt; IEC &gt; VMK &gt; VM9. Conclusions: To reproduce ND color by DP needs proper color shade guide selection due to color differences from one brand to another even in the same shade guide tab. Clinical Significance: There is a lack of information on how identical natural dentin color to dentin porcelain is at the same shade guide.