Dental And Ceramic And Shade

OBJECTIVES: Although the presence of a chairside CAD/CAM system in the dental office saves time and cost, it deprives the dentist from the dental technologist' skills and experience. The dentist now has to gain and acquire knowledge and skills about how to finish, characterize, stain, and glaze ceramic restorations. The main objectives of this article is to teach novel and reproducible techniques for surface color, texture, glaze and polish for either the chairside or laboratory fabricated indirect ceramic restoration...

BACKGROUND: Although, the influence of cement and background shade on the final color and translucency of zirconia reinforced lithium silicate (ZLS) and lithium disilicate (LDS) ceramics has been previously investigated, there is still little data on the translucency of LDS and ZLS ceramics in decreased thickness (0.4 and 0.6 mm). The aim of this study was to investigate ceramic thickness', background and cement shades' effects on the zirconia reinforced lithium silicate (ZLS) and lithium disilicate (LDS) ceramics' translucency...

This study investigated the effect of translucency and absorbance of conventional (FiltekTM -Z350-XT) and bulk-fill (Tetric® -N-Ceram) composites on temperature change during photopolymerization, using a non-contact infrared sensor. Three shades from each composite were selected to prepare disk-shaped specimens (n=3), which then photopolymerized with LED-light for 20 s. A second light exposure was performed on the photopolymerized specimens. The first peak temperature rise during composite photopolymerization (ΔTtotal ), second peak temperature rise by the light (ΔTlight ), and net peak temperature rise by composite curing heat (ΔTcomposite ) were obtained from the temperature change vs...

OBJECTIVE: This article demonstrates the use of a multicolored 3D-printed model for laboratory shade evaluation of ceramic veneers. CLINICAL CONSIDERATIONS: A young female patient presented with peg lateral incisors and diastemata between her maxillary incisors. Four ceramic veneers for her maxillary incisors were fabricated using a digital workflow. A multicolored 3D-printed model was manufactured using material jetting technology. The multicolored model and try-in pastes were used to evaluate and adjust the shade of the veneers...

The purpose of the study was the investigation of the polymerization of a preheated composite resin beneath lithium disilicate. First, lithium disilicate discs in two shades (HT A2 and HT A4) and three different thicknesses (2, 4, and 6 mm) were bonded on dentine with preheated composite resin that was photo-polymerized for 20 s. The composite resin microhardness, the double bond conversion (DC) and their correlation were estimated. Second, standardized occlusal veneers of two shades and two different thicknesses (4 and 6 mm) were bonded with preheated composite resin and photopolymerized for 60 or 270 s...

OBJECTIVES: Lithium disilicate (LDS) based glass ceramics are indispensable materials in the field of prosthetic dentistry due to their strength and excellent esthetics. Recently, novel fully crystallized LDS for the milling process have been introduced to the market, requiring only chairside polishing before delivery. Since limited data is available about subjecting this material to glazing, this study aimed to evaluate the wear properties, fracture resistance, and optical properties of the newly introduced fully crystallized LDS after glazing...

BACKGROUND: Computer-aided design and computer-aided manufacturing (CAD-CAM) materials for prosthetic is gaining popularity in dentistry. However, limited information exists regarding the impact of thickness and roughening treatment on the optical properties of contemporary CAD-CAM restorative materials. This study aimed to quantitatively evaluate the translucency and opalescence of six dental CAD-CAM materials in response to different thicknesses and roughening treatments. METHODS: Six dental CAD-CAM materials, lithium disilicate glass-ceramic (IPS e...

OBJECTIVE/AIM: This in vitro study aimed to evaluate the color stability of microhybrid and nanohybrid restorative composites after exposure to immersion media common in Yemen for different periods. MATERIALS AND METHODS: Two composite materials, nanohybrid Tetric N-Ceram and microhybrid Te-Econom Plus, were investigated. Six groups of 30 cylindrical specimens (n = 5/group; diameter, 10 mm; thickness, 2 mm; shade A2) of each restorative material were immersed for 1 week in distilled water, qat solution, Yemeni coffee, traditional Yemeni coffee (qishr), red tea, and Dilsi cola...

Erbium:yttrium-aluminum-garnet (Er:YAG) laser debonding is a promising removal method in prosthodontics. This study aimed to assess Er:YAG laser energy transmission through novel zirconia ceramics. Five types of ceramic samples: lithium disilicate ceramic (LDC), self-glazed zirconia (SGZ), 3 mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP), 4Y-TZP and 5Y-TZP with 5 thicknesses (0.5, 1.0, 1.5, 2.0, 2.5 mm) and 2 shades (A1, A3), 50 specimens total, were made. Fourier transformation infrared absorption spectra were obtained for each ceramic type, and Er:YAG laser energy transmission tests were conducted for each specimen...

OBJECTIVE: The aim of this in vitro study is to evaluate the masking ability of polymer-infiltrated ceramic-network materials (PICN) with different translucencies and thicknesses on multiple types of substrates. MATERIALS AND METHODS: Ceramic samples were prepared of VITA ENAMIC blocks in two different translucencies (2M2-T, 2M2-HT) in a thickness range of 0.5-2.5 mm (±0.05 mm). Layered specimens were obtained using composite substrates in nine shades and transparent try-in paste...

The use of vaping or electronic cigarette devices (ECDs) has recently increased as an alternative to conventional tobacco smoking products. By recording the CIELAB coordinates (L*a*b*) and computing the total color difference (ΔE) values using a spectrophotometer, the effect of ECDs on contemporary aesthetic dental ceramics was investigated in this in-vitro study. A total of seventy-five (N = 75) specimens from five different ( n = 15) dental ceramic materials (Pressable ceramics (PEmax); Pressed and layered ceramics (LEmax); Layered zirconia (LZr); Monolithic zirconia (MZr) and Porcelain fused to metal (PFM)) were prepared and exposed to aerosols produced by the ECDs...

PURPOSE: To investigate the effect of coffee stain and whitening systems on the color stability of CAD/CAM glazed lithium disilicate glass-ceramics (LDGCs). METHODS:  68 glazed LDGC discs (12 × 10 × 2 mm) were fabricated using blocks of CAD/CAM systems (IPS e.max CAD ceramic). Baseline color was measured (CIE/L*a*b*), and specimens were randomized into four groups (n = 17). All specimens were stained (coffee solution; 24 h/d × 12) and then subjected to two whitening protocols...

AIM: This study aimed to determine the clinical effectiveness of android mobile digital application shade matching on tooth shade reproduction. SETTING AND DESIGN: This was a double-blind randomized controlled clinical trial (REF/2021/03/042258). MATERIALS AND METHODS: Thirty participants were selected from the two dental centers. The participant who required full-coverage restorations in one of the central incisors with adjacent central incisor untouched was the main inclusion criteria...

PURPOSE: To study the degree of accuracy in gingival colour matching of undergraduate students using a computer application. MATERIAL AND METHODS: Seventy-six undergraduate dental students were evaluated in gingival shade selection using an in-house developed computer application. Fifteen intraoral gingival photographs and 21 pink gingival colour porcelain samples were used. The environmental conditions were standardised, and no time limit was set for answering in the computer application...

OBJECTIVE: the aim of this study was to evaluate the effect of resin composite layering on discolored substrates to obtain masking ability with monolithic ceramics. MATERIALS AND METHODS: Four groups (n = 8) of computer-aided design/computer aided manufacturing (CAD/CAM) monolithic ceramics, shade A1, with thicknesses of 1.0 and 1.5 mm, were tested: feldspathic (FC), leucite-reinforced (LC), lithium disilicate-reinforced (LD), and translucent zirconia (5YSZ)...

OBJECTIVE: To evaluate the translucency and color difference of the individual layers of two multi-layered zirconia materials at different sintering temperatures and to compare them with lithium disilicate. METHODS: Multi-layered zirconia systems with four distinct layers were selected for this study: DD cube ONE ML (4Y-TZP), DD cubeX2 ML (5Y-TZP); and compared with IPS e.max CAD HT (LS2). Plate-shaped A2-shade specimens were obtained from LS2 and individual layers of both zirconia materials...

This study evaluated the effect of the thickness and translucency of lithium disilicatebased glass ceramics on resin composite substrates on color change and masking effect. Laminate veneers were fabricated using IPS e.max CAD (A1) blocks with two different light transmittance values (High translucent [HT], Low translucent [LT]). Slices of two different thicknesses (0.3 mm, 0.5 mm) were obtained (n=10) and laminate veneers were cemented on the resin composite substrates of two different shades (A2, A3.5). The color change (ΔE values) was evaluated with the CIELab color system using a spectrophotometer, while the masking effect was calculated...

PURPOSE: The purpose of this in vitro study was to assess the color match of ultra-translucency multilayer zirconia restorations with different designs and backgrounds. MATERIALS AND METHODS: Thirty ultra-translucency multilayer zirconia crown specimens were made in VITA classical shade B2 for a prepared maxillary central incisor. The specimens were divided into 3 groups based on the restoration design: veneered zirconia with a trestle design (VZT), veneered zirconia with a dentin core design (VZD), and full-contour zirconia (FCZ)...

PURPOSE: The aim of this study is to evaluate the effect of resin cement color, cement thickness, and thermocycling on the final color of monolithic lithium disilicate crowns. MATERIALS AND METHODS: A total of ninety prepared central incisors of typodont teeth were restored with lithium disilicate crowns which have different cement thicknesses (40 µm, 80 µm, and 120 µm) and cement shades (clear, yellow, and white). Color parameters of restorations were measured with a spectrophotometer in three different steps 1) before cementing 2) after cementing and 3) after thermocycling with 10000 cycles...

OBJECTIVE: To explore and characterize the effect of the discrepancy between crestal bone height (CB) and pulp chamber floor (PCF) in the fatigue performance of endodontically-treated teeth rehabilitated with an endocrown restoration. MATERIALS AND METHODS: A total of 75 human molars free of defects, caries history or cracks were selected, then endodontically treated and randomly allocated into 5 groups (N = 15) according to the difference between PCF and CB, as follows: PCF 2 mm above, PCF 1 mm above, PCF leveled, PCF 1 mm below and PCF 2 mm below...