Resin Cement Shade Research Articles

Zirconia-Reinforced Lithium Silicate Ceramic in Digital Dentistry: A Comprehensive Literature Review of Our Current Understanding.

Zirconia-reinforced lithium silicate (ZLS) ceramic is a new innovative dental material with unique a chemical composition that is designed to combine harmoniously with the appropriate optical properties of lithium disilicate and the enhanced mechanical strength of zirconia. A thorough understanding of ZLS materials is essential for both clinicians and dental technicians. At present, the mechanical behavior and optical properties of the ZLS ceramic system have not been extensively researched, and there is still a lack of consensus regarding the fabrication process and clinical behavior of ZLS all-ceramic restorations. The aim of the present study was to present a selection of comprehensive information concerning zirconia-reinforced lithium silicate ceramics and their optical and mechanical properties, as well as to assess data regarding cementation procedures and clinical outcomes for ZLS all-ceramic restorations. Three electronic databases (PubMed, Web of Science, and the Cochrane Library) were used for the research by two independent reviewers. The search was limited to articles published in the English language, as well as clinical and in vitro studies of color and studies on mechanical behavior and the cementation procedures of ZLS restorations. The exclusion criteria comprised abstracts, questionnaire-based studies, case reports, literature reviews, and studies that were not available in English. Zirconia-reinforced lithium-silicate-based ceramic presents a unique and complex microstructure that increases mechanical resistance but decreases aesthetic appearance, especially its translucency, due to tetragonal zirconia content. A material's thickness, the color of the underlying tooth structure, and the resin cement shade are important factors that influence the final shade and aesthetic appearance of ZLS restorations. Mechanical properties, which are defined by the fracture toughness, flexural strength, elastic modulus, and hardness of ZLS ceramic are higher compared to feldspathic, lithium disilicate, and hybrid ceramics, as well as resin nanoceramics; however, they are lower than translucent or high-translucency zirconia. Acid etching, sandblasting, and laser etching represent the most used methods to prepare the ZLS restoration surfaces for proper bonding procedures.

The capacity of conservative preparations for lithium disilicate glass-ceramic laminates luted with different resin cements to mask different substrate shades: A minimally invasive esthetic approach.

Demonstrate the ability of 0.5 mm thickness lithium disilicate laminates associated with resin cement to mask different substrate saturations. 60 specimens (n = 5) were prepared with CAD/CAM lithium disilicate glass-ceramic IPS e.max CAD, 0.5 mm thick, in three degrees of translucency (HT, MT and LT); cemented by Variolink Esthetic LC Light+ (L) and Neutral (N) on composite resin substrates A1 and A4 shades. Color measurements were performed by a spectrophotometer (CM-3700d -Konica Minolta). The L*, a*, b* parameters of the tri-layer structure (laminate/ resin cement/ substrate) were used to calculate color difference ( ) by CIEDE2000 formula and Translucency Parameter ( ). This study adopted = 0.8, as perceptibility threshold (PT), and = 1.8, as acceptability threshold (AT). Statistical analyses were performed by one-way ANOVA and Tukey tests (a = 0.05). Color difference between resin cement shades showed statistical differences (p < 0.0001) and > 1.8 for all groups. Color difference between substrates saturations showed a significant statistical difference (p < 0.0001) and values above AT for all groups. The demonstrated significant statistical differences (p < 0.0001). The LTL combination, the opaquest set, showed the smallest values between substrate shades differences, however, above AT. The translucency of the lithium disilicate, the substrate saturation and the resin cement opacity influenced final color of restoration. The ceramic translucency impact on final color was reduced by opaque resin cement. Furthermore, the LT lithium disilicate and the Light+ resin cement reduced the translucency of the restoration, contributing to mask saturated substrate. This study shows the influence of conservative lithium disilicate laminates with different degrees of translucency associated with resin cement on final color of saturated substrate restorations. A minimally invasive esthetic protocol for masking substrates is demonstrated by associating low translucency ceramic laminates and opaque resin cement.

Masking Ability of Monolithic CAD/CAM Laminate Veneers Over Different Resin Cement Shades and Substrate Colors.

To compare the masking ability of monolithic CAD/CAM veneers placed over different resin cement shades and substrate colors. Veneers were milled from four different monolithic CAD/CAM restorative materials: feldspathic ceramic (VMII), lithium disilicate ceramic (Emax CAD), zirconiareinforced lithium silicate ceramic (VS), and high-translucency zirconia ceramic (YZ-XT). Veneers were luted on natural tooth-colored (ND1) or discolored substrates (ND3 or ND5) using two different resin cement shades (opaque white or translucent). Each CAD/CAM material, resin cement shade, and substrate combination comprised 9 sample veneers (N &#61; 216). Color parameters were obtained using a dental spectrophotometer before and after luting. Color differences (ΔE00) were calculated using CIEDE2000 formula and compared to perceptibility (P &#61; .81 ΔE00 units) and acceptability (AT &#61; 1.77 ΔE00 units) visual thresholds. Color variation data were statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests with Bonferroni-Holm correction (α &#61; .05). The highest ΔE00 value was obtained in the VMII group placed over a discolored substrate, followed by the Emax CAD, YZ-XT, and VS groups. The effect of material types on ΔE00 values was significantly observed when the veneers were luted on discolored substrates using translucent resin cement (P < .05). Restorative material type, substrate color, and resin cement shade affect the masking ability of monolithic CAD/CAM laminate veneers.

In vivo Evaluation of Shade Replication of Different Generations of Zirconia to Natural Teeth Using Digital Color Determinations.

The color difference between the final shade of restorations milled from different zirconia blocks, and the control teeth in the esthetic zone is yet uncertain. For eight patients who required a singular maxillary central incisor restoration, twenty-four crowns made of zirconia were created. These were grouped into three categories based on the shade and nature of zirconia (Zr) utilized (white core, colored core, and monolithic high-translucency (ht) Zr crowns). The difference in color (ΔE) between the three zirconia crowns and the neighboring teeth was calculated by the use of Easyshade spectrophotometer. Two shades of resin luting cement were used. The measured ΔE values were evaluated based on a clinically acceptable color difference of 1.6ΔE, which is not visible to the human eye. Among the three groups, no differences of statistical significance were observed in terms of ΔE with different Zr types and resin cement color. Within the limits of this study, the usage of different shades of zirconia blanks and resin cements did not display a statistically significant effect on the final color of the crown. Changing the shade of resin cements does not appear to add value to the final shade of crown. In addition, the generation of zirconia does not influence the shade of the crown. Crowns made of zirconia can be cemented with opaque or transparent cement with no effect on the final color.

Efficacy of try-in paste and resin cement shades in prediction of the Final Color of multilayer Zirconia Veneers (An In-Vitro Study).

Efficacy of try-in paste and resin cement shades in prediction of the Final Color of multilayer Zirconia Veneers (An In-Vitro Study).

Effect of abutment types and resin cements on the esthetics of implant-supported restorations.

The aim of the study was to evaluate the optical properties of new generation (3Y-TZP) monolithic zirconia (MZ) with different abutment types and resin cement shades. A1/LT MZ specimens were prepared (10 × 12 × 1 mm, N = 30) and divided into 3 groups according to cement shades as transparent (Tr), yellow (Y) and opaque (O). Abutment specimens were obtained from 4 different materials including zirconia (Group Z), hybrid (Group H), titanium (Group T) and anodized yellow titanium (Group AT). MZ and abutment specimens were then cemented. L*, a*, and b* parameters were obtained from MZ, MZ + abutment, and MZ + abutment + cement. ΔE001* (between MZ and MZ + abutment), ΔE002* (between MZ and MZ + abutment + cement) and ΔE003* (between MZ + abutment and MZ + abutment + cement) values were calculated. Statistical analyses included 2-way ANOVA, Bonferroni, and Paired Sample t-Tests (P < .05). Abutment types and resin cements had significant effect on L*, a*, b*, ΔE001*, ΔE002*, and ΔE003* values (P < .001). Without cementation, whereas zirconia abutment resulted in the least discoloration (ΔE001* = 0.68), titanium abutment caused the most discoloration (ΔE001* = 4.99). The least ΔE002* = 0.68 value was seen using zirconia abutment after cementation with yellow shaded cement. Opaque shaded cement caused the most color change (ΔE003* = 5.24). Cement application increased the L* values in all groups. The least color change with/without cement was observed in crown configurations created with zirconia abutments. Zirconia and hybrid abutments produced significantly lower ΔE002* and ΔE003* values in combination with yellow shaded cement. The usage of opaque shaded cement in titanium/anodized titanium groups may enable the clinically unacceptable ΔE00* value to reach the acceptable level.

Investigation of Color Change of Different Restoration Thickness, Background Color and Resin Cement Shade on CAD/CAM Glass Ceramic Materials

The aim of this study is to investigate the color change of different restoration thicknesses, backgrounds and resin cement colors on lithium disilicate and zirconium reinforced lithium silicate materials in vitro. In this study, IPS emax CAD (LT C14) and Celtra Duo (LT C14) are used as full ceramic materials, and Variolink Esthetic LC (warm, neutral) used as resin cement and Tokuyama Estelite Sigma Quick (A3, A2) is used as composite materials. A total of 160 samples in the form of 40 pieces of 5 × 5 0.4 mm thick 40 pieces of 5 × 5 0.6 mm thick square discs from each of the all-ceramic materials in block form were obtained using a water jet device (DWJ1525-FA; Dardi International Corporation, Nanjing, China). Glass ceramic samples produced in 2 different thicknesses were cemented on 2 different backgrounds with 2 different resin types of cement. Color measurements of the samples before and after cementation were performed on a grey background with spectrophotometer Vita EasyShade V (Vita Zahnfabrik, Bad Sackingen, Germany) and color parameters (L*, a*, b*, ΔE) were calculated according to the CIE Lab (Commission Internationale de L’Eclairage) system. Average values for each group (ΔE) were not affected by ceramic type, material thickness, background color, resin cement color, and the interaction of these four variables (p > 0.05). When the triple interactions between the groups were examined, there were no statistically significant differences (p > 0.05). In the evaluation of pairwise interactions between two groups (material type-material thickness, material type-background color, and thickness of material-background interactions) statistically significant differences (p 0.05).

Final Colour of Ultratranslucent Multilayered Zirconia Veneers, Effect of Thickness, and Resin Cement Shade

Background Aesthetic restorations should be able to mimic the natural colour depth of teeth, affected by several factors including material properties. There is a lack of information regarding the effect of cement shade and material thickness on the final colour of ultratranslucent multilayered zirconia veneers. Objectives This study evaluated the effect of ceramic thickness and resin cement shade on the final colour of different layers of ultratranslucent multilayered (UTML) zirconia veneers. Methods This in vitro study produced 90 rectangular-shaped specimens with nonsintered Katana UTML monolithic zirconia (Kuraray Noritake Dental, Tokyo, Japan), shade A1 blocks. Ceramic samples were prepared in two groups of 0.7 mm and 0.5 mm thicknesses, 45 of each (a: 8 × 11 × 0.5 mm; b: 8 × 11 × 0.7 mm). Specimens of each thickness were further divided into 5 groups: universal, clear, brown, white, and opaque (n = 9). Each adhesive resin cement (Panavia V5) was applied between the ceramic samples and composite substrate. The colour values were measured using a spectrophotometer in baseline and after resin cement application according to the CIELab system. For all samples, ΔE00 values were obtained. Data were evaluated with SPSS 25 using the three-way ANOVA test (p < 0.05). Results The factors of cement shade, ceramic thickness, and ceramic layers have statistically significant effect on ΔE00 values (p < 0.001). The results showed lower ΔE00 values with thicker ceramic veneers. Tukey test results showed that the opaque and brown shade had a significantly greater ΔE00 values comparing to universal (p = 0.004), clear, and white shades (p < 0.001). Conclusion The colour change was greater in lower ceramic thickness. Different shades of resin cement and layers of UTML zirconia differently affected the final colour.

Luting resin cement shades and their effect on the color of ceramic ingot

This study aimed to evaluate and explore the consequence of luting resin cement shade on the color of ceramic ingot at different periods (24 h &amp; 7 d). Disc-shaped ceramic samples having 10 mm in diameter and 1 mm in thickness were fabricated (N = 30). Variolink Esthetic LC Refill with three different shades (Neutral, Warm, Light+) were chosen to apply on the ceramic samples (n = 10). The color measurements were made by CIELAB color space using a spectrophotometer device. Color measurements were taken as baseline, 24 hours after complete polymerization of the cement and after 7 days of fabrication. Analysis of variance, i.e., One-way ANOVA and Tukey’s post hoc test were used to explore the data (P &lt; 0.05). A statistically significant difference between cement type and the time point was observed (p = 0.000). Furthermore, time duration had a significant effect on the Δ? value (p = 0.001). Moreover, the interaction effect of the cement type and time had a significant effect on the Δ? value (p = 0.000). There is an obvious consequence of luting resin cement shade used on the shade of pressed ceramics. Time is an essential factor that affects and influence luting resin cement shade on the final color of the prosthesis.

The effect of resin cement shade and restorative material type and thickness on the final color of resin-matrix ceramics

This study aims to evaluate the effects of cement shade, restorative material type, and thickness on the final color of resin-matrix ceramics. Ninety A2 shade resin-matrix ceramic specimens were prepared from Vita Enamic, GC Cerasmart, and Lava Ultimate at 0.5 and 1.0 mm thicknesses. Sixty resin cement disks were fabricated from different shades (A1, A3O, B05, and TR) of RelyX Ultimate at 0.1 mm thickness. CIE color coordinates were measured using a spectrophotometer, and color differences (∆E00) were calculated. Data were statistically analyzed (P =0.05). The ΔE00 values were influenced by the cement shade, restorative material type, thickness, and their interactions (P < 0.05). A3O cement caused clinically unacceptable values for all groups at 0.5 mm thickness and GC at 1.0 mm thickness. A1 and TR cement shades demonstrated visually perceptible but clinically acceptable values, except for VE-A1 and LU-A1 at 0.5 mm thickness. The ∆E00 values of the B05 cement shade were lower than the visually perceptible threshold for both thicknesses except for GC at 0.5 mm thickness. The shade of the resin cement and the type and thickness of the resin-matrix ceramic material significantly affected the resulting final color. To provide a shade matching with natural dentition and to obtain esthetic restorations, especially for the anterior teeth, the resin cement shade and resin-matrix ceramic material should be carefully selected.

Effect of thickness, cement shade, and coffee thermocycling on the optical properties of zirconia reinforced lithium silicate ceramic.

ObjectiveTo investigate the effect of thickness, cement shade, and coffee thermocycling (CTC) on the optical properties of zirconia reinforced lithium silicate (ZLS) paired with different shades of a resin cement.Materials and MethodsThirty ZLS specimens were prepared in two different thicknesses (0.8 and 1.5 mm) and three different resin cement shades (Tr, A2, and A3) were applied (n = 5). Color determinations were done before and after 5000 CTC by using a noncontact spectroradiometer. Color change due to CTC and relative translucency parameter (RTP) before and after CTC were calculated by using CIEDE2000. Data were analyzed using ANOVA and Bonferroni‐corrected t‐tests(α = 0.05).ResultsMaterial thickness and resin cement shade (P < 0.001) affected baseline color. Material thickness affected color difference (P = 0.025). Thickness, resin cement shade, and CTC (P ≤ 0.0001) affected RTP. The difference between the color changes of the 0.8‐ and 1.5‐mm specimens combined with A2 shade cement after CTC was significant (P = 0.01). RTPs of all pairs decreased after CTC (P < 0.001).ConclusionsCement shade and material thickness affected the baseline color. The thickness of ZLS affected the color change after CTC only with A2 resin cement and the color change was less when the ZLS was thicker. CTC reduced the translucency of all pairs.Clinical SignificanceClinicians and patients should be aware of a potential color change after long‐term coffee consumption when zirconia reinforced lithium silicate is used particularly for laminate veneers with A2 shade of the tested resin cement.

Effect of Universal Shade of Resin Cement on the Final Color of Ceramic Restorations

Effect of Universal Shade of Resin Cement on the Final Color of Ceramic Restorations

Colour agreement between try-in paste and resin cement: effect of background on zirconia-reinforced lithium silicate.

To investigate colour agreement between different shades of Panavia V5 resin cement and their try-in pastes under zirconia-reinforced lithium silicate ceramics. Forty-four zirconia-reinforced lithium silicate ceramic specimens were prepared at 0.8 ± 0.01 mm thickness. Composite resin tooth-shaded background specimens were obtained in two shades. Resin cement specimens were fabricated at 0.1-mm thickness. Colour difference values (ΔE) between Aquagel and both the try-in paste and resin cement were calculated using the CIE-Lab system. The CIEDE2000 (ΔE00) colour formula was used to determine colour differences. The three-way ANOVA test and a multiple comparisons test were used for statistical analysis (α = 0.05). A statistically significant difference was found between the ΔE00 values obtained from the cement shade colour measurements for all specimens (P < 0.05). According to the three-way ANOVA test, lower ΔE00 values were observed in the try-in paste group compared to the resin cement group. The ΔE00 values were significantly affected by the cement shade and tooth-shaded background (P < 0.05). The colour agreement between the try-in pastes and the corresponding resin cement differed, and the try-in pastes could not mask the dark dental background as much as the corresponding resin cement.

Effect of ceramic thickness, translucency and cement shade on color masking ability of pressable zirconia based lithium silicate laminate veneer

Objective: This in-vitro study aimed to evaluate the effects of ceramic thicknesses and translucencies as well as resin cement shades on the masking ability of zirconia based lithium silicate discs (ZLC). Materials and Methods: Eighty-four ceramic discs were manufactured from high translucent (HT) and translucent (T) ZLC ceramic. Discs were divided into three equal subgroups, according to their thickness (0.5, 1, 1.5 mm). Background composite resin discs (shade C4D) were used to simulate the color of dark abutments. Ceramic discs were cemented to composite ones with either translucent or opaque resin cements. Color parameters were measured using a spectrophotometer and recorded by CIELab system, color difference between ceramic discs and cemented ceramic discs to composite were calculated as E. All data were statistically analyzed, using unpaired-t test, ANOVA test and Tukey HSD test. Statistical significance was set at p < 0.05. Results: A statistically significant color difference (E) was found between (HT) and (T) discs (P<0.05). E values of both translucencies were affected by ceramic thickness (P=0.000). Resin cement shade had no significant effect on E values when the thicknesses of ceramic veneer were 1.0 mm or 1.5 mm (P values=0.495 and 0.265 respectively). While the cement shades had a highly significant effect on E values when ceramic, disc thickness was 0.5mm. (P value<0.0001). Conclusion: As the veneer thickness increased, color change decreased significantly. Ceramic translucency and cement shade significantly influence the final color of pressable ZLC veneers only if the thickness is less than 1 mm.

The Effect of Substrate and Resin Cement Shades on The Optical Properties of Two Ceramic Laminate Veneer Materials

Purpose: The current study aimed to investigate the effect of substrate and resincement shades on the optical properties of two ceramic laminate veneer materials.Materials and Methods: Sixty four thin slices of ceramics were made from the twomaterials (IPS e.max CAD, Vita Suprinity).They were divided into two equal groups(n=32). Each group was subdivided into two subgroups (n=16) regarding to substrateshade (A3,C4)on which each ceramic slice was cemented. Each Subgroup was furthersubdivided into 2 divisions (n=8) according to resin cement shade (A1,WO). Colormeasurement was done after cementation by using reflective spectrophotometer thenthermal aging process was done for 5000 cycles.(ΔE) values from a reference color (A1shade) was calculated.Results: By comparing ceramic types vita suprinity recordedstatistically significant lower mean (ΔE) values than IPS e.max CAD.By comparingresin cement shade on (ΔE) ,white opaque cement recorded statistically significantlower mean (ΔE) value than A1 cement. As regards the effect of substrate,C4 compositerecorded statistically significant higher mean(ΔE)value than A3 composite. Finallythermal aging effect on (ΔE),color change mean values after aging was statisticallynon-significant higher than that before aging. Conclusion: The mean color change(ΔE) was clinically acceptable for Vita Suprinity group than E.max CAD group, vitasuprinity ceramic can mask dark substrate more than E.max CAD and white opaquecement shade also give better masking effect of dark substrate. After thermo cyclingcolor change was statistically non-significant higher than that before aging.

The influence of zirconia veneer thickness on the degree of conversion of resin-matrix cements: an integrative review.

The mainaim of this study was to conduct an integrative review on the influence of the zirconia veneer thickness on the degree of conversion of resin-matrix cements. An electronic search was performed on PubMedusing a combination of the following search items: zirconia, thickness, veneer, degree of conversion, resin cement, light curing, and polymerization. Articles published in the English language, up to July 2020, were included regarding the influence of ceramic veneer thickness on the degree of conversion of resin-matrix cements. Randomized controlled trials and prospective cohort studies were also evaluated. Of the 21 selectedstudies, 9 investigated the light-curing effect, while five other articles evaluated the ceramic translucency. Three studies evaluated the degree of conversion of the resin-matrix cement while four articles assessed the veneer thickness. Results revealed a significant decrease of light transmission through the zirconia with a thickness ranging from 0.1 upto 1.5 mm. However, the ultra-thin thickness around 0.1 and 0.3 mm allowed a full polymerization of the dual-curing resin-matrix cement resulting in the integrityof the interface properties. The light-curing process of resin-matrix cements is also affected by the shade, chemical composition, and microstructure of zirconia and resin cement. Optimalconditions of light-curing are required to reach the threshold intensity of light and energy for polymerization of resin-matrix cements. The increase in zirconia veneer thickness negatively affects the degree of conversion of resin-matrix cements. Also, shade and microstructure are key factor to improve the light curing of resin cements. Clinicians should consider the zirconia thickness on resin-based cementation since a higher veneer thickness can negatively affect the light irradiation intensity towardsthe dual-curing resin-matrix cement. Thus, the degree of conversion of the resin-matrix cement candecrease leading to a low chemical stability (e.g., color instability) and poor mechanical properties.

Optical effect of resin cement, abutment material, and ceramic thickness on the final shade of CAD-CAM ceramic restorations

Statement of problemHigh-translucency ceramics can be influenced by the underlying structure, altering the restoration shade. How this affects color matching is unclear. PurposeThe purpose of this in vitro study was to investigate the optical effects of cement shade, ceramic type, ceramic thickness, and abutment material on the final color of computer-aided design and computer-aided manufacturing (CAD-CAM) ceramic restorations. Material and methodsTwo shades of resin cement (yellow, translucent), 3 types of background (titanium, white zirconia, yellow zirconia), and 3 types of high-translucent ceramic (each type shade A1 and A3) were used in this study. For the experimental groups, a total of 72 ceramic specimens were produced across 4 groups based on ceramic thickness (1.0 mm, 1.5 mm, and 2.0 mm). For the control groups, each ceramic type and shade was prepared at a thickness of 4 mm. A total of 8 resin cement specimens were produced in 4 groups based on shade by using a plastic mold (12×12×0.2 mm). To demonstrate the effect of implant abutment materials, 3 types of background were fabricated with a thickness of 2 mm. For the experimental groups, 3 specimens (ceramic, cement, and background) were sequentially placed with glycerin in the center of each background specimen. Color measurements of the experimental groups were made with a spectrophotometer and recorded in the Commission Internationale de l’Eclairage Lab coordinate system. The color differences (ΔE) between experimental and control groups were then calculated. The Kruskal-Wallis test (α=.05) was used to analyze the multiple comparisons of ceramic thickness, ceramic type, and abutment material. The Mann-Whitney U test (α=.05) was used to analyze cement shade. ResultsSignificant differences were found for different ceramic thicknesses, ceramics types, and abutment materials (P≤.001). A clinically acceptable shade (ΔE≤3) was found in 1.5- and 2.0-mm ceramics with the titanium and 2.0-mm ceramics with the yellow zirconia background. However, the color between the experimental group and the control group was similar when using the 2 cement shades (P>.05). ConclusionsAn increase in ceramic thickness could minimize alteration of the final shade. High-translucency ceramics, together with a resin cement, were able to successfully mask titanium with a ceramic thickness of at least 1.5 mm. However, only a ceramic with a thickness of 2.0 mm was able to mask the yellow zirconia background.

Effect of color of the cement and the composite resin foundation on the resultant color of resin-matrix ceramics

Statement of problemAn improper restoration color match to the adjacent natural teeth can jeopardize esthetic success. The type of resin-matrix ceramic (RMC), the shade of the underlying foundation, and the shade of cement may affect the optical behavior of RMC materials, but studies on this issue are lacking. PurposeThe purpose of this in vitro study was to assess the cumulative effect of different shades of composite resin foundation (CRF) and cement on the optical behaviors of 3 different RMCs. Material and methodsForty-five rectangular RMC specimens (14×12×1 mm, shade A2) were prepared from 3 different blocks, including a polymer-infiltrated ceramic network (Vita Enamic [VE]), a resin nanoceramic (Lava Ultimate [LU]), and a flexible nanoparticle-filled resin (GC Cerasmart [GC]) (n=15 per RMC block). CRFs (14×12×4 mm) were fabricated in white and dentin shades (n=1 per composite resin shade). Cement specimens (G-CEM LinkForce) were prepared from 3 shades (A2, opaque [OP], and translucent [TR]) (n=15 per shade). For control groups, 3 rectangular RMC foundations (14×12×4 mm) were also milled from RMC blocks (n=1 per block). Color coordinates were recorded by using a digital spectrophotometer. The coordinates of 4-mm-thick RMC foundations served as the control groups. The coordinates of RMC specimens on each combination of CRF and cement served as test groups. The CIEDE2000 (ΔE00) formula was used to assess color differences. Data were subjected to 3-way ANOVA and Tukey honestly significant difference (HSD) tests (α=.05). ResultsΔE00 values of specimens were influenced by the CRF shade, cement shade, RMC type, as well as the interaction terms of the 3 variables (P<.001). Color differences in groups VE-A2-dentin, VE-OP-dentin, LU-OP-dentin, and GC-OP-dentin showed perceptible but clinically acceptable values (0.8<ΔE00≤1.8). The highest and lowest ΔE00 values were observed in the white-OP-LU (5.32 ±0.34) and dentin-OP-VE (0.94 ±0.31) groups. ConclusionsOpaque cement on the white foundation led to the highest ΔE00 values in the resultant colors of all RMC groups. When used with the same shade on the dentin foundation, this cement produced clinically acceptable results.

Evaluation of shade correspondence between current monolithic CAD/CAM blocks and target shade tab by considering the influence of cement shade and restorative material thickness.

It was aimed to evaluate shade matching between novel CAD/CAM blocks and the A2 target shade tab by considering the influence of cement shade and restorative material thickness on the chromatic background. A total number of 120 rectangular-shaped specimens were subtracted from four different prefabricated CAD/CAM blocks [Vita Enamic (VE), Lava Ultimate (LU), GC Cerasmart (GC), and Vita Mark II (VMII)]. These specimens had thicknesses of 0.5mm and 1.0mm. Three different shades (A2, opaque, and translucent) of dual-polymerized resin cement were chosen. The dentin shade (A3.5) restorative composite foundation was incrementally fabricated in a silicon mold. For control group, the A2 shade tab of the Vitapan classical shade guide was used. Different restorative material-cement-foundation assemblies were generated with optic gel. Color readings were performed by using a clinical spectrophotometer, and CIEDE2000 (ΔE00) formula was used to assess color differences. Data were statistically analyzed (α = 0.05). With increasing thickness, color difference values decreased. Higher mean ΔE00 units were observed in all restorative material sub-groups for 0.5mm thickness. In TR shade, no statistically significant difference was detected among the mean ΔE00 values of 0.5mm-thick restorative materials. Color differences in groups 1.0mm-opaque-LU and 1.0mm-opaque-GC indicated perceptible but clinically acceptable values (0.8˂ΔE00 ≤ 1.8). The highest and lowest ΔE00 units were observed in the 0.5mm-A2-VE group (ΔE00 = 7.07) and 1mm-opaque-GC group (ΔE00 = 1.46), respectively. Luting cement shade, restorative material type, and thickness significantly influenced the resultant color of restoration. Opaque cement on dentin foundation exhibited lower color differences.

Masking Tetracycline Stained Teeth: Effect of Translucency and Thickness of Multiple CAD-CAM Masking Tetracycline Stained Teeth: Effect of Translucency and Thickness of Multiple CAD-CAM Veneer Materials and Shades of Resin Cements

Abstract This study aimed to assess the masking potential of different CAD-CAM veneer restorations to restore tetracycline-stained teeth. One-hundred-eight CAD-CAM ceramic discs, shade 1M1, with high (HT) and low (LT) translucencies and 1mm and 0.7mm thicknesses were prepared from three CAD-CAM materials (IPS-e.max-CAD (EMC), VITA Enamic (VE) and Vita Suprinity (VS)). Resin cements, shades A1, white opaque (WO) and translucent (T), were used for cementation against a dark base. Color differences (ΔE*) between the restorations (veneer/resin cement/dark base) and a standard 1M1 shade-guide-tab were calculated. Mann-Whitney-U and Wilcoxon-signed-rank tests; and one-way ANOVA, Kruskal-Wallis and Bonferroni-post-hoc tests were used to compare between two and three groups respectively (P ≤0.05). Groups EMC-LT-0.7-T, VE-LT-1-A1 and VE-LT-1-T rendered restorations with ΔE* below the perceptibility threshold (<1.74), while EMC-LT-0.7-A1 and all LT-0.7mm VE restorations were within the acceptability threshold (<3.48). VS had significantly higher (ΔE*) compared to of EMC and VE materials. Ceramic thicknesses had no significant effect on (ΔE*), while the effect of translucency level of the ceramics and the shade of resin cement was significant. It was concluded that low translucency ceramic veneers can better mask darkly stained teeth, irrespective of their thicknesses, with resin cements shades affecting the color of the final restorations.