Variability in Colour Reproduction of Metal-Ceramic Crowns

The aim of the present study was to objectively assess the variability in color reproduction of metal-ceramic (MC) single crowns fabricated by blending different color of opaque and body ceramic in order to point out which shade of the ceramic layers influences mostly the final color of the restorations. Eight nickel-chromium ceramic metal alloy copings were fabricated, on the same cast, following by blending the ceramic for the specific A3 color as follows: one reference ceramic (R) was blended, according to the producer s recommendation, and seven tests crowns have been build-up by considering as variables each one of the two uniform opaque layers, and dentin layer. Color of each manufactured crowns was measured after the three important steps of the technological workflow: the last opaque layer, enamel-dentin correction and final glaze firing using Vita Easyshade spectrophotometer. The best final color match (color difference of deltaE=0.8) was obtained for specimen no. 5, with a lighter opaque firs layer (A1). Fabricated specimens of all groups, except for no.4, with a darker dentin layer (A 3.5), showed deltaE values between 0.8 and 2.8, in the limit of the threshold perception in the oral cavity, and were scored as good. Within the limits of the present study, we can conclude that the dentin-enamel layer mostly influences the final color of the MC crowns.

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Color matching of full ceramic versus metal-ceramic crowns - a spectrophotometric study

Medicine and Pharmacy Reports ◽

10.15386/mpr-1330 ◽

2019 ◽

Cited By ~ 1

Author(s):

Delia Cristina Greța ◽

Cristina Gasparik ◽

Horațiu Alexandru Colosi ◽

Diana Dudea

Keyword(s):

Color Difference ◽

Spectrophotometric Study ◽

Zirconia Ceramic ◽

Coding System ◽

Color Match ◽

Posterior Teeth ◽

Metal Ceramic ◽

Ceramic Crowns ◽

Fair Poor ◽

Instrumental Methods

Background and aims. To verify the color match of metal-ceramic and full ceramic crowns, using instrumental methods. Methods. A number of 153 teeth (anterior and posterior teeth), in 62 patients, were restored with metal ceramic (MC, n=119), pressed-ceramic (PC, n=28), and zirconia-ceramic (ZC, n=6) full coverage crowns. The shade of a reference natural tooth was recorded instrumentally with a dental spectrophotometer (Vitaeasyshade Advance 4.0) in “single tooth measurement”, which provided the base color in Vita Classic (VC) and Vita 3D Master shades (3D). For verifying the outcome of the restoration “verify restoration” mode was used, and ΔE values were recorded for both VC and 3D Master shade guides. Moreover, matching symbols were also recorded (***=good, **=fair, *=poor). Descriptive statistics was performed and data were analyzed (One-sample z-Test, α=0.05) for comparison with visual thresholds in dentistry (Perceptibility Threshold – PT=1.2 and Acceptability Threshold – AT=2.7). Results. The data did not follow a normal distribution (Kolmogorov-Smirnov test, p<0.05). Recorded color difference was significantly higher than PT and AT, for all types of restorations, regardless of the coding system (p<0.05). For MC crowns in 2.52% (4.20% for 3D) of the cases the color difference was smaller than PT, in 19.32% (the same for 3D) of cases was between PT and AT, and in 78.15% (76.47% for 3D) of cases was higher than the AT. For PC crowns in 3.57% (0% for 3D) of the cases the color difference was smaller than PT, in 25% (32.14% for 3D) of cases was between PT and AT, and in 71.42% (67.85% for 3D) of cases was higher than the AT. In the case of ZC crowns none of the restorations had color difference smaller than PT, but in 16.66% of cases was between PT and AT, and in 83.33% of cases was higher than the AT, for both VC and 3D. Conclusion. Within the limitations of the study, a better color match was achieved in the case of pressed ceramic crowns, made of lithium disilicate. In most of the situations the color difference between the restoration and the reference tooth exceeded the perceptibility thresholds, but the matching was recorded as “fair” by the spectrophotometer.

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Influence of Varying Dentin and Enamel Layer Thicknesses of Nano-composite Resins on Color Match between Lithium Disilicate Dental Ceramic and Composite Resins

Frontiers in Dentistry ◽

10.18502/fid.v18i12.6137 ◽

2021 ◽

Author(s):

Elmira Saati Khosroshahi ◽

Elmira Jafari Navimipour ◽

Fatemeh Pournaghi Azar ◽

Mehdi Abed-Kahnamoui ◽

Mahmoud Bahari

Keyword(s):

Calculated Data ◽

Lithium Disilicate ◽

Color Difference ◽

Composite Resins ◽

Color Match ◽

Nano Composite ◽

Dental Ceramic ◽

The Difference ◽

Dentin Thickness ◽

Enamel Layer

Objectives: The aim of this study was to evaluate the influence of varying dentin and enamel layer thicknesses of two nano-composite resins on color match of composite resins and lithium disilicate dental ceramic. Materials and Methods: Twenty-six specimens of two types of nano-composite resins, Opallis and Vittra, were fabricated using the two-layered technique with different thickness ratios of enamel and dentin composites (A2 shade) with a total thickness of 1.2mm. Thirteen discs of the same shade and thickness of IPS e.max Press LT (low translucency) lithium disilicate dental ceramic were also fabricated. Specimen color was measured with a spectrophotometer. The difference in color (ΔE00) of composite and ceramic specimens, and the translucency parameter (TP) of all specimens were calculated. Data were analyzed using multi-factor ANOVA (P<0.05). Results: The color difference (ΔE00) values of composites and ceramic were not clinically acceptable in any areas of either of the two composites (ΔE00>2.25). But ΔE00 between the two composite resins was in the clinically acceptable range (ΔE00<2.25). The mean TP value of IPS e.max Press was greater than that of Vittra and lower than that of Opallis. Conclusion: In similar thicknesses, composite resins with any enamel/dentin thickness ratio could not successfully simulate the color and translucency of IPS e.max Press LT ceramic.

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Influence of Cusp Inclination and Type of Retention on Fracture Load of Implant-Supported Crowns

Brazilian Dental Journal ◽

10.1590/0103-6440201701342 ◽

2017 ◽

Vol 28 (1) ◽

pp. 92-96

Author(s):

Cibele Oliveira de Melo Rocha ◽

Diogo Longhini ◽

Rodrigo de Paula Pereira ◽

João Neudenir Arioli Filho

Keyword(s):

Testing Machine ◽

Fracture Load ◽

Second Molar ◽

Significant Difference ◽

Metal Ceramic ◽

Mandibular Second Molar ◽

Ceramic Crowns ◽

Post Hoc ◽

Single Crowns ◽

Supported Metal

Abstract There are few informations about the influence of cusp inclination on the fracture strength of implant-supported crowns. The study aimed to evaluate the influence of cusp inclination and retention type on fracture load in implant-supported metal-ceramic single crowns. Sixty crowns were made, classified as cemented and screw-retained with screw access hole (SAH) sealed or not. Standard (33°) and reduced (20°) cusp inclinations were tested for each group (n=10). To support crowns of a mandibular second molar, analogs of external hexagon implants 5.0 were used. The fracture load was measured in a universal testing machine EMIC DL2000 (10 kN load cell; 0.5 mm/min). Two-way ANOVA (retention and cusp inclination) followed by post hoc Tukey’s honest significant difference test was used for the statistical analyses (a=0.05). Crowns with reduced cusp inclination exhibited significantly higher fracture load (p<0.01) than crowns with standard cusp inclination. Cemented crowns showed significantly higher fracture load (p<0.01) than screw-retained crowns. The interaction among these factors was not significant (p>0.05) for the fracture load. The sealing of SAH did not influence the fracture load of screw-retained crowns (p>0.05). In conclusion, fracture load of implant-supported metal-ceramic crowns was influenced by retention and cusp inclination, and there was no influence of the sealing of SAH.

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Influence of Restorative Materials on Color of Implant-Supported Single Crowns in Esthetic Zone: A Spectrophotometric Evaluation

BioMed Research International ◽

10.1155/2017/5034358 ◽

2017 ◽

Vol 2017 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Min Peng ◽

Wei-Jie Zhao ◽

Mandana Hosseini ◽

Wen-Juan Zhou ◽

Ting Xiao ◽

...

Keyword(s):

Soft Tissue ◽

Subjective Evaluation ◽

Color Difference ◽

Spearman Correlation ◽

Color Match ◽

Anova Analysis ◽

All Ceramic ◽

Implant Crown ◽

Single Crowns ◽

Match Score

Restorations of 98 implant-supported single crowns in anterior maxillary area were divided into 5 groups: zirconia abutment, titanium abutment, and gold/gold hue abutment with zirconia coping, respectively, and titanium abutment with metal coping as well as gold/gold hue abutment with metal coping. A reflectance spectrophotometer was used to evaluate the color difference between the implant crowns and contralateral/neighboring teeth, as well as the color difference between the peri-implant soft tissue and the natural marginal mucosa. The mucosal discoloration score was used for subjective evaluation of the esthetic outcome of soft tissue around implant-supported single crowns in the anterior zone, and the crown color match score was used for subjective evaluation of the esthetic outcome of implant-supported restoration. ANOVA analysis was used to compare the differences among groups and Spearman correlation was used to test the relationships. A gold/gold hue abutment with zirconia coping was the best choice for an esthetic crown and the all-ceramic combination was the best for peri-implant soft tissue. Significant correlation was found between the spectrophotometric color difference of peri-implant soft tissue and mucosal discoloration score, while no significant correlation was found between the total spectrophotometric color difference of implant crown and crown color match score.

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Evaluation of Different Color-Difference Formulae by Means of an Experiment on Color Scaling-Preliminary Report

Color Research & Application ◽

10.1002/j.1520-6378.1977.tb00106.x ◽

1977 ◽

Vol 2 (1) ◽

pp. 13-18 ◽

Cited By ~ 6

Author(s):

Roberto D. Lozano

Keyword(s):

Preliminary Report ◽

Color Difference ◽

Different Color

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Fit of metal ceramic crowns cast in Au-1.6wt% Ti alloy for different abutment finish line curvature

Dental Materials ◽

10.1016/j.dental.2005.04.025 ◽

2006 ◽

Vol 22 (5) ◽

pp. 397-404 ◽

Cited By ~ 12

Author(s):

Jianxiang Tao ◽

Masanobu Yoda ◽

Kohei Kimura ◽

Osamu Okuno

Keyword(s):

Ti Alloy ◽

Finish Line ◽

Metal Ceramic ◽

Ceramic Crowns

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Veterans Administration Cooperative Studies Project No. 147. Part III: Assessment of blindness in a clinical evaluation of alternative alloys for metal-ceramic crowns

Journal of Prosthetic Dentistry ◽

10.1016/0022-3913(86)90146-0 ◽

1986 ◽

Vol 56 (6) ◽

pp. 692-697 ◽

Cited By ~ 5

Author(s):

Harold F. Morris

Keyword(s):

Clinical Evaluation ◽

Veterans Administration ◽

Metal Ceramic ◽

Ceramic Crowns

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PROSPECTS FOR MANUFACTURING FRAMES OF METAL CERAMIC STRUCTURES OF DENTAL PROSTHESES BY THE METHOD OF SELECTIVE LASER SINTERING

"Medical & pharmaceutical journal "Pulse" ◽

10.26787/nydha-2686-6838-2021-23-6-232-239 ◽

2021 ◽

pp. 232-239

Author(s):

Stepanov V.A. ◽

Shemonaev V.I. ◽

Buyanov E.A. ◽

Grachev D.V. ◽

Parchomenko A.N. ◽

...

Keyword(s):

Objective Assessment ◽

Selective Laser Sintering ◽

Clinical Effectiveness ◽

Study Groups ◽

Laser Sintering ◽

Dental Prostheses ◽

Metal Ceramic ◽

Abutment Teeth ◽

Ceramic Crowns ◽

Solid Tissues

The article presents the results of evaluating the prototyping of metal-ceramic structures made by casting and selective laser sintering. To achieve this goal, 27 patients with fabricated metal-ceramic crowns and bridgeworks were examined. Two study groups were created. The first group included 14 patients for whom dental prosthesis frameworks were made by casting. The second group consisted of 13 people, for whom the frames of dentures were made by the method of selective laser sintering. The analysis of clinical effectiveness was carried out according to the following criteria: 1- precision of the felling of prosthesis frame to solid tissues of abutment teeth; 2- the condition of the marginal periodontium; 3- the integrity of the ceramic cladding. The results of the study showed that the precision to solid tooth tissues of metal-ceramic dental prostheses made by laser selective sintering is higher than of frames made by casting. In accordance to the second criteria the best results were also shown by the participants of the second group. No chipping of the ceramic veneer from the metal-ceramic denture frameworks made by laser selective sintering was found. Thus, dentures which frameworks are made by the method of selective laser sintering are characterized by a higher objective assessment of their precision to the solid tissues of the abutment teeth. Lesions of the marginal periodontium both inflammatory and dystrophic were less in the participants of the second group. The frequency of defects in the coating of metal-ceramic dentures was significantly lower in the case of fabrication frameworks by laser selective sintering.

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