scholarly journals A Spectrophotometric Analysis of Color Changes in Metal Ceramic Restorations by Varying Porcelain Thickness and Repeated Firings: An in vitro Study

2015 ◽  
Vol 5 (2) ◽  
pp. 38-43
Author(s):  
Sunantha Selvaraj ◽  
Ramesh Raju ◽  
Vidhya Zankari ◽  
Manonmani Vijayakumar
Keyword(s):  
In Vitro Study ◽  
Color Stability ◽  
Spectrophotometric Analysis ◽  
Statistic Analysis ◽  
Dental Ceramics ◽  
Color Changes ◽  
Paired Samples ◽  
Metal Ceramic ◽  
Ceramic Restorations

ABSTRACT The dental profession has long been concerned with the problem of matching the appearance of porcelain restorations with a patient's natural dentition. The esthetics of any restoration depends on outline form, surface form, translucency and color. Purpose The objective of this study is to find out the adequate porcelain thickness required for metal ceramic restorations to match the color of the shade guide and effect of repeated firing on quality and physical characteristics of dental ceramics. Methods Preparation of samples done first by preparing alloy substructure. A total of 15 samples of uniform thickness 0.5 mm was prepared using Ni-Cr alloy. Fusion of porcelain to alloy substructure done. Fifteen samples, five 0.5 mm thickness samples, five 1 mm samples and five 1.5 mm porcelain thickness samples were prepared. Color evaluation done by spectrophotometer. Statistic analysis Statistic analysis methods employed in the present study were ANOVA-one way, Scheffe's post hoc test and paired samples ‘t’ test. Conclusion The thickness of porcelain significantly affects the color of a given porcelain sample. Increasing the thickness gives better results. On repeated firings two and 10 firing did not affect the color stability. How to cite this article Raju R, Selvaraj S, Zankari V, Vijayakumar M. A Spectrophotometric Analysis of Color Changes in Metal Ceramic Restorations by Varying Porcelain Thickness and Repeated Firings: An in vitro Study. Int J Prosthodont Restor Dent 2015;5(2):38-43

scholarly journals Marginal Strength of Collarless Metal Ceramic Crown

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Sikka Swati ◽  
R. Chowdhary ◽  
P. S. Patil
Keyword(s):  
Fracture Strength ◽  
Testing Machine ◽  
Compressive Load ◽  
In Vitro Study ◽  
Instron Testing Machine ◽  
Metal Ceramic ◽  
Ceramic Crowns ◽  
Ceramic Restorations ◽  
Ceramic Crown

Metal ceramic restorations have been implicated for the discoloration in area of labiogingivalmargin. Attempts to rectify this, by altering the design of metal frameworkswill lead to decrease in fracture strength atmargin. This in vitro study compared the fracture strength at margins of metal ceramic crowns cemented to metal tooth analogs. Crowns evaluated with different marginal configurations, shoulder and shoulder bevel with 0 mm, 0.5 mm, 1 mm, and 1.5 mm, were selected.Methods. Maxillary right canine typhodont tooth was prepared to receive a metal ceramic crown with shoulder margin. This was duplicated to get 20 metal teeth analogs. Then the same tooth was reprepared to get shoulder bevel configuration. These crowns were then cemented onmetal teeth analogs and tested for fracture strength atmargin on an Instron testing machine. A progressive compressive load was applied using 6.3 mm diameter rod with crosshead speed of 2.5 mm per minute. Statisticaly analysis was performed with ANOVA, Student's “t” test and “f” test.Results. The fracture strength of collarless metal ceramic crowns under study exceeded the normal biting force. Therefore it can be suggested that collarless metal ceramic crowns with shoulder or shoulder bevel margins up to 1.5 mm framework reduction may be indicated for anteriormetal ceramic restorations.Significance. k Collarless metal ceramic crowns have proved to be successful for anterior fixed restorations. Hence, it may be subjected to more clinical trials.

The Effect of Bleaching Agents on the Color Stability of Ceromer and Porcelain Restorative Materials In Vitro

2012 ◽  
Vol 38 (1) ◽  
pp. E1-E8 ◽  
Author(s):  
HB Kara ◽  
F Aykent ◽  
B Ozturk
Keyword(s):  
Color Change ◽  
Glass Ceramics ◽  
In Vitro Study ◽  
Color Stability ◽  
Color Changes ◽  
Bleaching Procedure ◽  
Significant Difference ◽  
Restorative Materials ◽  
The Difference

SUMMARY Purpose The aim of this in vitro study was to determine the color changes of five different restorative materials after exposing these materials to two different home bleaching agents. Methods This study applied bleaching agents to an ultralow-fusing porcelain, a low-fusing porcelain, two types of heat-pressed glass ceramics, and a ceromer. A total of 24 disc-shaped specimens were fabricated (with a diameter of 10 mm and a thickness of 2 mm) from each material (n=12). The initial color measurements were taken with a spectrophotometer. The first set of specimens were bleached with 10% hydrogen peroxide (HP) for one hour daily for 10 days. The other set of specimens were bleached with 10% carbamide peroxide (CP) bleaching gel for eight hours daily for 14 days. Data were analyzed with the one-way analysis of variance and Kruskal-Wallis statistical test. The difference in the prebleaching and postbleaching color of each material was considered to be statistically significant at p < 0.05. Results The study found a statistically significant difference among the color changes of the test groups after exposing them to both bleaching agents (p<0.05). Appreciable color change was observed in the Estenia (ΔE=3.99) specimens that were bleached with the HP, and noticeable color changes were observed in the Estenia (ΔE=1.89) and IPS Empress 2 (ΔE=1.66) groups when they were treated with the CP. Conclusions Restorations (especially polymer-containing restorative materials) should be protected before any bleaching procedure due to the high risk of color change.

Effect of Children's Drinks on Color Stability of Different Dental Composites: An in vitro Study

2017 ◽  
Vol 41 (2) ◽  
pp. 120-125 ◽  
Author(s):  
Ahmed Nour El-din Ahmed Habib ◽  
Soad Abdelmoniem Abdelmoniem ◽  
Sara Ahmed Mahmoud
Keyword(s):  
Color Change ◽  
In Vitro Study ◽  
Color Stability ◽  
Dental Composites ◽  
Chocolate Milk ◽  
Water Control ◽  
Color Changes ◽  
Significant Difference ◽  
Mango Juice

Aim: To assess the effect of four different children's drinks on color stability of resin dental composites. Study design: A total of one hundred and twenty specimens were prepared from Grandio SO, Filtek Z350 XT and Filtek Z250 XT (forty specimens each). Specimens were thermocycled, then each group was further subdivided into four subgroups (n=10) according to the immersion media which were chocolate milk, mango juice, orange fizzy drink, and water (control). The initial color parameters of each specimen were recorded before immersion (baseline) and color change values were recorded three and seven days after immersion in each solution using a digital spectrophotometer. Atomic force microscope was used to measure the surface roughness in randomly selected samples after one week immersion in children's drinks. Results: All the children's drinks produced color changes in the examined resin dental composites, yet there was no statistical significant difference between the effects of tested drinks on the color changes (mean ΔE) of the three different dental composites (P>0.05). Conclusions: All tested children's drinks caused clinically unacceptable color changes of the tested resin dental composites. Immersion in chocolate milk and orange fizzy led to the highest color changes in the tested resin dental composites.

scholarly journals Evaluation of color changes of white spot lesions treated with three different treatment approaches: an in-vitro study

2020 ◽  
Vol 25 (1) ◽  
pp. 26-27
Author(s):  
Shaza M. Hammad ◽  
Noha A. El-Wassefy ◽  
Mohamed A. Alsayed
Keyword(s):  
Color Change ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Color Stability ◽  
White Spot ◽  
Control Group ◽  
White Spot Lesions ◽  
Color Changes ◽  
Icon Resin Infiltrant

ABSTRACT Objective: To qualitatively and quantitatively assess the color changes effect and the color stability of the resin infiltrant on white spot lesions (WSLs), in comparison with nano-hydroxyapatite (nano-HA) toothpaste and microabrasion. Methods: WSLs were artificially created on sixty human premolars enamel surfaces and randomly assigned to equal four groups (n = 15 each): nano-HA toothpaste, microabrasion (Opalusture), resin infiltrant (Icon) treatment, or artificial saliva (control group). The color change (ΔE) of each specimen was measured by dental spectrophotometer (Vita Easyshade) at different time points: baseline, after WSLs’ creation, after application of treatments, one month, three and six months after treatments application. Results: The ΔE value did not differ significantly for the four groups at baseline measurement before treatment (p> 0.05). Icon resin infiltrant improved the color of WSLs significantly immediately after its application, giving the lowest ΔE value (3.00 ± 0.59), when compared to other treatments (p< 0.001). There were no significant changes in ΔE (p> 0.05) for all groups during the follow up intervals (one month, three and six months after treatments application). Conclusion: Resin infiltrant can improve the color of WSLs and restore the natural appearance of enamel better than nano-HA toothpaste and microabrasion.

scholarly journals Influence of the Arabic-Coffee on the Overall Color of Glazed or Polished Porcelain Veneers – In vitro Study

2019 ◽  
Vol 13 (1) ◽  
pp. 364-370 ◽  
Author(s):  
Nabiel Alghazali ◽  
Afaf A. Hakami ◽  
Ghadah A. AlAjlan ◽  
Rawan M. Alotaibi ◽  
Faris N. Alabdulwahab ◽  
...  
Keyword(s):  
Colour Change ◽  
In Vitro Study ◽  
Color Stability ◽  
Color Changes ◽  
Significant Difference ◽  
Oral Environment ◽  
Before And After ◽  
Feldspathic Porcelain

Background: Sometimes, porcelain restorations experience some degree of colour change in oral environment, which could be related to the quality of diet and surface roughness of these restorations. Objective: The aim of this in-vitro study was to evaluate the influence of Arabic-Coffee on the overall color of glazed or polished porcelain veneers fabricated from four different porcelain materials and two different thicknesses. Materials and Methods: A total of 160 porcelain disc of tested specimens were fabricated to a standardized thickness of 1.00 mm and 0.6mm using the following materials: Feldspathic porcelain, Zircon, E-max Press, and E-max CAD; (80 discs for each thickness and 20 specimens of each material used). Veneer specimens from each material were randomly divided into two subgroups (n = 10): 10 specimens were kept as glazed, were the other 10 tested specimens were adjusted with diamond burs, and then polished with Ivoclar Vivadent ceramic polishing kits using the recommended protocol for polishing provided by the company. A color of all tested specimens was measured using Vita Easy Shade Spectrophotometer. Then, all specimens were immersed in Arabic coffee (Al Mosafer Coffee, Saudi Arabia) and theromcycled for 1 week, and the colors of all tested specimens were then recorded again. Results: It was shown that there is a significant difference in the average color changes before and after immersing in Arabic-Coffee for all materials and thicknesses used in the current study. In-addition, significant differences in color changes were noticed between glazed and polished specimens. Moreover, colour change caused by the coffee was not significantly related to the thickness of the specimens used. Conclusion: Color stability of porcelain materials could be affected by surface treatment whether glazing or polishing. All aesthetic restorations should be deglazed whenever any adjustments have been done to maintain the color match and stability in an oral environment. Also, Arabic-Coffee is considered as a staining drink to a limited extend where patient should be assured to maintain their oral health to maintain the colour stability of their restorations.

scholarly journals In vitro study of color stability of polycrystalline and monocrystalline ceramic brackets

2014 ◽  
Vol 19 (4) ◽  
pp. 114-121 ◽  
Author(s):  
Cibele Braga de Oliveira ◽  
Luiz Guilherme Martins Maia ◽  
Ary Santos-Pinto ◽  
Luiz Gonzaga Gandini Júnior
Keyword(s):  
Red Wine ◽  
Color Change ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Color Stability ◽  
Black Tea ◽  
Color Changes ◽  
Ceramic Brackets ◽  
Dye Solutions

OBJECTIVE: The aim of this in vitro study was to analyze color stability of monocrystalline and polycrystalline ceramic brackets after immersion in dye solutions. METHODS: Seven ceramic brackets of four commercial brands were tested: Two monocrystalline and two polycrystalline. The brackets were immersed in four dye solutions (coffee, red wine, Coke and black tea) and in artificial saliva for the following times: 24 hours, 7, 14 and 21 days, respectively. Color changes were measured by a spectrophotometer. Data were assessed by Multivariate Profile Analysis, Analysis of Variance (ANOVA) and Multiple Comparison Tests of means. RESULTS: There was a perceptible change of color in all ceramic brackets immersed in coffee (ΔE* Allure = 7.61, Inspire Ice = 6.09, Radiance = 6.69, Transcend = 7.44), black tea (ΔE* Allure = 6.24, Inspire Ice = 5.21, Radiance = 6.51, Transcend = 6.14) and red wine (ΔE* Allure = 6.49, Inspire Ice = 4.76, Radiance = 5.19, Transcend = 5.64), but no change was noticed in Coke and artificial saliva (ΔE < 3.7). CONCLUSION: Ceramic brackets undergo color change when exposed to solutions of coffee, black tea and red wine. However, the same crystalline structure, either monocrystalline or polycrystalline, do not follow the same or a similar pattern in color change, varying according to the bracket fabrication, which shows a lack of standardization in the manufacturing process. Coffee dye produced the most marked color changes after 21 days of immersion for most ceramic brackets evaluated.

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