PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Prosthesis Coloring”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources
PubMed2001

In vitro testing of the bond between soft materials used for maxillofacial prostheses and cast titanium.

STATEMENT OF PROBLEM: The choice of soft materials for maxillofacial prostheses is important for covering extraoral defects after tumor surgery or radiation therapy. The use of cast commercially pure titanium as reinforcement seems to be a suitable option. PURPOSE: Making use of the advantages of titanium frameworks for maxillofacial prostheses requires exploring ways of combining it with soft materials. This study investigated such combinations and evaluated discoloration of the soft material to determine whether it was attributable to the titanium reinforcement. MATERIAL AND METHODS: Five soft materials used for maxillofacial prostheses and their bond strengths to cast titanium were tested. Different ways of conditioning the titanium surface and different adhesives were used. Plain mechanical retention was also studied. The Gretag SPM 100 was used to determine the potential effects on coloring after 24 hours of radiation in the Suntest rapid exposure unit. RESULTS: Suitable material combinations for bonding soft materials to titanium were found for all soft materials studied. Bond strength varied depending on the chemical basis of the soft material. Results indicated that maximal bond strengths were obtained by the combinations Supersoft with Super-Bond, Supersoft with subsequent silicoating, and bonding with Dentacolor connector. Few color shifts attributable to the titanium reinforcement were evident in the 2-mm layers of the soft materials applied. CONCLUSION: The results of this study showed that it is possible to combine a titanium framework and soft silicone materials.

Acrylic Resins↗
PubMed2001

Accelerated color change in a maxillofacial elastomer with and without pigmentation.

STATEMENT OF PROBLEM: Maxillofacial prostheses require frequent replacement because the elastomer and its color additives undergo changes. PURPOSE: This study attempted to determine whether predictable color changes occur when 3 pigments are individually incorporated into a specific silicone elastomer. MATERIAL AND METHODS: The materials included an RTV elastomer; 1 natural inorganic pigment, burnt sienna; and 2 synthetic organic pigments, Hansa yellow and alizarin red. Eight test groups of 10 polymerized specimens were established. Groups 1 and 2, acting as the control, involved only the elastomer. Groups 3 and 4 were composed of elastomer and burnt sienna. Groups 5 and 6 consisted of elastomer and Hansa yellow. Groups 7 and 8 comprised elastomer and alizarin red. Odd-numbered groups were assigned to a test site in Miami, Fla., whereas the even numbered groups went to Phoenix, Ariz. Specimens weathered in Miami and Phoenix received sunlight exposures of 1305.7 MJ/m2 and 1310.2 MJ/m2, respectively, over time. Before and after weathering, the L* a* b* color parameter (DeltaE*) of each specimen was determined spectrophotometrically. RESULTS: Mean color changes that occurred in Arizona were larger than those produced in Florida. Specifically, these differences ranged from 0.4 (alizarin red groups) to 2.36 units for the 2 unpigmented control groups. Other differences showed significance for the unpigmented (P=.001), burnt sienna (P=.006), and Hansa yellow groups (P=.001). CONCLUSION: Outdoor weathering tests in which documented ASTM methods were used provided a valid baseline for future research on color changes in maxillofacial prostheses.

Analysis of Variance↗
PubMed2004

Application of a digital technique in evaluating the reliability of shade guides.

There appears to be a need for a reliable method for quantification of tooth colour and analysis of shade. Therefore, the primary objective of this study was to show the applicability of graphic software in colour analysis and secondly to investigate the reliability of commercial shade guides produced by the same manufacturer, using this digital technique. After confirming the reliability and reproducibility of the digital method by using self-assessed coloured images, three shade guides of the same manufacturer were photographed in daylight and in studio environments with a digital camera and saved in tagged image file format (TIFF) format. Colour analysis of each photograph was performed using the Adobe Photoshop 4.0 graphic program. Luminosity, and red, green, blue (L and RGB) values of each shade tab of each shade guide were measured and the data were subjected to statistical analysis using the repeated measure Anova test. The L and RGB values of the images taken in daylight differed significantly from those of the images taken in studio environment (P < 0.05). In both environments, the luminosity and red values of the shade tabs were significantly different from each other (P < 0.05). It was concluded that, when the environmental conditions were kept constant, the Adobe Photoshop 4.0 colour analysis program could be used to analyse the colour of images. On the other hand, the results revealed that the accuracy of shade tabs widely being used in colour matching should be readdressed.

Color↗
PubMed2004

Selecting nanotechnology-based composites using colorimetric and visual analysis for the restoration of anterior dentition: a case report.

Currently it is possible to use direct composites and layering techniques to replicate the complex internal structures, visible shape, color, and surface anatomy of natural teeth. To do so, however, requires dentists to understand the principles of nature and the science of dental materials to determine the most suitable restorative material for a specific indication. By incorporating relatively new technologies--colorimetric analysis, which provides computerized shade guide definitions of a tooth and essential information to verify shade mapping, and a new nanotechnology-based direct composite--into composite layering techniques, dentists can more predictably replicate the esthetics of natural teeth. This article presents a case in which both technologies, used in combination with a composite layering technique, contributed to the esthetic and functional restoration of the maxillary central incisors.

Adult↗
PubMedDate not supplied

Communicating shades: a clinical and technical perspective.

The creation of a natural-looking ceramic crown which blends harmoniously with the surrounding dentition is not merely a matter of recording a shade. The subtleties of colour, translucency, discrete staining, texture, lustre and shape are all essential features. Accurate shade taking and correct tooth preparation are all necessary elements but are of little value if the information cannot be precisely communicated to the technician.

Color↗
PubMed2001

Color stability of different denture teeth materials: an in vitro study.

The aim of this in vitro study was to compare the color stability of commercially available porcelain, reinforced acrylic, and conventional acrylic denture teeth materials used in removable prostheses. Two brands of porcelain (Unilux-Enta Lactona-Holland and Vivoperl-Ivoclar-Liechtenstein), 2 brands of reinforced acrylic (Optodent-Bayer-Germany and Ivolek-Ivoclar-Liechtenstein), and 2 brands of conventional acrylic (Isodent-Güney Diş Deposu-Turkey and Samed-Turkey), were made, for a total of 6 different denture teeth groups. Denture teeth were subjected to 3 staining solutions (filtered coffee, tea, and cola) and distilled water. From each group of denture teeth, 4 sets of maxillary anterior denture teeth were immersed in each of the 4 solutions. The color values of denture teeth were measured colorimetrically with the Gardner XL 20 Tristimulus Colorimeter (Gardner Lab. Inc., Bethesda, Maryland, USA). Color changes were characterized in the CIEL*a*b* color space. Color change values were determined after 1 day, 1 week, 2 weeks, and 4 weeks. The color difference values were calculated and then evaluated by two-way ANOVA statistically. The filtered coffee solution was found to be more chromogenic than the other 2 staining solutions, while porcelain denture teeth materials were more color stable. Assuming the color change of deltaE* < 1.0 as a discernible limit and deltaE* = 3.3 as an acceptable value, the filtered coffee, tea, and cola had slight staining effects on all 6 groups of denture teeth.

Acrylic Resins↗
PubMed2006

Effect of enamel shades on color of layered resin composites.

The purpose of this study was to evaluate the effect of the covering enamel layer of various thicknesses on the color of layered resin composites (LRC). To this end, the CIELAB parameters of the following were evaluated: underlying base (ULB: 2.0 mm of body shade + 3.0 mm of opaque shade), inherent color of the enamel shade (4.0 mm of enamel shade + ULB), and LRC disks (0.5, 1.0, 2.0, 3.0 mm of enamel shade + ULB) of Filtek Supreme (FS, 3M) and Gradia Direct (GD, GC). To assess the effect of the enamel layer on the color of LRC, color difference between ULB and LRC was calculated. With FS, the enamel layer had no major effect on the color of LRC--regardless of thickness. With GD, the enamel layer had a significant effect on the color of LRC, even if the thickness was only 0.5 mm. The difference in enamel layer effect between the two products could be attributed to the difference in color characteristics of the two enamel shades.

Acrylic Resins↗
PubMed1999

Three-dimensional shade analysis: perspectives of color--Part I.

Although color is evident in daily function, it is often misunderstood and obscured by misconceptions. While the literature focuses on mathematical formulas and specific facets of color, little research exists on the fundamental aspects of color realization. This article demonstrates the principles of color, which include definitions, measurements, sensations, and perceptions in conjunction with its practical application in restorative dentistry. The second segment of the article discusses shade selection and the use of contemporary shade systems for the fabrication of dental prostheses.

Color↗
PubMed2002

Effect of layering feldspathic porcelain on resulting veneer color with aluminum oxide core.

OBJECTIVE: To evaluate the resulting color of veneers affected by adding a layer of veneering porcelain on Procera aluminium oxide core. METHODS: Fifteen aluminium oxide disks were randomized into three groups. Each of five disks was veneered with porcelain of the Vita shade Al, A2 and B4 respectively. The color of the substrate covered with non-veneered disks and the veneered disks was measured separately and the color differences were calculated. RESULTS: Statistically significant differences (P < 0.01) in color coordinates of dark substrate were recorded between the substrate covered by an aluminium oxide disks and the addition of veneering porcelain to aluminium oxide disks. Mean coordinates color difference (DeltaE, DeltaL *, Deltaa *, Deltab *) after adding the three shades of veneering porcelain showed increase from Al (2.311) to A2 (4.313) to B4 (8.778) in DeltaE, decrease from Al (-1.530) to A2 (-3.369) and B4 (-3.358) in DeltaL *, and increase from Al (-1.440) to A2 (2.198) to B4 (7.955) in Deltab *. The direction of the color modification correlated with values obtained from the liberation. The resulting color was also affected by the color of the underlying structure. CONCLUSION: This study illustrates that color of aluminium oxide shell could be modified with feldspathic veneering porcelain, which may be used by practitioners to alter the esthetic outcome of porcelain veneers.

Aluminum Oxide↗
PubMed2000

[Effect of glazing techniques on color of porcelain-fused-to-titanium restorations].

OBJECTIVE: To study the effect of various glazing techniques on color of porcelain-fused-to-titanium restorations and their surface texture. METHODS: Standard samples of Dentsply Tibond porcelain fused-to-metal restorations were made. Selfglazing and over-glazing techniques were used. Color parameters were tested by cs-5 spectrophotometer with CIE1976LAB color system before and after glazing. Statistical analysis was done and the color differences were calculated. The samples' surface structure was observed under the same background. RESULTS: No statistical significance existed in all of the color parameters between two groups before and after glazing. The values of color difference were all smaller than 1.5. The samples had the same surface structure after treated by different glazing techniques. CONCLUSIONS: Glazing techniques had no effect on final color of porcelain-fused-to-titanium restoration. No matter what kind of glazing techniques were used, the same surface structure and color would be obtained as long as the same polish way was used before glazing.

Color↗
PubMed2003

[Study on color masking ability of restoration material Vita Mark II].

OBJECTIVE: The purpose of this study was to evaluate the color masking ability of Computer Aided Design/Computer Aided Manufacture(CAD/CAM) machining ceramic Vita Mark II, this ability was affected by thickness and shade. METHODS: Each of 5 specimens of 0.5 mm, 1.0 mm and 1.5 mm Vita Mark II A3C/18 and A2C/18 were prepared and the color change was measured after the substrate simulating stained teeth was covered with the specimen. RESULTS: Statistically significant differences (P < 0.01) were recorded in the substrates covered with different thickness and shade of Vita Mark II. The color changes (delta E) were 15.181, 17.691, 19.667 and 15.653, 16.880, 18.002 after the substrates were covered with 0.5 mm, 1.0 mm and 1.5 mm Vita Mark II A3C/18 and A2C/18. CONCLUSION: As a dental material, CAD/CAM Vita Mark II has high quality to mask the underlying color. Being a veneer, the masking ability with A2C/18 is better than that with A3C/18, but being an inlay, the result is reverse.

Color↗
PubMed1995

Color stability of light-cured and post-cured composites.

PURPOSE: To determine the color stability of five composites after light-curing and recommended post-curing using reflection spectrophotometry. MATERIALS AND METHODS: Samples of the composites were prepared as disks 10 mm in diameter and 1 mm thick. The pre-cured samples were prepared with a clear plastic sheet on the top and bottom of disk, pressed between two glass slabs to the thickness of the mold, and then removed from between the glass slabs. The color of the samples was measured with the clear plastic sheets in place. The color of the composites before curing served as the control. RESULTS: Light-curing caused barely perceptible to perceptible color changes for all of the composites from the pre-cured shade. Clearfil and TrueVitality changed color significantly more than Charisma, Conquest C&B and Herculite XRV. Once the composites were light-cured, post-curing caused no further perceptible changes in shade.

Analysis of Variance↗
PubMedDate not supplied

Color differences coefficients of body-opaque double layers.

Porcelain restorations have double-layer color effects resulting from the presence of body and opaque layers. The purpose of this study was to quantify the color differences resulting when a defined thickness of body porcelain is fired on an opaque porcelain of the same shade designation and from the same porcelain brand. A color difference coefficient was defined as the color change resulting from a 1-mm-thick layer of body porcelain on an opaque porcelain of the same shade and brand. Six shades and four porcelain brands were evaluated in this study. The range of color difference coefficients for all shades and brands was 6.76 to 14.32. There was no significant difference between shades or between brands. The use of color difference coefficients is a practical method of evaluating porcelain shades and brands and should provide guidance in the choice of porcelains and the fabrication of porcelain restorations to better achieve the desired esthetics.

Color↗
PubMedDate not supplied

Color attributes and accuracy of Vita-based manufacturers' shade guides.

The shades of several tooth-colored restoratives are now keyed to the Vita Lumin shade guide. The purpose of this study was to determine whether manufacturers' shade guides had color attributes that were similar to the Vita Lumin guide to which they are supposedly keyed. The overall color accuracy between the different guides was also compared via colorimetry. Results showed that none of the manufacturers' shade tabs evaluated had all L*, a*, and b* values that were identical to their respective Vita shade tabs. For the shades evaluated, manufacturers' tabs were generally darker than their corresponding Vita shade tabs. When shade guides were compared, the color accuracy of Z100 and Fuji II LC shade guides was significantly better than that of Durafill VS and TPH. Dyract's shade guide was the most accurate and was significantly better than the shade guides of Fuji II LC, Durafill VS, and TPH. The accuracy of manufacturers' shade guides was not consistently product dependent but was shade dependent.

Analysis of Variance↗
PubMed2006

Metameric effect between dental porcelain and porcelain repairing resin composite.

OBJECTIVES: The objectives were to evaluate the metameric color and hue angle (degrees) changes between dental porcelain and porcelain repairing resin composites. METHODS: Color of three shades (A2, A3, A3.5) of one brand of dental porcelain and three original shades (A2, A3, A3.5) and three combinations (A2-A3, A3-3.5, A2-A3.5) of three brands of porcelain repairing resin composites (ABT, FSP, TCR) were measured relative to the three standard illuminants (D65, A and F2). Specimen was 2mm in thickness, and 1mm of each shade was layered to make combined shades. Color differences (DeltaEab*) between each shade of dental porcelain and repairing resin composites relative to the three illuminants were calculated, and the ratios of color difference (modified metamerism index) by the change of illuminant were calculated. The ratios of hue angle changes were also compared. RESULTS: Differences in modified metamerism index and the ratio of hue angle changes were influenced by the porcelain shade, brand of resin composites and shade of resin composites. In all three brands of resin composites, A3.5 shade showed the smallest values in modified metamerism index regardless of the shade of porcelain. The average ratio of hue angle changes between each porcelain shade and all the shades of each resin composites showed similar trend when illuminant was changed from D65 to F2. SIGNIFICANCE: Metameric effect between dental porcelain and repairing resin composites varied depending on the shade of porcelain, brand of resin composite and the illuminant. Therefore, shade matching between porcelain and repairing resin composite should be performed carefully. This study confirmed that shades should be matched under the light corresponding to that of use.

Analysis of Variance↗
PubMed2006

Changes in the translucency of porcelain and repairing resin composite by the illumination.

OBJECTIVES: The objectives were to evaluate the difference in the translucency parameter (TP) by the illuminants, to determine the correlation between the contrast ratio (CR) and three TP values relative to the illuminants, and to measure the correlation between the differences in TP (DeltaTP) and color (DeltaE(ab)*) by the illuminants based on dental porcelain and porcelain repairing resin composites. METHODS: Color and spectral reflectance of three shades of one dental porcelain and three porcelain repairing resin composites were measured before and after thermocycling for 3000 cycles relative to the CIE standard illuminants D65, A and F2 over a white and a black backgrounds. Specimen was 1.8mm in thickness after polishing. CR was calculated, and the differences in TP and color caused by the change of illuminants were compared. Three-way analysis of variance by the material (porcelain or resin composite), shade and illuminant was used to compare differences (alpha=0.05). RESULTS: The TP value was influenced by the illuminant (p<0.05), and the TP values relative to the illuminants A and F2 were higher than those relative to D65. The correlation coefficients between the CR and three TP relative to the three illuminants were around -0.95. Color difference was positively correlated with the difference in translucency in resin composites (r=0.65 between A and D65 and 0.47 between F2 and D65), but was negatively correlated in porcelain (r=-0.37 between A and D65 and -0.69 between F2 and D65). SIGNIFICANCE: Difference in translucency by illumination should be considered when matching shade of porcelain and repairing resin composite.

Analysis of Variance↗