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 73 records · Page 4Linked to original sources
PubMedDate not supplied

Comparison of aesthetic properties of tooth-colored restorative materials.

The objective of this study was to compare the aesthetic properties of color and translucency of Vita shade-based tooth-colored restorative materials, including composite resins, a polyacid-modified composite resin, and resin-modified glass-ionomer cements via clinical discrimination by human evaluators. The hue/chroma, value, and translucency of the five different materials chosen to represent the range of commercially available tooth-colored restoratives were graded by 40 dental personnel against the body of their respective Vita shade tabs using a five-point scale (1 = very poor; 2 = poor; 3 = average; 4 = good; 5 = excellent). Results confirm the clinical observation that the hue/chroma, value, and translucency of the different materials evaluated do not match the Vita shade guide to which they are supposedly keyed. The aesthetic properties of hue/ chroma, value, and translucency for the material evaluated were all shade dependent. Comparison of pooled results revealed that none of the materials had good or excellent ratings and that the composite resins had significantly better hue/ chroma, value, and translucency match to the Vita shade guide than the other materials evaluated.

Color↗
PubMedDate not supplied

The effect of core translucency on the aesthetics of all-ceramic restorations.

Recent advances in ceramic technology have revolutionized aesthetic dentistry. When treating a single anterior tooth in need of a full-coverage restoration, a multitude of options in restorative materials and techniques is available to the clinician. The learning objective of this article is to present and evaluate a selection of all-ceramic dental materials currently available for aesthetic full-coverage crown restorations. When selecting an all-ceramic system, there are several major factors to consider, including the inherent translucency of the ceramic material and of the adjacent dentition, the color of the prepared tooth, and the forces anticipated in that region. Preparation and restoration of discolored and nondiscolored tooth structure are reviewed. The techniques presented can be utilized to obtain predictable results in the anterior region for aesthetic all-ceramic full-coverage restorations.

Color↗
PubMed1997

Communication is vital to produce natural looking metal ceramic crowns.

Many in the dental profession believe that accurate shade matching of the single anterior tooth is impossible. Fabricating an anterior porcelain crown to accurately match surrounding teeth is the most difficult task in our industry. However, it is not impossible. For many years, I took custom shades for a large dental group, and while there were many successes, there were also many failures. In one incident, the dentist, his team and I all agreed on a Vita Lumin A-2 for a patient. I attended the try-in. To everyone's surprise, the crown did not match the patient's natural teeth. After taking a new shade and delivering the new crown, the shade matched more closely, but still "no cigar." This particular failure resulted in the loss of a patient. Unfortunately, this was one of several incidents involving a mismatched shade and unsatisfied patient. These experiences caused me to question the techniques I was using. From them, I developed a technique for taking shades which could be shared with others to eliminate the frustrations we have all encountered.

Color Perception↗
PubMedDate not supplied

Shade selection for single-unit anterior metal ceramic crowns: a 5-year retrospective study of 2,500 cases.

PURPOSE: The purpose of this study was to investigate the distribution of shades selected for metal ceramic crowns provided at a dental teaching hospital. MATERIALS AND METHODS: Data on the selection of shade for 2,500 metal ceramic crown units, placed over a 5-year period at the University Dental Hospital of Manchester, were collected and analyzed. Only those crowns placed adjacent to minimally restored vital teeth were included in the study. RESULTS: The results indicate that the most frequently chosen shades were in the mid-range of reddish-brown hue. Furthermore, shades in the reddish-grey range of hue were rarely chosen. The selection of more than one shade for a crown ("mixed shades") was generally restricted to the maxillary anterior teeth. CONCLUSION: Knowledge of the distribution of shades selected for permanently luted metal ceramic crowns may be a useful adjunct in shade selection, particularly for the inexperienced operator.

Adolescent↗
PubMed1997

Reconstruction of the constricted orbital cavity in patients with artificial anophthalmy.

In cases, in which not only the globe of the eye, but the whole conjunctival sack is missing and the eyelids are due to scarring attached either to the orbital tissues and/or to each other, it is not possible to insert a prosthesis. This is a major aesthetic defect. The cavity that allows artificial eye insertion can be formed by surgery. One of the best methods is the orbital cavity reconstruction developed and suggested by the Hungarian István Csapody. He constructed two instruments to perform the operation: a butterfly shaped marker to prepare skin graft with proper size and shape, and an adjustable cone formed spacer to keep the reconstructed socket open during the healing process. We use free autologous split skin graft to line the cavity. If the shapes of the eyelids are intact, and the color of the prosthesis matches the fellow eye and it fits perfectly, then the postoperative cosmetic result can be excellent.

Cicatrix↗
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↗
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↗
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↗
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↗
PubMed1998

Color stability of provisional resin restorative materials.

STATEMENT OF PROBLEM: Use of temporary crowns and fixed partial dentures is especially relevant when the treatment plan requires restorations for long interim periods, and the in-service discoloration of provisional restorative materials is a major drawback. PURPOSE: This study evaluated the discoloration effect of coffee and tea on some materials that are commonly used in the fabrication of provisional restorations. MATERIAL AND METHODS: Six commercially available provisional resins (Jet, Caulk TBR, Protemp Garant, Luxatemp Solar, Provipont DC and SR-Ivocron-PE) were evaluated after 1 day, 7 days, and 30 days of immersion in various staining solutions. Color measurements were obtained by using a Dr Lange Micro Color tristimulus colorimeter and color differences (delta E*) were estimated. RESULTS: The 2 chemically activated resins (Jet and Caulk TBR) and the heat-cured resin (SR-Ivocron PE) exhibited the least color changes, whereas the Provipont-DC resin was the least color stable. After immersion for 30 days, the combination with the coffee solution resulted in unacceptable discoloration for all the tested materials. CONCLUSIONS: Provisional restorative materials, staining solutions, and immersion time were significant factors that affected color stability. After immersion for 7 days, all materials showed observable color changes. The composite-based materials, especially light-curing composites, were the least color stable. The coffee solution exhibited more staining capacity than the tea solution.

Analysis of Variance↗
PubMed1998

Evaluation of visual and instrument shade matching.

STATEMENT OF PROBLEM: Visual color matching to determine shades in dentistry is inconsistent and unreliable. If accurate, instrumental measurement of tooth color would provide objective, quantified data to match natural teeth to clinical shade guides. PURPOSE: This study evaluated and compared the ability of a new computerized colorimeter and a simple visual test to match ceramic shade guide teeth. MATERIAL AND METHODS: Thirty-one (n = 31) observers with normal color vision were allowed unlimited time to match one set of Vita Lumin shade guide teeth to the corresponding shade guide teeth of a second Vita Lumin shade guide. The same test was administered to 14 of the observers several months later to determine within-subject variability. A computerized colorimeter (Colortron II) equipped with a positioning guide was used to measure the middle third of each shade guide tooth. Through a "match tool" present in the computer's software, readings from one shade guide were matched with readings of the other shade guide by using CIELAB measurements and DeltaE values. The mean number of correct matches by the colorimeter and of correct matches in visual test were compared with a 1-tailed t test. Repeatability for both tests was determined with a paired t test. RESULTS: The Colortron II instrument correctly matched 8 of the 16 tabs (50% correct), whereas visual matching by examiners averaged 7. 7 of 16 correct matches (48% correct) (standard deviation 2.7). No statistically significant differences existed between the 2 methods. The colorimeter demonstrated 100% repeatability and the visual test demonstrated fair repeatability (correlation coefficient r =.60). CONCLUSIONS: Shade determination by visual means was inconsistent. Accuracy of a new colorimeter in matching porcelain shade guide teeth was only slightly better.

Ceramics↗
PubMed1999

Five-year color changes of light-cured resin composites: influence of light-curing times.

OBJECTIVES: The purpose of this study was to investigate the influence of light-curing times on the color changes of light-cured resin composites, over specified periods of time. METHODS: Silux Plus (3M Dental Products) light-cured resin composite disks (shades: U, Y, DY, L, G, UO, YO), 10 mm in diameter and 1 mm in thickness were prepared with 20, 40, and 120 s of light exposure through a 1 mm thick glass plate. The specimens were stored in artificial saliva at 37 degrees C. Colorimetric values of the specimens immediately after curing and after every 6 months for 5 years were measured backed by a light trap, and a white colored plate using a fast spectrophotometer. The CIE 1976 L*a*b* color system was used for the determination of the color difference. RESULTS: For specimens backed by a white colored plate, the delta E*ab of all shades increased for 3 years and 6 months to 5 years, to the time elapsed during all curing times. However, the a*b* values to the time elapsed differed among the shades and light curing times. In the 20 and 120 s curing time groups, the opacity% of all shades increased for 4 or 5 years to the time elapsed. SIGNIFICANCE: The modes of color changes of Silux Plus resins differed among the shades and light curing times.

Analysis of Variance↗
PubMedDate not supplied

Human-eye versus computerized color matching.

This project compared the difference in color matching between human-eye assessment and computerized colorimetry. Fifty dental personnel were asked to color match Vita Lumin shade tabs to seven different randomly arranged test tabs from the Z100 shade guide. All evaluators were blinded to the shades of the test tabs and were asked to match only body shade of the Vita Lumin tab to the middle third or body of each test tab. The results obtained were subsequently computed into L*a*b* values and compared with results obtained by computerized colorimetry. Results indicate that the difference in color matching between human-eye assessment and computerized colorimetry is shade dependent. Discrepancy was significant for b* coordinates for shades A1 and B2 and L* and b* coordinates for shade C4. For all shades evaluated, color difference between human-eye and computerized color matching is perceivable under clinical settings, as delta E values are greater than 3. There is a need for correction factors in the formal specification of the color-matching software due to the discrepancy between human-eye and computerized colorimetric color matching.

Color↗