A shade guide
for acrylic
resin facial
prostheses
Antonio J. Godoy, DDS, MS,a James C. Lemon, DDS,b Stanley H. Nakamura,, DDS,c and Gordon E. King, DDSd The University of Texas M.D. Anderson Cancer Center, Houston, Tex. The value and success of a well-fitting and anatomically correct prosthesis are compromised if the color does not match the adjoining tissue. Color and color science are reviewed to help develop a simplified acrylic resin shade guide to aid fabricating acrylic resin facial prostheses. This guide will help the clinician obtain a good intrinsic shade and minimize extrinsic coloration. (J PROSTHET DENT 1992;68:120-2.)
arely is one’s prosthetic expertise more available for inspection by the casualobserver as in facial prosthetics. An extraoral prosthesismay be judged bad or good,artificial or lifelike without considerationof the nature of the defect or the limitations of restorative materials. The prosthodontist must strive for acceptable cosmeticswhile attempting to blend artificial materials with living, movable tissue. An esthetic facial prosthesisresults from the successful interaction and management of many variables. These variables include accurate anatomic representations of form and texture aswell as blending the prosthesisto the patient with inconspicuous margins and proper color match. Use of color scienceis valuable in analyzing skin color and obtaining a color match with restorative materials. The value and successof a well-fitting and anatomically correct prosthesisare compromisedif the color doesnot match the adjoining tissue.Hence, a prosthesisthat isgiven a solid flat color is unrealistic and will appear artificia1.l It is by intrinsic coloration that a baseshadeisbest produced. Different dyes and pigmentshave beenhistorically usedas coloring agentsfor acrylic resins.Although the acrylic resin polymers are extremely stiff and hard and have esthetic limitations, acrylates are still usedfor restoration of head and neck defects. This article discussesthe principles of color scienceand its application to devisean acrylic resinshadeguide to help fabricate acrylic resin facial prostheses.
LITERATURE
REVIEW
Color sciencespansphysics, physiology, and psychology and the application of color scienceto dentistry. Clarklw5in the 1930sdiscussedhow color sciencecould and should be
aFellow,Departmentof DentalOncology. bAssistantProfessor,Departmentof DentalOncology. CPrivatePractice,La Jolla,Calif.;FormerFellow,Departmentof DentalOncology. dProfessor andChairman,Departmentof Dental Oncology. 10/l/35595
120
in
applied to the reproduction of tooth color in dental porcelain. Sproulles established the shade range of natural teeth through the use of spectrophotometry. He stressedthe three-dimensionalnature of color and the use of proper terminology. Preston and Bergen9developed a training manual “for seeing,understanding, and working with color” and attempted to define and separate art from sciencein color.g Culpepper’Oevaluated matching of tooth shadeswith various shadeguides and several light sources. Color mixing Additive color mixing refers to the mixing of colored lights to yield white light.g This phenomenon applies to light, not to pigment systems.The additive primaries are red, green, and blue. Subtractive color mixing is the combination of three subtractive primaries producing black.g It is the converseof the additive color system. The three primary subtractive Hues are cyan, magenta, and yellow. Colors seenon the surface of objects operate in a very different way from those seenin beamsof light. When incident light strikes a surface, certain wavelengths may be absorbedand others reflected by its pigments, or coloring matter. The reflected wavelengthsblend to form the color seenby the viewer. In traditional color theory, there are three pigment colors (red, blue, and yellow) that cannot be mixed from other colorsand from which all other colorscan be mixed. These characteristics define them as primary colors. In paint mixing, it is not possibleto mix all colors from any basicthree primaries. Sometheorists would, therefore, add green to the list of paint pigment primaries to make more mixtures possible. Albert Munsell, as reported by Preston and Bergen,gdeparted from tradition by usingfive principle Hues: red, yellow, blue, green,and purple. He devised an ordered and logical system called the Munsell color notation. His system, consistingof 10 Hues, 10 Valuessegments,and an open-endedChroma scale,provides a method for description and communication of color in dentistry. The concept that only three primary colorsexist
JULY
1992
VOLUME
68
NUMBER
1
SHADE
GUIDE
FOR
FACIAL
PROSTHESES
is more theoretical than real when one is dealing with paint pigments instead of lights. Human
skin
color
According to Edwards and Duntly as cited in Fine,i’ skin color can be attributed to five pigments: melanin, melanoid, oxyhemoglobin, reduced hemoglobin, and carotene. These pigments, which are found in different layers of the skin, contribute to the total reflected light and determine the Hue, Value, and Chroma of the skin. Melanin especially affects the absorptive characteristics of skin, but other modifiers are oils, secretions, fat, keratin, and hair. Wasserman, as cited in Fine,ll performed a spectrophotometric analysis of the skin color of 631 individuals of three ethnic groups. Irrespective of race, the dominant reflected Hue was red. Value was greater in the lightskinned group. Saturation varied markedly but was highest in brown skin and lower in white- and black-skinned individuals. Differences between races and differences within the same ethnic group were governed by melanin content. Skin pigments absorb heavily in the blue end of the spectrum.ll Because of the skin turbidity, light of shorter wavelengths is refracted more. This refraction adds a blue component to the total light reflected and tints the dominant red Hue. Color
reproduction
in facial
prosthetics
The color of a facial prosthesis results from the addition of colorants to a restorative material. The final color is affected by the color stability of the matrix and the colorants used. Colorants are pigments or dyes that impart color to otherwise colorless objects or modify perceived color.ll Pigments are insoluble particles that most frequently produce light-scattering layers. Dyes are molecularly dispersed substances that most frequently produce transparent layers. Dyes and pigments are derived from organic or inorganic sources. Inorganic pigments often absorb light characteristics of the ionic component of the compound. Some examples are titanium oxide (white), iron oxide (brown), cobalt oxide (blue), and chromium or copper oxide (green). Inorganic pigments are usually selected because their color qualities are more durable and permanent than those of organic pigments. The technique of coloring facial prostheses has evolved slowly as new materials have been developed. Kazanjian12 and others called for an extrinsic application of colorant to achieve a desired skin tone. Barnhart13 used colored methyl methacrylate powders applied intrinsically to silicone rubber. Tashima14 added inorganic pigment powders to clear methyl methacrylate powder and then applied these intrinsically to a medical-grade silicone rubber. Firtell and BartlettIs added inorganic pigments directly into silicone rubber. Schaaf16 used a tattooing machine to apply pigments to the prosthesis. Ouellett17 used an artist’s spray
THE
JOURNAL
OF PROSTHETIC
DENTISTRY
gun for extrinsic color application. Bartlett et al.18 chose a silicone medical adhesive as the vehicle for extrinsic coloring of the prosthesis. ACRYLIC TECHNIQUE
RESIN
SHADE
GUIDE
An acrylic resin shade guide was developed by mixing different colors of autopolymerizing acrylic resin or by combining the different color mixes with dry earth pigments (Artskin Products Co., Norfolk, Va.). The dry earth pigments were measured with a Roach wax carver, which loads up to an average of 0.0158 gm, and with a Hue-Friedy Cleoid discoid 89/92 carver, which carries an average of 0.0024 gm. These weights were the results of the average of four readings on an H6 scale (capacity, 160 gm) (Mettler Instrument Corp., Heightstown, N.J.) Because most dentists may not have a precision balance available, the volumetric amounts of dry earth pigments obtained from either the discoid end of the Hue-Friedy instrument or the cup end of the Roach carver were used in developing shades. This degree of accuracy provided consistent results. The acrylic resin polymer was measured with a l-ounce plastic medicine cup that had graduations of 1 teaspoon, 1 tablespoon, and 2 tablespoons. One teaspoon of acrylic resin polymer weighed 4 gm; 3 teaspoons or 1 tablespoon weighed 12 gm. When skin tones do not conform to the guide, the formulation can be adjusted to obtain an approximate intrinsic color. Formulation suggested for the different skin shades are as follows: Color No. 1. 50% Pink nonfibered polymer (Fastcure, Kerr, Romulus,Mich.) and 50% Jet acrylic resin shadeNo. 62 (Lang Dental, Chicago, Ill.). Color No. 2. 50% Pink nonfibered polymer and 50% Jet
acrylic resin shadeNo. 77. Color No. 3. One teaspoonof pink nonfibered polymer to
which wasadded 1 tablespoonof clear polymer (Orthodontic Acrylic Resin, Modern Materials,) and 4 Hue-Friedy Cleoiddiscoid carver measures(discoid end) of light brown earth pigment (Artskin Product, Norfolk, Va.). No. 4. One teaspoon of pink-fibered polymer (Cold-Dent Pink-Fibered, Modern Materials, St. Louis, MO.), to which wasadded1 tablespoonof clearpolymer and 4 Hue-Friedy carver measuresof light brown earth pigment. Color
No. 5. One teaspoon of pink-fibered polymer, to which wasadded 1 tablespoonof clear polymer and 4 HueFriedy carver measuresof medium brown earth pigment. Color
Color No. 6. One tablespoonof pink-fibered polymer, 2 Roach wax carver (cup end) measuresof medium brown and 1 Hue-Friedy carver measuresof black earth pigment. Color No. 7. One tablespoonof pink nonfibered polymer,
121
OODOU
2 Roach wax carver measures of medium brown, and 2 Hue-Friedy carver measures of black earth pigment. tabs with dimensions of 6 cm x 3 cm X 1.5 mm were prepared by first making tabs of baseplate wax. The wax tabs were invested in conventional denture flasks with dental plaster. The wax was boiled out, tinfoil substitute was applied to the plaster, and the flask was allowed to cool. The acrylic resin mixture was prepared and pressed, and time was allowed for complete cure. The tabs were recovered and excesses trimmed. Color
DPSCUSSION The color stability of acrylic resin is good when the material is managed properly. The esthetics attained is equal to any material available. Previous attempts at developing a clinical shade guide for acrylic resin facial prostheses appear to be complicated. The intent was to keep the intrinsic shade guide simple, easy to reproduce, with fewer colors that cover a wide range of the most common shades seen in clinical situations. Autopolymerizing acrylic resin was selected because of its availability, and its use is understood by most dentists. Autopolymerized acrylic resin prostheses are generally not invested but fabricated with a “sprinkle-on” technique. The thickness of the color tabs for the shade guide was established at 1.5 mm, which approximated the usual thickness of an acrylic resin prosthesis. Thickness must be taken into account in selecting a color, because the background of the anatomical defect will influence the color of the prosthesis. The different colors were obtained by trying several techniques and mixing different commercially available materials. Autopolymerizing acrylic resin polymers of various shades were mixed with dry earth pigments to obtain a uniform blend. The monomer wals added, mixed, flasked, and allowed to polymerize. The shades were obtained by trial and error until they resembled the skin color of different ethnic groups. The number of colors developed was limited to make the shade guide more practical to use. Coloring agents should be readily miscible with acrylic resin and should be nontoxic, nonirritating, and noncarcinogenic.11,15 Earth pigments are so intense that only minute quantities are needed to oibtain the desired shade. The amount of pure pigment incorporated within a prosthesis can be measured in micrograms so that possible toxicity is remote.14 However, nontoxic colors should be selected whenever possible.
122
ET AL
SUMMARY Esthetics is an important factor for patient acceptance of a facial prosthesis. A prerequisite for achieving a good base shade is intrinsic coloration. It was determined that an acrylic resin shade guide would be of value to dentists who were not completely familiar with the reproduction of skin colors on prosthetic materials. An acrylic resin shade guide was developed using materials and instruments available in the dental office, namely autopolymerizing acrylic resin in different colors (clear, pink, and tooth-colored) and dry earth pigments. When necessary, these shades can be altered by changing the proportions of a given formula. REFERENCES 1. Clark EB. The color problem in dentistry, a practical application of the primary psychological primary colors. Dent Digest 1931;37:571-82. 2. Clark EB. The color problem in dentistry. Dent Digest 1931;37:499-509. 3. Clark EB. The color problem in dentistry, the physical nature of color. Dent Digest 1931;37:646-60. 4. Clark EB. The color problem in dentistry, applied color-mixture. Dent Digest 1931;37:732-41. 5. Clark EB. The color problem in dentistry, color and illumination. Dent Digest 1931;37:815-26. 6. Sproull RC. Color matching in dentistry. Part I. The three-dimensional nature of color. J PROSTHET DENT 1973;29:416-24. 7. Sproull RC. Color matching in dentistry. Part II. Practical applications of the organization of color. J PROSTHET DENT 1973;29:556-66. 8. Sproull RC. Color matching in dentistry. Part III. Color control. J PROSTHET DENT 1974;31:146-54. 9. Preston JD, Bergen SF. Color science and dental art. A self-teaching program. St Louis: CV Mosby Co, 1980. 10. Culpepper WD. A comparative study of shade-matching procedures. J PROSTHET DENT 1970;24:166-73. 11. Fine L. Color and its application in maxillofacial prosthetics. J PROSTHET DENT 1978;39:188-92. 12. Kazanjian VH. Modern accomplishments in dental and facial prosthesis. J Dent Res 1932;12:651-70. 13. Barnhart GW. A new material and technic in the art, of somatoprostheses. J Dent Res 1960;39:836-44. 14. Tashma J. Coloringsomatoprostheses. J PROSTHET DENT 1967;17:303-5. 15. Firtell DN, Bartlett SO. Maxillofacial prostheses: reproducible fabrication. J PROSTHET DENT 1969;22:247-52. 16. Schaaf NG. Color characterizing silicone rubber facial prostheses. J PROSTHET DENT 1970;24:198-202. 17. Ouellett JE. Spray coloring of silicone elastomer maxillofacial prostheses. J PROSTHET DENT 1969;22:271-5. 18. Bartlett SO, Pineda LY, Moore DJ. Surface characterization of the silicone rubber prosthesis. J PROSTHET DENT 1971;25:69-71. Reprint requests to: DR. GORDON E. KING DEPARTMENT OF DENTAL ONCOLOGY, Box 9 UNIVERSITY OF TEXAS M. D. ANDERSON CANCER CENTER 1515 HOLCOMBE BLVD. HOUSTON, TX 77030
JULY
1992
VOLUME
68
NUMBER
1
for acrylic
resin facial
prostheses
Antonio J. Godoy, DDS, MS,a James C. Lemon, DDS,b Stanley H. Nakamura,, DDS,c and Gordon E. King, DDSd The University of Texas M.D. Anderson Cancer Center, Houston, Tex. The value and success of a well-fitting and anatomically correct prosthesis are compromised if the color does not match the adjoining tissue. Color and color science are reviewed to help develop a simplified acrylic resin shade guide to aid fabricating acrylic resin facial prostheses. This guide will help the clinician obtain a good intrinsic shade and minimize extrinsic coloration. (J PROSTHET DENT 1992;68:120-2.)
arely is one’s prosthetic expertise more available for inspection by the casualobserver as in facial prosthetics. An extraoral prosthesismay be judged bad or good,artificial or lifelike without considerationof the nature of the defect or the limitations of restorative materials. The prosthodontist must strive for acceptable cosmeticswhile attempting to blend artificial materials with living, movable tissue. An esthetic facial prosthesisresults from the successful interaction and management of many variables. These variables include accurate anatomic representations of form and texture aswell as blending the prosthesisto the patient with inconspicuous margins and proper color match. Use of color scienceis valuable in analyzing skin color and obtaining a color match with restorative materials. The value and successof a well-fitting and anatomically correct prosthesisare compromisedif the color doesnot match the adjoining tissue.Hence, a prosthesisthat isgiven a solid flat color is unrealistic and will appear artificia1.l It is by intrinsic coloration that a baseshadeisbest produced. Different dyes and pigmentshave beenhistorically usedas coloring agentsfor acrylic resins.Although the acrylic resin polymers are extremely stiff and hard and have esthetic limitations, acrylates are still usedfor restoration of head and neck defects. This article discussesthe principles of color scienceand its application to devisean acrylic resinshadeguide to help fabricate acrylic resin facial prostheses.
LITERATURE
REVIEW
Color sciencespansphysics, physiology, and psychology and the application of color scienceto dentistry. Clarklw5in the 1930sdiscussedhow color sciencecould and should be
aFellow,Departmentof DentalOncology. bAssistantProfessor,Departmentof DentalOncology. CPrivatePractice,La Jolla,Calif.;FormerFellow,Departmentof DentalOncology. dProfessor andChairman,Departmentof Dental Oncology. 10/l/35595
120
in
applied to the reproduction of tooth color in dental porcelain. Sproulles established the shade range of natural teeth through the use of spectrophotometry. He stressedthe three-dimensionalnature of color and the use of proper terminology. Preston and Bergen9developed a training manual “for seeing,understanding, and working with color” and attempted to define and separate art from sciencein color.g Culpepper’Oevaluated matching of tooth shadeswith various shadeguides and several light sources. Color mixing Additive color mixing refers to the mixing of colored lights to yield white light.g This phenomenon applies to light, not to pigment systems.The additive primaries are red, green, and blue. Subtractive color mixing is the combination of three subtractive primaries producing black.g It is the converseof the additive color system. The three primary subtractive Hues are cyan, magenta, and yellow. Colors seenon the surface of objects operate in a very different way from those seenin beamsof light. When incident light strikes a surface, certain wavelengths may be absorbedand others reflected by its pigments, or coloring matter. The reflected wavelengthsblend to form the color seenby the viewer. In traditional color theory, there are three pigment colors (red, blue, and yellow) that cannot be mixed from other colorsand from which all other colorscan be mixed. These characteristics define them as primary colors. In paint mixing, it is not possibleto mix all colors from any basicthree primaries. Sometheorists would, therefore, add green to the list of paint pigment primaries to make more mixtures possible. Albert Munsell, as reported by Preston and Bergen,gdeparted from tradition by usingfive principle Hues: red, yellow, blue, green,and purple. He devised an ordered and logical system called the Munsell color notation. His system, consistingof 10 Hues, 10 Valuessegments,and an open-endedChroma scale,provides a method for description and communication of color in dentistry. The concept that only three primary colorsexist
JULY
1992
VOLUME
68
NUMBER
1
SHADE
GUIDE
FOR
FACIAL
PROSTHESES
is more theoretical than real when one is dealing with paint pigments instead of lights. Human
skin
color
According to Edwards and Duntly as cited in Fine,i’ skin color can be attributed to five pigments: melanin, melanoid, oxyhemoglobin, reduced hemoglobin, and carotene. These pigments, which are found in different layers of the skin, contribute to the total reflected light and determine the Hue, Value, and Chroma of the skin. Melanin especially affects the absorptive characteristics of skin, but other modifiers are oils, secretions, fat, keratin, and hair. Wasserman, as cited in Fine,ll performed a spectrophotometric analysis of the skin color of 631 individuals of three ethnic groups. Irrespective of race, the dominant reflected Hue was red. Value was greater in the lightskinned group. Saturation varied markedly but was highest in brown skin and lower in white- and black-skinned individuals. Differences between races and differences within the same ethnic group were governed by melanin content. Skin pigments absorb heavily in the blue end of the spectrum.ll Because of the skin turbidity, light of shorter wavelengths is refracted more. This refraction adds a blue component to the total light reflected and tints the dominant red Hue. Color
reproduction
in facial
prosthetics
The color of a facial prosthesis results from the addition of colorants to a restorative material. The final color is affected by the color stability of the matrix and the colorants used. Colorants are pigments or dyes that impart color to otherwise colorless objects or modify perceived color.ll Pigments are insoluble particles that most frequently produce light-scattering layers. Dyes are molecularly dispersed substances that most frequently produce transparent layers. Dyes and pigments are derived from organic or inorganic sources. Inorganic pigments often absorb light characteristics of the ionic component of the compound. Some examples are titanium oxide (white), iron oxide (brown), cobalt oxide (blue), and chromium or copper oxide (green). Inorganic pigments are usually selected because their color qualities are more durable and permanent than those of organic pigments. The technique of coloring facial prostheses has evolved slowly as new materials have been developed. Kazanjian12 and others called for an extrinsic application of colorant to achieve a desired skin tone. Barnhart13 used colored methyl methacrylate powders applied intrinsically to silicone rubber. Tashima14 added inorganic pigment powders to clear methyl methacrylate powder and then applied these intrinsically to a medical-grade silicone rubber. Firtell and BartlettIs added inorganic pigments directly into silicone rubber. Schaaf16 used a tattooing machine to apply pigments to the prosthesis. Ouellett17 used an artist’s spray
THE
JOURNAL
OF PROSTHETIC
DENTISTRY
gun for extrinsic color application. Bartlett et al.18 chose a silicone medical adhesive as the vehicle for extrinsic coloring of the prosthesis. ACRYLIC TECHNIQUE
RESIN
SHADE
GUIDE
An acrylic resin shade guide was developed by mixing different colors of autopolymerizing acrylic resin or by combining the different color mixes with dry earth pigments (Artskin Products Co., Norfolk, Va.). The dry earth pigments were measured with a Roach wax carver, which loads up to an average of 0.0158 gm, and with a Hue-Friedy Cleoid discoid 89/92 carver, which carries an average of 0.0024 gm. These weights were the results of the average of four readings on an H6 scale (capacity, 160 gm) (Mettler Instrument Corp., Heightstown, N.J.) Because most dentists may not have a precision balance available, the volumetric amounts of dry earth pigments obtained from either the discoid end of the Hue-Friedy instrument or the cup end of the Roach carver were used in developing shades. This degree of accuracy provided consistent results. The acrylic resin polymer was measured with a l-ounce plastic medicine cup that had graduations of 1 teaspoon, 1 tablespoon, and 2 tablespoons. One teaspoon of acrylic resin polymer weighed 4 gm; 3 teaspoons or 1 tablespoon weighed 12 gm. When skin tones do not conform to the guide, the formulation can be adjusted to obtain an approximate intrinsic color. Formulation suggested for the different skin shades are as follows: Color No. 1. 50% Pink nonfibered polymer (Fastcure, Kerr, Romulus,Mich.) and 50% Jet acrylic resin shadeNo. 62 (Lang Dental, Chicago, Ill.). Color No. 2. 50% Pink nonfibered polymer and 50% Jet
acrylic resin shadeNo. 77. Color No. 3. One teaspoonof pink nonfibered polymer to
which wasadded 1 tablespoonof clear polymer (Orthodontic Acrylic Resin, Modern Materials,) and 4 Hue-Friedy Cleoiddiscoid carver measures(discoid end) of light brown earth pigment (Artskin Product, Norfolk, Va.). No. 4. One teaspoon of pink-fibered polymer (Cold-Dent Pink-Fibered, Modern Materials, St. Louis, MO.), to which wasadded1 tablespoonof clearpolymer and 4 Hue-Friedy carver measuresof light brown earth pigment. Color
No. 5. One teaspoon of pink-fibered polymer, to which wasadded 1 tablespoonof clear polymer and 4 HueFriedy carver measuresof medium brown earth pigment. Color
Color No. 6. One tablespoonof pink-fibered polymer, 2 Roach wax carver (cup end) measuresof medium brown and 1 Hue-Friedy carver measuresof black earth pigment. Color No. 7. One tablespoonof pink nonfibered polymer,
121
OODOU
2 Roach wax carver measures of medium brown, and 2 Hue-Friedy carver measures of black earth pigment. tabs with dimensions of 6 cm x 3 cm X 1.5 mm were prepared by first making tabs of baseplate wax. The wax tabs were invested in conventional denture flasks with dental plaster. The wax was boiled out, tinfoil substitute was applied to the plaster, and the flask was allowed to cool. The acrylic resin mixture was prepared and pressed, and time was allowed for complete cure. The tabs were recovered and excesses trimmed. Color
DPSCUSSION The color stability of acrylic resin is good when the material is managed properly. The esthetics attained is equal to any material available. Previous attempts at developing a clinical shade guide for acrylic resin facial prostheses appear to be complicated. The intent was to keep the intrinsic shade guide simple, easy to reproduce, with fewer colors that cover a wide range of the most common shades seen in clinical situations. Autopolymerizing acrylic resin was selected because of its availability, and its use is understood by most dentists. Autopolymerized acrylic resin prostheses are generally not invested but fabricated with a “sprinkle-on” technique. The thickness of the color tabs for the shade guide was established at 1.5 mm, which approximated the usual thickness of an acrylic resin prosthesis. Thickness must be taken into account in selecting a color, because the background of the anatomical defect will influence the color of the prosthesis. The different colors were obtained by trying several techniques and mixing different commercially available materials. Autopolymerizing acrylic resin polymers of various shades were mixed with dry earth pigments to obtain a uniform blend. The monomer wals added, mixed, flasked, and allowed to polymerize. The shades were obtained by trial and error until they resembled the skin color of different ethnic groups. The number of colors developed was limited to make the shade guide more practical to use. Coloring agents should be readily miscible with acrylic resin and should be nontoxic, nonirritating, and noncarcinogenic.11,15 Earth pigments are so intense that only minute quantities are needed to oibtain the desired shade. The amount of pure pigment incorporated within a prosthesis can be measured in micrograms so that possible toxicity is remote.14 However, nontoxic colors should be selected whenever possible.
122
ET AL
SUMMARY Esthetics is an important factor for patient acceptance of a facial prosthesis. A prerequisite for achieving a good base shade is intrinsic coloration. It was determined that an acrylic resin shade guide would be of value to dentists who were not completely familiar with the reproduction of skin colors on prosthetic materials. An acrylic resin shade guide was developed using materials and instruments available in the dental office, namely autopolymerizing acrylic resin in different colors (clear, pink, and tooth-colored) and dry earth pigments. When necessary, these shades can be altered by changing the proportions of a given formula. REFERENCES 1. Clark EB. The color problem in dentistry, a practical application of the primary psychological primary colors. Dent Digest 1931;37:571-82. 2. Clark EB. The color problem in dentistry. Dent Digest 1931;37:499-509. 3. Clark EB. The color problem in dentistry, the physical nature of color. Dent Digest 1931;37:646-60. 4. Clark EB. The color problem in dentistry, applied color-mixture. Dent Digest 1931;37:732-41. 5. Clark EB. The color problem in dentistry, color and illumination. Dent Digest 1931;37:815-26. 6. Sproull RC. Color matching in dentistry. Part I. The three-dimensional nature of color. J PROSTHET DENT 1973;29:416-24. 7. Sproull RC. Color matching in dentistry. Part II. Practical applications of the organization of color. J PROSTHET DENT 1973;29:556-66. 8. Sproull RC. Color matching in dentistry. Part III. Color control. J PROSTHET DENT 1974;31:146-54. 9. Preston JD, Bergen SF. Color science and dental art. A self-teaching program. St Louis: CV Mosby Co, 1980. 10. Culpepper WD. A comparative study of shade-matching procedures. J PROSTHET DENT 1970;24:166-73. 11. Fine L. Color and its application in maxillofacial prosthetics. J PROSTHET DENT 1978;39:188-92. 12. Kazanjian VH. Modern accomplishments in dental and facial prosthesis. J Dent Res 1932;12:651-70. 13. Barnhart GW. A new material and technic in the art, of somatoprostheses. J Dent Res 1960;39:836-44. 14. Tashma J. Coloringsomatoprostheses. J PROSTHET DENT 1967;17:303-5. 15. Firtell DN, Bartlett SO. Maxillofacial prostheses: reproducible fabrication. J PROSTHET DENT 1969;22:247-52. 16. Schaaf NG. Color characterizing silicone rubber facial prostheses. J PROSTHET DENT 1970;24:198-202. 17. Ouellett JE. Spray coloring of silicone elastomer maxillofacial prostheses. J PROSTHET DENT 1969;22:271-5. 18. Bartlett SO, Pineda LY, Moore DJ. Surface characterization of the silicone rubber prosthesis. J PROSTHET DENT 1971;25:69-71. Reprint requests to: DR. GORDON E. KING DEPARTMENT OF DENTAL ONCOLOGY, Box 9 UNIVERSITY OF TEXAS M. D. ANDERSON CANCER CENTER 1515 HOLCOMBE BLVD. HOUSTON, TX 77030
JULY
1992
VOLUME
68
NUMBER
1
