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Systematic Research and Analysis of the Tooth Color

Systematic Research and Analysis of the Tooth Color

André Hoffmann

 

Systematic Research and Analysis of the Origin of Color, Reflection Spectra and Influencing Factors on Layered and Complex Materials with Different Degrees of Liquid Contents from Wet to Dry – Before, During and After the Dehydration and Rehydration: The Basic research on Teeth (2000)

 

Light, Beam Path, Gloss or Lustre Effect, Filter,

Light Types, Illumination, Illuminant, Metamerism,

Measurement Geometries, Observation Angle, System Type, Measurement Mode,

Measuring System-Object Relation, Positioning, Displacement, Reproducibility,

Sizes of the Measuring Surface and Measuring Opening,

Water, Liquid, Liquid Content, Liquid flow, Drying or Dehydration, Thermogravimetry, Suction, Capillary Effect, Permeability, Liquid Absorption or Rehydration, Reversibility,

Subjectivity, Subjective-Objective, Perception,

Individuality (Identification, Authentication), Sex, Age, Time, Time of Death, Color Space, Monitoring, Spectral Curves,

Crown Curvature, Layering, Pulp, Dentine, Enamel, Size, Dimensioning, Weight, Structure, Paradox, Learning, Reconstruction, Simulation, Superimposition, Influencing Factors,

Neural Network, Dental Clock, Tooth Memory...

 

You can find books by the author everywhere in bookshops or as e-book here.

 

[...]

1. Introduction

This book shows a small excerpt from the author’s systematic original research with highest precision at human teeth and dental shade guides with high-precision measuring systems and high-precision positioning systems in vitro. Due to this scientific basic research, it was possible to quantify and isolate the manifold fundamental factors influencing the color of teeth and its measurement, for the first time. These include, for example, the light or measuring light and the type of illumination and color temperature, the optical beam path of the light or the measuring geometry, the observation angle (2°, 10°), the size of the measuring surface and measuring opening, the gloss effect on color coordinates, the liquid content (with scientific evidence of the relationship between liquid content and tooth color), effect of drying (dehydration), moisture and rehydration, the correlation between the liquid content and the gloss, the subjectivity of visual subjective shade matching, crown curvature, type of system (spectrophotometer, tristimulus colorimeter), measuring mode (contact or non-contact), measuring system-object-relation, positioning, repeatability or reproducibility, lens shift, displacement between sample, measuring surface and measuring system and further intra- and interindividual factors. In addition, subjective-visual color matching and objectified measurements were examined in subjective-objective comparisons using color coordinates comparisons. The coordinates are taken from shade guide analyses of a preliminary study. All these influencing factors are investigated on moist or wet, drier (various specific drying and rehydration states) and dry teeth. The analyses are based on the brightness (L*), color measurement values, such as a*, b* (CIELAB), C*, h, (CIELCH), ΔE, the metamerism index, of spectral values and curves, patterns (tabs) of dental shade guides (VITAPAN 3D-MASTER, VITAPAN classical) and tooth color spaces …

As part of this exploration, phenomena (e.g. changes and breaks in behaviour as well as highly individual developments in color coordinates, paradoxes between the values of subjective determination using shade guide tabs and the values of objective measurements) were identified, and insights into the very complex color dynamics through dehydration and rehydration were shown (up to more than >8 days). The development of the individual color coordinates gave information about the liquid flow through the tooth and its tissues, in particular during drying and liquid reabsorption, and liquid dynamics, structure influences and the temporal extent of these processes.

Based on this data, the author had developed several methods for research and practice, suggestions for feasible innovations, such as monitoring of dental treatment to protect against devitalisation by drying, and reconstructing the color of naturally moist teeth based on teeth that have been already drying for a while, the identification of the living and the dead via the “dental fingerprint” (biometrics) and a novel method of measuring the time of death for forensic medicine. In addition, a temporal drying limit was specified up to which relatively natural, suitable shade values and results are obtained and from which time of drying no shade matching should be carried out in order to obtain reasonable tooth color results. This book shows the rehydration time (after drying) to get correct values and results again, with relevance for shade matching, dental color measuring and the right tooth color.

 Since everything intertwines with everything, it makes little sense to form chapters in the discussion section. Chapters in the discussion have therefore been omitted in order to avoid repetition and for the benefit of the appropriate networking of knowledge. However, in order to be able to find some certain aspects quickly, the section “Some Discussion Keywords and Key Phrases (Selection)” following the table of contents is useable.

The findings also show that teeth are able to store information on, for example, the condition (liquid content, color and spectral values) and the time within the drying and liquid reabsorption chronology. The author articulates a “dental chronometer (tooth clock), dental data store (tooth data store) and a dental memory (tooth memory”). Novel reference-dependent and reference-independent method approaches have been described ‒ perhaps the first reference-independent method in natural science.

 

2. Literature Review

Colors determine every personʼs life. They make life as we know it possible in the first place. If mankind would not know any colors and thus also contrast the world would not be tangible, objects would be indistinguishable from their surroundings, there would be no optical-descriptive language and no optical-orienting movement – the human would not be human. And colors arouse emotions, influence feelings and have their own aesthetics. In dentistry, dental or tooth color aesthetics ‒ the authorʼs word creation of dental or tooth color and aesthetics ‒ is one of two pillars (color and shape) of dental aesthetics and at the same time the more decisive one for a successful restoration. Deviations in the dental color are perceived even before deviations in the tooth shape and may be perceived as disturbing, as the author of the current work knows to report on the basis of his experience. Dentistry as a whole, on the other hand, can be divided into function (masticatory function, health) and aesthetics. Nothing was more obvious than to understand the emergence of the tooth color as a whole as a system of manifold influencing factors. It was not expedient to deal with a single aspect or to investigate a single question. It was necessary to systematically analyse the tooth color and to investigate it with high-precision measuring systems in order to extract from it the secret of the orchestral interplay of the factors that make up it.

Until the year 2000, the author of this present work had isolated and clearly quantified the factors that form the dental color of human teeth and which influence the origin or development and perception of color, measurement and visual color determination or dental shade matching (factors of influence on the dental color). At that time, there were 44 metrological studies, essentially. Of these, 18 were based on spectrophotometer measurements (see bibliography ‒ bold and italic, [Bolt et al. 1994, el-Sayed et al. 1994, Fay et al. 1999, Groh et al. 1992, Horn et al. 1998, Ichesco et al. 1991, Ishikawa-Nagai et al. 1992, 1994, Kleber et al. 1998, Koertge et al. 1998, Leard and Addy 1997, OʼBrien and Groh 1990, 1989, 1997, Takeda et al. 1996, van der Burgt et al. 1990 , White and OʼBrien 1989, Zhu et al. 1998]) and 25 (see bibliography ‒ bold [Belli et al. 1997, Douglas 1997, Goldstein and Schmitt 1993, Goodkind and Schwabacher 1987, Johnston and Kao 1989, Kowitz et al. 1994, Lenhard 1996, Lu and Zhao Y. 1993, Ma et al. 1999, Manly 1947, Matis et al. 1998, Matis 1998, Millstein et al. 1988, Nakamura et al. 1993, Nathoo et al. 1994, Nissan et al. 1992, OʼBrien et al. 1989, Okubo et al. 1998, Ouellet et al. 1992, Rosenstiel et al. 1991, Rosenstiel et al. 1996, Rosenstiel et al. 1989, Rustogi and Curtis 1994, Seghi et al. 1990, Seghi et al. 1989]) were performed with a simpler colorimeter. They mostly dealt with the color of artificial material (no natural or human teeth) or a very specific question, for example, such as the effects of toothpaste and bleaching or the influence of certain substances, such as chlorhexidine, fluoride gels, coffee or tea (see bibliography).

For the first time, the tooth color, its origin and essential influencing factors and phenomena were spectrophotometrically and colorimetrically measured, isolated, analysed and scientifically proved by the present author.

Bolt et al. (1994) could indeed mention an interesting effect in terms of the of window size (spectrophotometer equipped with external windows of 3, 4, and 5 mm). However, this influence may have been significantly influenced, for example, by very rapid drying processes after storage in particularly volatile liquid (formalin) and during the time of mounting and changing of the “windows” and thus this factor of influence has not been clearly isolated. In fact, there is also a double effect in this study. The measuring light directed onto the sample and the light reflected by the sample must pass through the measuring opening and are influenced by the window size. However, in the studies of the present work, the effect was analyzed in such a way that the microscopic chromameter used allows only the reflected light to pass through the measuring opening and the switching from 1.8 mm to 0.3 mm measuring opening size and vice versa in a fraction of a second via the intended switch. Measurements on these two different measuring surface sizes were therefore carried out without any significant delay and without any significant drying influence. The emitted light was only sent through an aperture during the contact procedures.

In addition, influencing factors, such as drying, could be quantified and thus taken into account in the analyses of the present work.

Positioning, i.e. the object-system relation, has an influence on the values and their reproducibility. The reproducibility in vitro with jig (see Douglas 1997), an intraoral positioning aid, was better and already good, but not sufficient enough for basic research with the highest precision, so that the decision was made in favour of the present in vitro studies with high-performance precision systems (high-end systems for this particular purpose[1] ‒ tooth color measurement with highest-precision positioning) and with novel high-precision positioning systems – self-developments. The precision and repeatability ‒ see Douglas (1997), Goldstein and Schmitt (1993) ‒ can thus be very significantly increased by the author of the present work. This was one of the prerequisites for the isolation of individual influencing factors and the recording of the temporal extent of drying (˃ 1 week) and the answer to the question: how long does a tooth dry?

It is a well-known phenomenon that teeth dried with rubber dam or cotton rolls or extracted appear brighter. Textbooks have mentioned this indirectly in the context of dental shade matching. But there was no scientific proof of this. This would only be possible if both the brightness or color values as well as the weight or weight loss could be measured as an expression of the drying and the resulting curves could be covered and measured curves have peculiarities that could only be explained by drying.

There are a lot of publications on the water of teeth and water content in teeth and their hard tissues (see LeFevre and Manly 1938, Bird et al. 1940, Deakins 1942, Atkinson 1947, Trautz 1955, Burnett and Zenewitz 1958, Pople et al. 1959, Pimentel and McClellan 1960, Bergman and Siljestrand 1962, Bergman 1963, McConnel 1963, Bradbury et al. 1964, Little and Casciani 1966, Marguerite et al. 1966, LeGeros et al. 1979, Papa 1994) in the course of the 20th century, but no study has dealt with this fundamental issue of brightness or tooth color and tooth color values (e.g. L*a*b*C*h etc.) depending on the liquid content, drying and liquid absorption processes. One aim of the investigations was therefore to establish the relationship between liquid content, liquid loss (drying, dehydration), liquid absorption (rehydration) and tooth color. This basic research has also been developed to provide information on various color influencing factors, the liquid flow within the tooth, the role of the dental liquid and the dynamics of the tooth liquid in and on the tooth tissue during drying and redydration, information on which more far-reaching conclusions will be based.

Another key was the choice of systems. Two measuring systems were identical in construction, from the same manufacturer and differed only in the measuring geometry. One of the measuring geometries worked with gloss inclusion (specular included) and the other with gloss exclusion (specular excluded). Thus it was possible to determine the differences between the values and curves of these systems ‒ specular included and specular excluded ‒ and in consequence the gloss influence on the color coordinates of moist, drying, dryer and dry teeth. At the same time, it was possible to determine the proportion of liquid in the dental gloss and to answer the questions: what influence does the tooth have and what influence does dental liquid have on the dental gloss? And what influence does the gloss have on the tooth color and the color coordinates?

An analysis and also a proof are characterized by not only suspecting, but also isolating, recognizing and quantifying in extent. It must therefore somehow be possible to eliminate, to reduce sufficiently or to calculate further influencing factors to an insignificant level. For a clear analysis, the single influencing factor must remain – overlay-free. An analysis cannot be carried out without isolation. Without real or computational freedom of overlay, an explanation would remain only a hypothesis. A study using apparatuses of different measuring geometries, different manufacturers, (and thus also) different device concepts, device compositions and device tunings and possibly other overlapping influencing factors (e.g. positioning) will not be able to prove that, for example, the measuring geometry is a possible source of influence and it will certainly not be able to determine the extent of a conceivable influence. This is all the more true if the values – in particular obtained from flat surfaces with different systems – are within the framework of the device conformity (i.e. the deviation of the same systems of the same manufacturer) or the additional system influence (different systems of the same manufacturer) or “manufacturer influence” (different systems of different manufacturers) and are therefore without validity. In addition, this does not say anything about the application on curved surfaces, such as a tooth. On the other hand, within the current studies, the extent of the influence of the measuring geometry on human teeth and shade guide tabs (curved surface) was examined and isolated for the first time, and thus evidence was also provided that the measuring geometry actually has an influence on color detection and all color coordinates by using identical systems from the same manufacturer, which differed only in the measuring geometry.

Systematizing and geometrically arranging or presenting colors, as in a room, goes back to the Greek philosophers Plato and Aristotle. The measuring general color science knows the so-called color space. And in dentistry, Goodkind and Schwabacher may have measured a room in 1987 that could be called tooth color space. In addition, VITA points out in connection with its VITAPAN 3D-MASTER that it is based on a tooth color space. For the first time, tooth color spaces of moist or wet, drying, drier and dry teeth were shown in the course of the work of the present author. Measurements were made for the first time with special high-performance spectrophotometers. They are representations that provide insight into the drying-based population dynamics and insight into something that is likely to happen after the death of teeth and humans – the teeth become brighter and different in color, translucency and opacity.

Forensic dentistry, for example, deals with the identification of people and dead. Identification or authentication – in the broadest sense the verification of an alleged identity – is becoming increasingly important for the security of people and data, even in everyday life and in a modern society, as is common in specific areas such as a high-security area (e.g. face recognition). According to the author of the current work who hereby lays the scientific foundation stone, both in forensic medicine for the identification of the dead and in this safety-relevant biometrics of living persons, it would be interesting of to use tooth color and dental reflection spectra directly or via image technology for this purpose.

In addition, this research was based on the exploration and quantification of influencing factors. This includes, for example, the light or measuring light and the light types of different color temperatures, the beam of the light or the measuring geometries (places of light sources and sensors in relation to the sample), the observation angle (2°, 10°), the size of the measuring surface and the measuring opening, the gloss, the liquid content (with scientific proof of the relationship between liquid content and tooth color), effect of drying and liquid reuptake (dehydration, rehydration), reversibility of these processes, the proportion of the liquid content in the gloss effect, the subjectivity of visual determination, crown curvature, system type (spectrophotometer, tristimulus colorimeter), measurement mode (contact or non-contact), measurement system-object relation, positioning, repeatability or reproducibility. In addition, subjective-visual determinations and objective measurements were investigated in subjective-objective comparisons via value comparisons. All these influencing factors are analyzed not only on moist, but also on drier (various specific drying or rehydration states) and dry teeth based on, among other things, brightness (L*), color coordinates such as a*, b*, C*, h, metamerism index, spectral values, tooth color samples of shade guides and tooth color spaces. Further and more specifying publications, in particular on this, will follow shortly.

[...]

 

André Hoffmann systematically researched the tooth colour and its origin with highest precision - for the first time in 2000. This book shows an excerpt of this systematic original research at human teeth and dental shade guides with high-precision measuring systems and high-precision positioning system in vitro ‒ with the highest precision. Due to his basic scientific research, he was able to quantify and isolate manifold factors influencing the colour of teeth. These include, for example, the light or measuring light and the type of light (illuminant) and illumination and colour temperature, the optical beam path of the light or the measuring geometry, the observation angle (2°, 10°), the size of the measuring surface, and measuring opening, the gloss, the liquid content (with scientific evidence of the relationship between liquid content and tooth colour), effect of dryingmoisture and rehydration, the correlation between the liquid content and the gloss effect, the subjectivity of visual subjective shade matchingcrown curvaturetype of system (spectrophotometertristimulus colorimeter), measuring mode (contact or non-contact), system-object-relationpositioningrepeatability or reproducibilitylens shiftdisplacement between sample and measuring surface and further intra- and interindividual factors. In addition, subjective-visual determinations and objectified measurements were examined in subjective-objective comparisons using colour coordinates comparisons. All these influencing factors are investigated on moistdryingdrier (various specific dehydration and rehydration states) and dry teeth based on the brightness (L*), on colour measurement values, such as a*b* (CIELAB), C*, h, (CIELCH), ΔE, on the metamerism index, on spectral values and curvestabs of dental shade guides and on tooth colour spaces …

As part of this exploration, phenomena (e.g. changes and breaks in behaviour as well as highly individual developments in colour values, paradoxes between the values of subjective determination using tooth shade patterns and the values of objective measurements) were identified and insights into the very complex colour dynamics through dehydration and rehydration were shown (up to more than >8 days). The development of the individual color measurement values was based on the liquid flow through the tooth and its tissues, in particular during drying and rehydration, and gave information about dynamics and the temporal extent of these processes.

On the basis of this data, Hoffmann had developed several methods for research and practice, suggestions for feasible innovations, such as monitoring of dental treatment to protect against pulp damage based on drying, and reconstructing the color of naturally moist teeth on those that have already dried, the identification of the living and the dead, human and animals via the “dental fingerprint” and a novel method for measuring the time of death for forensic medicine
He also described a time limit of drying up to which relatively natural, suitable color values and shade matching results can be obtained and after which no color determination should be carried out; and he established the rehydration time after the end of the drying or dental treatment, which must be waited in order to regain a natural tooth color and to get correct values and results again.  


His findings also show that teeth are able to store information on, for example, the condition (liquid contentcolour values) and the time within the drying and liquid reabsorption chronology. The author articulates a “dental chronometer” (“tooth clock”), “dental data store” (“tooth data store”) and a “dental memory” (“tooth memory”) and believes that significant progress in this area may include and could be achieved via a neural network for colour measurement apparatus.

 

You can find books by the author everywhere in bookshops or as e-book here.

 

 

Novel Method for Measuring the Time of Death on Teeth ‒ Liquid ContentsReflection Spectra

 

 

 

8.  Bibliography / Literature

 

Atkinson HF. An investigation into the permeability of human enamel using osmotic methods. Brit. dent, J., 83:205–14 (1947)

Belli S, Tanriverdi FF, Belli E. Colour stability of three esthetic laminate materials against to different staining agents. J Marmara Univ Dent Fac. 2(4):643-8 (1997)

Bergman G, Siljestrand B. Water evaporation in vitro from human dental enamel. Arch. Oral Biol. 8:37–8 (1962)

Bergman G. Microscopic demonstration of liquid flow through human dental enamel. Arch. Oral Biol. 8:233–4 (1963)

Billmeyer FW, Saltzman MJ. Grundlagen der Farbtechnologie. Muster-Schmidt Verlag, Göttingen, Zürich (1993)

Billmeyer FW, Saltzman M. Principles of color technology. New York: Interscience (1966)

Billmeyer FW, Saltzmann M. Principles of color technology. 2nd.Ed., New York (NY): J. Wiley & Sons (1981)

Billmeyer FJ. Survey of Color Order Systems, Color Research and Application 12:173–186 (1987)

Bird MJ, French EL, Woodside MR, Morrison MI, Hodge HC. Chemical analysis of deciduous enamel and dentin. J. dental Res. 19:413–23 (1940)

Bolk L. Das Gewicht der Zähne. Anat. Anz. 59 (1925)

Bolt RA, Bosch JJ, Coops JC. Influence of window size in small-window colour measurement, particularly of teeth. Phys Med Biol. 39(7):1133-42 (1994)

Bradbury J. H., Forbes W. F., Leeder J. D., West G. W.: Proton magnetic resonance study of sorption of water and alcohols by wool. J. Polym. Sei. A2, 3191–6 (1964)

Burnett G. W., Zenewitz J. A.: Studies of composition of teeth. VII. The moisture content of calcified tooth tissues. J. dental Res., St. Louis 37:581–9 (1958)

Carlström C., Glas J. E., Angmar B.: Ultra structure dental enamel. V. State of water in human enamel. J: Ultrastruct. Res. 8:24–39 (1963)

Carlström D.: Polarization microscopy of dental enamel with reference to incipient carious lesions. Advances oral Biol., New York 1:255–96 (1964)

CIE (Commission Internationale de I’Eclairage): Colorimetry, official recommendations of the international Commission on Illumination 2nd Dc. CIE 15.2: Paris, Bureau Central de la CIE (1985)

CIE (Commission Internationale de l’Eclairage): Recommendations on uniform color spaces. color-difference equations. psychometric color terms. Supplement No. 2 to CIE Publication No. 15 (E-1.3.1) 1971. (TC-1.3) 1978. Bureau Central de la CIE. Paris (1978)

Clark E. B.: An analysis of tooth color. J Am Dent Assoc; (18):2093–103 (1931)

Clark E. B.: Seventy-fourth Annual Session of the American Dental Association; 9, 15, Buffalo (NY) (1932)

Clark E. B.: The Clark tooth colour system. Part 3. Dent Mag Oral Top 50:249–258 (1933)

Clark E. B.: The color problem in dentistry. Dent Dig. 37:499–509 (1931)

Clark E. B.: Tooth Color selection. J Am Dent Assoc; 20:1065–73 (1933)

Clarke F. J. J.: Measurement of colour of human teeth. In: McLean, J Wed. Dental Ceramics: Proceedings of the First International Symposium on Ceramics. Chicago: Quintessence Publishing Co Inc.:441–88 (1983)

Commission Internationale de lEclairage: Colorimetry. Farbmessung. Publ. CIE Nr. 15 (1971)

Commission Internationale de lEclairage: Empfehlungen für empfindungsgemäß gleichförmige Farbenräume, Farbabstandsformeln und zugehörige Begriffe. Suppl. Nr. 2, Publ. CIE Nr. 15 (1978)

Commission Internationale de l’Eclairage: Verfahren zur Messung und Kennzeichnung der Farbwiedergabe‑Eigenschaften von Lichtquellen. Publ. CIE Nr. 13. 2 (1974)

Commission Internationale de lEclairage: Vocabulaire internationale de lE`clairage. International lighting vocabulary. Internationales Wörterbuch der Lichttechnik. 3. Aufl. Publ. CIE Nr. 17 (1970)

Cremer H. D.: Die chemische Untersuchung der Zähne In: Die Zahn-, Mund- und Kieferheilkunde, hrsg. v. W. Meyer:393–404. Urban & Schwarzenberg, München, Berlin (W) (1958)

Culpepper W. D.: A comparative study of shade matching procedures. J Prosthet Dent 1970 8; 24(2):166–73

Culpepper W. D.: A comparative study of shade-matching procedures. J. Prosth. Dent. 24:166 (1990)

Culpepper W. D.: Letter to the editor: a comparative study of shade-matching procedures. J Prosthet Dent. 1; 25(1):100–1 (1971)

De Jonge Th. E.: Anatomie der Zähne In: Zahn-, Mund-, Kieferheilkunde, Urban und Schwarzenberg, herausgegeben von Mayer W. München, Berlin (1958)

Deakins M.: Changes in the ash, water, and organic content of pig enamel during calcification. J. dent. Res. 21:429–35 (1942)

DIN 5031: Teil 1–7: Strahlungsphysik im optischen Bereich und Lichttechnik (1967‑71)

DIN 5033: Farbmessung, Teil 3: Farbmaßzahlen. Beuth Verlag, Berlin (1980)

DIN 5033: Farbmessung. Beuth Verlag, Berlin (1980)

DIN 5033: Farbmessung; Teil 1: Grundbegriffe der Farbmetrik; Teil 2: Normvalenz-Systeme; Teil 3: Farbmaßzahlen; Teil 4: Spektralverfahren, Teil 5: Gleichheitsverfahren; Teil 6: Dreibereichsverfahren; Teil 7: Meßbedingungen für Körperfarben; Teil 8: Meßbedingungen für Lichtquellen, Teil 9: Weißstandard für Farbmessung und Photometrie. Beuth Verlag, Berlin (1981)

DIN 5033: Teil 1–9: Farbmessung (1964 bis 1978)

DIN 53236: Prüfung von Farbmitteln; Meß- und Auswertebedingungen zur Bestimmung von Farbunterschieden bei Anstrichen, ähnlichen Beschichtungen und Kunststoffen. Beuth-Verlag, Berlin

DIN 55600: Bestimmung der Signifikanz von Farbabständen bei Körperfarben nach der CIELAB-Formel (mit Beiblatt). Beuth Verlag, Berlin

DIN 55981: Bestimmung des relativen Farbstichs von nahezu weißen Proben. Beuth Verlag, Berlin

DIN 61649 Teil 1 u. 2: DIN‑Farbenkarte. Nebst Beibl. 1‑25: Farbmuster [matt] für Farbton 1 bis 24 u. unbunte Farben (1960/62); Beibl. 101‑125: Farbmuster [glänzend] für Buntton 1‑24 und unbunte Farben (1979ff.)

DIN 6167: Beschreibung der Vergilbung von nahezu weißen oder nahezu farblosen Materialien. Beuth Verlag, Berlin (1973)

DIN 6169: Blatt 2, 4, 5 und 6. Farbe 22:309‑24 (1973)

DIN 6169: Farbwiedergabe, Teil 1: Allgemeine Begriffe; Teil 2: Farbwiedergabe-Eigenschaften von Lichtquellen; Teil 6: Verfahren zur Kennzeichnung der Farbwiedergabe in der Farbfernsehtechnik. Beuth Verlag, Berlin 1962–1973 (1973)

DIN 6172: Metamerie-Index von Probenpaaren bei Lichtartwechsel. Beuth Verlag, Berlin (1973)

DIN 6173: Farbabmusterung. Teil 1: Allgemeine Farbabmusterungsbedingungen; Teil 2: Beleuchtungsbedingungen für künstliches mittleres Tageslicht. Beuth Verlag, Berlin 1974 (1981)

DIN 6174 (Vornorm): Farbmetrische Bestimmung von Farbabständen (1974)

DIN 6174: Farbmetrische Bestimmung von Farbabständen bei Körperfarben nach der CIELAB-Formel. Beuth Verlag, Berlin (1981)

DIN 6174: Farbmetrische Bestimmung von Farbabständen bei Körperfarben nach der CIELAB-Formel, Beuth Verlag, Berlin (1995)

DIN 6175: Farbtoleranzen in der Automobilindustrie. Teil 1: Unilackierungen, Teil 2: Effektlackierungen. Beuth Verlag, Berlin

DIN 6176: Entwurf – Farbmetrische Bestimmung von Farbabständen bei Körperfarben nach der DIN99-Formel. Beuth Verlag, Berlin

DIN EN 27491: Dentistry; Dental materials; Determination of colour stability of dental polymeric materials (ISO 7491; 1985). Beuth Verlag, Berlin (1991)

DIN ISO 10012: Forderungen an die Qualitätssicherung von Meßmitteln. Beuth Verlag, Berlin

DIN-Fachbericht 49: Verfahren zur Vereinbarung von Farbtoleranzen. ISSN 0179-275X. Beuth Verlag, Berlin

Douglas RD. Precision of in vivo colorimetric assessments of teeth. J Prosthet Dent. 77(5):464-70 (1997)

DR. LANGE: Grundlagen der Farbmessung, Anwendungsbericht Nr. 10d (1998)

DR. LANGE: Objektive Farbzahlbestimmung in der chemischen, pharmazeutischen und kosmetischen Industrie, Anwendungsbericht Nr. 3. 8d (1998)

el-Sayed SM, Shereif AH, Farghaly A. Effect of fluoride application on specular reflectance and stain potential of unfilled and photocured microfilled resin veneering materials. Egypt Dent J. 40(3):813-22 (1994)

Fay RM, Servos T, Powers JM. Color of restorative materials after staining and bleaching. Oper Dent. 24(5):292-6 (1999)

Goldstein GR, Schmitt GW. Repeatability of a specially designed intraoral colorimeter. J Prosthet Dent. 69(6):616-9 (1993)

Goodkind R. J., Keenan K. M., Schwabacher W. B.: A comparison of Chromascan and spectrophotometric color measurements of 100 natural teeth. J Prosthet Dent 1; 53(1):105–9 (1985)

Goodkind R. J., Loupe M. J.: Teaching of color in predoctoral and postdoctoral dental education J Prosthet Dent. 1992 5; 67(5):713–7 (1988)

Goodkind RJ, Schwabacher WB. Use of a fiber-optic colorimeter for in vivo color measurements of 2830 anterior teeth. J Prosthet Dent. 11;58(5):535-42 (1987)

Groh CL, OʼBrien WJ, Boenke KM. Differences in color between fired porcelain and shade guides. Int J Prosthodont. 11-12;5(6):510-4 (1992)

Hellwig E., Klimek J., Attin T.: Einführung in die Zahnerhaltung. 2. Auflage, Urban & Fischer, München, Jena (1999)

Hoffmann A: Erforschung der Entstehung von Farben, Reflexionsspektren und Einflußfaktoren an geschichteten und komplex aufgebauten Materialien ‒ Grundlagenforschung an Zähnen (2000)

Hoffmann A: Novel Method of Measuring the Time of Death on the Tooth ‒ Based on Liquid Contents, Reflection Spectra and Color: First also Reference-Independent Measurement and Analysis Method due to Reversibility of Drying and Absorption of Liquid or Water (2000)

Horn DJ, Bulan-Brady J, Hicks ML. Sphere spectrophotometer versus human evaluation of tooth shade. J Endod. 24(12):786-90 (1998)

Horn DJ, Hicks ML, Bulan-Brady J. Effect of smear layer removal on bleaching of human teeth in vitro. J Endod. 24(12):791-5 (1998)

Hosoya Y., Goto G.: Primary tooth color (II). Chromatic measurement with a light-guided color difference meter CD-270, Shoni Shikagaku Zasshi; 24 (3):428–37 (1986)

Hosoya Y., Goto G.: Primary tooth color. (I.) Chromatic measurement using a color and color difference meter 1001 DP, Shoni Shikagaku Zasshi; 23 (1):69–77 (1985)

Ichesco WR, Ellison RL, Corcoran JF, Krause DC. A spectrophotometric analysis of dentinal leakage in the resected root. J Endod. 17(10):503-7 (1991)

Ishikawa-Nagai S, Sato R, Furukawa K, Ishibashi K. Using a computer color-matching system in color reproduction of porcelain restorations. Part 1: Application of CCM to the opaque layer. Int J Prosthodont. 1992;5(6):495-502.

Ishikawa-Nagai S, Sato RR, Shiraishi A, Ishibashi K. Using a computer color-matching system in color reproduction of porcelain restorations. Part 3: A newly developed spectrophotometer designed for clinical application. Int J Prosthodont.7(1):50-5 (1994)

Johnston WM, Kao EC. Assessment of appearance match by visual observation and clinical colorimetry. J Dent Res. 68(5):819-22 (1989)

Ketterl W.: Endodontie. Hüthig, Heidelberg (1984)

Kleber CJ, Moore MH, Nelson BJ. Laboratory assessment of tooth whitening by sodium bicarbonate dentifrices. J Clin Dent 9 (1998)

Koertge TE, Brooks CN, Sarbin AG, Powers D, Gunsolley JC. A longitudinal comparison of tooth whitening resulting from dentifrice use. J Clin Dent. 9(3):67-71 (1998)

Körber K. Ceraplatinkronen, Hüthig Verlag, Heidelberg (1984)

Körber K. Zahnärztliche Prothetik. 3. Auflage. Thieme Verlag, Stuttgart, New York (1985)

Kowitz GM, Nathoo SA, Rustogi KN, Chmielewski MB, Liang LJ, Wong R. Clinical comparison of Colgate Platinum Toothwhitening System and Rembrandt Gel Plus. Compend Suppl. (17):S646-51 (1994)

Kreudenstein Th. Spreter v.: Über den Dentinliquor. Schweiz. med. Wochenschr. 88:635–9 (1958)

Leard A, Addy M. The propensity of different brands of tea and coffee to cause staining associated with chlorhexidine. J Clin Periodontol. 24(2):115-8 (1997)

LeFevre ML, Manly RS. Moisture, inorganic and organic contents of enamel and dentine from carious teeth. J. amer. dental Assoc., Chicago 25:233–42 (1938)

LeGeros RZ, Bonel G, Legros R. Types of “H2O” in human enamel and in precipitated apatites. Calcif. Tissue Res., Berlin (W) 26:111–8 (1979)

Lehmann KM., Hellwig E. Einführung in die restaurative Zahnheilkunde, Urban & Schwarzenberg, München – Wien – Baltimore, 7. Auflage (1993)

Lenhard M. Assessing tooth color change after repeated bleaching in vitro with a 10 percent carbamide peroxide gel. J Am Dent Assoc. 127(11):1618-24; quiz 1665 (1996)

Little M. F., Casciani F. S.: The nature of water on sound human enamel. (A preliminary study). Arch. oral Biol., London 11:565–71 (1966)

Little MF, Cueto ES, Rowley J. Chemical and physical properties of altered and sound enamel – I. Arch, oral Biol. Vol. 7:173–84. Pergamon Press Ltd., Oxford, London (1962)

Little MF, Cueto ES, Rowley J. Chemical and physical properties of altered and sound enamel I. Ash, Ca, P, Co2, N, water, microradiolucency and density. Archs oral Biol. 1:173–84 (1962)

Little MF, Posen J. Chemical and physical properties of “altered” and sound human enamel – II. Dissolution and residue light absorption (color). J. dent. Res. Dent Res 41: 471475 (1962)

Little MF, Steadman LT. Chemical and physical properties of altered and sound enamel. IV. Arch. oral Biol., London 11:273–8 (1966)

Lu Z, Zhao Y. [Study on the color modification buring surface staining of PLAT castable ceramic restorations]. Hua Xi Yi Ke Da Xue Xue Bao. 24(1):75-7. Chinese (1993)

Ma T, Johnson GH, Gordon GE. Effects of chemical disinfectants on surface characteristics and color of three fixed prosthodontic crown materials. J Prosthet Dent. 82(5):600-7 (1999)

Manly RS. Tristimulus photoelectric colorimetry of human incisors. J Dent Res. 26(6):459 (1947)

Marguerite F, Little MF, Casciani FS. The nature of water in sound human enamel. Archs oral Biol. 11:565–71 (1966)

Matis BA, Cochran MA, Eckert G, Carlson TJ. The efficacy and safety of a 10% carbamide peroxide bleaching gel. Quintessence Int. 29(9):555-63 (1998)

Matis BA. Dentifrice whitening after professional bleaching. J Indiana Dent Assoc. 77(3):27-32 (1998)

McConnell D. Hydrogen ion incorporation in crystal. Science.141–71 (1963)

Millstein PL, Harlan J, Nathanson D. Colour effect of denture base on denture tooth materials. J Oral Rehabil. 15(2):173-9 (1988)

Minolta. Exakte Farbkommunikation! (Broschüre der Minolta GmbH, Ahrensburg) (1996)

Nakamura T, Nakajima H, Salimee P, Hino T, Maruyama T. Effect of bleaching on vital discoloured teeth ‒ a colorimetric evaluation in three patients. Asian J Aesthet Dent. 1(1):25-8 (1993)

Nathoo SA, Chmielewski MB, Rustogi KN. Clinical evaluation of Colgate Platinum Professional Toothwhitening System and Rembrandt Lighten Bleaching Gel. Compend Suppl. (17):S640-5 (1994)

Nissan R, Trope M, Zhang CD, Chance B. Dual wavelength spectrophotometry as a diagnostic test of the pulp chamber contents. Oral Surg Oral Med Oral Pathol. 74(4):508-14 (1992)

OʼBrien WJ, Groh CL, Boenke KM. A new, small-color-difference equation for dental shades. J Dent Res. 69(11):1762-4 (1990)

OʼBrien WJ, Groh CL, Boenke KM. One-dimensional color order system for dental shade guides. Dent Mater. 5(6):371-4 (1989)

OʼBrien WJ, Hemmendinger H, Boenke KM, Linger JB, Groh CL. Color distribution of three regions of extracted human teeth. Dent Mater. 13(3):179-85 (1997)

OʼBrien WJ, Vazquez L, Johnston WM. The detection of incipient caries with tracer dyes. J Dent Res. 68(2):157-8 (1989)

Okubo SR, Kanawati A, Richards MW, Childress S. Evaluation of visual and instrument shade matching. J Prosthet Dent. 12;80(6):642-8 (1998)

Ouellet D, Los S, Case H, Healy R. Double-blind whitening Night-Guard study using ten percent carbamide peroxide. J Esthet Dent. 4(3):79-83 (1992)

Papa J, Cain C, Messer HH. Moisture content of vital vs endodontically treaded teeth, Endod Dent Traumatol. 4; 10(2):91–3 (1994)

Pimentel GC. McClellan A. L.: The Hydrogen Bond: 296. Freeman, San Francisco (1960)

Pople JA. Schneider W. G., Bernstein H. J.: High Resolution Nuclear Magnetic Resonance:460‒462. McGraw-Hill, New York (1959)

Pounder DJ. Postmortem Changes and time of death. Department of Forensic Medicine, University of Dundee (1995)

Preston JD. Bergen S. F.: Color science and dental art. CV Mosby, St Louis (1980)

Preston JD. Current status of shade selection and color matching. Quintessence Int.; 16(1):47–58 (1985)

Preston JD. Farbe in der zahnärztlichen Keramik. In: Schärer P., Rinn L. A., Kopp F. R (Hrsg): Ästhetische Richtlinien für die rekonstruktive Zahnheilkunde. Quintessenz, Berlin:13–26 (1980)

Richter M. Das System der DIN-Farbenkarte. Farbe: 85-ff. (1952/53)

Richter M. Der Farbkörper des DIN-Farbsystems. Die Farbe 2, 137 (1953)

Richter M. Die Transformation der trichromatischen Koordinaten einer Farbe auf Ostwaldkoeffizienten. Z. techn. Phys. 12:582–7 (1931)

Richter M. Einführung in die Farbmetrik. De Gruyter, Berlin, New York (1981)

Richter M. Untersuchungen zur Aufstellung eines empfindungsgemäß gleichabständigen Farbsystem. Zeitschrift für wissenschaftliche Photographie 45:139–62 (1950)

Rosenstiel SF, Gegauff AG, Johnston WM. Duration of tooth color change after bleaching. J Am Dent Assoc. 122(4):54-9 (1991)  

Rosenstiel SF, Gegauff AG, Johnston WM. Randomized clinical trial of the efficacy and safety of a home bleaching procedure. Quintessence Int. 27(6):413-24 (1996)

Rosenstiel SF, Porter SS, Johnston WM. Colour measurements of all ceramic crown systems. J Oral Rehabil. 16(5):491-501 (1989)

Ruegg JC: Muskel. In: Schmidt RF, Thews G: Human Physiologie, Springer, Berlin, Heidelberg, New York. 67-86 (1989)

Rustogi KN, Curtis J. Development of a quantitative measurement to assess the whitening effects of two different oxygenating agents on teeth in vivo. Compend Suppl. (17):S631-4 (1994)

Seghi RR, Hewlett ER, Kim J. Visual and instrumental colorimetric assessments of small color differences on translucent translucent dental porcelain. J Dent Res 68(12):1760 (1989)

Seghi RR, Johnston WM, O’Brien WJ. Spectrophotometric analysis of color differences between porcelain systems. J prossthet Dent 7; 56(7)d:35–40 (1986)

Seghi RR. Effects of instrument-measuring geometry on colorimetric Assessments of dental porcelain. J Dent Res 5; 69(5):1180–3 (1990)

Seghi RR, Gritz MD, Kim J. Colorimetric changes in composites resulting from visible-light-initiated polymerization. Dent Mater. 6(2):133-7 (1990)

Seghi RR, Johnston WM, OʼBrien WJ. Performance assessment of colorimetric devices on dental porcelains. J Dent Res.;68(12):1755-9 (1989)

Spreter von Kreudenstein TH, Stuben J. Dentinstoffwechselstudien. III. Mitteilung: Die thermische Methode zum Nachweis des Dentinliquors. Dtsch Zahnärztl. Z. 10:1178–82 (1955)

Sproull RC. Color matching in dentistry. I. The three-dimensional nature of color. J Prosthet Dent. 4; 29(4):416–24 (1973)

Sproull RC. Color matching in dentistry. II. Practical applications of the organization of color. J Prosthet Dent. 5; 29(5):556–66 (1973)

Sproull RC. Color matching in dentistry. Part III. J Pros Dent: 2, 31(2):146–54 (1974)

Sproull RC. Color matching problems in dentistry. In: ISCC Subcommittee for Problem 35 Report. Color Res Appl: 1 (3):134–6 (1976)

Takeda T, Ishigami K, Shimada A, Ohki K. A study of discoloration of the gingiva by artificial crowns. Int J Prosthodont. Mar-Apr;9(2):197-202 (1996)

Trautz OR. X-ray diffraction of apatites. In: Recent Advances in the Study of Structure Composition and Growth of Mineralized Tissues, New York academy of Science Vol. 60, article 5 (1955)

Trautz OR. X‑ray diffraction of biological and synthetic apatites. Ann. N. Y. Acad. Sci., New York 60:696–712 (1955)

van der Burgt TP, ten Bosch JJ, Borsboom PC, Kortsmit WJ. A comparison of new and conventional methods for quantification of tooth color. J Prosthet Dent. 63(2):155-62 (1990)

Vaupel P, Ewe K: Funktion des Magen-Darm-Kanals – Mundhöhle, Pharynx und Oesophagus. In: Schmidt RF, Thews G: Physiologie des Menschen. Springer, 806-846 (1995)

Vita-Zahnfabrik (Produktinformation): Farbnahme. Das neue Farbsystem VITAPAN 3D-MASTER. Vita-Zahnfabrik, Bad Säckingen (1998)

Vollmann M. VITAPAN 3D-MASTER – Theorie und Praxis. Dental Lab; 46(8): 1247–54 (1998)

White JM, OʼBrien WJ. The colors of mixtures of dental opaque porcelains. J Dent Res. 68(9):1319-22 (1989)

Yamamoto M. Die Entwicklung des Vintage-Halo-CCS-Systems: Computergesteuerte Farbbestimmung und innovative Keramikwerkstoffe. Quintessenz, Berlin (1998)

Yap AU, Sim CP, Loh WL, Teo JH. Human-eye versus computerized color matching. Oper Dent. 11–12; 24(6):358–63 (1999)

Zhu J, Zhao Y, Zhu H. [In vivo color measurement of 410 healthy maxillary anterior teeth]. Zhonghua Kou Qiang Yi Xue Za Zhi. 33(5):297-9 (1998)

 
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