A book for anyone interested in the natural Sciences - with further title: "... 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..." For the first time, André Hoffmann systematically researched the tooth color and its origin. 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 systems (self-developments) in vitro ‒ with the highest precision. Due to his basic scientific research, the pioneer in the field of photonics was able to quantify and isolate manifold factors influencing the color of teeth. All these influencing factors are investigated on moist, drying, drier (various specific dehydration and rehydration states) and dry teeth based on the brightness (L*), on color measurement values, such as a*, b* (CIELAB), C*, h, (CIELCH), ΔE, on the metamerism index, on spectral values and curves, tabs of dental shade guides and on tooth color spaces … As part of this exploration, phenomena (e.g. changes and breaks in behaviour as well as highly individual developments in color 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 color 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 of 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 content, color values) and the time within the drying and liquid re-absorption 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 color measurement apparatus.weiterlesen