André Hoffmann innovator researcher and developer pioneer in the field of optical
technologies (photonics) systematically researched the tooth colour and its origin with
highest precision (see publication 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. 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 drying moisture and rehydration the correlation between the
liquid content and the gloss effect the subjectivity of visual subjective shade matching
crown curvature type of system (spectrophotometer tristimulus colorimeter) measuring mode
(contact or non-contact) system-object-relation positioning repeatability or reproducibility
lens shift displacement 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 moist drying drier (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) DeltaE on the metamerism
index on spectral values and curves tabs 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 shade guides 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 colour 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 colour 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 methodof measuring the time of death for forensic
medicine.He also described a time limit of drying up to which relatively natural suitable
colour values and shade matching results can be obtained and after which no colour
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 colour
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 colour 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 field may include and could be achieved via a neural
network for colour measurement apparatus.A book for anyone interested in the natural sciences.
