Ferreira, M.M.C., “On animal dental calculus deposits”. Heidelberg, Germany, 6-10/10/1996: 3rd European Congress on Mathematics Applied to Biology and Medicine (ECMBM), Book of Abstracts, 259 (1996). Poster.

                               On animal dental calculus deposits

                                          Márcia M. C. Ferreira
                                                              UNICAMP
                                                         Instituto de Química
                                              Campinas, SP, BRAZIL, 13081-970
                                                 e-mail: marcia@iqm.unicamp.br
 

Mathematical technique  have been applied  to  unresolved  higher  order  data  (generated  by  hyphenated
instruments)  emission-excitation fluorescent spectra  of several animal dental calculus deposits  (which can
lead to periodolntal disease).   Red fluorescence has been observed  in animals when  dental calculus is irra-
diated with ultraviolet  light  and  preliminary  analysis  suggests  that  canine  calculus  contain  porphyrinic
compounds although  the spectra couldn't  be  physically  resolved.   The spectral resolution can be accom-
plished mathematically using  the  trilinear  decomposition  method.   A  singular  value  decomposition was
used for preliminary indication  of the number of  fluorescent species in  the samples.   It  is clear  from the
chemometric analysis that even in presence of nonlinearities,  three porphyrinic spectral profiles   (emission
and excitation)  can be nicely attained.   The method also indicates that one of  the porphyrins are common
to cats and dogs while from the other two, one predominates in canine samples while the other in the feline
samples.   The method also will be used to build mathematical calibration models.
 
 
 
 
 
 

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