Spectrophotometric Evaluation of Color Alterations of Teeth Exposed to Different Conditions in Time

Human teeth consist of organic and anorganic tissue components similair to bones. Therefore, it is assumable that the registration of structural changes of teeth color in different enviromental conditions may prove useful within forensic taphonomy field, for example, for verification of burial environment and postmortem interval (PMI). Registration of very smal alterations of teeth color is nowadays possible due to well developed dental spectrophotometers. It is known that teeth exposed to air quickly dehydrate, but the degree and the pattern of these color changes in time intervals have not been objectively measured. Purpose: The objective was to determine the degree and patern of color alterations of teeth exposed to three different conditions in time. Material and Methods: The impacted third molars were used in this study because they were not previously exposed to any enviromental conditions. Their CIE L*a*b* values after exposure to dry conditions, NaCl and artificial saliva (control) were measured with dental spectrophotometer in time intervals of 1 hour, 24 hours, 1 week, 3 weeks, 5 weeks and 7 weeks by one trained operator. Results: The L*-lightness and the b*-blue-yellow color coordinate increased in dry conditions (p < .001 and p ≤ .050 respectively), which was statistically significant, whereas a*-green-red color coordinate showed shifts of color in this condition which were not statistically significant. The exposure of extracted third molars to dry conditions caused significant increase of L* and b* color coordinate towards more light and more yellow in comparison to the exposure of teeth to artificial saliva and NaCl. The a* color coordinate displayed high variability of its alteration in all tested conditions. Conclusions: The exposure of extracted impacted wisdom teeth to dry conditions caused a considerable consecutive increase of lightness (L*) and blueness-yellowness (b*) in comparison with the exposure of teeth to NaCl and artificial saliva.