In vitro study on color changes of desiccated teeth

Methods: 52 extracted premolars (30 upper premolars and 22 lower premolars) were taken into our study. All teeth were disinfected, suffered a professional cleaning protocol and their roots were embedded in pink acrylic resin. Teeth were kept in water to preserve the state of humidification they would have in the mouth. Dental shades were recorded for each tooth using the Vita Easy Shade Spectrophotometer on both buccal and lingual surfaces at two time points: first immediately after taking them out of water and second time point after leaving the tooth for two hours to dry. For each measurement we recorded the shades given by the spectrophotometer in both Vita Classical and 3DMaster Shades and also the L*, a* and b* values provided in the CIE L*a*B* system of coordinates for color. Data was interpreted using descriptive statistics and t-Student tests: Paired Two Samples for Means and Two-Sample Assuming Unequal Variances.

Results: Comparing initial measurements on buccal and lingual surfaces of the wet extracted teeth it was observed a statistically significant difference (p<0, 05) between L coordinates but no statistical difference for a and b coordinates. However, studying the Dental shades , L*, a* and b* coordinates from initial and second time points we found multiple statistically significant differences between the recorded values.

Conclusions: For better clinical results, restorative materials should have the same optical properties as natural teeth and shade registration for the teeth should be done in a humid state because measuring in a desiccated state tooth color values can be significantly different.