Coronal tooth discoloration and white mineral trioxide aggregate

By Felman D, Parashos P

Date: 01/2013
Journal: JOE


Quantify coronal tooth discoloration by wMTA


N = 44 single rooted unrestored extracted teeth

All staining removed. Apical 3mm of root resected. Canals c&s from apex to pulp horns to eliminate coronal microleakage variable. NaOCl & EDTA used. Whole blood collected from volunteer. 3mm wMTA was placed in the most coronal part of preparation. Cotton pellet was placed over wMTA, then either blood or saline was used to saturate the cotton pellet. Photographs were taken at specified time points, then randomized to the researcher when assessing shade of tooth.

Experimental groups (n = 18 each): (1) wMTA + saline. (2) wMTA + blood.

Positive/negative control (n = 4 each): (+) blood only. (-) saline only.

Criteria of evaluation:

  • CIE L*a*b* color space tooth shade assessment.
  • L* = lightness, a* = green to red gradient, b* = blue to yellow gradient.
  • Evaluation at 3 time points
  • T0 = baseline, T1 = 1 day after material placement, T35 = 35 days after material placement.


  • Positive control (only Blood) had the most statistically significant color discoloration.
  • Teeth with wMTA, regardless of the presence of saline or blood, had statistically significant more discoloration in the cervical 1/3 of tooth than negative control.
  • Significant changes only observed describing lightness of tooth. No ss changes in hue or chroma.

Clinical Significance:

  • wMTA can discolor ex vivo teeth
  • Presence of blood adjacent to wMTA can exacerbate the degree of discoloration.
  • Inform your patients the possibility of discoloration if using wMTA – regeneration, perforation repairs, etc.