Study on the mechanism of discoloration and the efficacy of bleaching in non-infected traumatically discolored teeth
Wang, Y.-N.; Chen, F.-Y.; Jiang, T.
Zhonghua Kou Qiang Yi Xue Za Zhi 39(6): 492-495
2004
ISSN/ISBN: 1002-0098 PMID: 15854323 Document Number: 568580
To investigate the mechanism of discoloration and the efficacy of bleaching in non-infected traumatically discolored teeth. In vitro model of discolored teeth: sample of fresh erythrocytes was placed in the pulp cavity of 20 extracted teeth and centrifuged for 3 consecutive days. These discolored teeth were divided equally and randomly into two groups: group A (control group); group B (bleaching group), bleached with 10% carbamide peroxide gel for 4 weeks. And then all teeth were prepared for histological examination and subjected to a series of histochemical tests to analyze some of the biochemical changes following haemorrhage into the pulp chamber and post-bleaching. Haemoglobin and haematin were detected in the dentinal tubules of discolored teeth from group A and no evidence of ferric or haemosiderin. Specimens from group B demonstrated a negative response to histochemical tests. In the absence of bacterial invasive, haemoglobin and haematin could cause discoloration of non-infected traumatized teeth. Peroxide bleaching agent can effectively remove haemoglobin and haematin.