非感染性创伤性变色牙的变色机制及漂白疗效研究

目的　探讨非感染性创伤性变色牙的变色机制及漂白疗效。方法　在 2 0颗离体牙的髓腔内封入新鲜红细胞 ,连续离心制备变色牙模型。变色牙随机分为A、B 2组 ,A组为漂白对照组 ,B组进行漂白 ,所有牙均经常规组织学处理并进行系列组化染色显微观察。结果　A组变色牙的牙本质小管内存在高铁血红素和血红蛋白 ,缺乏铁离子和含铁血黄素 ;B组漂白后的组织学标本组化染色均呈阴性 ,未见红细胞的分解产物。结论　在非感染条件下 ,血红蛋白和其他形式的高铁血红素分子可以导致创伤牙变色 ,过氧化物漂白剂能有效与其作用而产生漂白效果

Study on the mechanism of discoloration and the efficacy of bleaching in non-infected traumatically discolored teeth

Objective To investigate the mechanism of discoloration and the efficacy of bleaching in non-infected traumatically discolored teeth Methods 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 Results 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 Conclusions In the absense of bacterial invasive,haemoglobin and haematin could cause discoloration of non-infected traumatized teeth Peroxide bleaching agent can effectively remove haemoglobin and haematin