过氧化脲凝胶对牙髓腔的渗透性研究

Peroxide penetration into pulp chamber from carbamide peroxide

目的研究不同浓度过氧化脲对牙髓腔的渗透性。方法 40颗离体上颌中切牙随机分为4组,醋酸注入根尖拔髓后的牙髓腔内,A组为对照组,仅接触蒸馏水,B组采用10%过氧化脲,C组采用16%过氧化脲,D组采用22%过氧化脲,提取髓腔内液体至试管中,加入无色结晶紫和辣根过氧化物酶后,通过紫外分光光度仪检测液体的光学浓度。结果各组之间差异具有统计学意义(P<0.01),对照组髓腔内无过氧化氢残留,实验组过氧化氢含量:D组(0.595±0.022)μg>C组(0.297±0.017)μg>B组(0.148±0.018)μg。结论过氧化脲家用漂白剂浓度越高,牙髓腔内过氧化氢的渗透越多。

Objective To investigate peroxide penetration from carbamide peroxide into the pulp chamber.Methods Forty extracted human maxillary central incisor teeth were divided randomly into four groups.The intracoronal pulp tissue was removed from root apical,and the pulp chamber was filled with acetate buffer.The teeth in the control group（A） were exposed only to distilled water.Buccal crown surfaces of teeth in the experimental groups were subjected to either a whitening gel（B group 10% carbamide peroxide,C group containing 16% carbamide peroxide,D group containing 22% carbamide peroxide）.The acetate buffer solution in each tooth was then transferred to a test tube and leuco-crystal violet and enzyme horseradish peroxidase were added.The optical density of the resultant blue colour in the tubes was measured by a UV-visible spectrophotometer.Results Statistically significant differences were found between all of the groups（P0.01）.Pulpal peroxide was not observed in group A.The amount of hydrogen peroxide（μg）found in the pulp chamber of group D（0.595±0.022）group C（0.297±0.017） group B（0.148±0.018）.Conclusions Peroxide penetration into the pulp increased with higher levels of carbamide peroxide.