不同浓度过氧化物漂白剂对人牙釉质表面硬度和粘结强度的影响

摘要

Objective To evaluate the effects of high concentrations of hydrogen peroxide (HP) bleaching agents on enamel micro hardness and shear bond strength . Methods Forty intact premolars were randomly divided into 4 groups. Deionized water (ddH2O), 10% HP bleaching agent, 15% carbamide peroxide (CP) and 30% HP bleaching agent were applied on the enamel specimens in each group for 4 weeks (6～8 h/d , 37 ℃ , 100% relative humidity ) . Surface microhardness and shear bond strength were measured after treatment . Results Compared with the group of enamel treated with ddH2O , the microhardness of enamel treated with 30% HP has no significant difference (P>0 .05) , but the shear bond strength was significantly reduced (P<0 .05); the microhardness and shear bond strength of enamel treated with 10% HP or 15% CP have no significant difference (P>0.05). Conclusion Bleaching agent with 30% HP does not have any significant effect on the microhardness of enamel ; however , it can significantly reduce the shear bond strength of enamel . 10% HP and 15% CP do not have any significant effects on the microhardness and shear bond strength of enamel .%目的 评价高浓度过氧化氢漂白剂对釉质表面硬度以及粘结强度的影响.方法 选择正畸拔出的双尖牙40颗,随机分为对照组(去离子水ddH2O处理)、10%过氧化氢漂白组、15%过氧化脲漂白组、30%过氧化氢漂白组.在37 ℃、100%湿度条件下每天漂白6~8 h,持续4周,测量釉质表面的显微硬度以及粘结强度.结果 与对照组比较,30%过氧化氢漂白4周后釉质的显微硬度差别无统计学意义(P＞0.05),剪切粘结强度明显下降(P＜0.05);10%过氧化氢漂白组及15%过氧化脲漂白组的牙釉质显微硬度及剪切粘结强度差别无统计学意义(P＞0.05).结论 30%过氧化氢对釉质显微硬度没有明显影响,但可以降低釉质的粘结强度;10%过氧化氢及15%过氧化脲漂白剂对釉质的显微硬度及粘结强度无明显影响.