比较两种漂白剂髓室内漂白后对牙体抗力的影响

Comparison on the effect of two bleaching agents on tooth resistance after pulp chamber bleaching

目的 比较过氧化氢(HP)与过硼酸钠(SP)在髓室内漂白后对牙体抗力的影响。方法 40颗进行根管治疗的完整离体前磨牙,随机分为HP组、SP组、SP+HP组、对照组,每组10颗。对照组进行水处理、HP组进行过氧化氢处理, SP组进行过硼酸钠处理, SP+HP组进行过氧化氢+过硼酸钠处理。四组牙齿均建立体外髓室内漂白模型,最后置于万能试验机上测试最大载荷,记录每个样本最大承受压力。比较四组牙齿的抗力值。结果 HP组、SP组、HP+SP组抗力值分别为(868.37±94.47)、(796.07±32.88)、(1072.09±56.34)N,均低于对照组的(1244.17±98.40)N,差异有计学意义(P<0.05)。HP组与SP组抗力值比较,差异无统计学意义(P>0.05)。HP+SP组抗力值高于HP组及SP组,差异有统计学意义(P<0.05)。结论 过氧化氢及过硼酸钠用于髓室内漂白均会降低牙体抗力,过硼酸钠更为显著,但两者联合时对牙体抗力的影响变小。

Objective To compare the effect of hydrogen peroxide(HP)and sodium perborate(SP)on tooth resistance after pulp chamber bleaching.Methods 40 intact premolars were treated with root canal therapy and randomly divided into HP group,SP group,SP+HP group,control group,with 10 premolars in each group.The control group was given water treatment,HP group was given hydrogen peroxide treatment,SP group was given sodium perborate treatment,and SP+HP group was treated with hydrogen peroxide and sodium perborate treatment.The four groups of teeth were built with three-dimensional external pulp chamber bleaching model,and finally placed on the universal testing machine to test the maximum load,record the maximum bearing pressure of each sample,and compare the resistance value of the four groups.Results The tooth resistance value of HP group,SP group and HP+SP group were(868.37±94.47),(796.07±32.88)and(1072.09±56.34)N,respectively,which were lower than that of(1244.17±98.40)N of control group,and the difference was statistically significant(P<0.05).There was no statistically significant difference in tooth resistance value between HP group and SP group(P>0.05).The tooth resistance value of HP+SP group was higher than that of HP group and SP group,and the difference was statistically significant(P<0.05).Conclusion Hydrogen peroxide and sodium perborate used in pulp chamber bleaching can reduce tooth resistance,especially sodium perborate.But the combination of the two has a smaller impact on tooth resistance.