漂白对人牙釉质与树脂粘接强度的影响

目的 研究漂白对人牙釉质深层与树脂粘接强度的影响,探讨漂白后瓷贴面修复的粘接时机.方法 96个人恒牙试件均分为6个组,第1组不漂白,直接磨除釉质0.6～0.8 mm,第2～6组分别在35%过氧化氢漂白剂冷光辅助漂白后即刻、1、4、7、14 d磨除釉质0.6～0.8 mm,分别用粘接剂A(One-step plus)和B(Single bond)粘接.测量拉伸强度,作为粘接强度.结果 每个时间点两种粘接剂粘接强度的差异无统计学意义(P>0.01).A和B两种粘接剂中,第2、3、4组粘接强度[(17.79±3.53)和(19.41±3.37)MPa、(17.50±4.29)和(19.66±3.48)MPa、(18.39±3.58)和(19.53±3.21)MPa]比第1组[(25.94±4.88)和(28.02±4.36)MPa]降低约30%;第5组粘接强度[(22.46±3.98)和(23.74±5.04)MPa]与第1组的差异无统计学意义(P>0.01);第6组粘接强度[(26.03±4.47)和(27.88±4.78)MPa]与第1组相差不大.结论 漂白后人牙釉质深层与树脂粘接剂的粘接强度明显下降,最好在漂白两周后进行瓷贴面粘接.

Relationship between resin bonding strength and time on deep enamel after bleaching treatment

Objective To study the effect of pre-restoration bleaching treatment on tensile strength of resin bonding agents to deep enamel and its duration, and to estimate the optimal timing of porcelain veneers bonding operation after bleaching treatment. Methods A total of 96 extracted human permanent teeth were allocated into 6 groups, 16 teeth for each. In 5 study groups, 80 teeth were bleached using 35% hydrogen peroxide activated by cold light. Right after bleaching and at 1,4, 7, and 14 days after bleaching,the teeth were prepared with removal of 0.6 to 0.8 mm depth of enamel respectively. And then each study group was divided into two subgroups and bonded with resin bonding agents A( One-step plus) and B (Single bond). In the control group, 16 unbleached teeth were divided into two subgroups and bonded with the two bonding agents respectively. The tensile bonding strength was measured. Results The tensile strength was [(17.79±3.53) and (19.41±3.37) MPa],[(17.50±4.29) and (19.66±3.48) MPa], and [(18. 39±3.58) and (19. 53±3. 21) MPa] right after bleaching 0 day, 1 day, and 4 days, which were significantly smaller ( about 30% ) than that of the control group [ ( 25.94 ± 4.88 ) and ( 28.02±4. 36) MPa] (P < 0. 001 ). At 7 days after bleaching the tensile strength [ (22.46±3.98) and (23.74±5. 04) MPa] reached 87% and 85% of that in the control(P > 0. 01 ). At 14 days after bleaching treatment,the strength [ (26.03±4. 47) and (27.88±4.78) MPa] reached the same level as that in the control(P >0. 01 ). There was no significant difference in bonding tensile strength between the two resin bonding agents.Conclusions The bonding strength of resin bonding agents to deep enamel was low during 2 weeks after bleaching treatment. It is suggested that porcelain veneer bonding operation should be performed till 2 weeks after bleaching treatment.