Tiwari Sakshi, Dharmadeep Garadappagari, Shetty K Sadashiva, Shiri Deepthi
Department of Orthodontics & Dentofacial Orthopedics, G Pulla Reddy Dental College and Hospital, Kurnool, Andhra Pradesh, India.
Department of Orthodontics & Dentofacial Orthopedics, Bapuji Dental College & Hospital, Davangere, Karnataka, India.
J Oral Biol Craniofac Res. 2022 Jan-Feb;12(1):204-207. doi: 10.1016/j.jobcr.2021.12.003. Epub 2021 Dec 21.
The primary objective was to assess and compare the shear bond strength of orthodontic brackets bonded on bleached enamel with and without using an anti-oxidizing agent.The secondary objective was to compare the shear bond strength of brackets between the groups with anti-oxidant application along with immediate bonding and that of delayed bonding without any anti-oxidant treatment, on bleached teeth.
MATERIALS & METHODS: 75 premolars were collected and thereafter randomly distributed into the 5 groups. Group 1 to 4 had undergone bleaching with 10% carbamide peroxide and group 5 was control. Group 1 was bonded immediately after bleaching while bonding was delayed in group 4 for a period of 1 week. Groups 2 and 3 received the anti-oxidant treatment with 10% sodium ascorbate gel and 10% green tea gel respectively. Hounsfield universal testing machine was used for testing the shear bond strength.
For group 1, the shear bond strength was significantly lower (mean 4.9 MPa) than group 5 (mean 12.5 MPa). The significant differences were observed on comparing the shear bond strength of antioxidant-treated and delayed bonding groups with control (p < 0.05). Mean shear bond strength in groups 2, 3 and 4 were 7.5 MPa, 9.6 MPa and 5.8 MPa respectively.
The bond strength of brackets reduces immediately after the bleaching procedure. The bond strength can be reversed either by delaying the bonding for a period of 1 week or by using the anti-oxidizing agents but it is not up to the level of unbleached enamel.
主要目的是评估和比较在使用和不使用抗氧化剂的情况下，正畸托槽粘结在漂白釉质上的剪切粘结强度。次要目的是比较在漂白牙齿上，抗氧化剂应用组立即粘结与无抗氧化剂处理的延迟粘结组之间托槽的剪切粘结强度。
收集75颗前磨牙，然后随机分为5组。第1组至第4组用10%过氧化脲进行漂白，第5组为对照组。第1组在漂白后立即粘结，而第4组的粘结延迟1周。第2组和第3组分别接受10%抗坏血酸钠凝胶和10%绿茶凝胶的抗氧化处理。使用Hounsfield万能试验机测试剪切粘结强度。
第1组的剪切粘结强度（平均4.9MPa）显著低于第5组（平均12.5MPa）。在比较抗氧化处理组和延迟粘结组与对照组的剪切粘结强度时观察到显著差异（p<0.05）。第2组、第3组和第4组的平均剪切粘结强度分别为7.5MPa、9.6MPa和5.8MPa。
漂白过程后托槽的粘结强度立即降低。粘结强度可以通过将粘结延迟1周或使用抗氧化剂来恢复，但达不到未漂白釉质的水平。
