Mirhashemi Amir Hossein, Hosseini Mohammad Hashem, Chiniforoush Nasim, Soudi Armin, Moradi Meisam
Associate Professor, Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Department of Orthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
Assistant Professor, Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Department of Orthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
J Dent (Tehran). 2018 Jan;15(1):54-62.
Rebonding of isolated brackets is an economic option that can be conducted using available in-office or commercial recycling methods. Nowadays, lasers are known as an efficient modality for composite removal, but there is not much information available about using lasers for removal of adhesive remnants from the ceramic bracket base.
Fifty human premolar teeth were divided into five groups. Samples in all groups were bonded to ceramic brackets. Brackets in four groups were debonded and the remaining adhesive was removed by Er:YAG laser, Er;Cr:YSGG laser, sandblasting or direct flame. After removing adhesives from the tooth surfaces by carbide bur, the recycled brackets were bonded again. in the control group, new ceramic brackets were bonded. Finally, all brackets were debonded by universal testing machine and their shear bond strength (SBS) was measured. The adhesive remnant index (ARI) was calculated under a stereomicroscope at ×10 magnification. Data were analyzed using oneway ANOVA and Tukey's test.
SRS values showed no significant difference among the five groups (P=0.568). The highest SRS was noted in the control group (7.46±1.4 MPa), followed by Er:YAG laser group (7.40±1.24 Mpa) and the lowest was noted in the flame group (6.32±2.3 Mpa). ARI scores indicated that most of the adhesive remained on the tooth surface in all groups.
Recycling of ceramic brackets with Er:YAG laser is an efficient in-office method which causes the least damage to the bracket base. However, all methods of bracket recycling showed acceptable SBS.
孤立托槽的重新粘结是一种经济的选择，可以使用现有的诊所内或商业回收方法来进行。如今，激光被认为是去除复合材料的一种有效方式，但关于使用激光去除陶瓷托槽基底上的粘结剂残余物的信息并不多。
50颗人类前磨牙被分为五组。所有组的样本都粘结了陶瓷托槽。四组中的托槽被拆除，剩余的粘结剂通过铒钇铝石榴石激光、铒铬钇钪镓石榴石激光、喷砂或直接火焰去除。用硬质合金车针从牙齿表面去除粘结剂后，将回收的托槽再次粘结。在对照组中，粘结新的陶瓷托槽。最后，用万能试验机拆除所有托槽并测量其剪切粘结强度（SBS）。在体视显微镜下以×10放大倍数计算粘结剂残余指数（ARI）。使用单因素方差分析和Tukey检验对数据进行分析。
五组之间的SBS值无显著差异（P = 0.568）。对照组的SBS最高（7.46±1.4兆帕），其次是铒钇铝石榴石激光组（7.40±1.24兆帕），火焰组最低（6.32±2.3兆帕）。ARI评分表明，所有组中大部分粘结剂仍留在牙齿表面。
用铒钇铝石榴石激光回收陶瓷托槽是一种高效的诊所内方法，对托槽基底造成的损伤最小。然而，所有托槽回收方法的SBS都可接受。
