Baherimoghadam Tahreh, Akbarian Sahar, Rasouli Reza, Naseri Navid
Department of Orthodontics, School of Dentistry, Yasuj University of Medical Sciences, Yasuj, Iran.
Department of Operative Dentistry, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
Eur J Dent. 2016 Apr-Jun;10(2):193-198. doi: 10.4103/1305-7456.178296.
To evaluate shear bond strength (SBS) of the orthodontic brackets bonded to fluorosed and nonfluorosed teeth using Light Bond with and without adhesion promoters and compare their enamel damages following debonding.
In this study, 30 fluorosed (Thylstrup and Fejerskov Index = 4-5) and 30 nonfluorosed teeth were randomly distributed between two subgroups according to the bonding materials: Group 1, fluorosed teeth bonded with Light Bond; Group 2, fluorosed teeth bonded with adhesion promoters and Light Bond; Group 3, nonfluorosed teeth bonded with Light Bond; Group 4, nonfluorosed bonded with adhesion promoters and Light Bond. After bonding, the SBS of the brackets was tested with a universal testing machine. Stereomicroscopic evaluation was performed by unbiased stereology in all teeth to determine the amount of adhesive remnants and the number and length of enamel cracks before bonding and after debonding. The data were analyzed using two-way analysis of variance, Kruskal-Wallis, Wilcoxon Signed Rank, and Mann-Whitney test.
While fluorosis reduced the SBS of orthodontic bracket (P = 0.017), Enhance Locus Ceruleus LC significantly increased the SBS of the orthodontic bracket in fluorosed and nonfluorosed teeth (P = 0.039). Significant increasing in the number and length of enamel crack after debonding was found in all four groups. There were no significant differences in the length of enamel crack increased after debonding among four groups (P = 0.768) while increasing in the number of enamel cracks after debonding was significantly different among the four groups (P = 0.023). Teeth in Group 2 showed the highest enamel damages among four groups following debonding.
Adhesion promoters could improve the bond strength of orthodontic brackets, but conservative debonding methods for decreasing enamel damages would be necessary.
使用Light Bond粘结剂在有或没有粘结促进剂的情况下，评估正畸托槽粘结于氟斑牙和非氟斑牙的剪切粘结强度（SBS），并比较脱粘后它们的釉质损伤情况。
在本研究中，30颗氟斑牙（Thylstrup和Fejerskov指数=4 - 5）和30颗非氟斑牙根据粘结材料随机分为两个亚组：第1组，用Light Bond粘结氟斑牙；第2组，用粘结促进剂和Light Bond粘结氟斑牙；第3组，用Light Bond粘结非氟斑牙；第4组，用粘结促进剂和Light Bond粘结非氟斑牙。粘结后，用万能试验机测试托槽的SBS。通过无偏体视学对所有牙齿进行立体显微镜评估，以确定粘结前和脱粘后粘结剂残留量以及釉质裂纹的数量和长度。数据采用双向方差分析、Kruskal - Wallis检验、Wilcoxon符号秩检验和Mann - Whitney检验进行分析。
虽然氟斑牙降低了正畸托槽的SBS（P = 0.017），但Enhance Locus Ceruleus LC显著提高了氟斑牙和非氟斑牙正畸托槽的SBS（P = 0.039）。在所有四组中，脱粘后釉质裂纹的数量和长度均显著增加。四组脱粘后釉质裂纹长度增加量无显著差异（P = 0.768），而脱粘后釉质裂纹数量增加量在四组间有显著差异（P = 0.023）。脱粘后，第2组牙齿在四组中显示出最高的釉质损伤。
粘结促进剂可提高正畸托槽的粘结强度，但需要采用保守的脱粘方法以减少釉质损伤。
