The Effect Of Self-Ligation Orthodontic Brackets With Reverse-Curve Arch Wire To The Periodontal Health

Objective:In the orthodontic clinic, there is always lots of dispute on the effect of self-ligation orthodontic brackets to the periodontal. The objective of this test is to measure the effect of self-ligation orthodontic brackets and ordinary metal brackets to the periodontal, through the detection of the gingival index (GI), plaque index (PLI), probing depth (PD) and aspartate aminotransferase (AST) in gingival crevicular fluid (GCF) at the time of before the appliance were fixed to the patients’teeth, after they were fixed four weeks and after the Reverse-curve arch wires were fixed four weeks. Tough the analysis of change law to aspartate aminotransferase (AST) in gingival crevicular fluid (GCF), we can get the message of biochemical event in the periodontium restoration indirectly. Meanwhile moving forward a single step approach to influence of orthodontic appliance to periodontal health, supply theory consult to orthodontic clinic.Materials and Methods:The metal standard straight wire brackets and self-ligation orthodontic brackets, gluma acid etching, adhesive resin of orthodontic non-tone-based chemical curing adhesive mixing, and AST kits were chose.48patients of12～18years old acceptting orthodontic treatment randomly in oral orthodontic division of shandong province hospital were selected.30patients wre randomly divided into four groups according to the type of fixed appliance they wearing:groupA1. the metal standard straight wire brackets were wearing; groupA2. the metal standard straight wire brackets and reverse-curve arch wire were wearing; groupB1. the self-ligation brackets were wearing; groupB2. the self-ligation brackets and reverse-curve arch wire were wearing. There were twelve patients in every group. The gingival index (GI), plaque index (PLI), probing depth (PD) and aspartate aminotransferase (AST) in gingival crevicular fluid(GCF) were detected at the time of before the appliance were fixed to the patients’teeth, after they were fixed four weeks and after the Reverse-curve arch wires were fixed four weeks. To ensure the quality of the GCF and clinical check, the teeth plaque index (PLI) were recorded firstly, then the GCF were collected, finally the depth (PD) and gingival index (GI) measurement were probed. Before GCF specimen taking cleaned the plaque of each tooth surface, used the cotton to separate the wet, chose lip (cheek) axial angle (2locus/teeth) for of the selected teeth, immediate weighing, being kept in a refrigerator in-85℃. The AST level of GCF was measured by biochemical analyzer. The data were processed by SPSS17.0statistical software, and t-test was made between related of data groups. Result:1. The GI、PLI and PD of ordinary metal brackets group and self-ligation brackets group increased gradually in stage T1and T2, and the GI、PLI increase was significant(P<0.05); there was no significant difference between the GI、PLI and PD of ordinary metal brackets group and self-ligation brackets group in stage T1, but the difference was significant between the GI、PLI of them in stage T2(P<0.05).2. The AST content in GCF of ordinary metal brackets group and self-ligation brackets group increased gradually in stage T1and T2, and the increase was significant (P<0.05); there was no significant difference between them in stage T1, but the difference was significant between them in stage T2(P<0.05).3. The comparison AST content in GCF between the three tooth showed that only the teeth31in groupB2had a significant difference in stage T2(P<0.05).4. Among all the teeth31、33、35,31teeth had the most increment of AST content in GCF in stage T1、T2, and35teeth were secondary,33teeth were the last.Conclusion:1. In the initial stage of wearing the fixed appliance, periodontal health was affected in a certain extent. Different teeth bit is affected at different degree, incisor and premolar are more severity, canine teeth is lighter. The influence of the self-ligation brackets and ordinary brackets to periodontal health was compared, the former is better.2. With the extension of treatment time, in process of the Spee’s curve leveling, lower mandible incisive periodontal health degree further reduced. Since the self-ligation brackets with gentle stress force they make for the periodontal health maintenance in the process of intrusion.3. The AST level of GCF can react tooth periodontal health in the process of orthodontic more objective and accurate, higher sensitivity than clinical index.