title: OPG and RANKL levels around miniscrew implants during orthodontic tooth movement.
abstract: BACKGROUND
  The aim of this study was to determine the peri-miniscrew implant crevicular fluid receptor activator of nuclear factor-кB ligand (RANKL) and osteoprotegerin (OPG) levels around loaded and unloaded miniscrew implants at different time intervals.
  
  
  METHODS
  Twenty loaded and 16 unloaded miniscrew implants were included in this study. All miniscrew implants were placed bilaterally between the maxillary second premolars and first molars as anchorage units for canine distalization. Peri-miniscrew implant crevicular fluid was taken from the mesiobuccal aspects of the loaded and unloaded miniscrew implants before loading; at 24, 48, and 168 hours; and on day 30 after force application. Enzyme-linked immunosorbent assay kits were used to determine RANKL and OPG levels in the peri-miniscrew implant crevicular fluid samples. Wilcoxon, Mann-Whitney U, and Spearman correlation tests were used for statistical evaluations at the P <0.05 level.
  
  
  RESULTS
  Although the total amount of OPG was not different between the groups, the total amount of RANKL was significantly elevated in the loaded miniscrew implant group (P <0.05) at all time periods. Peri-miniscrew implant crevicular fluid volume was the highest at 48 hours in the loaded group. Also, the OPG/RANKL ratio in the peri-miniscrew implant crevicular fluid was significantly decreased in the loaded miniscrew implant group.
  
  
  CONCLUSIONS
  The OPG and RANKL levels vary around loaded and unloaded miniscrew implants as a result of force application.
authors.affiliation: Department of Periodontology, Faculty of Dentistry, Izmir Katip Celebi University, Izmir, Turkey.
authors.forename: Sukru
authors.initials: S
authors.lastname: Enhos
authors.forename: Ilknur
authors.initials: I
authors.lastname: Veli
authors.forename: Omer
authors.initials: O
authors.lastname: Cakmak
authors.forename: Faruk Izzet
authors.initials: FI
authors.lastname: Ucar
authors.forename: Arzu
authors.initials: A
authors.lastname: Alkan
authors.forename: Tancan
authors.initials: T
authors.lastname: Uysal
mesh_terms: D000293:Adolescent; D003722:Dental Alloys / Q000737:chemistry; D015921:Dental Implants; D003764:Dental Materials / Q000737:chemistry; D005260:Female; D005500:Follow-Up Studies; D005883:Gingival Crevicular Fluid / Q000737:chemistry*; D006801:Humans; D008297:Male; D008904:Miniaturization; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D053244:Osteoprotegerin / Q000032:analysis*; D053245:RANK Ligand / Q000032:analysis*; D013193:Stainless Steel / Q000737:chemistry; D013314:Stress, Mechanical; D014025:Titanium / Q000737:chemistry; D014087:Tooth Movement Techniques / Q000295:instrumentation*
chemical_list: D003722:Dental Alloys; D015921:Dental Implants; D003764:Dental Materials; D053244:Osteoprotegerin; D053245:RANK Ligand; C506030:TNFRSF11B protein, human; C505688:TNFSF11 protein, human; D013193:Stainless Steel; D014025:Titanium