title: In vitro oxidative stress induced by conventional and self-ligating brackets.
abstract: OBJECTIVE
  To determine the in vitro oxidative stress induced by conventional and self-ligating brackets made of different materials.
  
  
  METHODS
  The concentration of oxidative stress marker 8-hydroxy-2'-deoxyguanosine (8-OHdG) in DNA of murine fibroblast cells L929 after in vitro exposure to three types of conventional and four types of self-ligating brackets was assessed. To determine viability and changes in the number of cells before and after exposure, trypan blue dye was used. Analysis of variance (ANOVA) was used for statistical analysis.
  
  
  RESULTS
  No significant difference in cell viability was noted between metal, ceramic, and polymeric conventional brackets, and self-ligating brackets made of combinations of those materials, but viability was significantly higher compared with positive controls (P < .05). The conventional sapphire ceramic bracket (Inspire Ice) showed high viability, the largest increase in the number of cells, and the lowest oxidative stress. A higher concentration of markers of oxidative stress was observed in full metal conventional and self-ligating brackets (MiniSprint and Speed) and in conventional polyurethane brackets (Quantum) compared with negative controls (P < .05).
  
  
  CONCLUSIONS
  All types of orthodontic brackets, regardless of the constituent materials, are a source of oxidative stress in vitro, but the highest stress was induced in the full metal and polyurethane brackets. Conventional ceramic brackets show the highest degree of biocompatibility compared with polymeric and metal brackets and self-ligating brackets made from combinations of these materials.
authors.affiliation: Department of Paediatric Dentistry and Orthodontics, School of Medicine, University of Rijeka, Rijeka, Croatia.
authors.forename: Zorana Ivankovic
authors.initials: ZI
authors.lastname: Buljan
authors.forename: Sonja Pezelj
authors.initials: SP
authors.lastname: Ribaric
authors.forename: Maja
authors.initials: M
authors.lastname: Abram
authors.forename: Ante
authors.initials: A
authors.lastname: Ivankovic
authors.forename: Stjepan
authors.initials: S
authors.lastname: Spalj
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000537:Aluminum Oxide / Q000494:pharmacology; D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D015415:Biomarkers / Q000032:analysis; D002452:Cell Count; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002516:Ceramics / Q000737:chemistry; D002858:Chromium Alloys / Q000494:pharmacology; D004396:Coloring Agents; D004247:DNA / Q000032:analysis; D003722:Dental Alloys / Q000494:pharmacology; D003764:Dental Materials / Q000494:pharmacology*; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000032:analysis; D005347:Fibroblasts / Q000187:drug effects*; D008422:Materials Testing; D051379:Mice; D009532:Nickel / Q000494:pharmacology; D016910:Orthodontic Brackets; D018384:Oxidative Stress / Q000187:drug effects*; D011076:Polycarboxylate Cement / Q000494:pharmacology; D011108:Polymers / Q000494:pharmacology; D011140:Polyurethanes / Q000494:pharmacology; D012238:Rhodium / Q000494:pharmacology; D013193:Stainless Steel / Q000494:pharmacology; D013997:Time Factors; D014025:Titanium / Q000494:pharmacology; D014343:Trypan Blue
chemical_list: D001672:Biocompatible Materials; D015415:Biomarkers; D002858:Chromium Alloys; D004396:Coloring Agents; D003722:Dental Alloys; D003764:Dental Materials; D011076:Polycarboxylate Cement; D011108:Polymers; D011140:Polyurethanes; C040654:titanium nickelide; D013193:Stainless Steel; C005506:polycarbonate; D009532:Nickel; D000080242:8-Hydroxy-2'-Deoxyguanosine; D004247:DNA; D014025:Titanium; D012238:Rhodium; D003849:Deoxyguanosine; D014343:Trypan Blue; D000537:Aluminum Oxide