title: In vitro cytotoxicity of orthodontic primers.
abstract: OBJECTIVE
  The aim of this study was to evaluate the cytotoxicity of four orthodontic primers: Transbond XT and Transbond MIP (3M, USA), Eagle Fluorsure (American Orthodontics, USA) and Ortho Solo (Ormco, USA).
  
  
  METHODS
  Balb 3T3 cells were exposed to different concentrations of primers (0-0.25 mg/ml). Mitochondrial dehydrogenase activity was evaluated by MTT assay and cell necrosis was measured by flow cytometry (propidium iodide staining).
  
  
  RESULTS
  All the materials decreased cell viability in a dose related manner. Cytotoxicity of orthodontic primers based on concentrations which caused a 50% decrease of mitochondrial activity was ranked as follows: Transbond XT (45.57 mg/ml) > Eagle Fluorsure (49.27 mg/ml) > Transbond MIP (64.35 mg/ml) > Ortho solo (70.09 mg/ml).
  
  
  CONCLUSIONS
  Our results suggest that the cytotoxic potencies demonstrated by orthodontic primers might be of clinical relevance since they disturbed cell metabolism and induced cell death in monolayer cultures.
authors.affiliation: Institue of Composite and Biomedical Materials - Naples, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: D'Antò
authors.forename: Gianrico
authors.initials: G
authors.lastname: Spagnuolo
authors.forename: Ilaria
authors.initials: I
authors.lastname: Polito
authors.forename: Sergio
authors.initials: S
authors.lastname: Paduano
authors.forename: Luigi
authors.initials: L
authors.lastname: Ambrosio
authors.forename: Rosa
authors.initials: R
authors.lastname: Valletta
mesh_terms: D000818:Animals; D041702:BALB 3T3 Cells; D016923:Cell Death / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004396:Coloring Agents; D017220:Dentin-Bonding Agents / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000633:toxicity; D005434:Flow Cytometry; D008422:Materials Testing; D008689:Methacrylates / Q000633:toxicity; D051379:Mice; D008928:Mitochondria / Q000201:enzymology; D009336:Necrosis; D010088:Oxidoreductases / Q000187:drug effects; D019279:Resin Cements / Q000633:toxicity*; D013778:Tetrazolium Salts; D013844:Thiazoles
chemical_list: D004396:Coloring Agents; D017220:Dentin-Bonding Agents; D008689:Methacrylates; C508972:OrthoSolo; D019279:Resin Cements; D013778:Tetrazolium Salts; D013844:Thiazoles; C477790:Transbond XT; C458821:Transbond moisture-insensitive primer; D000431:Ethanol; D010088:Oxidoreductases; C022616:thiazolyl blue