title: New nanostructural biomaterials based on active silicate systems and hydroxyapatite: characterization and genotoxicity in human peripheral blood lymphocytes.
abstract: OBJECTIVE
  To characterize and investigate the genotoxic effect of a new endodontic cement based on dicalcium- and tricalcium-silicate (CS) with hydroxyapatite (HA) on human lymphocytes.
  
  
  METHODS
  Hydrothermal treatment was applied for synthesis of CS and HA. The final mixture HA-CS, with potential to be used in endodontic practice, is composed of CS (34%) and HA (66%). Human lymphocytes were incubated with HA, HA-CS and CS for 1 h, at 37 °C and 5% CO2. Cell viability was determined using the trypan blue exclusion assay. To evaluate the level of DNA damage comet assay (single cell gel electrophoresis) was performed. For the statistical analysis anova and Duncan's Post Hoc Test were used.
  
  
  RESULTS
  The SEM analysis indicated that CS consisted mostly of agglomerates of several micrometers in size, built up from smaller particles, with dimensions between 117 and 477 nm. This is promising because dimensions of agglomerates are not comparable with channels inside the cell membranes, whereas their nano-elements provide evident activity, important for faster setting of these mixtures compared to MTA. Values of DNA damage obtained in the comet assay indicated low genotoxic risk of the new endodontic materials.
  
  
  CONCLUSIONS
  The significantly improved setting characteristics and low genotoxic risk of the new material support further research.
authors.affiliation: Department for Restorative Dentistry and Endodontics, School of Dental Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: V
authors.initials: V
authors.lastname: Opačić-Galić
authors.forename: V
authors.initials: V
authors.lastname: Petrović
authors.forename: S
authors.initials: S
authors.lastname: Zivković
authors.forename: V
authors.initials: V
authors.lastname: Jokanović
authors.forename: B
authors.initials: B
authors.lastname: Nikolić
authors.forename: J
authors.initials: J
authors.lastname: Knežević-Vukčević
authors.forename: D
authors.initials: D
authors.lastname: Mitić-Ćulafić
mesh_terms: D001672:Biocompatible Materials / Q000633:toxicity*; D017610:Calcium Compounds / Q000138:chemical synthesis / Q000633:toxicity*; D002245:Carbon Dioxide / Q000737:chemistry; D018929:Cell Culture Techniques; D002470:Cell Survival / Q000187:drug effects; D020552:Comet Assay; D004249:DNA Damage / Q000235:genetics; D017886:Durapatite / Q000138:chemical synthesis / Q000633:toxicity*; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects*; D008297:Male; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D009152:Mutagenicity Tests; D009153:Mutagens / Q000633:toxicity*; D053758:Nanoparticles / Q000633:toxicity*; D012387:Root Canal Filling Materials / Q000138:chemical synthesis / Q000633:toxicity*; D017640:Silicates / Q000138:chemical synthesis / Q000633:toxicity*; D013052:Spectrometry, X-Ray Emission; D013696:Temperature; D013997:Time Factors; D014961:X-Ray Diffraction; D055815:Young Adult
chemical_list: D001672:Biocompatible Materials; D017610:Calcium Compounds; D009153:Mutagens; D012387:Root Canal Filling Materials; D017640:Silicates; C013481:dicalcium silicate; D002245:Carbon Dioxide; C506393:tricalcium silicate; D017886:Durapatite