title: Human epithelial tissue culture study on restorative materials.
abstract: OBJECTIVE
  Health condition of the gingival tissues contacting the surfaces of fixed prostheses is a result of multiple etiologic factors. The aim of the investigation discussed here was to evaluate the attachment and proliferation rate of cultured human epithelial cells on three commonly used restorative materials under in vitro conditions.
  
  
  METHODS
  Morphological and chemical structure of polished lithium-disilicate (IPS e.max Press, Ivoclar Vivadent AG, Germany), yttrium modified zirconium dioxide (5-TEC ICE Zirkon Translucent, Zirkonzahn GmbH Srl, Germany) and cobalt chromium alloy (Remanium star, Dentaurum GmbH & Co. KG, Germany) discs were examined by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and atomic force microscopy (AFM). Human epithelial cells harvested and cultured from one donor, were applied to investigate cell attachment (24h observation) and proliferation (72h observation) via dimethylthiazol-diphenyl tetrazolium bromide (MTT) and AlamarBlue(®) (AB) assays on control surface (cell-culture plate) and on the restorative materials (n=3×20 specimens/material).
  
  
  RESULTS
  SEM and AFM revealed typical morphology and roughness features for the materials. Zirconia presented significantly higher Ra value. EDS confirmed typical elements on the investigated restorative materials: lithium-disilicate (Si, O); Zirconia (Zi, Y, O); CoCr (Co, Cr, W). All surfaces except CoCr exhibited significant cell proliferation according to MTT and AB assays after 72h compared to 24h. Among the restorative materials, CoCr samples showed the highest cell attachment as indicated by MTT assay. AB results showed that attachment and proliferation of human epithelial cells is supported more on lithium-disilicate. Both assays indicated the lowest value for zirconia.
  
  
  CONCLUSIONS
  The results indicate that the restorative materials examined are equally suitable for subgingival restorations. Lithium-disilicate exhibited the best biocompatibility.
  
  
  CONCLUSIONS
  The examined materials are indicated for use in restorative procedures, directly contacting the sulcular epithelial tissues. Thus it is essential to monitor the biological acceptibility of these materials in order to better understand their clinical properties. The results indicate that Lithium-disilicate is a suitable material for such purposes.
authors.affiliation: Department of Operative and Esthetic Dentistry, Faculty of Dentistry, University of Szeged, Szeged, Hungary. Electronic address: andras.forster@me.com.
authors.forename: András
authors.initials: A
authors.lastname: Forster
authors.affiliation: Department of Oral Biology and Experimental Dental Research, Faculty of Dentistry, University of Szeged, Szeged, Hungary.
authors.forename: Krisztina
authors.initials: K
authors.lastname: Ungvári
authors.affiliation: Department of Oral Biology and Experimental Dental Research, Faculty of Dentistry, University of Szeged, Szeged, Hungary.
authors.forename: Ágnes
authors.initials: Á
authors.lastname: Györgyey
authors.affiliation: Department of Applied and Environmental Chemistry, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary; MTA-SZTE "Lendület" Porous Nanocomposites Research Group, Szeged, Hungary.
authors.forename: Ákos
authors.initials: Á
authors.lastname: Kukovecz
authors.affiliation: Department of Oral Biology and Experimental Dental Research, Faculty of Dentistry, University of Szeged, Szeged, Hungary.
authors.forename: Kinga
authors.initials: K
authors.lastname: Turzó
authors.affiliation: Department of Oral Surgery, Faculty of Dentistry, University of Szeged, Szeged, Hungary.
authors.forename: Katalin
authors.initials: K
authors.lastname: Nagy
mesh_terms: D000293:Adolescent; D000328:Adult; D001672:Biocompatible Materials / Q000494:pharmacology*; D002448:Cell Adhesion / Q000187:drug effects; D018929:Cell Culture Techniques; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D002858:Chromium Alloys / Q000737:chemistry; D004396:Coloring Agents; D003764:Dental Materials / Q000494:pharmacology*; D003776:Dental Porcelain / Q000737:chemistry / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects; D006801:Humans; D007202:Indicators and Reagents; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D009061:Mouth Mucosa / Q000166:cytology / Q000187:drug effects*; D010078:Oxazines; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties; D013778:Tetrazolium Salts; D013844:Thiazoles; D013997:Time Factors; D014966:Xanthenes; D055815:Young Adult; D015019:Yttrium / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D002858:Chromium Alloys; D004396:Coloring Agents; D003764:Dental Materials; C508050:IPS e.max Press; D007202:Indicators and Reagents; D010078:Oxazines; D013778:Tetrazolium Salts; D013844:Thiazoles; D014966:Xanthenes; C493120:lithia disilicate; C499362:yttria stabilized tetragonal zirconia; D003776:Dental Porcelain; C005843:resazurin; D015019:Yttrium; D015040:Zirconium; C022616:thiazolyl blue
keywords: AlamarBlue assay; Cobalt chromium alloy; Human epithelial cell culture; Lithium-disilicate; MTT assay; Zirconia