title: Cytotoxic evaluation of hydroxyapatite-filled and silica/hydroxyapatite-filled acrylate-based restorative composite resins: An in vitro study.
abstract: BACKGROUND
  Although the physical and mechanical properties of hydroxyapatite-filled dental restorative composite resins have been examined, the biocompatibility of these materials has not been studied in detail.
  
  
  OBJECTIVE
  The purpose of this in vitro study was to analyze the toxicity of acrylate-based restorative composite resins filled with hydroxyapatite and a silica/hydroxyapatite combination.
  
  
  METHODS
  Five different restorative materials based on bisphenol A-glycidyl methacrylate (bis-GMA) and tri-ethylene glycol dimethacrylate (TEGDMA) were developed: unfilled (H0), hydroxyapatite-filled (H30, H50), and silica/hydroxyapatite-filled (SH30, SH50) composite resins. These were tested for in vitro cytotoxicity by using human bone marrow mesenchymal stromal cells. Surface morphology, elemental composition, and functional groups were determined by scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), and Fourier-transformed infrared spectroscopy (FTIR). The spectra normalization, baseline corrections, and peak integration were carried out by OPUS v4.0 software.
  
  
  RESULTS
  Both in vitro cytotoxicity results and SEM analysis indicated that the composite resins developed were nontoxic and supported cell adherence. Elemental analysis with EDX revealed the presence of carbon, oxygen, calcium, silicon, and gold, while the presence of methacrylate, hydroxyl, and methylene functional groups was confirmed through FTIR analysis.
  
  
  CONCLUSIONS
  The characterization and compatibility studies showed that these hydroxyapatite-filled and silica/hydroxyapatite-filled bis-GMA/TEGDMA-based restorative composite resins are nontoxic to human bone marrow mesenchymal stromal cells and show a favorable biologic response, making them potential biomaterials.
authors.affiliation: Senior Research Fellow, Centre for Polymer Science and Engineering, Indian Institute of Technology Delhi, New Delhi, India.
authors.forename: Harshita
authors.initials: H
authors.lastname: Chadda
authors.affiliation: Postdoctoral Research Fellow, Tissue Engineering Group, National Orthopaedic Centre of Excellence in Research and Learning, Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Sangeetha Vasudevaraj
authors.initials: SV
authors.lastname: Naveen
authors.affiliation: Graduate student, Tissue Engineering Group, National Orthopaedic Centre of Excellence in Research and Learning, Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Saktiswaren
authors.initials: S
authors.lastname: Mohan
authors.affiliation: Associate Professor, Centre for Polymer Science and Engineering, Indian Institute of Technology Delhi, New Delhi, India. Electronic address: bhabaniks@gmail.com.
authors.forename: Bhabani K
authors.initials: BK
authors.lastname: Satapathy
authors.affiliation: Professor, Centre for Biomedical Engineering, Indian Institute of Technology Delhi, New Delhi, India.
authors.forename: Alok R
authors.initials: AR
authors.lastname: Ray
authors.affiliation: Deputy director (professional/clinical), University of Malaya Medical Centre, Kuala Lumpur, Malaysia.
authors.forename: Tunku
authors.initials: T
authors.lastname: Kamarul
mesh_terms: D000179:Acrylates / Q000009:adverse effects / Q000627:therapeutic use; D001854:Bone Marrow Cells / Q000187:drug effects; D003188:Composite Resins / Q000009:adverse effects* / Q000737:chemistry / Q000627:therapeutic use; D017886:Durapatite / Q000009:adverse effects* / Q000627:therapeutic use; D006801:Humans; D066298:In Vitro Techniques; D059630:Mesenchymal Stem Cells / Q000187:drug effects; D008855:Microscopy, Electron, Scanning; D012822:Silicon Dioxide / Q000009:adverse effects / Q000627:therapeutic use; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000179:Acrylates; D003188:Composite Resins; D012822:Silicon Dioxide; D017886:Durapatite; C036658:acrylic acid