title: Cytocompatibility of HEMA-free resin-based luting cements according to application protocols on dentine surfaces.
abstract: OBJECTIVE
  To evaluate the transdentinal cytotoxicity of resin-based luting cements (RBLCs), with no HEMA in their composition, to odontoblast-like cells.
  
  
  METHODS
  Human dentine discs 0.3 mm thick were adapted to artificial pulp chambers (APCs) and placed in wells of 24-well plates containing 1 mL of culture medium (DMEM). Two categories of HEMA-free RBLCs were evaluated: group 1, self-adhesive Rely X Unicem (RU; 3M ESPE), applied directly to the dentine substrate; and group 2, Rely X ARC (RARC; 3M ESPE), applied to dentine previously acid-etched and treated with a bonding agent. In group 3 (control), considered as representing 100% cell metabolic activity, no treatment was performed on dentine. The APC/disc sets were incubated for 24 h or 7 days at 37 °C and 5% CO2 . Then, the extracts (DMEM + dental materials components that diffused through dentine) were applied to cultured odontoblast-like MDPC-23 cells for 24 h. After that, the cell viability (MTT assay), cell morphology (SEM), total protein production (TP) and alkaline phosphatase (ALP) activity were assessed. Data from MTT assay and TP production were analysed by Kruskal-Wallis and Mann-Whitney tests (α = 5%). Data from ALP activity were analysed by one-way anova and Tukey's test (α = 5%).
  
  
  RESULTS
  In group 1, a slight reduction in cell viability (11.6% and 16.8% for 24-h and 7-day periods, respectively) and ALP activity (13.5% and 17.9% for 24-h and 7-day periods, respectively) was observed, with no significant difference from group 3 (control) (P > 0.05). In group 2, a significant reduction in cell viability, TP production and ALP activity compared with group 3 (control) occurred (P < 0.05), regardless of incubation time. Alteration in MDPC-23 cell morphology was observed only in group 2.
  
  
  CONCLUSIONS
  HEMA-free Rely X ARC cement caused greater toxicity to odontoblast-like MDPC-23 cells than did Rely X Unicem cement when both resin-based luting materials were applied to dentine as recommended by the manufacturer.
authors.affiliation: Department of Physiology and Pathology, Araraquara School of Dentistry, Universidade Estadual Paulista - UNESP, Araraquara, São Paulo, Brazil.
authors.forename: D G
authors.initials: DG
authors.lastname: Soares
authors.affiliation: Department of Dentistry, Paulista University, Goiânia, Goiás, Brazil.
authors.forename: C A
authors.initials: CA
authors.lastname: Brito
authors.affiliation: Department of Dental Materials and Prosthodontics, Araraquara School of Dentistry, Universidade Estadual Paulista - UNESP, Araraquara, São Paulo, Brazil.
authors.forename: R H B
authors.initials: RH
authors.lastname: Tavares da Silva
authors.affiliation: Department of Dentistry, Federal University of Brasilia, Brasilia, Campus Universitario Darcy Ribeiro, Brazilia, Brazil.
authors.forename: A P D
authors.initials: AP
authors.lastname: Ribeiro
authors.affiliation: Department of Orthodontics and Pediatric Dentistry, Araraquara School of Dentistry, Universidade Estadual Paulista - UNESP, Araraquara, São Paulo, Brazil.
authors.forename: J
authors.initials: J
authors.lastname: Hebling
authors.affiliation: Department of Physiology and Pathology, Araraquara School of Dentistry, Universidade Estadual Paulista - UNESP, Araraquara, São Paulo, Brazil.
authors.forename: C A
authors.identifier: http://orcid.org/0000-0002-7455-6867
authors.initials: CA
authors.lastname: de Souza Costa
mesh_terms: D000469:Alkaline Phosphatase / Q000187:drug effects / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003738:Dental Cements / Q000009:adverse effects / Q000627:therapeutic use*; D003804:Dentin / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D009804:Odontoblasts / Q000187:drug effects; D011506:Proteins / Q000378:metabolism; D012117:Resins, Synthetic / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D003738:Dental Cements; D011506:Proteins; D012117:Resins, Synthetic; D000469:Alkaline Phosphatase
keywords: cell culture; cytotoxicity; dentine; resin-based cements