title: Chemical, mechanical and biological properties of contemporary composite surface sealers.
abstract: OBJECTIVE
  To evaluate the chemical, mechanical, and biological properties of modern composite surface sealers (CSS) having different compositions.
  
  
  METHODS
  The CSS products tested were Biscover LV (BC), Durafinish (DF), G-Coat Plus (GC), and Permaseal (PS). The tests performed were: (A): degree of conversion (DC%) by ATR-FTIR spectroscopy; (B): thickness of O2-inhibition layer by transmission optical microscopy; (C): surface hardness, 10 min after irradiation and following 1 week water storage, employing a Vickers indenter (VHN); (D): color (ΔE*) and gloss changes (ΔGU) after toothbrush abrasion, using L*a*b* colorimetry and glossimetry; (E): accelerated wear (GC,PS only) by an OHSU wear simulator plus 3D profilometric analysis, and (F): cytotoxicity testing of aqueous CSS eluents on human gingival fibroblast cultures employing the methyl-(3)H thymidine DNA labeling method. Statistical analyses included 1-way (A, B, ΔE*, ΔGU) and 2-way (C, F) ANOVAs, plus Tukey post hoc tests. Student's t-test was used to evaluate the results of the accelerated wear test (α=0.05 for all).
  
  
  RESULTS
  The rankings of the statistical significant differences were: (A) PS (64.9)>DF,BC,GC (56.1-53.9) DC%; (B) DF,PS (12.3,9.8)>GC,BC (5.2,4.8) μm; (C): GC (37.6)>BC,DF (32.6,31.1)>PS (26.6) VHN (10 min/dry) and BC,DF (29.3,28.7)>GC(26.5)>PS(21.6) VHN (1w/water), with no significant material/storage condition interaction; (D): no differences were found among GC,DF,BC,PS (0.67-1.11) ΔE*, with all values within the visually acceptable range and PS,BC (32.8,29.4)>GC,DF (19.4,12.9) ΔGU; (E): no differences were found between GC and PS in volume loss (0.10,0.11 mm(3)), maximum (113.9,130.5 μm) and mean wear depths (30.3,27.5 μm); (F): at 1% v/v concentration, DF showed toxicity (23% vital cells vs 95-102% for others). However, at 5% v/v concentration DF (0%) and BC (9%) were the most toxic, whereas GC (58%) and PS (56%) showed moderate toxicity.
  
  
  CONCLUSIONS
  Important chemical, mechanical, and biological properties exist among the CSS tested, which may affect their clinical performance.
authors.affiliation: Department of Operative Dentistry, School of Dentistry, University of Athens, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Anagnostou
authors.affiliation: Department of Operative Dentistry, School of Dentistry, University of Athens, Greece.
authors.forename: George
authors.initials: G
authors.lastname: Mountouris
authors.affiliation: Biomaterials Science Research Group, School of Dentistry, University of Manchester, UK.
authors.forename: Nick
authors.initials: N
authors.lastname: Silikas
authors.affiliation: Laboratory of Cell Proliferation and Ageing, Institute of Biology, National Center for Scientific Research 'Demokritos', Athens, Greece.
authors.forename: Dimitris
authors.initials: D
authors.lastname: Kletsas
authors.affiliation: Department of Biomaterials, School of Dentistry, University of Athens, Greece. Electronic address: geliad@dent.uoa.gr.
authors.forename: George
authors.initials: G
authors.lastname: Eliades
mesh_terms: D000179:Acrylates / Q000737:chemistry* / Q000528:radiation effects / Q000633:toxicity; D003764:Dental Materials / Q000737:chemistry* / Q000528:radiation effects / Q000633:toxicity; D005347:Fibroblasts / Q000187:drug effects; D005881:Gingiva / Q000166:cytology; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D055595:Mechanical Phenomena; D020366:Methylmethacrylate; D019279:Resin Cements / Q000737:chemistry* / Q000528:radiation effects / Q000633:toxicity; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties
chemical_list: D000179:Acrylates; C481141:BisCover; D003764:Dental Materials; C000618616:DuraFinish; C000618651:G-Coat Plus; C000618652:PermaSeal; D019279:Resin Cements; D020366:Methylmethacrylate
keywords: Biocompatibility; Composite surface sealers; Curing; Hardness; Optical properties; Wear