title: In vitro studies on the cytotoxic potential of surface sealants.
abstract: OBJECTIVE
  The objective of this in vitro study was an initial screening of the cytotoxic potential of widely used smooth enamel surface sealants.
  
  
  METHODS
  A total of 20 products were allocated to four groups based on their chemical composition: (1) filled resin-based sealants, (2) unfilled resin-based sealants, (3) a resin-modified, glass ionomer-based sealant, and (4) silicone-based sealants. All materials were applied to human enamel slices both in accordance with manufacturers' instructions and in additional experiments applying 50% undercuring and 50% overcuring. An agar overlay assay was then used to test the specimens following ISO 10933. The cytotoxic potential of each material was interpreted based on a reaction index that summarized the decolorization and lysis scores obtained.
  
  
  RESULTS
  The cytotoxic potential decreased as follows: unfilled resin-based sealants > filled resin-based sealants > resin-modified, glass ionomer-based sealant > silicone-based sealants. In 75% of the resin-based products, deliberate undercuring was associated with more extensive decolorization zones, leading to higher rates of cytotoxic potential in two of those products. Overcuring, by contrast, was associated with a tendency for smaller decolorization zones in 50% of the resin-based products.
  
  
  CONCLUSIONS
  Surface sealants derived from resin monomers exhibited cytotoxic potential in the agar overlay assay. There is also evidence of a possible association with curing, as undercuring can increase the cytotoxic potential, whereas normal curing (as per manufacturers' instructions) or overcuring may help minimize such effects. More research into the biological implications of these materials is needed, especially with regard to their potential impact on the adjacent gingiva.
authors.affiliation: Department of Orthodontics, University of Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany, sebastian.zingler@med.uni-heidelberg.de.
authors.forename: S
authors.initials: S
authors.lastname: Zingler
authors.forename: B
authors.initials: B
authors.lastname: Matthei
authors.forename: A
authors.initials: A
authors.lastname: Kohl
authors.forename: D
authors.initials: D
authors.lastname: Saure
authors.forename: B
authors.initials: B
authors.lastname: Ludwig
authors.forename: K
authors.initials: K
authors.lastname: Diercke
authors.forename: C J
authors.initials: CJ
authors.lastname: Lux
authors.forename: R
authors.initials: R
authors.lastname: Erber
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003764:Dental Materials / Q000633:toxicity*; D005347:Fibroblasts / Q000187:drug effects* / Q000473:pathology*; D008422:Materials Testing / Q000379:methods; D051379:Mice; D010895:Pit and Fissure Sealants / Q000737:chemistry / Q000633:toxicity*; D018675:Toxicity Tests
chemical_list: D003764:Dental Materials; D010895:Pit and Fissure Sealants