ATLA::Alternatives to Laboratory Animals

Volume 25, Number 3

An ultrastructural evaluation of the SKIN²™ ZK1200 system as an in vitro model of the human oral mucosa.

ATLA 25, 263-270, May/June 1997

Dorthe Arenholt-Bindslev,1 Lis Andersen Torpet2 and Kaj Josephsen1

1Department of Dental Pathology, Operative Dentistry and Endodontics, Royal Dental College, Faculty of Health Sciences, University of Aarhus, Vennelyst Boulevard 9, 8000 Aarhus C, Denmark; 2Department of Oral Pathology, School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Norre Allé 20, 2200 Copenhagen N, Denmark

SUMMARY

At present, there are no validated experimental models for the preclinical oral mucosa irritancy screening of dental materials and oral hygiene products. Standardised in vitro models for the assessment of skin irritancy have been marketed, and have made possible the application of such models in preclinical skin irritancy testing. Some of these are currently undergoing international interlaboratory validation. The aim of the present study was to evaluate the histology of the commercially available SKIN²™ ZK1200 system as a potential in vitro model of the human oral mucosa. Histological evaluation by light microscopy and transmission electron microscopy over 6 days revealed a fibroblast-rich matrix covered by an 8-12 cell layer of stratifying epithelium, which shared a number of basic characteristics with non-keratinised human oral mucosa (for example, desmosomes, dispersed tonofilaments, glycogen deposits, membrane-coating granules, and keratohyalin granules, both the spherical and ribosome-associated types). Exposure to a methacrylate-based dental fissure sealant for 24 hours caused structural changes in the epithelium which were not reflected by a cytochemical cytotoxicity assay (MTT).

Keywords: SKIN²™ ZK1200, oral mucosa model, differentiation, oral mucosa irritancy, fissure sealant, cytotoxicity.