Electron microscopic analysis of the effects of chemical retraction agents on cultured rat keratinocytes☆☆☆★★★

Abstract 

Statement of Problem. Chemical retraction agents used in fixed prosthodontics for temporary displacement of free gingival tissue before impression making can cause injury to the gingival tissue cells. Purpose. This study evaluated changes in cultured rat keratinocytes treated with 2 chemical agents used for gingival retraction. Treated cultures were compared with untreated cultures. Material and Methods. Keratinocytes of rat gingiva were grown in a specific medium for 10 days. After treating 1 group of specimens with 0.05% tetrahydrozoline and another group with 25% aluminum chloride, both for 10 minutes, the cultured cells were examined with scanning and transmission electron microscopy and compared with control specimens. Results. Twenty-five percent aluminum chloride produced a significantly greater extent of cellular damage than 0.05% tetrahydrozoline, which caused only mild changes in the cultured cells. Conclusion. On the basis of the morphologic and ultrastructural changes in primary cell cultures of rat keratinocytes observed in this study, it was concluded that 25% aluminum chloride was significantly more aggressive than 0.05% tetrahydrozoline.(J Prosthet Dent 2002;87:51-6.)