IN-VITRO LYMPHOCYTE-PROLIFERATION TEST IN THE DIAGNOSIS OF ORAL MUCOSAL HYPERSENSITIVITY REACTIONS TO DENTAL AMALGAM

Patch testing was carried out in 23 patients with oral lichenoid Lesio ns (OLL) topographically related to dental amalgam fillings. Twelve pa tients displayed positive reactions to several mercury compounds, wher eas 11 patients were negative. An in vitro lymphocyte proliferation (L yPro) test was carried out using different mercury compounds and other metal salts, Mercuric chloride and phenyl mercuric acetate caused pos itive proliferation in 3/12 patch test-positive and in 5/11 negative p atients. One out of seven healthy control subjects had a positive LyPr o result. The mean stimulation index (SI) values between the patient g roups or compared with the control subjects did not differ significant ly, Zinc, tin, copper or silver salts caused in vitro lymphocyte stimu lation in most of the patients and in healthy control people. Total (1 4) or partial (4) replacement of amalgam fillings was carried out in 1 8 patients, Complete healing of lichenoid lesions was seen in 4/6 LyPr o test-positive and in 5/10 patch test-positive patients at followup e xaminations 12 months after the replacement of amalgam fillings. The i n vitro proliferation assay seems not to be a specific test for identi fying the patients who would benefit from amalgam replacement.