AMALGAM-ASSOCIATED ORAL LICHENOID REACTIONS - CLINICAL AND HISTOLOGIC-CHANGES AFTER REMOVAL OF AMALGAM FILLINGS

Objective and study design. Forty-nine consecutive patients with clini cally diagnosed oral lichenoid reactions in contact with amalgam filli ngs were studied clinically and histologically. The long-term effect o f replacement of these fillings was also examined. Results. Seventeen (35%) patients showed positive reactions to mercury at the epicutaneou s patch test that was carried out before treatment. After treatment, t otal regression of the lesions was found clinically in 33 (69%) and hi stologically in 26 (55%) patients. Most of the remaining lesions chang ed clinically and histologically to a less pronounced tissue reaction. Lesions in direct contact with amalgam fillings (group I) showed sign ificantly better healing results than lesions that exceeded the contac t area (group II). No difference in healing capacity was noted in the two groups between patients with positive patch reactions to mercury c ompared with those with negative reactions. Lesions that histologicall y were classified as benign oral keratosis showed a similar healing pa ttern as those classified as oral lichen planus. Conclusion. In group I all lesions changed histologically and clinically to a normal mucosa or to a less affected tissue reaction. In group II this change was le ss pronounced, which suggests that the fillings themselves were not th e only factor involved in the cause of these lesions. The results sugg est that various etiologic factors are involved in lichenoid reactions and that the effect of removal of amalgam fillings cannot be predicte d by epicutaneous patch testing and biopsies.