ORAL LICHEN-PLANUS LESIONS IN CONTACT WITH AMALGAM FILLINGS - A CLINICAL, HISTOLOGIC, AND IMMUNOHISTOCHEMICAL STUDY

Fifty-one consecutive patients had clinically diagnosed oral lichen pl anus (OLP) lesions in total or partial contact with amalgam fillings. The clinical features of the OLP lesions were characterized and regist ered, and biopsies were obtained from each OLP lesion. Histologic and immunohistochemical studies were performed, as well as tests for aller gy to dental materials. The clinical diagnosis of OLP corresponded to the World Health Organization (WHO) morphologic OLP criteria in 31 (61 %) cases. The remaining lesions were histologically diagnosed as mild OLP in 11 (22%) or as benign oral keratosis in nine (17%) cases. The i mmunohistochemical examination showed a positive reaction to fibrinoge n in the basement membrane zone (BMZ) in 10 (20%) patients and to comp lement C3 in one (2%) patient. No positive reactions in the BMZ were f ound for IgA, IgG, and IgM. In 17 (33%) patients, an allergic reaction to mercury was found, and candidiasis was diagnosed in 13 (25%) patie nts. The true nature of OLP-like lesions in contact with amalgam filli ngs still remains to be explained. For that matter, we do not know whe ther OLP is one disease or a number of similar immunologic or other re sponses to various interacting stimuli. One such stimulus might be mer cury from corroding amalgam fillings.