RESUMO

INTRODUCTION: The aim of this report is to present a clinical case of oral lichenoid lesions associated with amalgam restorations with the presence of desquamative gingivitis for a nine months follow up period. CASE REPORT: The histopathologic characteristics and direct immunofluorescence were compatible with Oral Lichenoid Lesion (LLO). Diagnosis was based on a synthesis of all available information, including medical history, clinical examination, histopathology and the results of specific tests, such as the patch test, which confirmed allergy to thimerosal, an organic compound of mercury. DISCUSSION: The replacement of amalgam restorations has brought improvements to the instrument, as evidenced by the disappearance of desquamative gingivitis, aspect erythematosus and erosive lesions. The fading does not complete the same, however, indicates the need to continue has been under continuous observation, the patient, having in view the possibility of the existence of an underlying lichen planus.