Polishing-paste-induced silica granuloma of the gingiva

Polishing-paste-induced silica granuloma of the gingiva, an uncommon condition, may mimic various local or systemic pathological entities. A 33-year-old woman and a 42-year-old man were referred for a localised refractory gingival inflammation. Clinical diagnoses included allergy, lichen planus and herpes. Biopsy showed well-demarcated non-caseating granulomas, associating epithelioid and Langhans giant cells. Special bacterial and mycological stains were negative. Systemic examination and laboratory tests ruled out sarcoidosis and Crohn's disease. Polarised light revealed birefringent crystalline foreign material. A diagnosis of silica granuloma was made. Both patients had frequent dental hygiene treatment including polishing with abrasive paste, suggesting an iatrogenic implantation of the foreign bodies. Gingival damage can result from the use of some dental materials containing silica. Often asymptomatic, sometimes producing visible lesions, granulomatous gingivitis may mislead into wrong diagnosis and treatment. Old silica granulomas may become symptomatic if the patient contracts sarcoidosis.