Diagnosis of pneumoconiosis was made in 2 dental technicians presenting with interstitial lung disease. The occupational origin of inhaled dust was confirmed by mineralogic analyses, which disclosed mainly large amounts of chromium-cobalt-molybdenum particles originating from Vitallium prostheses, but also showed abrasives (silica and silicon carbide) and asbestos in 1 patient. The presence of Vitallium and its chemical stability in bronchoalveolar lavage and lung several years after cessation of exposure confirm the resistance of this alloy to corrosion by body fluids. This contrasts with the high solubility of cobalt described in cobalt or hard metal disease. We suggest that dental technician's pneumoconiosis is a complex pneumoconiosis distinct from silicosis, asbestosis, or hard metal disease and that Cr-Co-Mo alloys play a role in its pathogenesis.