Dental technician's pneumoconiosis. A report of two cases

Our plain-English summary of Dental technician's pneumoconiosis. A report of two cases, by P. De Vuyst, R. Vande Weyer, A. De Coster, et al (The American Review of Respiratory Disease, 1986).

The study

• Authors: P. De Vuyst, R. Vande Weyer, A. De Coster, F.X. Marchandise, P. Dumortier, P. Ketelbant, J. Jedwab, J.C. Yernault
• Journal: The American Review of Respiratory Disease
• Published: 1986;133(2):316-20
• Type of article: Case report
• Cited by: 45 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 001156).

Abstract

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.

In plain English

This article, by authors from Brussels, Belgium, reported two cases of lung disease in dental technicians. Patient 1, a 49-year-old man, had worked as a dental technician since 1949, mainly shaping and polishing parts made of Vitallium, a chromium-cobalt-molybdenum alloy, with silicon carbide grinding wheels. He also cut asbestos foils used in casting. Patient 2, a 30-year-old woman, had sandblasted Vitallium parts half-time from 1972 to 1979 and had no known asbestos contact. Both had chest X-ray shadowing mainly in the upper lobes, and their biopsies showed fibrosis with dust deposits. Lung washings (bronchoalveolar lavage) from both patients, and lung tissue from Patient 1, contained mainly chromium-cobalt-molybdenum particles. Patient 1's samples also held silicon carbide, talc, chromium oxide and asbestos bodies: 22 and 68 per ml of lavage fluid, and 160 per gram of wet lung. Patient 2's lavage fluid held no asbestos bodies or fibers. The authors judged silicosis and asbestosis unlikely explanations. They suggested this is a distinct pneumoconiosis in which the alloy might play a central role, a hypothesis they said still needs experimental confirmation.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: case report (two patients) with mineralogic analyses of bronchoalveolar lavage fluid and lung tissue
• Who was studied: 2 dental technicians, reported by authors from hospitals and a geochemistry laboratory in Brussels, Belgium. The article does not state where the patients lived or worked. Patient 1 was a 49-year-old man evaluated in September 1980 who had been a dental technician since 1949. Patient 2 was a 30-year-old woman seen in September 1981 who had worked half-time in a dental laboratory from 1972 to 1979.
• Exposure: Dust from Vitallium (chromium-cobalt-molybdenum alloy) prosthetic parts in both patients. Patient 1 was also exposed to carborundum (silicon carbide) abrasive and to asbestos dust from cutting asbestos foils (fiber type not stated). Patient 2 had no known contact with asbestos or beryllium. No dust level measurements were made.
• Main results:
  • In both patients, mineralogic analyses found mainly large amounts of chromium-cobalt-molybdenum particles, attributed to Vitallium prostheses
  • Patient 1: asbestos bodies in bronchoalveolar lavage fluid, 22 AB/ml in sample 1 and 68 AB/ml in sample 2
  • Patient 1: 160 asbestos bodies per gram of wet lung in the lung tissue specimen
  • Patient 1: silicon carbide, talc, and chromium oxide were also present in large amounts
  • Patient 2: bronchoalveolar lavage fluid (her only sample analysed mineralogically) contained Vitallium, iron, iron-chromium and silica particles, but no asbestos bodies or fibers
  • Histologic appearance in both patients was fibrosis with dust deposits
  • Patient 1 stopped work in May 1982. One year later his chest X-ray showed progression of the disease and his lung function had deteriorated.
  • The chemical composition of the alloy particles had not changed 2 and 1 years after exposure ended
  • The authors judged silica probably not responsible on its own, because no typical silicotic nodules were found
  • The authors judged asbestosis not a likely diagnosis: no asbestos was found in Patient 2's lavage fluid, the X-ray pattern predominated in the upper lobes, and the asbestos body count in Patient 1 was low
• The authors' conclusion: The authors concluded that dental technician's pneumoconiosis is thought to be a real entity distinct from silicosis, hard metal disease, or asbestosis, and suggested that chromium-cobalt-molybdenum alloys might play a central role in causing it
• Limitations the authors state:
  • Beryllium cannot be detected by the authors' energy-dispersive X-ray method because of its low atomic number
  • No dust level measurements were made in Patient 1's workplace
  • The role of the alloy is a hypothesis that remains to be confirmed by experimental studies

Topics

Medical terms in this study, explained in our Lexicon: Pneumoconiosis, Interstitial Lung Disease, Bronchoalveolar Lavage (BAL), Silicosis.

Related studies

• Occupational lung diseases among dental technicians — D. Choudat (1994)
• Respiratory morbidity in a population of French dental technicians — S. Radi, J.C. Dalphin, et al. (2002)
• Exposure to methyl methacrylate and its subjective symptoms among dental technicians, Tehran, Iran — F. Golbabaei, M. Mamdouh, et al. (2005)
• Experimental infective pneumoconiosis: effect of asbestos dust and Candida albicans infection on the lungs of rhesus monkeys — S.H. Zaidi, R. Shanker, et al. (1973)
• Quantitative x ray microanalysis of pulmonary mineral particles in a patient with pneumoconiosis and two primary lung tumours — S. Anttila, S. Sutinen, et al. (1984)
• Pleural malignant mesothelioma in dental laboratory technicians: A case series — C. Mensi, F. Ciullo, et al. (2017)

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