A longitudinal study on lung disease in dental technicians: what has changed after seven years?

Characterization of dental dust particles and their pathogenicity to respiratory system: a narrative review

OBJECTIVES

Dental professionals are exposed to large amounts of dust particles during routine treatment and denture processing. This article provides a narrative review to investigate the most prevalent dust-related respiratory diseases among dental professionals and to discuss the effects of dental dust on human respiratory health.

MATERIALS AND METHODS

A literature search was performed in PubMed/Medline, Web of Science, and Embase for articles published between 1990 and 2022. Any articles on the occupational respiratory health effects of dental dust were included.

RESULTS

The characterization and toxicity evaluation of dental dust show a correlation between dust exposure and respiratory system injury, and the possible pathogenic mechanism of dust is to cause lung injury and abnormal repair processes. The combination use of personal protective equipment and particle removal devices can effectively reduce the adverse health effects of dust exposure.

CONCLUSIONS

Dental dust should be considered an additional occupational hazard in dental practice. However, clinical data and scientific evidence on this topic are still scarce. Further research is required to quantify dust in the dental work environment and clarify its pathogenicity and potential toxicological pathways. Nonetheless, the prevention of dust exposure should become a consensus among dental practitioners.

CLINICAL RELEVANCE

This review provides dental practitioners with a comprehensive understanding and preventive advice on respiratory health problems associated with dust exposure.

ACR Appropriateness Criteria® Occupational Lung Diseases

Ordering the appropriate diagnostic imaging for occupational lung disease requires a firm understanding of the relationship between occupational exposure and expected lower respiratory track manifestation. Where particular inorganic dust exposures typically lead to nodular and interstitial lung disease, other occupational exposures may lead to isolated small airway obstruction. Certain workplace exposures, like asbestos, increase the risk of malignancy, but also produce pulmonary findings that mimic malignancy. This publication aims to delineate the common and special considerations associated with occupational lung disease to assist the ordering physician in selecting the most appropriate imaging study, while still stressing the importance of a multidisciplinary approach. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Dental Technicians' Pneumoconiosis

A 40-year-old female dental technician visited our hospital for the investigation of a chest X-ray abnormality. Chest computed tomography demonstrated centrilobular nodules and lung volume reduction, and her serum KL-6 level was elevated. A histological analysis of the specimens obtained on a surgical lung biopsy showed peribronchiolar fibrosis with pigmented macrophages and cholesterol clefts. An energy-dispersive X-ray analysis showed that these lung tissues contained some metals, including indium. The serum indium level was also elevated. We diagnosed this patient with pneumoconiosis caused by exposure to sandblasting certain dental metals. This is the first reported case of pneumoconiosis in a dental technician associated with exposure to indium.

Respiratory Systems of Dental Technicians Negatively Affected during 5 Years of Follow-Up

BACKGROUND

Dental laboratory technician is one of the professions in which dust exposure is frequently experienced and therefore the health of workers has to be monitored.

AIMS

In this study, changes in the pulmonary functions and of pneumoconiosis frequencies among dental technicians after five years were investigated by comparing the results of two screenings carried out in 2008 and 2013.

STUDY DESIGN

Cohort study.

METHODS

In 2008 and 2013, Provincial Health Directorate carried out two different health screenings covering all of the dental technicians working in dental laboratories in Denizli. In both screenings, a questionnaire was applied, with which socio-demographic and workplace properties of the technicians were obtained. In addition, Pulmonary function tests (PFT) and standard chest X-rays of the technicians were performed. The results of these two screenings were evaluated by a chest specialist, and physical examinations were performed as necessary. In 2013, technicians who had pathologies underwent computerized tomography (HRCT). In this study, the study group was composed of dental laboratory technicians that participated in both screenings (2008 and 2013) and the data obtained from the screenings were compared. The gathered data were analyzed using paired student-t and X(2) tests.

RESULTS

A total of 125 dental laboratory technicians participated in the two screenings. Overall, 92% of the technicians were male and the mean age of the participants was 35. Technicians were working for 9 hours a day, 6 days a week. Total exposure time was calculated to be around 41 thousand hours. Approximately 60% of workers were smokers. When the results of PFT were analyzed, 73% of the first evaluations were found to be normal; however, this ratio decreased to 51% in the second analysis five years later. In the second PFT measurement, compared to the first, there was a 23% decrease in the forced vital capacity (FVC) value, and a 15.7% decrease in forced expiratory volume in one second (FEV1). While restrictive disorder was found 25% in the first PFT evaluations, this ratio increased to 31% in the second PFT. When the radiological results were considered, 62% of the first X-ray results were found to be normal but this ratio decreased to 18% in 2013. While reticular/reticulonodular opacities were found in 11% of cases in 2008, it increased to 30% in 2013. Seven technicians were diagnosed with pneumoconiosis (5.6%).

CONCLUSION

Respiratory tracts of the technicians were negatively affected during the five year period. The number of pneumoconiosis cases (5.6%) shows that it is necessary to adopt comprehensive work health and safety precautions for laboratories.

Dental technician pneumoconiosis mimicking pulmonary tuberculosis: a case report

Background

Dental laboratory technicians are at risk of developing occupational respiratory diseases due to exposure to various potentially toxic substances in their working environment. Since 1939, few cases of silicosis among dental technician have been reported.

Case presentation

We illustrate a 38 year-old female, who worked in a dental laboratory for 20 years, initially treated as pulmonary tuberculosis and chronic necrotising aspergillosis without much improvement. Computed tomography guided lung biopsy and bronchoscopic transbronchial lung biopsy were performed. Lung tissue biopsies showed presence of refractile dental materials within the areas of histiocyte proliferation. The diagnosis of dental technician pneumoconiosis was obtained and our patient underwent pulmonary rehabilitation.

Conclusions

This case highlights the importance of obtaining a detailed occupational history in tuberculosis endemic area, as pulmonary tuberculosis is a great mimicker of other respiratory diseases.

Pneumoconiosis and respiratory problems in dental laboratory technicians: analysis of 893 dental technicians

OBJECTIVES

To explore the rate of pneumoconiosis in dental technicians (DTP) and to evaluate the risk factors.

MATERIAL AND METHODS

Data of 893 dental technicians, who were admitted to our hospital in the period January 2007-May 2012, from 170 dental laboratories were retrospectively examined. Demographic data, respiratory symptoms, smoking status, work duration, working fields, exposure to sandblasting, physical examination findings, chest radiographs, pulmonary function tests and high-resolution computed tomography results were evaluated.

RESULTS

Dental technicians' pneumoconiosis rate was 10.1% among 893 cases. The disease was more common among males and in those exposed to sandblasting who had 77-fold higher risk of DTP. The highest profusion subcategory was 3/+ (according to the International Labour Organization (ILO) 2011 standards) and the large opacity rate was 13.3%.

CONCLUSIONS

To the best of our knowledge, it was the largest DTP case series (N = 893/90) in the literature in English. Health screenings should be performed regularly for the early diagnosis of pneumoconiosis, which is an important occupational disease for dental technicians.