Dental technologists spend much of their time in the lab creating cosmetic dental prostheses such as crowns and implants. This work creates dust and chemical fumes. Without proper protection, exposure to these may risk the health of the dental technologist.

The processes involved in building any kind of dental prosthesis have a number of stages where there is a potential health hazard to the dental technologist. First, the dentist makes a mould of the patient’s mouth or teeth which the dental technologist uses to make a plaster model. This is used to make up a metal framework for the prosthesis onto which porcelain is overlaid, using a sandblasting technique. After baking the metal-porcelain layers, there is grinding to achieve the required shape.

According to MMWR, occupational disease surveillance in five states found nine cases of silicosis among dental technologists. The case reports are revealing of the importance of protection against dust in the dental lab – as follows:

    Case 1 – worked 46 years in a dental lab, exposed to dust, cobalt and chemicals and never wore a respirator. Died of respiratory failure, pathology report showed silicosis.
    Case 2 – worked as dental technologist for 30 years, exposed to various mineral and metallic dusts. Pathology report showed silicosis, as well as asbestosis and beryllosis. Asbestosis is caused by exposure to asbestos which was once commonly used in the dental laboratory, while beryllosis is caused by exposure to the toxic metal beryllium which is a component of some of the alloys used in dental prostheses.
    Case 3 – died of renal failure, pathology showed silicosis. Worked for 28 years in dental labs and never wore a respirator or used an air cleaner for dental technicians, while exposed to various dusts when carrying out sandblasting processes.

A comment on this MMWR report notes that exposure to respirable crystalline silica in the dental lab occurs( dental lab equipment ) through procedures generating airborne dust such as:

    Mixing powders
    Removing castings from moulds
    Finding and polishing castings and porcelain
    Using silica sand for abrasive blasting.

In general, the smaller the particle the more likely it is to damage health. Of particular concern are the ultra-fine particles (UFPs) which have a size in the nano range – that is less than 0.1 microns, or 100 nanometres.

A recent study analysed the size range of particle which dental technologists may come into contact with during the course of their work. A number of blocks of composites used in dental prostheses were ground and the dust thus generated analysed. All of the composites released a certain amount of respirable dust. The size range of this dust extended down to the UFP level, showing that a potential health hazard exists in the dental laboratory setting.