ALMOST every time someone has dental treatment, the dentist uses a drug or material characteristic of dentistry. This is obvious. But ask yourself this: are they safe?
We are all conditioned to trust our dentist to do their best, even me recently at Aspen Dental in Florida, USA. But then, are there any side effects of dental materials? Since these substances are not generally known to the public, how can one make a biological evaluation of them? This is especially true for Guyana, where 100 percent of the dental materials used are imported.
For many years, the dental profession worked mainly with rather inert (stable) materials that had limited contact with living tissue. The exception was dentures. The opportunity for local and systemic complications was therefore quite minimal. Now, materials and devices are being treated more like drugs. They must meet the safety and efficacy requirements of drugs and medical devices. For example, the Swedish government banned the use of silver (amalgam) fillings. This was after the whole world was using them for two centuries.
We in Guyana are fortunate in that we are relatively protected by restrictions on the manufacture of dental materials in countries like the United States and Britain. This cannot be said of dental materials originating in many Third World countries, including China, where the standardisation system does not require protracted testing before laboratories can release the materials to the market.
Since every dental drug and material is imported and local legislation does not currently regulate the use of any of these substances, dentists should be careful in their utilisation.
Certain dental materials, such as composite resin (used for anterior teeth fillings), are chemically active compounds and may have a detrimental effect on the pulp. Amalgam (silver filling material), because of its mercury content, and impression materials, because of their former lead content, also stimulated considerable interest.
Endodontic (root canal) therapy involves the most dangerous drugs in dentistry. Many of the medications used are very poisonous. The procedures require canal obturation with drugs and materials that remain in constant contact with living tissues.
The most common drug used in dentistry is lidocaine, which is used as a local anaesthetic mainly for extractions. The active ingredient is chemically similar to the illicit drug cocaine, but the part of the molecule which is toxic and causes addiction was removed.
Cocaine was discovered by the Incas, an indigenous tribe of South America, who used this extract from the coca plant to numb wounds on the skin. However, it was not until 1884 that Dr Carl Koller used cocaine medicinally as the first local anaesthetic.
It is interesting to note that even after nearly a century in which a weak solution of cocaine ceased to be used as an anaesthetic, Guyanese remain the only people that I know who refer to dental anaesthetic as cocaine.
Although we do not manufacture dental materials and drugs, there is a need to legislate and regulate their use. Biocompatibility is the keyword.
The history of the development of controls, standards, and guidelines began almost 500 years ago and is detailed chronologically to the present. An outline of the latest revised draft of the international document (ISO Technical Report No. 7405), completed recently for the harmonisation of human standards within the EC, has been presented.
The Bureau of Standards needs to include dental materials in its list of controlled drugs because “dental quacks” have a field day importing sub-standard materials from questionable sources. In fact, a way to eliminate these illegal practitioners is to restrict the availability of dental materials by making their possession illegal for people without a licence to practise dentistry.
There is such a law here in Guyana, but its implementation is difficult.
No amount of experimental study can guarantee absolute safety for any substance. However, toxicological investigations provide data from which reasonable projections and predictions can be made about the conditions under which the product can be safely used.
In today’s world, in which the development of a country is measured by how seriously it views standards, it would be a boost in this context for the authorities to examine this question.
