MORE than 90 percent of the times that someone has dental treatment, the attending dentist uses a drug or material characteristic to dentistry. But ask yourself this, are they safe? 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 a limited contact with living tissue (except dentures). The opportunity for local and systemic complications was therefore minimal. Now dental materials and devices are being treated more like drugs and have to meet the safety and efficacy requirements of drugs and medical devices. The government of Sweden banned amalgam (silver) fillings. This was after the whole world has been using it for nearly two centuries. A few years ago, I stopped using amalgam as a filling material in my clinic.

We in Guyana are fortunate in the sense that we are relatively protected by restrictions existent for the manufacture of dental materials in some countries like the United States and Britain. This cannot be said for dental materials originating in many Third World countries, where the standardisation system does not require protracted testing before the laboratories can release the materials on the market. Since every single dental drug and material is imported and because local legislation at the present time does not regulate in any way the use of any of these substances, dentists should be careful about 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. The majority of the medications used are very poisonous. The procedures require canal obtrusion 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 anesthetic 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 actually 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 anesthetic. It is interesting to note that even after the nearly a century in which a weak solution of cocaine ceased to be used for anesthetic, Guyanese remain the only people that I know who refer to dental anesthetic as cocaine.

Despite the fact that we do not manufacture dental materials and drugs there is 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 in a chronological fashion up to the present time. An outline of the revised draft of the International document (ISO Technical Report No. 7405), completed for the harmonisation of human standards within the EC was presented. The Bureau of Standards needs to include dental materials on its list of controlled drugs because “dental quacks” have a field day in importing sub-standard materials from questionable sources. In fact, a way to eliminate these illegal practitioners is to restrict the availability of dental material, by making its possession illegal for persons not licensed to practice dentistry.

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 serious it views standards, it would be a boost in this context for the authorities to examine this question.