Do dental diseases resemble ecological catastrophes?

Abstract

Ecological catastrophes can take many forms, and can come in all shapes and sizes! Nitrogenous fertilisers can be washed off farm-land into lakes and ponds, resulting in overgrowth by algae. Such an overgrowth can lead to secondary effects to the ecosystem; the algae can consume dissolved oxygen in the water leading to the loss of aerobic microbial, plant and insect life (eutrophication). Similarly, atmospheric pollution with sulphur dioxide and nitrogen oxides can produce acid rain causing damage to plants and trees and loss of aquatic life. On a larger scale, it has been postulated that the extinction of the dinosaurs followed climate change resulting from the impact of a meteorite. At the other end of the spectrum, it will be argued in this article that the key to a more complete understanding of the role of micro-organisms in dental diseases depends on a paradigm shift away from concepts that have evolved from studies of diseases with a simple and specific (e.g. single species) aetiology to an appreciation of ecological principles similar to those outlined above, where a substantial change to a key parameter influencing the habitat can disrupt the natural balance of the resident oral microflora. Acceptance of such principles can more readily explain the transition of the oral microflora from having a benign to a pathogenic relationship with the host, while opening up new opportunities for the control of dental plaque-mediated diseases.