Direct contact between tooth enamel and bacteria is currently considered a sine qua non of tooth decay. Any condition which encourages the deposit and accumulation of bacterial plaque represents a risk factor for tooth decay. Dental therapy often entails the use of bands or brackets which house metal apparatus used to apply force or support mobile devices (plates, etc.). It is therefore possible to hypothesise that, by preventing its mechanical removal, dental treatment can lead to quantitative and qualitative changes in bacterial plaque.