Gingivitis and Brushing of Teeth

To keep our gums healthy and to avoid dental caries, we are instructed by our dentists with reinforcment from family members to brush our teeth regularly preferably daily. I have personally noted that even omitting brushing for a day can result it the development on a visible film at the baseline between the gums and teeth. This film can become quite prominent if brushing is omitted for a period of several days. On restarting brushing there often is some bleeding of the gums suggesting the presence of early gingivitis.

Could brushing be a cause rather than a preventer of gingivitis by a mechanism whereby the antiseptics and/or antibiotics present in the toothpaste kill off the natural flora in the mouth which would have killed those bacteria which produce the film, the acid which is believed to predispose teeth to decay, and even the gingivitis ?. Such iatrogenic diseases are common in medical practice. For example when we see our physicians for flu-like symptoms and the doctors prescribe antibiotics to kill the bacteria causing the infection, by killing off the natural saprophytic organisms, say in the gut, it could result in the introduction into the gut of specific drug resistant pathogenic micro-organisms In medicine we call this an iatrogenic disease.
In the 1950s in Edmonton while working as a plant pathologist with the Canadian Department of Agriculture, I hypothesized that the amino acids secreted and/or excreted into the rhizophere ( the regions around the roots ) by the cereals themselves resulted in a selection of those strains of the microbial pathogen Helminthosporium sativum which were less virulent.
Although I did demonstrate that a cytological mechanism existed for such a selective mechanism for this fungal pathogen, no cultural studies were done at the time to demonstrate " Koch's" postulate requirements for pathogenecity.
In the case of gingivitis similar investigations would be required to demonstrate that brushing produced gingivitis and even pyorrhoea before we could call brushing with toothpaste an iatrogenetic disease.