Over the years you have built up tartar inside yours gums, the tartar contains bacterias, the effects from this infection produces a gum inflammation, sometimes with bleeding gums and secondly and the most important, losing bone teeth support.
All this damage produced without important symptoms, but at the end you will have different problems like gums boils, tooth ache, and progressive movements of your teeth that end up falling out.
The treatment at the different stages of the process is basically to clean the root surface with different technicals systems.
The first step, the easiest, is to have a correct hygiene at home and combine it with a professional cleaning at the dentist every six month or when necessary.