Brushing and tooth paste are not necessary. But other methods of oral hygiene maintenance must be employed (rinsing, mouthwash, massaging gums etc)

As ther are no teeth, the need for bristle action is gone, there are no nooks or crevices, Hence the need for brushing teeth is lost. Said that there are still plenty of places food can get accumulated and can cause irritation of the gums. So regular mouth rising and tongue cleaning is necessary.

Your doubt is good but understand there is no replacement for mechanical cleaning... Brush and paste are made with the purpose of enhancing mechanical scrub action and create foam which will further clean and make you feel fresh... So if some one is not having any teeth... first point is get dentures or implants done asap as they will improve Chewing and further reduce stress on stomach and intestine of overwork ( digestion ) So better use your fingure and any paste or powder to massage n scrub and clean entire mouth like palate, gums, lips, cheek area and most IMP tongue... I hope this clears your doubt Further understanding replacement visit - https://www.ar32.in/Dental-Treatments/dental-denture.html

Hello, no need for brushing but mouthwash twice daily.

Hello No need of brush and paste ,but u have to mouthwash twice daily