The bubble of saliva can be sialolith/salivary stone or sialadenitis
Discontinue or replace the dentures if causing allergy or irritation.Sialogram
will help to investigate the nature of salivary growth and treatment can be planned based on that.
The calcific deposits within the saliva has to be drained.
Maintain oral hygiene
Also consistency of salivary secretion has to be evaluated.
Take plenty of fluids and water.
Please do visit a dentist
for further reference.