Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain slimy or pasty feeling in mouth that does not go away and also having a dental history of wearing dentures seems to be yeast infection known as
oral thrush.
You should consult an Oral Physician and get evaluated and a thorough clinical evaluation and microscopic examination of the coating can help in confirming the diagnosis..
You should take a course of anti
fungal medication like
Nystatin mouthwash and anti-fungal lozenges and taking more of probiotics like Yoghurt and garlic.
Drink plenty of water, avoid anti-microbial mouthwash and chew sugar free chewing gums as it will stimulate saliva flow..
Properly disinfect and clean your dentures and limit the hours for which you wear the dentures..
Always remove the denture at night and when you wear in the morning clean it well..
Hope this information helps..
Thanks and regards.
Dr. Honey Nandwani Arora.