There is a possibility that he may be allergic to what those certain dentures are made of. Though it is doubtful. Get a professional opinion, dear.
Hello,
The symptoms are suggestive of oral candidiasis.It appears as thick white or cream-coloured deposits on mucosal membranes.It is very common in denture users.It can be treated with topical anti-fungal drugs, such as nystatin, miconazole or amphotericin B. Topical therapy is given as an oral suspension which is washed around the mouth(swishes) and then swallowed by the patient. Severe cases may need oral antifungals.
I would suggest a dentist’s consultation and getting your husband prescribed topical antifungal medicines.
Hope it helps.Take care and pls do keep me posted on how your husband is doing.