Hello & welcome,
First & most important thing here is, just go for check up of your newly made Denture. This is so because, denture if over extended on palatal side, causes feeling of nausea
thereby leading to dizziness
Although this nausea & dizziness can be due to gastric irritation by the antibiotics taken by you, checking denture for over extension will be primary advise.
And if denture is found overextended, then can be treated by grinding & reducing extension of the denture to proper limits by your dentist
Absolutely, oral infection & brain has nothing to do with each others.
Tooth extraction can cause pain but not nausea.
You should not wear your denture if there is any residual infection in extraction socket which should be treated immediately.
You can undergo blood sugar examination as diabetes
patients suffer from delayed wound healing
& difficulty in wearing denture.