hello there ,
itself is a sensitive phase and extra care should be take before using any drugs or medications .
Few medications cross the placental barrier and may affect the growing foetus and its developement and hence their use is contraindicated .
so before taking any medicines you need to consult your OBGN doctor to know its safety for you.
As for your dental problems , you can take paracetamol
500 mg for pain relief and is safe for you.
For any dental infection antibiotic amoxycillin
can be taken twice daily.
maintain good oral hygiene
, use lukewarm saline water for regular oral rinsing to prevent any further infection.
Avoid exposure to X rays as you are running in your third trimester.
i hope this information helps ,