How can I alleviate pain at the dentist if I am pregnant?

Dentist + pregnancy. The local anesthetic injections typically used for routine dental procedures are safe in pregnancy. Poor dental hygiene, cavities and other oral infections have been linked to obstetrical complications. Therefore, it is very important to visit the dentist regularly and do not delay any necessary procedures. Discuss any concerns with your ob.
Local Anesthetic. A local anesthetic without epinephrine should be just fine for for both you and your baby. Discuss your concerns with your dentist.
THE DOC KNOWS. There are many topical and injectable drugs that are safe if you are pregnant.
Talk to your OB. Most doctors only recommend regular strength tylenol (acetaminophen) for pain. This may not help much, so the best thing is to have all your dental work completed asap, so you have limited pain.
FYI, dental care and dental anesthesia is safe and essential during pregnancy. Pregnancy is not a reason to defer routine dental care or treatment.
During or after? Pain during the visit should be prevented with the use of local anesthetics. During cleanings, this often isn't possible, so good oral hygiene between visits will keep the gum tissue healthy so it will not be as tender when you go in for your cleanings. If we're talking about post-op pain, tylenol (acetaminophen) should be safe for your baby, but avoid nsaids like Ibuprofen and aleve.