Is it okay to use lidocaine on gums?

Depends why. Lidocaine may be injected into the gums safely by your dentist for pain relief. If you are talking about using Lidocaine for teething pain in babies, the answer would be no. This would not be safe. Your pediatrician can recommend better remedies to help with teething pain. A cold teething ring often helps. If this doesn't answer your question, let us know!