Sometimes: It's a topical anesthetic, and so it will deaden pain if it's in contact with the exposed nerve.
Maybe - temporarily. You might get short term relief but it won't solve the underlying problem. Since it's a topical anesthetic, it may temporarily ease pain in the gum or a tooth that's open. But it won't help an infected tooth or deeper infection in the mouth. A toothache needs to be seen by the dentist for proper treatment.
Not effectively. Toothache caused by infection. Topical analgesic will not cure infection. Please, you need to see a Dentist ASAP.
Possible but. Possible. But does get treat the cause of the pain. See DDS ASAP.
Use it judiciously. Orajel contains Benzocaine in strengths of 10% to 20% which help relieve pain for mouth sores. This can be used to alleviate the pain for a few days, but if the symptoms do not get better, a dentist needs to be consulted. Oragel should not be used in kids less than 2 years. Oragel sore mouth rinse can be used by swishing to debride and clean the mouth.
Mouth sores. The main ingredient is orajel is benzocaine, which is a mild topical anesthetic. Orajel could provide temporary relief, however, it will not cure the mouth sores. I would suggest seeing your dentist or primary health care provider to help narrow down the cause of these mouth sores.