Are antibiotic injections often used to treat a tooth infection?

No: Most tooth infections can be cured with oral antibiotics. When they can't, they may need surgery.

In ER yes, but..: It happens often that someone goes to the er for tooth pain and they don't know how to treat the actual problem so they give pain med and antibiotic. I have seen both given in injection form, but it is not the best way. A few daily dosages for more than a week is more common. You need to see a dentist for treatment of the problem besides antibiotics and pain meds.

Only if the: Tooth infection has extended past the local area of the tooth and caused systemic symptoms of swelling, fever, malaise. Oral antibiotics are much more common. If u are in the er and have significant swelling with other system wide symptoms, expect an injection. In the dental office, oral route is the typical first line of attack.

Not usually: Infections from dental sources such as teeth, gums & bone, require that the cause of the infection be eliminated. As an adjunct to this and to prevent further spread and help the body cope with the infection, antibiotics are essential. Oral antibiotics are almost always the typical method. However, im & less frequently IV antibiotics work quicker, are more effective and used in severe cases.

Not often: Not often, majority of dental infections are treated with taking the medicine orally usually for 7 to 10 days. In cases with systemic problems or in cases that are not responding to oral medication the use of injection is indicated.