Will a dental x-ray always show if a tooth is infected? a lot of pain but dentist said i just need a good cleaning. and have gums receding.

Tooth pain?: There can be many causes for tooth pain--dental decay, an injury or infection, is just one. Read this link for possible causes and treatment options please: www.aae.org/patients/symptoms/tooth-pain.aspx

Radiograph: Not all dental infections show up on x-rays. There are many causes of dental pain, too many to list in this forum. If you trust your dentist, rely on his/her advice. If you don't, get a second opinion.

Not always: A conventional dental x-ray allows us to view a three dimension object in only one dimension. Translated, that means an infection associated with some part of the tooth, whether related to a problem related to the pulp or nerve of the tooth, or a periodontal problem may not always be visible on a conventional dental x-ray. A cone beam CT would provide more views and information.

Not necessarily. Hairline fractures and early nerve related problems do not always give evidence of infection on Xrays. Dentists can perform additional tests such as percussion, hot and cold, and electrical stimulation to focalize on the problem and diagnosis.

An x-ray is a 2 dimensional representation of a 3 dimensional object. There are limitations.. Pain can be from gum disease caused gum recession/root exposure, fracture, decay, pernicious habits, neurologic impairment, Mal;occlusion, fai9ling restoration, etc. Mightn be better to see an Endodontist who's specialty it is to diagnose intractable pain such as yours.