The ADA adopted Resolution 35H-2007 to call on third party payers to return radiographs. "When a dentist determines that it is appropriate to comply with a third party payer's request for images, it is recommended that a duplicate set be submitted and that the originals be retained by the practioner. ALL images, including duplicates, except those submitted in digital or other electronic form, and whether or not they have been requested, should be returned to the dentist for the patient's records."
Source: ADA: Radiographs should be returned. ADA News. November 17, 2008. http://www.ada.org/prof/resources/pubs/adanews/adanewsarticle.asp?articleid=3321. Accessed March 10, 2009.