Under federal HIPAA law you have the right to receive copies of your health information from your dentist (as well as other doctors and providers) including your dental records and all of the information in your patient file. So if the country of origin and/or other information about where your dental restoration was made is included in your patient record, you will be able to obtain that information by requesting a copy of your patient record from your dentist.
Typically dentists are required to include the dental laboratory slip, work order or prescription, which lists the name and address of the dental laboratory that will be receiving it, in the patient’s record. However, dentistry is primarily regulated by state law and most states do not have any requirements about whether the dental laboratory is required to tell the dentist if they are making your restoration themselves or whether they are sending it to another country to be made.
Information provided by the dental laboratory to the dentist will depend on the law in the state where you received the dental care. See the chart at https://dentallabs.org/state-regulation/ for states that require dental laboratories to disclose material content and point of origin to the dentist.
It is always best for you to ask your dentist upfront where your restoration will be made and what materials will be used, before they order your restoration. Most dentists are happy to provide you with this information. If the dentist doesn’t know or is reluctant to tell you, that is a warning sign and you should consider whether you want to see another dentist. Visit https://dentallabs.org/resources/ for additional resources.