There's no minimum age for NHS dental treatment.
Restorations such as crowns, inlays, veneers, and bridges would not usually be provided to patients under the age of 17 unless there are reasons why they must be provided earlier.
The decision if NHS dental treatment is provided to a patient would be made by the clinician based on their examination and assessment of the patient.
They must confirm the treatment is deemed to be clinically appropriate and receive fully informed consent of the patient or their parent or guardian.