A number of patients were harmed by students at Aberdeen's dental school, an inspection has found.
The General Dental Council (GDC) inspection highlighted a number of what were described as "adverse events".
These included treatment of the wrong tooth.
The GDC found that a third of final-year students last year did not graduate, and said it was disappointed issues were not identified earlier by the school.
Aberdeen dental school was inspected in two visits in April and June last year.
GDC head of education and quality assurance Jane Pierce said: "Ensuring patient safety is the core function of the GDC and we are working closely with Aberdeen dental school to ensure that the issues identified by our inspectors are addressed urgently.
"A further re-inspection will take place in the current academic year."
A spokesman for the University of Aberdeen, which runs the dental school, said: "All dental schools have rigorous standards of assessment, and as a relatively new dental school we are monitored regularly by the General Dental Council.
"We welcome these inspections as an opportunity for benchmarking our performance, and providing areas for learning, so that we continually improve in training student dentists for clinical practice.
"The GDC report noted the investigation and learning processes the school was following after 'adverse events' which had been reported while students were treating patients (which is under the supervision of fully-trained dentists).
"The patients involved were made immediately aware of any concern with their treatment and the problems were promptly addressed. There were no complaints from the patients, and all processes within the school were reviewed and further improved."