George Campbell is facing a fitness to practise hearing in central London after complaints over the treatment of 30 patients spanning over a decade.
Mr Campbell allowed staff to carry out orthodontic work and then referred patients for surgery at hospital which they did not need, it is claimed.
Further allegations against him include that he failed to spot treatment problems before dangerously exposing patients to harmful radiation during unnecessary x-rays.
On allegations that some orthodontic treatment given to patients was done by staff who were not fully qualified, Mr Campbell told the General Dental Council that there was a lack of guidance from the regulatory body on this issue.
He said: "There was no real guidance or supervision so we always aimed to provide the training and guidance ourselves.
"I was supervising new staff on a daily basis and with any queries on the supervision or tasks we would phone the GDC to check."
The dentist told the hearing that he did not see his staff's training certificates and presumed they were qualified to carry out orthodontic treatment.
Mr Campbell added: "I was aware of their training certificates, yes, but I hadn't seen them - I presumed they had their certificates.
A first complaint was made by consultants at Glasgow Dental Hospital on December 22, 2010, when they became alarmed after 13 of his patients were referred to them for further treatment.
Other concerns involved claims of unnecessary surgical interventions, missed diagnoses, and worries over Mr Campbell's clinical standards.
A second complaint was made to the GDC on July 22, 2011, by an oral surgeon at the Albion Clinic in Glasgow, relating to six patients.
The GDC decided Mr Campbell was to be barred from carrying out unsupervised work until the outcome of a full disciplinary hearing.
He initially faced a conduct and competence committee in October last year but the three-week hearing ran out of time and had to adjourned until this month.
Mr Campbell was allowed to continue practising during the adjournment subject to a number of restrictive conditions.
He told the hearing that he felt all the orthodontic treatment he gave to patients was necessary and of a high standard.
Mr Campbell added: 'I always told patients of the importance of keeping their teeth as clean as they can with no fizzy drinks and using mouth rinse every day.
'We always talked to the orthodontic patient's parents, show them in the mouth, and try to explain the sequence, which teeth were sticking out, then show them the x-ray.'
Mr Campbell is also charged with making inappropriate referrals for surgery in respect of eight patients at his centre, and of failing to diagnose root problems in four patients.
He is further accused of failing to manage his staff and premises correctly, and of not making sure that orthodontic therapists and trainee orthodontic therapists were adequately supervised.
Mr Campbell also allegedly failed to ensure that patient numbers could be adequately served by the size and suitability of his facilities, and his number of employees.
The dentist denies all charges against him.
If found guilty of misconduct, the maximum punishment that Mr Campbell can receive is a permanent ban from the profession.
The hearing continues.