The tribunal said Dr Moon showed no regard for the safety of the public by practising without the necessary equipment.
He was suspended from April 26, 2012 until May 8, 2012 when the Dental Council would confirm he was compliant with the Code of Practice.
Another dentist received a referral from Dr Moon during this period and reported it to the Dental Council. The Dental Council approached Dr Moon and he admitted to continuing to practise while suspended.
The tribunal found Dr Moon was guilty of professional misconduct by continuing to treat patients while suspended and censured him and fined him $5000 in March 2013. The decision was made public this week.
Dr Moon must undergo mentoring and study the ethics of dentistry or face a further one year suspension.
The tribunal found it would disadvantage his 11,000 patients, most of whom are Korean, for him to discontinue practising.
Dr Moon is bankrupt and currently working to pay back money owed to creditors. The Tribunal hoped if he continued to practice he could pay back those owed.
Dr Moon practises at Andy Moon Dental Surgery at Northcote and Toothcare West at Henderson, Auckland.
Chul Jun Cho set his brother-in-law's business alight after an argument about Dr Moon having a night out gambling with his partner Misook Kim - who died in the blaze on February 3, 2007.
Ms Kim worked at the Toothcare West dental surgery with Dr Moon.
Cho was found guilty of murder, and sentenced to life in prison in 2008.