A periodontist specialises in treating gum disease and dental implants.
Also a registered dentist, he said he was devastated to be facing a disciplinary charge, and believes he has been "singled out" for breaching guidelines that were confusing and uncertain at times.
It was a struggle working in PPE and anxiety levels were high. "But I did treat patients while trying to keep to the guidelines," he said.
Described by his lawyer as well regarded in the industry, the dentist operated on three patients in early May 2020 when New Zealand was at alert level 3.
They had to travel from as far away as Orewa to the Auckland practice for treatment, two of them accompanied by a support person.
All three had extractions and dental implants placed, including the elderly cancer survivor who had 10 broken teeth removed and five implants.
The dentist said the patients were at risk of worse outcomes if they were not treated at the time, when it was not known how long the lockdown would last.
Placing their implants immediately after extraction avoided two, or even three more surgeries down the line and was in the best interests of the patients, two of them elderly, he said.
The clinic had four staff on duty for the surgeries - the dentist, two nurses and a receptionist.
The surgical team wore full PPE gear, patients were screened for Covid-19 symptoms and travel history, and treated in separate rooms that were disinfected after use, he said.
But there are no records of any of this, and Tribunal Chair Royden Hindle said they will have to consider if the defendant is giving a full and accurate account of what happened.
The Dental Council has argued the treatments did not qualify as urgent or emergency care, the only procedures allowed under alert level 3.
It was the first year of the global pandemic when not much was known about the Covid-19 virus and vaccination was "still a pipedream", the council's lawyer Dr Jonathan Coates said on the first day of the hearing.
Virus control was focused on limiting movement and making sure people stayed home unless absolutely necessary, he said, and the dentist had failed to follow the Council's unequivocal guidelines around that.