His practice also considered patients' mental health when assessing whether they needed urgent or emergency care, he said.
The man faces a disciplinary charge by the Dental Council for operating on three patients in early May 2020.
All three patients had to travel significant distances - from Orewa, Warkworth and Waitoki - to the Auckland practice for treatment, two of them accompanied by a support person.
They had extractions and dental implants placed, including one patient who had 10 teeth removed and five implants.
The treatments were done on May 1 and 6, a period when two people died from Covid-19, six people were in hospital with the virus, and 15 significant clusters were active in the community.
It was an extraordinary time when the country was in level 3 lockdown, not much was known about the Covid-19 virus, and vaccination was "still a pipedream", said the council's lawyer Dr Jonathan Coates.
Under alert levels 3 and 4, only urgent and emergency care was allowed to go ahead. All other routine care had to be deferred, the Council had said in guidelines sent out to practitioners.
The Council said there were no records showing the dentist had triaged the patients to assess whether they needed urgent or emergency care, or took steps to reduce transmission risk like using PPE.
The procedures required three-member teams because of sedation, so at least two other staff would have had to break lockdown rules to travel to work, said periodontist William Gaudie, who provided expert opinion at the hearing.
He believed the treatments could have been deferred and posed significant public health risks at the time. Patient anxiety about their oral health, while a significant concern, was not enough to merit breaching the Dental Council guidelines, Gaudie said.
In his testimony, the accused dentist said his practice was closed throughout the lockdown and staff did triage patients over the phone. No one was treated at alert level 4.
The clinic saw four patients face-to-face at alert level 3, one of whom the Dental Council accepted did meet official guidelines for urgent or emergency care.
The practice was set up to receive emergency patients and staff wore PPE during the treatments, he said.
Two of the patients were in pain and could not eat, and antibiotics were or would not have been effective if prescribed. "At the time, there was no doubt in my mind that the extraction was urgent," he said.
"There was some uncertainty and confusion [around the guidelines and expectations] at the time, we were all learning as we went."
The hearing continues this week.
