The B.C. Dental Association says proper sterilization techniques were not being followed by Tung Shen Wu, also known as David Wu, who treated some 1,500 patients at his Burnaby home.
The College of Dental Surgeons of B.C. issued a public warning earlier this week that patients who had received dental treatment from Wu should be tested for HIV and hepatitis.
Wu was identified by the college as having no authority to practise dentistry.
"It's pretty scary [that] he's been working for 10 years in that environment, using those techniques for sterilization," said Dr. Bruce Ward of the B.C. Dental Association.
"It's totally different [for accredited dentists]. We sterilize all our instruments in sterilizers that need to be checked weekly," said Ward.
Video taken by investigators inside Wu's house show dental tools and orthodontic fittings in bins and boxes.
Wu had been operating as an unauthorized dentist for almost 20 years at various private residences in Metro Vancouver.
More than a decade ago, the College of Dental Surgeons tried to stop Wu from practising in Port Moody, but he simply set up shop in Burnaby.
Following the raid in May, the college found enough potential public health problems to call in Fraser Health and issue a public warning that former patients should get tested for HIV and hepatitis B and C.
"Very poor infection control … very poor hygiene, really none of the basic standards that we would expect from a proper dental office," said Michelle Murti, spokesperson for Fraser Health Authority.
The Fraser Health Authority says since issuing the public notice, hundreds of people have called in to their switchboard, which is staffed with Mandarin and Cantonese speakers.
So far, no actual infections have been reported.
Wu's current whereabouts are unknown, but a court hearing is scheduled for Monday.