Harry Robertson, who worked at the Kelburne Dental Surgery in Paisley, Renfrewshire, was kicked off the dental register.
Thousands of NHS and private patients in the town have had blood tests after being told there was a "very slight risk" they had been exposed to the virus after being treated by Mr Robertson.
More than 10,000 came forward for testing, but the health board is still trying to trace around 500 who have not yet been screened.
A spokeswoman for NHS Greater Glasgow and Clyde said: "We were able to contact the vast majority by letter.
"There were people who we could not trace because they had moved from the area and we conducted a public awareness campaign in the hope these people would present for testing.
"Ultimately, however, it was down to a personal decision by individuals on whether to respond to our appeal for testing.
"Not a single person was found to have caught HIV as a result of dental treatment."
Leading Glasgow lawyer Patrick McGuire, of Thompsons Solicitors, who is helping patients involved in a similar dental HIV scare in Drongan, Ayshire, claim compensation for their ordeal, said it was "shocking" that 500 people had still not been traced in Paisley.
He said: "In my experience most people want to know how something like this could have happened and it's clear the health board has some very serious questions to answer about how this dentist could have concealed his HIV status for so long.
"People need to know that the best checks are in place.
"I also think it's shocking that over 500 people treated by Mr Robertson have still not been traced.
"Many of my clients in Ayrshire were also missed by the health board but contacted me when they heard what was happening.
"I think it's extremely important that more is done to publicise what has happened with Mr Robertson so that anyone who was treated by him but has been missed by the health board does now come forward."
The General Dental Council (GDC) conducted a private hearing into Mr Robertson's actions and was struck off last week for "dishonest conduct".