"Unfortunately, Los Angeles is bombarded with more than we would like," said Teresa Lane, an inspector with the California Dental Board.
Lane's agency recently conducted an undercover investigation that resulted in a raid and the arrest of a man accused of practicing dentistry out of his home.
"We have found a full dental setup inside of the residence, inside of his actual bedroom," said Lane.
It's been a persistent problem for decades, but health officials say unlicensed dentistry is a growing problem in Los Angeles.
"They're making very good money, very good money," said Lane.
And the consequences could be severe. Erick Aguilar, who works for the Los Angeles County Department of Public Health, said there are real dangers.
"Possibly infections of contagious diseases -- HIV, Hepatitis C -- from improperly sterilized tools," said Aguilar.
Crudely constructed dental equipment has been confiscated from clandestine clinics all over the county.
"We see a whole range of things. I mean, we've seen mobile dentists…dentists working out of a garage, maybe out of an apartment, then it's working out of storefronts," said Aguilar.
Aguilar says some of the unlicensed dentists make house calls, and some even extract teeth in the back seats of cars.
Some illegal clinics are often hidden behind storefronts, while others operate out of houses and apartments. Aguilar says the so-called dentists often have little to no formal training.
"There was a guy that hired mechanics...that just kind of pull teeth basically," said Aguilar.
One woman said an unlicensed dentist extracted the wrong molar and didn't use any painkillers. She said the dentist told her she "would have to deal with the pain."
While illegal dentistry is certainly nothing new in Los Angeles County, the growing number of these operations has prompted the California Dental Board to step up its undercover investigations. In the past six months investigators have conducted 12 raids, resulting in 12 arrests.
The obvious question would be: Why would anyone choose to see an unlicensed dentist? In some cases, people feel like they can't afford to see a legitimate one. But county health officials say the reasons aren't always economic.
"They maybe feel it's a cultural thing, maybe feel better with somebody that is from their same culture, speaks the same language, and that kind of thing," said Aguilar.
The county's HALT Task Force recently teamed up with the California Dental Board on a raid in South Los Angeles after they were tipped off to the clinic by a former patient who underwent a root canal and later developed a life-threatening infection.
"These people aren't licensed to do it. They don't know what they're doing, other than taking advantage of people and making a lot of money off them," said L.A. County Supervisor Zev Yaroslavsky.
