A new treatment for dental cavities could mean that fewer kids need to squirm through complex dental surgeries or go under general anesthetic.

Dentist and University of Manitoba associate professor Robert Schroth is leading a small study involving 35 kids, testing the use of silver diamine fluoride (SDF) to stop the advance of tooth decay.

The product was approved in February by Health Canada. The procedure is simple: a dentist paints a couple drops of the clear liquid, which contains a high concentration of silver and fluoride, on a tooth. The substance kills the bacteria while hardening the softened tooth.

It also costs a fraction of a conventional filling.

Schroth says the treatment could help young kids who can't sit through a filling without getting put under. It could also serve as as "stop-gap" for low-income people or people in remote areas where dental surgery isn't readily available, halting the tooth decay until they can get more complex treatment.

"Right now I see this as really helpful for children who are very young, they might have some behaviour management issues, and it's very difficult to perhaps do conventional treatment in the chair setting," Schroth said.

Schroth is conducting the study in partnership with the Children's Hospital Research Institute of Manitoba. He's working with roughly 35 kids at Mount Carmel Clinic and ACCESS Downtown.

"These are inner-city, community-based dental clinics where often we tend to see individuals who are struggling financially, they don't have dental insurance quite often and otherwise without a product like SDF, they might fall through the cracks," Schroth said.

Black teeth better than alternatives

There is one downside: SDF turns the treated area black.

That fact hasn't deterred many of the parents Schroth has worked with, he said. In many cases, the kids are young so their baby teeth will fall out and new ones will replace them. The black spot also looks much the same as an untreated cavity.

"From what we've had with our small sample to date, most parents seem to be very accepting of this because they realize that they really didn't have an alternative."

The treatment won't eliminate the need for the dentist's drill. It doesn't rebuild the decayed portion of the tooth. It also won't work on teeth with advanced decay.

The treatment isn't yet widely available in dentist offices. Currently, private insurance policies don't cover it, but the Non-Insured Health Benefits Program is reviewing SDF, Schroth said.

Dentists also need to develop clinical guidelines, figuring out when to use SDF and in which cases.

Although SDF is a new treatment in Canada, Schroth says it has it has been used for years in other countries including Japan, Australia and Brazil. Some studies suggest SDF is effective in treating 80 per cent of cavities, he said.

Researchers are also working on finding a way to reverse the black staining, using potassium iodine.

Schroth sees a wide range of benefits to using SDF, including fewer kids travelling from the north for treatment under general anesthetic in hospital. Although Schroth hasn't used SDF on adults yet, he says a colleague in Ottawa is using it to treat tooth decay in meth addicts.