Online dentist marketplace Brighter has raised a $21 million round.

The Santa Monica firm will use its funds to hire engineers, as well as sales and customer service representatives.

Brighter is an online marketplace that rates dentists, lists co-pay rates, and schedules appointments. The internet firm sells its platform as a service to insurance providers, which then offer access to their members.

When it launched in 2011, Brighter was an open public marketplace for the uninsured to shop for dentist services. It later pivoted to become a service for self-insured businesses before deciding to sell its marketplace to insurance providers, which it views as more likely customers for its platform. The company recently signed a deal with Cigna – its first health insurance client.

Brighter Chief Executive Jake Winebaum said he hopes the marketplace will promote cost controls and transparency in the dentist industry.

“Unlike medical, there are very high co-pays for dentistry,” said Winebaum, adding that consumers want to shop around more when selecting their dentist. “It lends itself to consumerism because there is so much out-of-pocket cost.”

Brighter’s Series D financing was led by General Catalyst Partners with participation from Dag Ventures, Mayfield Fund, Benchmark, and Tenaya Capital.

Technology reporter Garrett Reim can be reached at [email protected]. Follow him on Twitter @garrettreim for the latest in L.A. tech news.