Santa Monica dental referral startup Brighter has raised $15 million to expand its recently revamped service into new U.S. markets.

The series C round was led by Menlo Park venture firm Tenaya Capital and includes existing investors Mayfield Fund and Benchmark, both also in Menlo Park. The financing brings Brighter’s total funding to $28 million.

Stewart Gollmer, Tenaya Capital managing director, will join Brighter’s board. He joins Navin Chaddha, Mayfield managing director; Bill Gurley, Benchmark general partner; entrepreneur Matt Coffin and former Hulu chief Jason Kilar.

“Brighter is flipping the dental insurance model on its head by creating a marketplace where dentists compete for patients based on price, quality and convenience,” Gollmer said in a statement. “We believe this is how health care should work, and are excited to invest in Brighter and support its remarkable team spearheading this transformation.”

Brighter launched in 2011 as a subscription service that helped the uninsured find discount dental services. In June this year the company scrapped its subscription fees in favor of a free service. Brighter makes its money by charging dentists a service fee for being part of its online network.

At the time of the relaunch, Brighter worked with 350 dentists in Los Angeles. The company now counts more than 600 dentists in L.A. County.