The Petaluma Health Center has a bit of good news for toothache and abscess sufferers.

The center's recent expansion also brought a much needed expansion of its dental services for low-income residents. The new facility opened June 21.

Formerly a stand-alone clinic on Maria Drive with one full-time and one part-time dentist, the service now occupies the entire south east corner of the new 53,000-square-foot center at 1179 North McDowell Blvd.

The health center has hired three dentists and added six more dental rooms, for a total of nine, where dental procedures are performed.

"It's huge," said Kathie Powell, the health center's chief executive, "when you think that most dentists take care of about 1,000 patients."

Powell said that prior to the expansion, the center could adequately serve about 1,500 dental patients a year. The center now has a capacity of about 4,000 patients, a figure that still falls far short of serving all 17,000 of its patients, she said.

Three more dentists represents a significant addition to the pool of dentists in Sonoma County that serves low-income residents.

According to a recent study by the Sonoma County Task Force on Oral Health, in 2010 there were 15 dentists for 109,000 low-income residents — a small fraction of the pool available to those with private insurance. The task force characterized the lack of dental services for low-income residents as a local health-care crisis.

Although many of the area's low-income residents have public dental insurance — primarily Denti-Cal — almost no local private-practice dentists will accept their coverage.

Ramona English, the health center dental director and one of the four dentists, said the clinic sees MediCal patients, sliding-scale payers and some private insurance patients.

English said the clinic's dental patients need to be existing patients in the medical and obstetrics departments of the Petaluma Health Center. But she added that the clinic will accept some non-center patients "on a case-by-case basis."