Adults who cannot afford dental care will be able to receive a free treatment Friday at one of 13 dentists’ offices in Cumberland and York counties.

The Greater Portland Dental Society is putting on the event, called Dentists Who Care for ME, for the fourth year.

Patients should arrive early Friday at one of the participating offices to make an appointment. Slots are likely to fill quickly, according to a news release about the event.

The offices will not make appointments before Friday.

Patients can choose one treatment among a cleaning, filling, extraction or referral to a specialist, who may or may not provide free care.

Volunteers for the day include dentists, dentist specialists, hygienists, office assistants and others.

Dr. Demi Kouzounas of Scarborough and Dr. Barry Saltz of Portland are coordinating the event.

Participating offices, their addresses and hours are:

— Dr. Michael Frost, 323 Main St., Cumberland Center, 7:30 a.m. – 2 p.m.

— Dr. Alan Chebuske, 110 Auburn St., Portland, 8 a.m. – 3 p.m.

— Dr. David Bagdasarian and Dr. Shane Bryant, 1334 Washington Ave., Portland, 7 a.m. – noon

— Dr. Kathryn Horutz and Dr. David Kerr, 173 Ocean Ave., Portland, 8 a.m. – 2 p.m.

— Dunstan Dental Center, 618 U.S. Route 1, Suite 4, Scarborough, 8 a.m. – 2 p.m.

— Dr. Mark Diamond and Dr. Lucas Homicz, 500 Enterprise Drive, Scarborough, 8 a.m. – 3 p.m.

— Dr. James Ortengren, 463 Cottage Road, South Portland, 9 a.m. – 2 p.m.

— Aspen Dental, 171 Maine Mall Road, South Portland, 8 a.m. – 2 p.m.

— Dr. Jean Paul Boudreau, 25 Long Creek Drive, South Portland, 8 a.m. – noon

— Bayview Dental Associates, 70 Bayview St., Yarmouth, 8 a.m. – 4 p.m.

— Gentle Dental, 440 Narragansett Trail, Buxton, 8 a.m. – 2 p.m.

— Dr. Jim Trentalange, 1389 Portland Road, Arundel, 8 a.m. – 3 p.m.

— Dr. Kenneth Myers, 2 Blackstrap Road, Falmouth, 8 a.m. – 2 p.m.