Two more hours. Finally, she was waved over to an X-ray machine under a basketball hoop.

Just as Matello expected to be called for her turn in the dentist’s chair, a volunteer announced in a loud voice: “Those up to number 500 will be seen today. The rest will have to come back tomorrow.”

“You have to be kidding!” yelled a frustrated woman behind Matello. “I have to do this all over again?”

Matello’s eyes filled with tears. She had been waiting 10 hours.

A volunteer gave her a wristband that would put her at the head of the line the next day. So she drove home in her 18-year-old Jeep, ate dinner chewing only on the right side yet again, and set her alarm.

By 7 a.m. the next day, she was finally in one of the reclining chairs, with a dentist pointing a bright light into her mouth.

She stared up at the arena’s high industrial black ceiling. The whir of drills across the open room competed with Billy Joel’s “New York State of Mind” playing over a loudspeaker.

Robert Testani, a volunteer dentist from Catonsville, Md., examined Matello and checked her X-ray before easing a syringe of novocaine into her mouth. He prepared to pull her broken molar.

“Don’t worry. This is routine,” he said. He paused and looked around. “Except for the setting.”

Over two days, 116 dentists treated 1,165 patients, providing $1 million worth of fillings and other care, according to the Mission of Mercy. Matello was grateful. She was told her panoramic X-ray and extraction would have cost $600 to $800 in a regular office.

She looked at some of the others who had come here, despite working for a living cutting down trees, building homes, minding a town library, running small businesses.

“We are not staying home, not sleeping and living off the government,” she said.

She wondered why there wasn’t a better system for people like her. She tried not to look at the 51-year-old truck driver lying next to her who had three teeth pulled, his mouth stuffed with bloody gauze.

“I am trying to think that this is not demeaning,” she said as she cleared the chair for the next person in line. “But it is. It’s like a Third World country.”