Organizers of a free dental clinic, overwhelmed by the turnout of those seeking help, turned away several hundred people Friday morning because they had reached capacity.

The doors leading into the clinic in Hall C at the Charlotte Convention Center were closed about 5:45 a.m., before the program was scheduled to begin at 6 a.m.

Dr. Bill Blaylock of the N.C. Dental Society, sponsor of the clinic, said there was capacity to handle about 2,000 people at the 36-hour clinic, which runs until 6 p.m. Sautrday. By some counts, more than 2,500 people were waiting at the convention center before daybreak Friday morning.

For some who had arrived in the early-morning hours, the development was a big disappointment.

Shawn Evans of Charlotte was among those who were shut out. She said she planned to return Friday night, in hopes of getting into the clinic Saturday.

"There will be another wait tonight," Evans said.

Another woman, identifying herself as Maria, said she had traveled from Lincolnton but also was not able to get in Friday morning.

"I'm staying here," she said at 9:15 a.m. Friday. "Someone told me nobody else would get in, but I'm hoping they will have enough room for more people."

Several other people waiting at the convention center Friday morning said organizers told them there would be additional free clinics elsewhere in North Carolina this fall -- next month in Sylva, in the western N.C. mountains; in October in Dare County, along the Outer Banks; and in November in Greensboro.

People began lining up at the convention center Thursday evening, and the crowd grew quickly during the night.

Earlier Thursday, Dr. Robert Stowe, a Winston-Salem dentist, said he planned to spend the wee hours of Saturday morning providing free dental services to uninsured Charlotte-area residents at the N.C. Dental Society's free clinic.

"This is a chance to be part of something very special," Stowe said.

The clinic runs until 6 p.m. Saturday. It's the first clinic of its kind to run for 36 hours nonstop.

Stowe, originally from Gastonia, recruited a group of five dentists and one hygienist to work the "graveyard" shift, from midnight to 6 a.m., at the clinic. He and his peers jumped at the opportunity to "help their fellow man."

"We do it because there's such a need. ... We want to help people and we know that with the economy the way it is, they just can't quite make it to the dentist," Stowe said.

About 20 people had already started lining up for the clinic early Thursday evening. Many of them said they don't have dental insurance, and if they did, the deductible was too high for them to afford. Some, like Kevin Jones, couldn't remember the last time they'd been to the dentist.

"I want to smile again," said Jones, who's missing his two front teeth on both the top and bottom. Jones, who's struggled with homelessness and drug addiction for eight years, said he sees fixing his teeth as a step on the road to recovery.

"I'm trying to look better so I can get a job," he said.

N.C. Missions of Mercy, a nonprofit group affiliated with the dental society, spread the word about the clinic through the media and local agencies such as the Salvation Army, the Urban Ministry Center and the Charlotte Rescue Mission, which helps homeless men and women dealing with poverty and addiction.

Clinic co-chair Dr. Evan Miller said local dental offices and agencies have been fielding dozens of calls about the clinic's details in the past few weeks.

"People are hearing about these things," Miller said. "You better expect a big crowd."

The clinic started Thursday night with the pre-screening of some patients, brought in by partnering Charlotte agencies.

Dentists will provide services on a first-come, first-served basis to adult patients with an annual income less than 200 percent of the federal poverty level - about $22,000 per individual or $44,000 for a family of four.

Dozens of free dental clinics are held in cities throughout the state every year. This is the first Missions of Mercy clinic ever held in Charlotte, Miller said, an area with great need for dental services.

The Urban Ministry Center, which serves the poor and homeless, works with the Charlotte Men's Shelter to provide free dental care to area homeless. But more help is needed, said Dale Mullennix, Urban Ministry's executive director.

"The demand for dental care is far in excess of what we're able to offer on a regular basis," Mullennix said.

According to the dental society's website, the state's largest free dental clinic served 902 patients in Kill Devil Hills in 2009. Organizers of the Charlotte event expect to treat between 2,000 and 2,500 patients.

Last weekend, more than 4,000 people waited in line for a two-day free dental clinic in Atlanta. Organizers say they helped about 2,200 patients.

Hundreds of dentists, assistants, hygienists and community members have volunteered to serve as many patients as possible in Charlotte. But once all the chairs are full, Miller said, there's only so much they can do.

"We only have so many units available," Miller said. "We're going to go as hard as we can."