There were tears but also laughter and freshly scrubbed smiles.
A Rohnert Park dentist opened his practice Sunday to give 18 children free cleanings, X-rays, fluoride treatments and other preventative oral care.
"You're doing so good, so brave. Close your eyes," Dr. Anthony Lieu said.
Cynthia Martinez, 9, took two very deep breaths.
Lieu swabbed an anesthetic onto her gums in preparation for pulling a stubborn baby tooth.
"Your gums are going to fall asleep, then we will take it out," he said.
Between 9 a.m. and about 1 p.m., Lieu and his staff treated children from 7 to 14, most referred by Big Brothers Big Sisters of the North Bay.
The children walked in with plaque and cavities and walked out with clean teeth, a bag of dental hygiene goodies, a dentist referral and a balloon.
"Big Sister" Lois Fisher, an urban designer from Windsor, waited in a lobby chair as her "Little," 8-year-old Jessica Mendoza, was being examined in the dentist's chair.
"I had a mouthful of cavities, and I don't think she has a dentist," Fisher said. "I'm hoping she's going to get fluoride."
A 2009 survey found dental problems are more likely to keep poor children out of school than more affluent students.
In 2009, 52 percent of Sonoma County's third graders had a history of tooth decay, above the state average, according to the poll done by the Sonoma County Task Force on Oral Health.
Only 15 dentists accept payments from Denti-Cal (Medi-Cal's dental program) for low-income patients.
Lieu said he called all of them to find practices that are taking new children patients. Only the Cotati Family Dentistry was accepting new clients, he said.
Lieu opened his practice in 2010, and said he had been thinking about offering a day of free care for some time. And in April he called the Big Brothers Big Sisters on a whim.
"When he called us, we thought, &‘Yes!'" said Lauren Grayman, programs director with Big Brother Big Sisters of the North Bay.
The donated time was worth between $1,500 and $2,000 in overhead costs, Lieu said.
Behind a partition wall, Geraldin Hernandez, 10, reclined in a pink dentist's chair as dental hygienist Karina Pereira scraped between her teeth.
"It's actually very fun. I got to see an X-ray of my teeth," Geraldin said.
Hernandez' brother Angel, 13, sat in the next room.
Oriana Biela, a dental hygienist and Lieu's wife, showed him a digital X-ray of a wisdom tooth pushing a molar.
"Does it hurt to get a wisdom tooth out?" asked Hernandez, who attends A. E. Kent Middle School in Kentfield with his sister. "I'm not worried, just wondering."
In the next room, Jessica, a Kawana Elementary School student, shook her head when Lieu asked if he could pull a tooth.
"I don't like needles," Jessica said. Big tears rolled down her cheeks.
Fisher squeezed the girl's hand.
"I promise it won't hurt," Lieu said.
The group consulted and decided to wait.
Office manager Karen Olson told Jessica to wiggle the tooth whenever she watched television to help it fall out.
Or, they could tie her tooth to a doorknob and try the slam-the-door trick, Olson said with a wink.