Every now and then, Dr. David Regine likes to go wild.

While his Bridgeville dental practice is obviously set up for human patients, the 59-year-old doesn’t mind squeezing the odd teething tiger into his busy schedule

“Teeth are teeth,” Regine says. “The procedures that work on humans seem to be working on animals, probably because they’re tried and true and make good medical sense.”

Since the early 1990s, Regine and his assistant-turned-fiancee, Tina Collavo, have donated their time and expertise to the Pittsburgh Zoo & PPG Aquarium in Highland Park. The duo’s client list reads like the passenger log book from Noah’s Ark and includes alligators, bears, beavers, cheetahs, dolphins, elephants, gorillas, hedgehogs, kangaroos, leopards, lions, meerkats, and monkeys.

Regine, an amateur scuba diver, once even made a splash with zoo administrators when he volunteered to clean the facility’s old shark tank, a daunting and potentially deadly chore. With razor-mouthed creatures swimming around him, he recovered lost shark teeth from the bottom of the glass enclosure and, upon surfacing, passed out the pointy souvenirs to wide-eyed zoo patrons.

David Regine with a young patient

In 1995, when he learned that Savannah, one of the resident elephants, was suffering from an infected tooth, Regine assisted a specialist with the extraction. Since then, he has filled a snow leopard’s cavity, wrestled some not-so-pearly whites from an alligator’s jaw, and helped a menagerie of other critters who were feeling down in the mouth.

For Regine, sticking his hands in a predator’s trap is all in a day’s work. “Fear has never, ever entered my mind,” he says. “I guess it’s that doctor mentality; you focus in on the problem, not on what’s going on around you.”

He’s even worked on some gorillas who were reluctant to open wide for the dentist’s drill. “They were funny,” Collavo says of the anxious apes. “They were on IVs so they were in la-la land. They would just hold on, real gently, to your finger.”

This past January, Regine made international headlines when he and Dr. Tom Klein, a veterinary dentist from Ohio State University, performed a root canal on a polar bear named Koda.

Pittsburgh Zoo officials determined that the 2-year-old, 600-pound cub had chipped his lower, right canine while roughhousing with his brother, Nuka. The damaged tooth became infected and put the polar bear – one of zoo’s most popular inhabitants — on antibiotics and out of commission.

After assessing the situation, Regine went shopping for dental supplies... at The Home Depot.

Because a polar bear root canal is such a rare procedure, the necessary tools for the job do not exist. Tossing aside his medical catalogs, Regine fabricated devices using plumbing hardware, including a large brass rod.

“You’re working in a vacuum,” he says. “The common instrumentation that we use on humans just isn’t going to cut it. In fact, it would probably get lost in a polar bear’s tooth.”

With a team of veterinarians and zoo keepers monitoring the bear’s vital signs and keeping a vigil by his bedside, the dentists were able to repair the tooth, which measured about seven inches from crown to root tip.

Koda was back on his paws within a few days.

“Right now, if you look at him, he’s frolicking, he’s playing. I love that,” Regine says. “It does my heart good to know that he’s happy; that there’s a little peace and contentment in his life now.”

Regine, the owner of a shaggy, gray pooch and a litter of kittens, has always maintained a soft spot for animals.

The walls of his Bridgeville office are covered with crayon drawings of the furry and feathered along with snapshots of his exotic clientele, including rare images of elephants marching underwater. Video footage of the submerged pachyderms – which was shot by Regine himself – has been shown in zoos around the world.

Due to his recent celebrity status, which includes mentions in USA Today and other national publications, local students have been recruiting the doctor for show-and-tell sessions, and the office has been bombarded with questions about canine oral hygiene. “We just got a call the other day from a woman who wanted to know if I would work on her dog’s teeth,” Regine says with a laugh.

A veterinarian, he explained, is better suited for such a task.

Regine, who graduated from the University of Pittsburgh School of Dental Medicine in 1980, says the field of animal dentistry is still relatively uncharted. He credits Dr. Barbara Baker, president and CEO of the Pittsburgh Zoo & Aquarium, for allowing himself and his colleagues to shed some light on the subject.

“It’s not because the animals are in captivity that they need this care,” he explains. “It’s because they’re in captivity that they can get this care.”

Throughout his career, Regine has been able to help both man and beast, and that, he says, gives him every reason to smile.