Dr. Doug Luiten worked on 300-pound Kunali -- measuring nearly 7 feet from backside to nose -- Thursday at the Alaska Zoo.
"It's the longest tooth I've ever worked on," Luiten said of more than three-inch (8 centimeter) canine.
The zoo had to order some special instruments to accommodate the longer tooth, and even had to modify those during the root canal.
Kunali was not restrained, and didn't wake up during the hour-long procedure thanks to anesthesia administered by Dr. David Brunson, a visiting veterinarian from Madison, Wis.
"He was a good boy, he handled things well," Brunson said.
Hours after the procedure, Alaska Zoo Executive Director Pat Lampi said 7-year-old Kunali was doing fine.
"It couldn't have gone any better today, it was perfect," said Dr. Riley Wilson, the zoo's veterinarian.
The root canal was necessary after Kunali fractured the tooth 4 or 5 years ago, likely when he hit a metal post.
"They're not chewing on things that break their teeth easily, but they're wrestling around," Wilson said. "It takes some trauma to chip that big of a tooth."
The fractured tooth didn't seem to distress Kunali, Luiten said, but the root canal will give him long-term protection from infection.
Root canals for animals are somewhat common, with previous procedures performed at the zoo on a polar bear, the zoo's other tiger, a wolverine, a wolf and two on a snow leopard.
But this was the first procedure in a recently opened operating room and the first for the zoo's new veterinary table, complete with hydraulic lift and fold-out leafs to accommodate limbs and tails.
Before the new operating room opened, procedures were conducted inside the animal's exhibits. "We were on our knees in dens," Lampi said.
Going to the animal's habitat was more of a challenge, Wilson said, because there was poor lighting, not enough room for everyone who needed to be involved and it was much colder.
The new table, worth about $9,000, was made locally and donated to the zoo.