Sisu the 600kg polar bear undergoes vital dental surgery at Yorkshire Wildlife Park

Animal dentist Dr Peter Kertesz carried out an hour-long tooth root filling on Friday when three-year-old polar bear Sisu needed the operation.

Keepers noticed that Sisu was suffering with a broken tooth, which if untreated can lead to severe infection and, in some cases, develop into an abscess.

Dr Kertesz said: “It was wonderful that the keepers have been so observant and attentive to the animals, and noticed this.

“I was glad we operated swiftly because a broken tooth can lead to severe infection and be very painful.”

Dr Kertesz completed the operation along with dental nurse Monika Mazurkiewicz and a vet specialised in the use of anaesthetics.

“It was a standard procedure, where we cleaned out the infected root canal of the canine tooth, which was over three inches long, and filled it,” Dr Kertesz said.

"We then had to build and shape the tooth, ensuring we kept its length."

He added: “Sisu will now have a pain and infection free tooth for the rest of his life.

“After the operation, Sisu was standing very quickly, but he was kept in his den to recover fully.”

Yorkshire Wildlife Park’s Director of Animals Charlotte McDonald said:” Sisu is now fully recovered and enjoying entertaining Half Term visitors with his antics.”

Sisu lives in the original 10 acre Project Polar reserve at the Park with Luca, Nobby and Hamish - and next door in the four acre project Polar 2 reserve are Flocke and her three cubs.

Yorkshire Wildlife Park is now the second largest polar bear facility in the world and the largest outside Canada.