KIEV, Ukraine (AP) _ Wielding elephantine dental drills, hoses and syringes, a group of British and Ukrainian veterinarians performed surgery Thursday on one of the world's largest teeth.

Their patient was Europe's largest elephant: Boy, a 26-year-old, 7-ton Asian elephant in the Kiev Zoo. Their goal: to fill a cavity in his tusk, infected after it broke in an accident last summer.

After months of searching for qualified specialists and the necessary funds, Kiev's cash-strapped zoo struck an agreement with England's Colchester Zoo, who sent five British specialists, including the zoo's director.

The complex surgery lasted most of Thursday, leaving Boy unconscious, his head resting on a mound of blood-soaked hay.

``We want to lessen his pain,'' said Kiev Zoo director Oleksy Lepeshkov, pacing around the large concrete pen where the operation was performed. ``But the risk involved is large. Very large.''

As soon as two tranquilizer shots kicked in and Boy collapsed on the hay, the crew rapidly set up a makeshift operating room.

Veterinarians and zoo employees stuffed oxygen tubes up his trunk, taped his eyes and began sawing off the infected portion of his tusk. Then they gave Boy an elephant-size ``filling.''

Veterinarian John Lewis said it will take Boy up to three months to recover, and they're hoping the tusk will grow back.

Lepeshkov said he hopes the operation will attract attention to his ailing park _ and perhaps even an offer of a mate for Boy, the zoo's lone elephant.