In 2002, an elephant's two tusks were fitted with stainless steel dental caps 19-in (50cm) long by 5-in (13-cm) diameter, the world's record largest dental caps, in a 3½-hr operation, on Spike, a 20-year-old Asian elephant at the Calgary Zoo, Alberta, Canada. After about one-third of its left tusk broke off, a crack in the remaining tusk needed protection against further damage to avoid a future medical problem of infection and pain that could require a complicated root canal treatment. The 28-lb (13-kg) prostheses were computer-designed by the Southern Alberta Institute of Technology. The other tusk was shortened and capped to maintained balance. Dental adhesive was supplied by 3M.«