The world's largest dental caps measure approximately 50 cm (19 in) long, 13 cm (5 in) in diameter and weigh 13 kg (28 lb) each. They were fixed onto a pair of cracked tusks belonging to Spike, a resident Asian elephant, at the Calgary Zoo, Alberta, Canada during a 3 hour 30 min operation on 4 July 2002. The stainless steel caps were designed and manufactured by the Southern Alberta Institute of Technology with metal donated by Corus Steel and adhesive by 3M (all Canada).More dental adhesive was used in this one proceedure than all the dentists in Canada used collectively throughout 2001! The dental caps have been a success in preventing further cracking and infection of the tusks and in replacing the third that was missing - they are now almost as long as his original tusks which were 94 cm (37 in) long. Spike originally cracked only his left tusk, after playing with tyres, but in order to keep him balanced, the caps were fitted to both. Although it is not unusual for caps to be fitted to tusks, these are the largest manufactured so far.