Canine guidance on crowned teeth: time for a rethink?

This paper aims to discuss the concept of canine guidance in light of recent research with regard to time to extraction of the restored canine tooth, with crowns representing the worst performing restoration at 15 years (66% cumulative survival). Given that the upper canine tooth may be considered the 'cornerstone' of the arch, reasons for this poor performance are discussed by examination of the existing literature on canine guidance and other aspects relating to the preparation of an upper canine tooth for a crown. The authors question previous recommendations that canine teeth should be placed into canine guidance when restored with crowns, given that the previously-published data indicate that survival of upper canine teeth which have been crowned is worse than when they are restored with any other restoration. It is also suggested that, if clinicians wish to prolong the life expectancy of an upper canine tooth, they must try to avoid crowning it.