Advantages and disadvantages of applying yttrium stabilized zirconium-dioxide post and core restorations

Abstract

Full ceramic restorations are associated with metal free post and core prosthodontics for teeth with seriously destroyed
clinical crowns. Using custom made zirconium-dioxide post and cores can be flattering not only to give a good aesthetic
result, but also to provide excellent retention. As none of the post systems stands all demands, prudent planning is
mandatory. Our paper deals with favourable and unfavourable conditions as well as common causes of failures of post
and core restorations. We took morphological, esthetical and functional considerations that can help to achieve the
best results. Amongst them individual anatomic constitution, shape, width and length of the root and root canal, shape
of the clinical crown, direction and magnitude of chewing forces are the most important factors. To give examples we
present two cases of zirconium-dioxide post and core restorations. In our first case the missing clinical crown and a too
wide root canal entrance created a questionable prognosis. To minimize adverse effect of the missing ferrule effect we
applied custom-made zirconium-dioxide post and core and an additional abutment. After 7 years the restoration is still
functioning. The second case represented a much favourable situation with 1,5 mm clinical crown height. The restoration
was a custom-made zirconia post and core and a full-ceramic crown as a single tooth restoration. Although in this
case we expected a better prognosis, 15 months later the patient showed up with a post fracture for applying extreme
forces on the crown.