Shall we opt for full ceramic (e. g. E. Max) or zirconia crowns?
Where a tooth replacement is required to meet the most exacting aesthetic standards patients are recommended zirconia crowns or full ceramic crowns in the front region. These are state-of-the-art solutions for aesthetic restoration.
As with anything else, there are pros and cons to be weighed. The present article aims to provide guidelines as to which type of crown to go with.
Both types of crowns
- are modern-day achievements ideally suited even for metal allergies
- are of a material that will cause no metallic taste in the mouth
- have a light transmission ability deceivingly similar to natural teeth, which cannot be said for conventional metal ceramic crowns.
- leave no grey line at the gumline
- are metal-free (metal-free crown, metal-free tooth replacement) and thus comply with high aesthetic standards.
- are capable of perfectly eliminating aesthetic flaws of front teeth such crowded teeth, gaps between teeth (diastema), tooth discolorations, incisal edges having chipped off in the wake of an accident and developmental defects of enamel.
- are capable of changing the size, location, colour and shape of front teeth
- have size and colour perfectly adjustable to original teeth.
The only downside frequently mentioned in connection with such crowns is their price which far exceeds that of conventional crowns.
Information on full ceramic crowns (E. Max) worth taking note of:
- It is not applicable with teeth abutted with a metal post-and-core since the greyish black hue shows through the full ceramic crown.
- Less dentin or enamel requires to be filed off as compared to conventional metal crowns.
- Getting accustomed to them causes no difficulty since they are rather thin and do not disturb the tongue and the lips.
- When preparing full ceramic crowns it may be well to bear in mind a number of individual characteristics. Full ceramic crowns are not advocated for individuals grinding or clenching their teeth (bruxism).
- The solution is not applicable in the molar region or for bridge replacement.
Case no. 1. The closure of diastema with E. Max full ceramic crowns.
Case no. 2. Aethetic restoration of discoloured teeth and cervical abrasion (tooth neck wear) with E. Max crowns.
Zirconia crowns have frames made of zirconium dioxide, whence their name. Zirconium, a high-strength metal, can also be found in the periodic table. However, in that form it cannot be used for medical purposes. It first needs to undergo a chemical procedure to react with oxygen and become zirconium dioxide which is a highly resistant, high-melting point and metal-free material.
- Perfectly suited for teeth abutted with metal post-and-cores.
- Also suited for dark, discoloured, root-canal treated tooth stumps as the greyish colour will not show through.
- The frames of the crowns are precision-manufactured using the CAD/CAM procedure, in which they are milled to the last micron by a computer-controlled machine.
- Can be used as a stand-alone crown or as part of a bigger bridge in the molar region.
- Can be used for original teeth as well as implant abutments.
Case no. 3. The replacement of an old metal ceramic crown, aesthetic restoration of tooth neck wear (cervical abrasion), and discoloured root canal treated teeth.
Case no. 4. The replacement of old crowns with zirconia crowns.
Whatever cutting edge technology is used in the production of metal-free tooth replacements or crowns, they require thorough home care and regular check-ups to last. Remember this even when the tooth replacement is complete
Keywords: zirconia crown, metal-free crown, metal-free tooth replacements, zirconium dioxide, full ceramic crown, E-Max, aesthetic restoration, diastema closure, implant, metal allergy, CAD/CAM procedure