The Rejuvenation of Worn Teeth with Zirconium Restorations
Dr Firdaus Hanapiah
BDS (Otago,NZ) MSc (Lon.) FDSRCS (England)
Introduction
Wear and tear of normal teeth is a fact of life that has to be faced by all of us as we get older. The enamel is worn down due to various factors. Unlike organs such as the bones, skin, liver or other parts of the body, the teeth do not rejuvenate itself. Therefore, the enamel that the tooth has at the beginning of eruption as a child is essentially the same enamel that we have as we age.
The most obvious reason for the wear in teeth is its use in normal mastication as we cut and tear our food over the years; we will, inevitably wear down the enamel on our teeth. The type of food also influences the wear rate of the teeth. The consumption of fizzy drinks will also cause erosion of the enamel. Other causes of tooth wear are the incorrect use of tooth brush that causes the wearing down of the enamel, as well as para-functional habits such as night grinding (bruxism).
The answer for the prevention teeth enamel wear would be to choose not to take too much food that can cause erosion in teeth as well as to use a softer tooth brush. As for the para-functional habits such as grinding, a night guard would help prevent tooth wear as well as it may alter these para-functional habits.
However, if the wear has become significant to an extent that it has caused the tooth to become sensitive or significant vertical cracks are seen or deformation of the shape of the teeth, then a crown would be an ideal solution. The standard porcelain fused to metal crown used to be the “gold standard” solution to this problem. The benefit would be the encapsulation of the tooth thus making it stronger as well as to protect the tooth from the external leakage from the crack enamel. There is a serious disadvantage to this solution and it is the aesthetics of this restoration. Often times, the metal below the porcelain will reflect a dark hue (colour) on the gums. This is very noticeable especially if the crowns are done for anterior (front) teeth. Today the gold standard would be a set of zirconium crowns.
Case Report
A 63-year-old patient came to our clinic with complaints of sensitive and discoloured lower teeth. She has had extensive posterior teeth restorations and was not very keen on the standard porcelain fused to metal crown as she was not happy with the colour of some of her own crowns.
Fig 1 worn down front lower teeth.
It was decided that she would need 6 lower anterior zirconium crowns to restore the worn down lower front incisor teeth.
Fig 2 Zirconium crowns on the articulator.
The zirconium crowns are made via CAD/CAM method via electronic scanning and milled to an accurate finish. The copings are then hand-layered using Noritake porcelain by a skilled dental technologist.
The result is well worth the effort as the patient is now fully restored with an aesthetically pleasing result as well as all the benefits of protection to the existing teeth.
Fig 3. Six lower zirconium crowns placed
Fig 4 lower front teeth with exactly the same colour and shade compared to natural upper teeth
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