Classic porcelain crowns use a metal base which means a more opaque and artificial-looking crown covering is needed. From an aesthetic perspective porcelain crowns fused to a zirconium base have a great advantage for the front and premolar teeth in that they allow for a more transparent, thus natural, appearance. Metal bases also cause a grey ring to form on the edge of the gums which can negatively affect the attractiveness of a smile as well as the gums. The use of zirconium bases removes this problem. Another advantage zirconium offers is that they don’t reflect the dark colouring root canal treatment caused in teeth. Zirconium is thus a perfect material for tooth restoration in cases of excessive loss of dental material and colouration after root canal treatment. In addition to being an effective treatment option that prevents the formation of grey rings on the gums, zirconium also prevents the gums from opening around the crowns or receding. Zirconium porcelain crowns can also be used to replace less aesthetic metal based bridges for the front and premolar teeth. However, it isn’t necessary to replace these metal based crowns and bridges if such problems don’t exist for 7-8 years after the previous dental restoration work.