Dental clinic produces single-piece zirconia crowns

While the cubic crystalline form is often used to make jewellery, zirconia has also been commonly used in a 'stabilised', toughened state to form the core of dental crowns and bridges which are then coated in dental porcelain and shaped to fit the patient.
 
Senior lecturer from CSU’s School of Dentistry and Health Sciences, Dr Rustum Baig, said advances in technology had made it possible to now produce crowns and bridges milled from a single block of Zirconia.
 
"The traditional restorations were vulnerable to cracking where the porcelain joined the core, which could be made from zirconia, gold or some other metal, and cracking of the porcelain coating itself," he said.
 
"The new method we are using at the Charles Sturt University Dental Clinic in Orange produces what is called a CAD/CAM monolithic crown, which is stronger and can provide a better fit for the patient."
 
CAD/CAM refers to computer-aided design and milling (an image of the patient’s tooth, or a cast of the tooth, is scanned into a computer then which controls the milling process), while 'monolithic' denotes the fact the crown is produced from a single material.
 
Dr Baig said several patients had already received the new crowns and the University was gathering clinical data to demonstrate the long-term effectiveness of the technique. 
 
"This is cutting edge technology, which gives us a better fitting, stronger, longer-lasting product for the patient at the same cost as traditional restorations," he said.
 
The Clinic’s adoption of new technology also extends to 3D printing and the production of partial dentures.
 
"The traditional method to produce removable dentures for patients who are missing several teeth was to create a plaster cast, then use that cast to create a wax model of the supporting framework to which the dentures would be attached," Dr Baig said.
 
"That wax model would be used to cast the final frame in metal, so accuracy was crucial. Now we’re able to scan the cast and use a 3D printer to create a framework that is just as accurate – arguably more accurate – at a much faster rate."
 
Dr Baig said the cost of the new techniques was currently about the same as that of traditional restorations, but would be reduced as they became more widely used.
 
"These new techniques not only produce a better result for the patient, they remove a number of steps from the production process. As the technology improves and long-term data becomes available, this will become even more pronounced; eventually we hope to be able to scan the patient’s teeth as they sit in the dentist’s chair and produce these restorations on-site, excluding the need for conventional impressions and other laboratory procedures," he said.