How to handle ill-fitting zirconia crowns

Among many types of healthy teeth, Zirconia porcelain teeth have been the most popular and widely used in the past decade. If PFM teeth have limited aesthetics, Emax is unsuitable for bridges, and Zirconia can meet all restorations of posterior teeth, anterior teeth, and bridges. Besides, with high durability, Zirconia teeth can withstand large chewing forces and are less abrasive for a long time. Zirconia teeth can last a lifetime if placed and maintained correctly. Because it is a new material, putting Zirconia teeth so that it fits snugly in the patient’s mouth is also a problem requiring dentists to learn from experience. A perfectly crafted zirconia tooth, but the inexperience of the dentist can lead to ill-fitting Zirconia crowns. A well-fitting crown will help the patient feel comfortable, solving later problems. Therefore, dentists need to learn how to place Zirconia crowns properly and how to adjust the fit of the crown to help seal the damaged part of the patient’s teeth while protecting the natural teeth from more damage

1. What are the possible causes of ill-fitting Zirconia crowns?

• Ill-fitting Zirconia Crowns are usually made in a hurry, leaving no time for technicians to design, grind or contour the finish accurately. An inadequate margin can create holes for saliva and bacteria to enter the crown, damaging the natural crown inside and causing cavities or periodontal problems.
• The improper filling process can also cause zirconia teeth not to fit correctly on the crown. Loose fillings allow saliva, leftover food, and bacteria to enter, causing infection and tooth decay.
• The wrong impression-taking process leads to inaccurate data provided to the dental lab, affecting the quality of Zirconia tooth production. As a result, the manufactured Zirconia tooth did not fit the patient.
• Error in preparation

2. How to fix ill-filling Zirconia crowns

•  If Zirconia teeth are found not to fit correctly, try changing the cementing process. It is best to check the fit of the Zirconia teeth in the patient’s mouth before cleaning the teeth with a pumice stone.
• Thorough cleaning of the intaglio surface of the zirconia restoration will help increase adhesion before applying the adhesive to the crown, cementing the crown, placing it in place, and removing the excess cement.

3. Three ways to remove the phosphate group

Remove the phosphate group help to prevent ill-fitting Zirconia crowns

• Sandblasting: most manufacturers recommend gentle in-tooth surface sandblasting with low pressure.
•  Sodium hypochlorite: Use gauze soaked with 5% sodium hypochlorite solution to wipe the intaglio of the crown, wash the restoration with water, and let it dry naturally.
• Ivoclean: Apply Ivoclean solution to the intaglio surface of the zirconia crowns for 20 seconds, then rinse. Let dry naturally and ready to bond.

 4. Problems with facial-lingually

• Some zirconia teeth have a close-fitting margin but have facial lingual problems, mainly because any irregularities in the digital image of the patient’s tooth are eliminated. In contrast, new restorations with smooth inner surfaces will not fit the actual undercuts of the patient.
• To overcome the facial-lingually problem, the dentist needs to set the computer program that can create well-fitting margins while specifying the space size between the fit surface and the prep site. This simple step replicates the function of a conventional die-spacer and will prevent zirconia crowns from rocking facial-lingually.

Where to find a quality outsourcing dental laboratory? In Vietnam, Xdent is one of the specialist dental partners for the foreign market. Xdent is a subsidiary of Nha Viet dental group – the largest distribution center of dental materials in the Vietnam market since 2006. With a long experience in the dental field, we will bring Zirconia crowns at competitive prices and high quality to the customers. You send us the correct and quality impressions, no ill-fitting Zirconia crowns you receive. To learn more about us, please visit LinkedIn: https://www.linkedin.com/in/xdentdentallab/ Facebook: https://www.facebook.com/Xdentdentallab Twitter: https://twitter.com/Xdentdentallab Author: Xdent lab