The Science Behind Zirconia Crowns: What Makes Them So Strong

Several years of research has gone into finding the best restorative material for dental sciences. From metal alloys to new age ceramics and Zirconia crowns, the dentists and researchers have spent thousands of hours and dollars into bringing forth the restorative material that has the most benefits for dental patients. But what is the expected benefit apart from replacing and functioning as an alternative tooth? The answer for this question goes well beyond just technical factors.

Esthetics is an important part of dental science today. More and more patients worldwide want the best of esthetic dental options to give a natural teeth-like appearance. Patients no longer worry about the cost factor as long as the restorative method and type is natural and teeth-like. Patients care more about dental options that are hard to distinguish with just a gaze. Millions of dollars are spent every year as new and improved materials are tested out and brought to the dental market for trial by dentists but only a handful of options have survived the test of time and Zirconia Crown is one among the rare few.

Characteristics of Zirconia Crowns

Zirconia ceramic crowns are a type of ceramic restorations that are made from Zirconium Oxide blocks. These Zirconium oxide blocks are Yttrium stabilised to give additional strength and biocompatibility to this material. Zirconia tooth crowns are by far the most biocompatible dental crowns that have ever existed and this is all thanks to the stable form of element nature that Zirconium possesses.

Zirconia crowns are not only strong, they are also durable owing to their high flexural strength, fracture resistance and resistance to chipping or breaking. They are also the most aesthetically pleasing materials that can be used for front and back teeth equally. Most materials that we know so far are either strong but not visually pleasing or they are visually pleasing but with a lack of strength and durability.

Much research has gone into determining the durability, strength and to enhance the natural teeth-like esthetics of Zirconia crowns. Although they come in white colour, some patients may think that it is too opaque and therefore less natural looking. To counter this claim, researchers have come up with a glazing technique with a Layered Zirconia crown tooth that can help in achieving a very similar colour and stain appearance as the patient has.

Below are some of the Characteristics of Zirconia Crowns that make them stand out from the rest of the dental materials:

1. Excellent Mechanical Properties

When it comes to mechanical properties, Zirconia crowns have no match. The crowns were found to have an extremely good threshold towards biting force and can be optimally used for molars and premolars. Given its esthetic qualities, it can also be used for anterior teeth such as Canines and Incisors. It is observed that stainless steel and zirconia have very common mechanical properties which provide metal alloy like properties to Zirconia crowns.

2. Exceptional Optical Properties

Optical performance of Zirconia crowns are excellent as it has an opaque white structure that is great for preparing crowns that can mimic the actual teeth appearance. For patients who desire more of a translucent shade to create real-life staining, glazing on layered Zirconia crowns are an excellent option. Many patients prefer higher translucency to create life-like tooth crowns and for this reason, more and more variants of Zirconia crowns are being designed by researchers to increase the effective usage of these crowns in patients.

3. High Fracture Resistance

Zirconia crowns have a fracture Resistance of 9-10MPa with a high resistance to traction when compared to most of the dental restorative materials available in the market today. This translates into extremely durable and chip-resistant crowns every time a patient chooses Zirconia crowns thanks to the Transformation process which involves retaining the tetragonal structure at room temperature. This is an important process that is conducted by scientists when developing Zirconia crowns to ensure optimum strength and sturdity.

4. High Flexural Strength

Flexural strength is an essential parameter when it comes to dental crowns. This is because the high flexural strength allows for better resistance to traction and lends into the fracture resistance and anti-chip properties of the tooth crown. Zirconia has a high Flexural strength of 90-120 MPa which is a good measure when compared to the other dental restorative methods.

This yields better strength and durability for a patient that can undergo a good amount of bite force for extended periods of time when in a patient's mouth.

5. Biocompatibility

Another stellar feature of Zirconia crowns is their biocompatibility. There are many different types of Zirconia crowns available in the market but the most biocompatible forms are Magnesium stabilised zirconia and Yttrium stabilised Zirconia. The Yttria Stabilised (Y-TZP) form of Zirconia that is used for making crowns are known to have minimal to no risk of gingival reactions or inflammations in most patients. Many years of research has verified the claim that Zirconia does not have any adverse effects on the body, no periodontal issues including changes in soft or hard tissues and nor does it have any cytotoxic effects when used for extended periods of time.

6. Unparalleled Esthetics

There are different kinds of Zirconia ceramic crowns in the market today and some have higher visual appeal than others. The most common type of Zirconia crown which has 35% Zirconium dioxide is lesser known for its translucency and optical abilities. It however is a great option for posterior teeth because of its high strength and durability. On the other hand, newer types of Zirconia materials such as the IPS e.max and ProCera AllCeram materials that utilise a hybrid of Zirconia with other materials are known for their better translucency and therefore more visual appeal when used for anterior teeth.

Full contour Zirconia crowns are an upcoming modern solution to the difficulty faced in the core material that leads to lack of translucency and natural appeal in the teeth. Full contour zirconia dental crowns have better shade value due to improved light transmission abilities.

7. Cost of Zirconia Dental Crowns

It is also important to note that given the excellent mechanical and optical abilities of the crown, the Zirconia crowns cost is not as high as one would imagine. The average Zirconia crown price is between a few hundred dollars in the US and is lower in some of the major cities. Given that there are multiple types of the crowns to choose from, Zirconia crown cost can be lowered based on the type of requirement of the patient especially if the restoration is in the posterior area of the mouth.

These are some of the mechanical properties and characteristics that make them one of the strongest options in the dental market today. More and more research is done every single day to improve the crowns made from Zirconia to suit all the needs and requirements of the modern day and for the different kinds of needs of the patient.

Benefits of Using Zirconia Crowns over other Options

Given that Zirconia crowns are the most modern solutions to all the dental issues especially in the esthetics and durability area, below are some of the benefits to patients when they choose a Zirconia dental crown over other types of dental restoration materials:

• Zirconia crowns are by far the most biocompatible options available in the market and are most suited for patients who want to stay away from metal based restorations and patients with high sensitivity to most elements.
• Zirconia crowns are one of the most aesthetic solutions in the market with different types of material combinations that help in providing the required translucency and visual appeal to patients for both posterior and anterior restorations.
• Zirconia crowns are sturdier and more durable than other visually pleasing materials such as Ceramic crowns that are available in the market with better mechanical and optical properties.
• They are at par to All Ceramic crowns and other visually appealing crowns when it comes to cost but offer better strength and durability at the same cost.
• Zirconia crowns are made in-house with modern CAD/CAM technologies that cut down on the manufacturing time and therefore helps patients in having a quicker dental restoration and crown preparation process.

These are some of the benefits of using Zirconia crown and choosing Zirconia based restorations for dental requirements. Zirconia crowns are widely available in all kinds of dental clinics and patients should ask for them before making their choice for a dental crown.