Matching The Single Unit: Layered Zirconia

mm Written by Andrew Sedler

One of the most difficult challenges for any dental team is matching an anterior single-unit restoration where esthetics is critical in ensuring a successful result.  The difficulties are rooted in properly communicating the color and characteristics of the surrounding dentition, coupled with fabricating a restoration based on the information provided.

While technology such as computer-aided design (CAD) and computer-aided manufacturing (CAM) have managed to advance dental procedures for the better, shade matching remains an artistic endeavor dependent on color communication between the clinician and the laboratory.

In many cases, especially those with detailed characteristics, the best fabrication technique is by layering porcelain. This fabrication type requires a high level of artistic prowess on the part of the laboratory and a high level of accurate color communication from the clinician.

Tips for Better Color Communication

One of the essential factors in the success of matching dental restorations to an existing oral environment is the communication of color and characteristics present.  Several factors affect the ability to properly choose a shade. The light source's quality is one of the most significant factors in influencing an accurate shade match.

While natural mid-day lighting provides the most precise lighting for selecting a color, it is not practical to rely on this for choosing a color on cases seen throughout the day. Therefore, the use of artificial light sources is the preferred option. Operatories with color-corrected lighting or full-spectrum LED lighting work well for this task. The ideal situation is that the lighting is balanced and as close to natural light as possible.

Indirect light sources can also affect the ability to properly choose a shade. These would include windows or outside lighting sources.  It is a good idea to block out these outside light sources altogether when taking the shade.

Color influencers can also create poor shade evaluation.  This includes the color of the operatory walls and floors. Bright colors on clothing or lipstick shades can cast colors that can be picked up when selecting the shade.  It is therefore crucial that any surrounding colors be neutralized before taking the shade. You can do this by draping a neutral-colored cloth over the patient to hide any colors in their clothing and ask them to remove lipstick.

Taking the Shade

When taking the shade, it is essential to note that a tooth should not be looked at for any longer than 5 seconds.  If it is necessary to evaluate any longer than 5 seconds, then look at a blue background to rest the eyes before selecting the color. The first evaluation of color is usually the most accurate.

Additional steps in taking the shade are as follows:

Matching The Single Unit: Layered Zirconia
Hold the entire guide up to the patient's tooth. (Figure 1)
  1. Take the shade early as dehydration can occur within a couple of minutes of the patient’s mouth being open. Dehydrated teeth will depict an increase in value and a decrease in the translucency and chroma, making the shade selection inaccurate.
  2. Have the patient sit in an upright position because the way light enters the mouth can affect the color selection.
  3. Reduce shadowing by using lip retractors.
  4. Take the shade while level with the patient’s teeth.
  5. Hold the entire guide up to the patient's tooth (Figure 1). Use the buccal portion of the tooth to help determine the hue.
  6. Hold the shade tab in the same position as the tooth being examined.
    - The guide should not be lingual of the teeth or held outside the mouth.
    - Hold the facial surface of the shade tab parallel to the facial plane of the tooth.
    - Hold the incisal edge of the guide to the incisal edge of the tooth being evaluated (Figure 2)
    - Take a photo of the tab next to the tooth.
  7. After preparation, take a shade of the prepped tooth and also a picture of the tab next to the prepped tooth.
Matching The Single Unit: Layered Zirconia
Hold the incisal edge of the guide to the incisal edge of the tooth being evaluated. (Figure 2)
Photography
Photography - dental restorations
A dual point flash or ring flash with a diffuser is recommended. (Figure 3)

Having clear photos is extremely helpful to technicians, especially in cases where the goal is to fabricate a restoration that matches the existing oral environment. While color cannot be communicated using photography, it can provide other information such as characterization attributes.

A dual point flash or ring flash with a diffuser is recommended to reduce the flash bounce back (Figure 3). The camera should be positioned at the same level as the patient's teeth, and the following shots should be taken:

  • Full face
  • Natural smile
  • Lips retracted
  • Pictures with the selected shade tabs.

With these protocols, an exact shade can be recorded and sent to the lab for case fabrication.

Layered Zirconia

One of the best fabrications of an anterior single unit is a restoration where the color and characterization are layered in porcelain. Restorations such as those with a zirconia substructure and then layered porcelain offer control when matching restorations in the esthetic zone.

The following case presented with a challenging shade and characterization match. The goal was to utilize a hybrid workflow using digital dentistry, and hand stacked layered porcelain to match this restoration to the surrounding oral environment.

The doctor took a digital impression and sent this data to the digital team at Burbank Dental Lab. The doctor also sent along the relative shade information and pictures showing the characterization needed to match the crown to the patient's existing teeth.

Match the crown to the patient's existing teeth
Match the Crown to the patient's existing teeth

The substructure was designed digitally to ensure accurate marginal fit, and the parameters set to ensure the coping was fabricated according to the materials specifications to maintain optimum strength.

Matching The Single Unit: Layered Zirconia
Matching The Single Unit: Layered Zirconia

The coping was then milled utilizing Burbank Dental Lab's proprietary ZIRMAX M zirconia with 1000 MPa strength.

The digital files were also used to print a working model used during the final fabrication process.

Matching The Single Unit: Layered Zirconia

The case was then moved to the ceramic department at Burbank Dental Lab, where highly skilled ceramists were tasked with looking at the doctor's photos and extrapolating the data to layer porcelain and add necessary staining that in the end helped this restoration blend in with the patient's dentition.

The patient’s teeth had varying translucencies, hypo calcification areas, and dark neck colorization. The case was fabricated with all of the necessary data incorporated into the restoration.

Matching The Single Unit: Layered Zirconia
Matching The Single Unit: Layered Zirconia

After completion, the case was sent to the clinician and was tried in. Both the patient and doctor were thrilled with the result, and this case was cemented on the first try.

The great result obtained with this case was in direct correlation to the excellent communication with the clinician.

Matching The Single Unit: Layered Zirconia
Result

The shade was accurately recorded, and the proper photos were sent.

This information in the hands of skilled dental technicians is what it takes to fabricate restorations that provide patients with a great dental experience.

For more information on layered zirconia restorations by Burbank Dental Lab, please chat or call us today.

Did you like this article?

Let us know by giving us a clap!

3+

Top 10 Most Clapped Articles

Resource Center

Products

Resources

Slide 1

Fabrication
of the future
is here!

Burbank Dental Lab has three new state-of-the-art Carbon M2 printers. We are very excited about the options that these cutting-edge printers will allow us to offer our dental clients. Here are some of the advantages that these printers will begin to deliver to you and your dental practice.

Our New
State-Of-The-Art
3d Printers

Carbon offers a highly dependable 3D manufacturing solution for many dental applications with its breakthrough Digital Light Synthesis™ technology, enabled by a wide range of dental materials.

Fabrication
of the future
is here!

Burbank Dental Lab has three new state-of-the-art Carbon M2 printers. We are very excited about the options that these cutting-edge printers will allow us to offer our dental clients. Here are some of the advantages that these printers will begin to deliver to you and your dental practice.

Our New
State-Of-The-Art
3d Printers

Carbon offers a highly dependable 3D manufacturing solution for many dental applications with its breakthrough Digital Light Synthesis™ technology, enabled by a wide range of dental materials.