Plenty of dentists are aware of the main benefits of digital dentistry, including time savings, convenience and excellent results of in-office restorations. But when it comes to the nuances of selecting the right equipment and materials to accomplish a goal like single-visit dentistry, finding all of the information in clear terms can sometimes be difficult.

Perhaps the most common misunderstanding among doctors purchasing in-office systems centers on a specific term used regarding milling material blocks: “sintering.” If you’re not entirely sure what a sintered block is, or what a fully sintered block like BruxZir^® NOW can do for you, you’re not alone.

Sintering is the process by which a powdered or porous mass, already formed into the desired shape, is converted into a solid through heating without melting or liquefaction.

If you’re familiar enough with milling blocks and their packaging, you’re probably aware that glass ceramic and zirconia blocks compatible with your in-office system have gone through some type of sintering process, simply because they’re likely labeled with the term “pre-sintered” or “partially sintered.” What you may not realize is that this sintering process is only half the story.

To understand the difference between pre-sintered blocks and fully sintered ones like BruxZir NOW (and BruxZir Esthetic NOW, designed for anterior crowns), it helps to know the specific stages required to create a finished, deliverable crown from a raw material such as zirconia. Sintering is a critical stage in densifying the material to produce hard, strong restorations with the desired esthetics.

As it pertains to restorations produced from zirconia milling blanks, sintering is critical in densifying the material to produce restorations that are hard, strong, and express desired esthetics.

1. Zirconia and other materials used to create permanent restorations begin in a powder form which manufacturers compact through pressing or other methods in order to produce "green state" bodies. These powder compacts are characteristically soft, fragile, and up to 50% larger than they will be in their final, fully sintered and densified form. Dental labs and dentists who perform in-office digital dentistry will never handle zirconia in its green state.
2. In order to produce a sturdier mass capable of withstanding stresses involved with milling and handling, manufacturers fire or pre-sinter the green state compacts to produce blocks in "bisque state." This pre-sinter firing process serves to remove organic binders which may be present to hold pressed compacts together and also to induce the onset of sintering to a partial degree, requiring a final firing operation to be performed by dentists. The bisque-state bodies resulting from pre-sintering have a soft, chalk-like consistency that's easy to mill and handle.
3. After milling restorations from partially sintered blocks and optionally precoloring, full sintering is performed by firing the milled bodies according to the block manufacturers’ firing profiles. Strong, dense, and hard restorations are yielded from the final sintering stage.

The takeaway here is that the majority of milling blocks for your in-office system arrive in the second of these three stages: they’re pre-sintered, meaning a final firing is needed prior to delivery. This is typically because it keeps the milling block soft enough to be milled by most in-office mills, while still being durable enough to achieve reasonable results and margin integrity.

This is where it becomes clear why BruxZir NOW fully sintered zirconia, and the glidewell.io^™ In-Office Solution, stand out from the crowd.

BruxZir NOW zirconia milling blocks arrive in a fully sintered state, having undergone both the pre-sintering and final sintering stages. Paired with the fastmill.io, the milling component of glidewell.io, BruxZir NOW blocks are a game changer for your digital workflow. Still not sure why this is the case? Take a look at the steps outlined below.

Designing, milling and delivering a single-unit in-office zirconia restoration is best achieved with milling blocks that require no oven time prior to delivery. As of now, BruxZir NOW zirconia blocks are unique in the market in that they arrive fully sintered and ready to go.

• The Best, Simplest Way to Provide Single-Visit Restorations
  Fully sintered BruxZir NOW blocks require no oven time, which not only cuts out the need for an oven, but also eliminates the time required between scanning the patient and final restoration delivery. The simplified workflow of BruxZir NOW eliminates multiple steps from the in-office process, allowing for the treatment of more patients in less time and increasing the doctor’s capabilities.
• Time Savings
  The ability to simply design, mill and deliver a restoration with no sintering required saves your patient time by eliminating second appointments. It’s also a major timesaver for you and your staff, since it removes a major step from the in-office restoration workflow. Because no oven is needed to deliver fully sintered zirconia, the learning curve of the process is simpler, and your staff will learn it much more quickly. What’s more, the removal of the oven step from the workflow simplifies the entire process by freeing up staff time that may have otherwise been spent setting up and tending to the oven. This free time is now available for other tasks that need attention in the clinic.
• Equipment — Simplified
  In-office ovens can be expensive, challenging to learn, and tricky to work into an efficient digital workflow. For many dentists, the oven is the reason they have not yet gone fully digital.

It’s true that milling blocks made from other types of materials will require oven time, in which case you may want to purchase one regardless. However, if you are only delivering single-unit zirconia restorations, then using fully sintered blocks will save you the oven investment.

Most likely, you chose zirconia for your single-unit restoration due to the material’s combination of strength and esthetics. The restorations you create from fully sintered zirconia, even though they’re easier and faster to use than those that arrive as pre-sintered blocks and require in-office firing, have the same strength you expect from zirconia and feature superb margin integrity.