An emax crown is an all-ceramic dental crown made from lithium disilicate, a type of glass ceramic known for its combination of strength and natural translucency. Manufactured by Ivoclar Vivadent, it has become one of the most widely used ceramic crown systems in modern dentistry, particularly for front teeth where appearance matters most. Its 10-year survival rate sits around 99.6%, making it one of the most reliable options available.
What Makes Emax Different From Other Crowns
The defining feature of an emax crown is its material: lithium disilicate glass ceramic. Unlike traditional porcelain-fused-to-metal crowns, which have a metal base covered by a porcelain shell, emax crowns are a single ceramic material all the way through. This eliminates the dark metal line that sometimes shows at the gum margin of older-style crowns.
The ceramic itself has an unusual internal structure. Rod-shaped crystals grow within the glass matrix during manufacturing, creating a reinforced structure similar to fiberglass. This crystal arrangement is what gives emax crowns their strength while still allowing light to pass through the material the way it does through a natural tooth. That light transmission is why emax crowns look remarkably lifelike, especially in the front of the mouth where thinner, more translucent teeth make aesthetics harder to match.
How Emax Crowns Are Made
Emax crowns are fabricated in two ways: milled by a computer (CAD/CAM) or heat-pressed in a dental lab. Each method starts with a different form of the material and produces slightly different results.
The CAD/CAM version begins as a pre-made block of lithium metasilicate, a partially crystallized, bluish-colored ceramic. Your dentist or a lab technician uses digital scans of your teeth to design the crown on a computer, then a milling machine carves it from the block. The crown is then fired in a furnace to complete the crystallization process, transforming it into its final, tooth-colored form. This method can sometimes allow same-day crowns in offices with the right equipment.
The press version uses a lost-wax technique. A wax model of the crown is created, invested in a mold, and then replaced with lithium disilicate ceramic under heat and pressure. In lab testing, the CAD version starts with slightly higher initial strength (around 612 MPa compared to 534 MPa for the pressed version), though both versions perform similarly over time as they undergo wear and thermal stress. Both methods produce clinically excellent crowns, and the choice often comes down to the dental lab’s capabilities and the complexity of the case.
Strength and Durability
Emax crowns sit in a middle ground between the high aesthetics of traditional porcelain and the extreme toughness of zirconia. Their flexural strength of roughly 500 to 600 MPa is more than adequate for front teeth and most back teeth, though they’re not the strongest option for heavy-duty grinding surfaces in people who clench or grind their teeth.
A large study tracking nearly 2,000 emax crowns over a decade found only seven outright failures (bulk fractures or chips large enough to require replacement), with the average failure occurring around 4.2 years in. Monolithic emax crowns, those made from a single block without a layered porcelain coating, showed a 96.5% survival rate at just over 10 years. Bilayered versions, where porcelain is added on top for extra aesthetic detail, reached 100% survival at nearly 8 years of follow-up.
Where Emax Crowns Work Best
Emax is the go-to choice for front teeth. Its high translucency mimics the way natural enamel interacts with light, which is difficult for more opaque materials to replicate. For incisors, canines, and premolars, emax consistently delivers the most natural-looking result among current crown options.
For back molars, emax works well in most patients, but your dentist may recommend zirconia instead if you have a strong bite, grind your teeth at night, or need a crown on a tooth with limited remaining structure. Zirconia is roughly twice as strong but less translucent, so it trades some visual realism for extra fracture resistance. Some dentists split the difference by using zirconia on molars and emax on everything visible when you smile.
How Your Tooth Is Prepared
Getting an emax crown requires removing a thin, precise layer of your natural tooth to create room for the ceramic. The amount varies by location:
- Front teeth: 1.2 mm removed from the biting edge and 1.5 mm from the sides
- Back teeth: 1.5 mm removed from the chewing surface and 1.5 mm from the sides
These are relatively conservative reductions compared to some older crown types, which means more of your natural tooth structure is preserved. The preparation creates a smooth, rounded shoulder at the gum line rather than a sharp ledge, which helps the crown fit precisely and reduces stress on the ceramic.
After preparation, your dentist takes a digital scan or traditional impression. If a lab is fabricating the crown, you’ll wear a temporary for one to two weeks. Some offices with in-house milling equipment can complete the entire process in a single visit.
How Emax Crowns Are Bonded
One of emax’s clinical advantages is how securely it bonds to tooth structure. Because it’s a glass-based ceramic, its inner surface can be chemically etched to create a microscopic texture that interlocks with dental cement. The bonding process involves treating the inside of the crown with a combined etching and priming agent for about 60 seconds, then rinsing and drying before cementation.
This adhesive bond does more than just hold the crown in place. It actually reinforces the ceramic, making the entire crown-and-tooth unit stronger than either component alone. This is a key difference from zirconia crowns, which rely more on friction and conventional cement rather than a true chemical bond. The strong adhesive connection is one reason emax performs so well on front teeth, where crowns experience more peeling and shearing forces.
Emax vs. Zirconia: Choosing Between Them
The two most common all-ceramic crown materials today are emax and zirconia, and they complement each other more than they compete. Emax wins on aesthetics. Its translucency closely matches natural teeth, making it the better choice for any tooth that shows when you talk or smile. Zirconia can be layered with porcelain to improve its appearance, but it still doesn’t transmit light the way emax does.
Zirconia wins on raw strength. It’s the better option for second molars, for patients with bruxism (teeth grinding), and in situations where the tooth has been heavily reduced and the crown needs to bear significant force. Cost is generally similar for both, though this varies by region and dental practice. Many treatment plans use both materials in the same mouth, placing each where it performs best.
What to Expect After Placement
Emax crowns require no special maintenance beyond normal oral hygiene. You brush and floss them like natural teeth. The ceramic surface is highly resistant to staining and doesn’t discolor over time the way composite fillings or natural enamel can.
Some sensitivity to hot and cold is normal for the first few days to weeks after placement, especially if the underlying tooth still has a living nerve. Your bite may feel slightly different at first, but this typically resolves within a few days as you adjust. If the crown feels high when you bite down, a quick adjustment at the dental office can correct it.
The main risk over the life of the crown is chipping or fracture, though as the survival data shows, this is uncommon. Habits like chewing ice, biting fingernails, or using your teeth to open packaging increase the risk. A night guard is worth considering if you grind your teeth, as it protects both the crown and the opposing natural teeth.