For most people, E.max (lithium disilicate) ceramic is the usual first choice for front teeth because it is translucent and looks very natural, while zirconia is often preferred for back teeth because it is stronger and copes better with heavy chewing. The right choice still depends on your bite, your habits and the tooth underneath.
What are zirconia and E.max crowns?
A crown is a tooth-shaped cap that covers a damaged tooth to restore its shape and strength. If you would like an overview of every option, start with our guide to the different types of dental crowns and when you need one. Zirconia and E.max are both metal-free and tooth-coloured, but they behave quite differently.
Zirconia (zirconium dioxide) is a very tough ceramic that resists fracture well. According to Cleveland Clinic, zirconia crowns can withstand heavier forces than other types of ceramic crowns. Older zirconia looked rather opaque and chalky; newer, more translucent versions look considerably more natural, although they tend to be slightly less strong.
E.max is a brand name for lithium disilicate, a glass-ceramic. “Glass-ceramic” means the material contains a glassy component that lets light pass through it, much like natural enamel. It is strong for a glass-ceramic, but not as strong as zirconia. It is usually bonded to the tooth with an adhesive resin cement, so that crown and tooth work together as one unit.
Front teeth: why appearance usually comes first
Front teeth take relatively light biting forces, but they are seen every time you speak or smile. Here the priority is a crown that matches the neighbouring teeth in colour, translucency and surface texture.
E.max is often favoured for front teeth because its translucency mimics natural enamel, especially near the biting edge, where real teeth look slightly see-through. Light passes into the crown instead of bouncing off a solid surface, so it tends to blend in well next to natural teeth.
Zirconia can still be a sensible choice at the front in some situations: when the tooth underneath is very dark, when there is a metal post inside it, or when a longer bridge is needed. Its greater opacity helps hide a dark core. When only the front surface of a tooth needs changing, a veneer may be more conservative than a full crown; our article on dental veneers, their types and lifespan explains the difference.
Back teeth: why strength usually comes first
Molars and premolars do most of the chewing, and the forces on them are much higher than on front teeth. They are also less visible, so strength and durability usually matter more than perfect translucency.
Monolithic zirconia, meaning a crown milled from one solid block without a separate porcelain layer on top, is a common choice for molars. Because there is no outer layer, there is little risk of the surface chipping off. It can also often be made thinner than a glass-ceramic crown, which may mean less of the tooth has to be removed when space is tight.
E.max can work well on premolars and, in carefully selected cases, on molars, provided there is enough room to make it thick enough. For people who clench or grind their teeth (bruxism), many dentists lean towards zirconia. If you are also weighing metal-based options, see our comparison of zirconia and porcelain-fused-to-metal crowns.
Other factors that guide the choice
The position of the tooth is only the starting point. Your dentist will also consider:
- Your bite and habits: grinding, clenching or a deep bite place extra stress on any crown.
- The colour of the tooth underneath: a heavily discoloured tooth or a metal post is easier to mask with a more opaque material.
- Available space: how much tooth can be reduced safely, and how tall the tooth is.
- Bonding conditions: E.max relies on adhesive bonding, which needs a clean, dry surface; edges placed deep under the gum can make this harder.
- Bridges and implants: zirconia is generally used for longer bridges, whereas lithium disilicate is usually limited to short bridges at the front of the mouth.
| Feature | Zirconia | E.max (lithium disilicate) |
|---|---|---|
| Strength | Very high | High for a glass-ceramic |
| Natural look | Good, more opaque | Very natural, translucent |
| Typical position | Molars, premolars, bridges | Front teeth, premolars |
| Masking a dark tooth | Easier | More difficult |
| Fixing method | Cemented or bonded | Usually bonded |
The procedure, comfort and aftercare
Step by step
- Examination and X-ray to check the root, the nerve and the gum around the tooth. If the nerve is infected, root canal treatment may be needed first.
- Preparation: the tooth is shaped under local anaesthesia to make room for the crown. This visit usually takes about one to two hours.
- Impression and shade: an accurate impression (mould) of the tooth is taken, and the shade is matched to your neighbouring teeth.
- Temporary crown: you wear a temporary crown while the laboratory makes the final one, usually for one to two weeks.
- Fitting: the crown is checked for fit, colour and bite, then cemented or bonded in place.
Pain and anaesthesia
Preparation is done with local anaesthesia, a numbing injection, so you should feel pressure and vibration rather than pain. Afterwards the gum may be sore and the tooth slightly sensitive to cold for a few days, which simple painkillers usually relieve.
Aftercare and lifespan
Brush twice a day with fluoride toothpaste, clean between your teeth daily and keep regular check-ups, because the tooth under the crown can still decay at the edge. If you grind your teeth, a night guard helps protect either material. With good care, both zirconia and E.max crowns commonly last 10 to 15 years or more.
Risks, alternatives and what determines the cost
Both materials are well established, but no crown is completely risk-free. Possible problems include chipping or fracture (more likely with E.max under heavy forces or when it is too thin), decay at the crown edge, gum irritation if the margin is not kept clean and, occasionally, the need for root canal treatment if the nerve becomes inflamed after preparation.
Alternatives depend on the tooth: a filling or composite bonding for smaller damage, an onlay (a partial crown) when some walls are still strong, a veneer for front teeth with mainly cosmetic concerns, or a metal-based crown in some back-tooth situations.
There is no single price for a crown, because the cost depends on factors that can only be judged at a consultation:
- The material chosen and whether the crown is monolithic or layered.
- The number of teeth to be treated.
- Any preliminary treatment, such as a build-up filling, root canal treatment or gum care.
- The laboratory work and the complexity of shade matching.
Zirconia and ceramic crowns at Ajam Dental Clinic in Tripoli
Ajam Dental Clinic, on Fouad Chehab Boulevard in Tripoli, offers both zirconia crowns and ceramic crowns as part of its prosthodontic treatments. Crowns, bridges and smile design are the focus of Dr. Abdel Rahman Ajam, who holds an MSc in Aesthetic and Prosthetic Dentistry. Patients come to us from across Tripoli — from Azmi Street and Al-Maarad to Al-Nour Square and Bab al-Ramel — as well as from Koura, Zgharta and the rest of North Lebanon. You can read more about our dentists.
At a consultation, the tooth is examined and the options are explained calmly, so that you can choose the material that suits your tooth, your bite and your expectations. To book, contact the clinic by phone or WhatsApp.
Frequently asked questions
Can I have zirconia crowns on my back teeth and E.max on my front teeth?
Yes, and this combination is common. Many people have strong zirconia crowns on their molars, where chewing forces are highest, and translucent E.max crowns or veneers on their front teeth, where appearance matters most. The key is shade matching: the laboratory adjusts the colour of each material so that both blend with your natural teeth and with each other. Because the two materials reflect light slightly differently, your dentist will usually check the shade in daylight and may ask you to approve it before the final crowns are fitted.
Will people be able to tell that I have a crown?
In most cases, no. A well-made E.max crown on a front tooth usually blends in closely with the neighbouring teeth, and modern zirconia looks far more natural than older versions. What makes the biggest difference is careful shade selection, the shape of the crown and healthy gums around its edge. A thin grey line at the gum is typical of older metal-based crowns, not of metal-free ceramics. If your gums recede over the years, the edge of the crown may become more visible, which is one reason why good gum care matters.
Can I whiten a zirconia or E.max crown?
No. Whitening gels lighten natural enamel, but they do not change the colour of ceramic. That is why, if you are thinking about whitening your teeth, it is usually best to do it before a crown is made, so that the crown can be matched to the new, lighter shade. It is wise to wait a little after whitening before the shade is taken, because the colour usually settles over the following days. If an existing crown no longer matches after whitening, the only way to change its colour is to replace it.
My new crown feels high or sensitive. Is that normal?
Mild sensitivity to cold and some gum tenderness for a few days after fitting are common and usually fade on their own. A crown that feels high when you bite, however, should be checked: even a small excess can make the tooth sore and put extra stress on the crown. The adjustment is quick and usually painless. Contact your dentist if the pain increases, if you have throbbing pain at night or swelling, or if sensitivity lasts more than a few weeks, as these can be signs that the nerve needs attention.
What happens if my crown chips or breaks?
Small chips at the edge can sometimes be polished smooth or repaired with composite resin, a tooth-coloured filling material. A larger fracture, or a crack that runs through the crown, usually means the crown has to be replaced. Keep any broken pieces, avoid chewing on that side and see your dentist promptly, because the exposed tooth may be sensitive or at risk of further damage. If grinding contributed to the break, your dentist may suggest a stronger material for the new crown and a night guard to protect it.
Does a tooth always need root canal treatment before a crown?
No. Many teeth receive a crown while the nerve is still healthy and alive. Root canal treatment is only needed if the nerve is infected, badly inflamed or no longer alive, which your dentist checks with an examination, simple tests and an X-ray before preparing the tooth. On the other hand, back teeth that have already had root canal treatment often benefit from a crown, because they can become more brittle over time. Your dentist will explain which situation applies to your tooth before any treatment begins.
Have a question about your teeth?
Send a WhatsApp message to Dr. Abdel Rahman Ajam or Dr. Soumaya Ajam, or call the clinic to book a consultation.
This article provides general information for patients. It does not replace an examination by a dentist, who can advise you on your own situation.