Porcelain and Dental Ceramics

Ceramics are grouped by what they are made of, and above all by how much glass they contain. A 2015 classification sorts them by whether a glass phase is present or absent, or whether ceramic particles are held in a resin². A 2020 review divides the glass-based ceramics further, by how many crystal particles are added to the glass¹.

• Feldspathic porcelain. Mainly glass, with only small amounts of other particles¹. It can look very lifelike, and it is weaker than the other ceramics. It is built up by hand in layers, for thin veneers and as the outer layer on zirconia and metal frameworks.
• Leucite-reinforced glass ceramics. Glass with added leucite crystals, which improve its strength but can make it look less lifelike¹.
• Lithium disilicate glass ceramic. Fine crystals of lithium disilicate held in a glass³, with no metal. It is stronger than feldspathic porcelain and still lets light through much like a natural tooth. A 2025 review describes feldspathic and leucite-reinforced ceramics as very lifelike but mechanically weaker, and lithium disilicate as a balance of appearance and strength⁴. Our lithium disilicate glass ceramic page explains it in depth.
• Zirconia. Patients often call it "zirconium", but zirconium itself is a metal; zirconia is its oxide, a ceramic with no metal. It is a polycrystalline ceramic: it contains no glass¹. A 2018 review describes zirconia as stronger than the other dental ceramics⁵. Its types differ, and the more translucent ones are weaker. Our zirconium (zirconia) page explains them.
• Metal-ceramic (porcelain fused to metal). A hybrid rather than an all-ceramic material: porcelain on a metal framework¹. The metal gives strength and the porcelain gives the tooth colour. Our metal-ceramic and dental alloys page explains the metals.

Trade names

Patients often meet a ceramic by a trade name. e.max is one manufacturer's product family. Its CAD and Press products are based on lithium disilicate glass-ceramic⁶, and the family also includes zirconia⁷. This is manufacturer information. Our e.max page explains what the name covers. A trade name alone does not tell you which material you would receive, so ask for the material and the product name.

Each ceramic suits some restorations better than others. In outline:

• Veneers on front teeth, to change colour or shape: feldspathic porcelain and glass ceramics. A 2025 review of veneers found no long-term data⁴ for zirconia veneers. Our laminate veneers page explains the treatment.
• Inlays and onlays, where enough of the tooth remains that a full crown is not needed: glass ceramics, and feldspathic porcelain¹.
• Single crowns: lithium disilicate, zirconia and metal-ceramic.
• Bridges: zirconia and metal-ceramic. For lithium disilicate, a review lists small three-unit bridges³ at the front of the mouth and in the premolar region, the teeth just in front of the molars. As a bridge material, it did less well in studies than metal-ceramic (see "Benefits and limitations").
• Frameworks and layers. Zirconia and metal can form a strong framework, with feldspathic porcelain layered over it for appearance¹.
• Implants. Crowns on implants, and the parts that connect them to the implant (abutments), can be made of zirconia. The opaque type of zirconia is used for frameworks and as an implant and abutment material⁸. Metal-ceramic crowns are used on implants too.

Zirconia is more often used as a single piece on back teeth¹, but it can also be a framework under porcelain.

How natural a ceramic looks depends mainly on how much light it lets through (its translucency), on its colour and on its surface.

• Glass-rich ceramics can look very lifelike. A 2020 review notes that glass-based ceramics such as feldspathic porcelain are used when appearance is the main concern, but they are weaker¹. Lithium disilicate lets light through in a way close to a natural tooth.
• Zirconia is more opaque. Even its more translucent types still let less light through than glass ceramics⁹ such as lithium disilicate.
• Metal-ceramic cannot let light through the metal. A layer of opaque porcelain is needed to hide the colour of the metal¹, and the crown may look darker¹. If the gum recedes, a dark line may show at its edge.

Layered or single-piece

A restoration can be made in one piece (monolithic), or as a strong core with a more lifelike ceramic layered on top. On a layered restoration, the outer ceramic gives the final shape, shade and appearance¹. A single-piece restoration can be stained to adjust its colour. Its appearance may not match that of a layered one¹, so it is used more often on back teeth.

Colour and shade

The shade is chosen before the restoration is made, usually with a shade guide. A review found that choosing shade by eye alone has lower accuracy and repeatability¹⁰, so photographs or a measuring instrument may be used as well.

Ceramic resists staining better than composite¹¹. Its colour is fixed: whitening does not lighten crowns or veneers¹². If you plan to whiten your natural teeth, say so before the shade is chosen.

Ceramics are much weaker in tension than in compression³: they resist being squeezed far better than being bent or pulled. A ceramic restoration therefore needs enough thickness and good support from the tooth beneath it.

• Strength classes. An international standard for dental ceramics, ISO 6872, sorts ceramics into classes by their minimum flexural strength, from 50 to 800 MPa¹³. MPa (megapascals) is a unit of stress. The class decides which restorations a ceramic may be used for.
• Order of strength. Mostly-glass ceramics such as feldspathic porcelain are the weakest¹. Glass ceramics with more crystals, such as lithium disilicate, are stronger, and zirconia is stronger still.
• Strength against translucency. Within zirconia, the more translucent types are weaker. A review of laboratory studies advises care with thin sections where biting forces are high⁹.
• Thickness. Each product has a smallest thickness for veneers and for crowns⁶, set by its manufacturer. These are lower limits for the ceramic, not the amount of tissue removed from your tooth. Our lithium disilicate page gives an example.
• Layered designs. In a layered restoration, the core gives strength and the outer layer gives the appearance. The bond between the two is one of the weakest links, prone to the layer coming away or fracturing¹.

Laboratory strength does not translate directly into how long a restoration lasts. For single crowns on natural teeth, survival in studies was close across lithium disilicate, zirconia and metal-ceramic (see "Benefits and limitations").

Preparing the tooth

The tooth is shaped so that the ceramic has room. For a veneer, usually only a thin layer of enamel is taken from the front. For a crown, the tooth is reduced on every surface, so far more tissue is removed. An inlay or onlay can keep more of the tooth than a full crown. Either way, the tissue removed does not grow back¹¹.

Bonded veneers depend on enamel. A study followed 580 porcelain veneers for up to 12 years. 99 in 100 survived where the preparation stayed in enamel¹⁴. Veneers bonded to the dentine beneath were about 10 times as likely to fail¹⁴. Across all the veneers in the study, the estimated survival was 86 in 100. These figures come from published studies, not from our own records.

Preparing a living tooth can also affect its nerve. A review pooled studies of teeth that were alive before they received crowns or other indirect restorations, or supported a bridge. In about 5 in every 100 of these teeth, the nerve lost its vitality¹⁵, and root canal treatment is then needed to keep the tooth. The certainty of this evidence is low, and the review gives no separate figure for veneers.

Bonding or cementing

• Bonding fixes the restoration with an adhesive resin. Glass-based ceramics contain glass, so their fitting surface can be etched with acid and treated with silane, which allows a strong adhesive bond⁴. Silane is a coupling agent that helps the adhesive grip the ceramic. Thin veneers depend on this bond.
• Zirconia contains no glass, and resin bonding to zirconia can be challenging⁴. Zirconia and metal-ceramic crowns are usually fixed with a cement, as their own pages describe.
• Crowns in lithium disilicate can be fixed either way. One manufacturer states that crowns from its milled product can be fixed adhesively, self-adhesively or with conventional cement⁶, depending on the clinical situation. This is manufacturer data.

Before the restoration is fixed, its fit, edges, colour and bite are checked in the mouth. The colour of a veneer cannot be changed¹⁶ after it has been bonded, so this is the moment to say if the shade looks wrong. Ask your dentist which method is planned for each restoration, and why.

Ceramic restorations are made in three main ways. All start from an impression or a digital scan of the prepared tooth.

• Built up and fired. Ceramic powder is mixed with a liquid and applied to a heat-resistant model, a foil or a metal framework¹. It is then fired at a high temperature. Feldspathic porcelain veneers and the porcelain layer of layered crowns are made this way.
• Pressed. A ceramic ingot is heated and pressed into a mould¹. Leucite-reinforced and lithium disilicate glass ceramics can be made this way.
• Milled (CAD/CAM). The restoration is designed on a computer and milled from a block. Zirconia is milled from a pre-sintered block or disc, about a fifth larger than its final size⁸. It then shrinks to size when it is heated in a furnace (sintered). Some lithium disilicate blocks are fired after milling; others are crystallised by the manufacturer and need no firing³. Feldspathic porcelain also comes in blocks for milling¹.

Milled restorations can be made at the clinic (chairside) or in a dental or manufacturer's laboratory¹. The surface is then polished or glazed, and colour can be added with stains.

Does the method matter?

A 2019 review of 14 clinical studies found that CAD/CAM restorations failed more often¹⁷ than conventionally made ones; the difference was statistically significant. Its search ended in 2017, so it may not reflect current materials and machines. Same-day chairside work is not assessed separately¹⁷, so the reviews we cite cannot tell us whether same-day crowns last as long as laboratory-made ones. Our CAD/CAM page gives the figures and their limits. Our lithium disilicate page compares pressed and milled veneers.

Ask the clinic how your restoration will be made, and whether it is made at the clinic or in a laboratory, and where.

Benefits

• Ceramics are tooth-coloured. All-ceramic restorations contain no metal, so no metal edge can show at the gum. The colour of the tooth underneath, or a receding gum, can still make the edge look darker.
• Ceramic resists staining better than composite¹¹.
• Glass ceramics can be bonded, which allows thin veneers and partial restorations that keep more of the tooth.
• There are long-term study data for ceramic veneers, inlays, onlays and crowns (see below).

How long they last in studies

Studies report how many restorations are still in place after a period of time; they do not give a lifespan. Staying in place does not mean no repair was needed. The figures below come from published studies, not from our own records.

• Veneers. A 2025 review pooled 29 studies of ceramic veneers. About 94 to 97 in every 100 were still in place after about 10 years⁴, depending on the material. The materials were feldspathic porcelain, leucite-reinforced and lithium disilicate; the review found no significant difference between them.
• Inlays and onlays. A meta-analysis pooled studies with more than five years of follow-up. Of every 100 glass-ceramic and porcelain inlays, onlays and overlays, about 92 to 95 were still in the mouth after five years¹⁸. After ten years the figure was about 91.
• Single crowns. A 2026 review looked at single crowns on natural teeth. For single-piece lithium disilicate, it estimated that about 98 to 99 in every 100¹⁹ were still in place after five years. For layered zirconia, metal-ceramic and single-piece zirconia, the figure was about 97. A stronger material does not mean the crown stays in the mouth longer.
• Bridges. A 2026 review of bridges on natural teeth found about 83 in every 100 lithium disilicate bridges still in place after five years²⁰. For metal-ceramic bridges, the figure was about 91. The difference was statistically significant. The figure of about 83 is for lithium disilicate only; the review reported zirconia bridges separately. Decay at the edges and loosening were more common with all-ceramic bridges²⁰.

Crown survival figures cannot be applied directly to bridges or implant crowns¹⁹.

Limitations

• Brittleness. Ceramics are brittle and can fracture¹, especially with clenching, grinding, knocks or biting hard objects.
• Appearance against strength. In general, glass-rich ceramics look more lifelike but need enough thickness and support; zirconia is stronger but more opaque.
• The tooth beneath. Preparing a tooth cannot be undone, and its nerve can be affected (see above). A restoration does not protect the tooth from decay, which can start at its edge.
• Fixed colour. Ceramic does not change colour with whitening.
• Wear and repair. Ceramic can wear the teeth it bites against, and a chipped restoration cannot always be repaired (see the next section).

Chipping and fracture

• Layered restorations chip more often. In a 2026 review, single-piece lithium disilicate and zirconia crowns had significantly fewer fractures and chips than crowns with porcelain layered on top¹⁹. Layered zirconia and metal-ceramic crowns both have a porcelain layer on top.
• Veneers. In a review of 25 studies, fracture and coming loose were the main reasons ceramic veneers failed²¹, mostly in the early years. A 2025 review pooled 29 studies of veneers in several ceramics. At an average follow-up of 10.4 years, 4.3% of ceramic veneers cracked, 3.5% chipped and 2.5% fractured completely⁴. In 2.2%, the veneer came off. The results varied widely between the studies.
• Inlays and onlays. The most common reason ceramic inlays and onlays fail is fracture or chipping of the restoration¹⁸.

The risk of fracture rises with clenching or grinding, with ceramic that is too thin, and with biting hard objects. In a small study of people who clenched or ground their teeth, those who wore a night guard had fewer veneer fractures²². The study was not randomised: a night guard may reduce the risk, but it does not remove it. These figures come from published studies, not from our own records.

Wear of the opposing teeth

Ceramic resists wear better than composite¹¹. It can also wear down the natural teeth it bites against. A 2024 review pooled seven small clinical studies of crowns on back teeth, followed for up to two years. Metal-ceramic and zirconia crowns caused significantly more wear than natural teeth²³. Opposite lithium disilicate crowns, the loss of enamel differed little from the wear natural teeth cause on each other, though the estimate was imprecise²³. The authors call for larger trials. A rough surface can add to wear, so ceramic that has been adjusted should be polished smooth again.

Repair

Not every chip means a new restoration. Small chips may be repaired, but sometimes a new veneer is needed²⁴. In the 2025 review, most technical problems with veneers were dealt with without replacing them⁴. Larger cracks and fractures may mean the restoration has to be replaced, and each replacement may take a little more tissue from the tooth.

Tell any dentist who later adjusts, repairs or re-bonds a restoration which ceramic it is. Glass ceramics and zirconia are prepared for bonding in different ways.

The first decision is whether a tooth needs a restoration at all, and which kind; the material comes second. If the only concern is colour or shape, whitening, composite bonding or tooth straightening may be considered first. They remove less tooth tissue, or none.

The material is then chosen for each tooth after an examination, with X-rays where needed. The main questions are:

• Where the tooth is, and how much of it shows when you smile.
• How much of the tooth and its enamel remain, and how much room there is for the ceramic.
• Your bite, and whether you clench or grind your teeth.
• Whether it is a veneer, an inlay or onlay, a single crown, a bridge or a crown on an implant.
• The colour of the tooth underneath. Thin, translucent ceramic may not hide a dark tooth; ask how the planned design affects how much of the tooth is removed.
• Any allergy to metals you know of, and what you expect of the appearance.

Decay and gum disease are treated first. Australian government health information (healthdirect) notes that veneers may not be suitable if you grind or clench your teeth or have gum disease¹⁶.

A 2020 review names material choice, restoration design, the bite and the cement¹ as factors in the success of a ceramic restoration.

Options that are not ceramic

• Composite resin is easier to fix if damaged, but not as stain- or wear-resistant¹¹ as ceramic.
• A full-metal (gold alloy) crown is still an option for back teeth that do not show, and for bites with very little space.

If a plan says only "porcelain" or "ceramic", ask which material it means for each tooth, and the product name. Ask too why it suits that tooth better than the alternatives. Our materials overview compares ceramics with the other materials used in dentistry.

• Brush twice a day with a fluoride toothpaste, and clean between your teeth every day, including where the restoration meets the gum.
• Do not bite hard objects such as ice, pens or your fingernails, and do not use your teeth as tools.
• If you clench or grind your teeth, wear the night guard your dentist recommends.
• Keep up regular check-ups. National guidance in England (NICE) says the interval should be set for each person according to their risk²⁵.
• Discuss whitening before treatment. A review based mainly on laboratory studies advises patients to avoid bleaching ceramic restorations, especially those of front teeth²⁶, as it may roughen their surface.

See a dentist if a restoration chips, cracks, feels rough or loose, or comes off. If it comes off, keep it and do not glue it back yourself. See a dentist too if sensitivity does not settle or gets worse, or if pain starts on its own. The same applies if the gum around it swells or bleeds.

If pain keeps increasing, or you have facial swelling or a high temperature, see a dentist without waiting for the clinic's reply. In England, if you have no dentist or cannot get an emergency appointment, the NHS says to call 111 or use 111 online²⁷. Elsewhere in the UK, check the urgent dental care route where you live.

Emergencies. With a suspected dental abscess, the NHS says the following need urgent medical help²⁷. In the UK, call 999 or go to A&E.

• It is hard to breathe, speak, swallow or open your mouth
• A swollen or painful eye, or sudden problems with your eyesight
• A lot of swelling inside your mouth

Before treatment, ask in writing:

• which ceramic will be used for each tooth, and whether it is layered or a single piece;
• the product name and its manufacturer, not only "porcelain" or a trade name;
• how each restoration will be made, and where: at the clinic or in a laboratory;
• what the clinic's written terms say if a restoration chips, breaks or comes off after you are home;
• who pays for the repair and for any extra trip.

Bring home for your UK dentist a written record. It should show the teeth treated, the type of restoration, the material, product and manufacturer, the shade and the laboratory. On request, Turkey's health tourism regulation entitles international patients to free copies of the records of the materials used, the tests and the imaging²⁸.

Aftercare. Problems after you return are usually first seen by your own dentist in the UK. The General Dental Council suggests speaking to your own dentist²⁹ before you consider treatment abroad; ask whether they will see you afterwards. The NHS website for England says the NHS is not liable for negligence or failure of treatment³⁰ when you have treatment abroad. It also says most travel insurance policies will not cover you for planned treatment abroad³⁰. Scotland, Wales and Northern Ireland run their own health services, with their own rules, which this page does not cover; if you live there, ask your dentist.

Your choice. Ceramic veneers, inlays, onlays, crowns and bridges are also available from dentists in the UK, and a UK opinion gives you something to compare. You can say no, or ask to stop, at any stage. Once a tooth has been prepared, that step cannot be undone.

Our dental crowns page lists the questions the General Dental Council and the NHS suggest you ask before treatment abroad.