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 is highly aesthetic, but its strength is low. 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 less aesthetically pleasing¹.
• 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 able to mimic a natural tooth's shade and translucency, but mechanically weaker⁴. It describes 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. According to a 2018 review, zirconia is stronger than the other dental ceramics⁵. Its types differ, and the more translucent ones are weaker. Our zirconia crowns page explains its types and the crowns made from it.
• 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. In Turkish, "porselen kaplama" (porcelain crown) is said of these crowns as well as of ceramic crowns and veneers without metal. 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 the manufacturer's own information. Our e.max crowns and veneers page explains the crowns and veneers made under this name. 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 data for zirconia veneers: the studies available followed them for an average of 2.6 years⁴. 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. An inlay fills a gap inside the tooth; an onlay also covers one or more of the cusps (the raised chewing points).
• Single crowns, which cover the whole visible part of the tooth: lithium disilicate, zirconia and metal-ceramic.
• Bridges: zirconia and metal-ceramic. According to a 2026 review of laboratory studies, not every type of zirconia suits every bridge⁸; ask which type is proposed, and why. For lithium disilicate, a review lists small three-unit bridges³ at the front of the mouth and in the premolar region. The premolars are the teeth just in front of the molars. A three-unit bridge usually replaces one missing tooth and is held by crowns on the teeth on either side. As a bridge material, lithium disilicate 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 a ceramic looks depends mainly on how much light it lets through (its translucency), on its colour and on its surface.

• Glass-based ceramics. Feldspathic porcelain is a highly aesthetic type of ceramic¹. 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 aesthetic 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. But ceramic cannot be whitened: whitening does not lighten crowns or veneers¹². The natural teeth around a veneer can discolour over time and no longer match it¹³. Over the years, a colour difference can appear at the edge of ceramic veneers⁴. 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 MPa¹⁴. MPa (megapascals) is a unit of stress. The standard links each class to the restorations that a ceramic in that class may be used for. Whether a ceramic suits your tooth also depends on the product's instructions for use and on the state of your tooth.
• 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, and that cannot be reversed¹¹. 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. Whichever is chosen, the tissue removed does not grow back.

Enamel matters for bonded veneers. One retrospective study reviewed 580 porcelain veneers, with follow-up of up to 12 years. 99 in 100 survived when the shaping of the tooth stayed within the enamel¹⁵. Veneers bonded to the dentine, the layer beneath the enamel, were about 10 times as likely to fail¹⁵. 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 died¹⁶. The studies followed the teeth for different lengths of time. In studies with more than ten years of follow-up, the figure was about 7 in every 100¹⁶. If the nerve dies, root canal treatment is 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; it is also called adhesive cementation. 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 in more than one 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; which method can be used depends on the product and on the tooth.

Before the restoration is fixed, its fit, edges, colour and bite are checked in the mouth. The colour of a veneer cannot be changed¹³ 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 compared ceramic restorations made by CAD/CAM with conventionally made ones. It found more failures with the CAD/CAM restorations¹⁷; the difference was statistically significant. Its search ended in 2017, so its findings may not reflect today's materials and machines. The review included laboratory milling. 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.

Your dentist will tell you how and where your restoration will be made: at the clinic or in a laboratory, and which laboratory. You can ask for this in writing.

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. The studies covered glass-ceramic and porcelain inlays, onlays and overlays (a larger form of onlay). Of every 100 of these, 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 estimated that about 83 in every 100 lithium disilicate bridges were 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 are more aesthetic 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.
• Colour. Whitening does not lighten ceramic, and the natural teeth around it can change colour over time.
• 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 single-piece zirconia crowns caused significantly more wear than natural teeth²³. Lithium disilicate crowns showed no clear difference from natural teeth in the enamel wear they caused on the opposing teeth, but 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 disease¹³.

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. A clinical guideline on dental check-ups recommends that the interval be set for each person according to their risk²⁵. For crowns on implants, the European Federation of Periodontology guideline calls for a structured supportive care programme²⁶ once the implants are in use.
• Discuss whitening before treatment. A review based mainly on laboratory studies advises patients to avoid bleaching ceramic restorations, especially those of front teeth²⁷. Bleaching 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. A dental abscess does not go away on its own and needs urgent treatment by a dentist²⁸.

Emergencies. With a suspected dental abscess, the following need urgent medical help²⁸. Do not wait for a dental appointment: go to a hospital emergency department or call 112.

• 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 the restoration will be layered or a single piece;
• the product name and its manufacturer: "porcelain" or a trade name alone is not enough;
• how and where each restoration will be made: at the clinic or in a laboratory, and in which laboratory;
• what will be done if a restoration breaks, chips or comes off, and how your written plan covers a repair or a remake.

You have the right to be told, on request, who the dentists and other staff treating you are, and their roles and titles²⁹.

Records. Under Turkish rules, private dental clinics record the diagnosis, the treatment and any X-rays in detail, with tooth numbers³⁰. You can examine your file and records and get a copy²⁹. Ask for a written record that shows the teeth treated, the type of restoration, the material, product and manufacturer, the shade and the laboratory. A dentist who treats you later can then see what was done.

Consent. Under Turkey's patient rights regulation, you are told about other options, with their benefits and risks, and the possible consequences of refusing²⁹. In private dental clinics, you are asked to sign a consent form for every intervention³⁰. Two copies of the form are signed, and one is given to you²⁹. Ask for your copy.

Your choice. A second opinion from another dentist gives you a point of comparison. You can say no, or ask to stop, at any stage. Once a tooth has been prepared, that step cannot be undone.