Translucency as the deciding quality
Lithium disilicate and glass ceramic are chosen where light behaviour matters most: the material lets light pass through in a manner closer to natural enamel than an opaque material allows, so a crown or veneer can look like a tooth rather than like a cap over one. That translucency is the category's defining quality, and it is why glass ceramic appears most often in anterior work, where a restoration is seen in daylight and compared with neighbouring teeth. A laboratory choosing glass ceramic should therefore start from the aesthetic demand of the case, not from a general idea of strength.
Translucency also brings a planning consequence: the preparation design, the shade of the underlying tooth, and the bonding approach all interact with the material's light behaviour, and those are clinical decisions outside a catalogue's evidence. This guide does not prescribe a preparation or a bonding protocol, because those belong to the dentist and the technician together, and a guide that prescribed them would overreach. The guide's job is to place glass ceramic correctly in the range, and to point the clinical questions to the right people.
Glass ceramic beside zirconia
In general terms, glass ceramic is chosen where translucency and enamel-like appearance matter most, while zirconia is chosen where a wider span of crown and bridge work, or a gradient shade in a single disc, matters most. That comparison is a planning direction, not a rule, because individual cases, preparation designs and laboratory routines all shift the balance. A posterior bridge with a long span points toward zirconia, an anterior veneer with a high aesthetic demand points toward glass ceramic, and a single anterior crown could suit either, depending on the shade and the preparation.
Ask for comparative strength and translucency figures for these families in an inquiry. A laboratory that needs a number for a particular case should ask for it in an inquiry, naming the material family and the measurement, and the answer can then be checked against the exact product.
Category names without product pages
Ceramic glass and press ingots appear in the source catalogue as category names beside lithium disilicate. This site therefore keeps both at category level, and a buyer who needs a press ingot or a specific ceramic glass block can ask about it in an inquiry.
The Cerec name appears on a disilicate lithium ceramics block listing as a third-party system reference, and this site keeps it in exactly that role. No page on this site presents Cerec as a company brand, a partner or an endorsement; a buyer who reads it as a partnership would assume a compatibility guarantee that was never given. The company's own brand on this site is XANGTECH, and every other brand name is a reference, not a possession.
Cases that suit glass ceramic
Glass ceramic suits crowns, inlays, onlays and veneers where the restoration is visible and the aesthetic demand is high, and where the preparation allows a bonded restoration rather than a full-coverage one. Those are general case directions, not clinical prescriptions, and the final decision belongs to the dentist and the technician who know the tooth, the preparation and the patient's expectations. A laboratory that receives a glass ceramic case should confirm the material form, the shade approach and the quantity in an inquiry, because those are the practical facts on which a correct delivery turns.
A laboratory that receives mostly posterior bridge work, or cases where a gradient shade in a single disc matters most, will usually look at zirconia first, and the zirconia selection guide covers that choice in more detail. The two guides together give a buyer both sides of the material comparison, so the choice can be made from the case rather than from a single guide's enthusiasm. Reading both guides takes longer than reading one, but it produces a better material decision.
Ordering glass ceramic
An order for lithium disilicate should name the material, the shade approach and the quantity range, and then confirm the minimum order quantity, lead time, shipping method and payment terms as buyer instructions. Those four confirmations vary by order and destination, and this site does not promise them in advance. A laboratory ordering glass ceramic for the first time should also note the case type, so the company can confirm that the stocked form matches the intended use, and the inquiry form has room for that note alongside the quantity questions.
Certificates for glass ceramic follow the site-wide rule: they are available upon request, and a buyer who needs a document for a particular market should name the product and the market. Ask for the certificate number and scope for this family in an inquiry. The order is complete when the material, the shade approach and those four confirmations are all settled.
Where to read more on glass ceramic
The lithium disilicate category page is the companion to this guide, listing the category names and the named product in one place, and the blog index links a background article on lithium disilicate glass ceramic restorations. A buyer who has read both the category page and this guide should be able to narrow to a material family, and then ask about the product within that family in an inquiry, naming the case type and the shade approach.
A buyer who still has a material question after reading both pages should use the inquiry form, naming the material family and the case type, and quoting the guide section the question follows. The form asks only for a name, an email address and the message, and a message that quotes the guide section will get a faster answer, because the company side can see exactly which comparison the buyer is asking about.