Glossary
The terms behind digital dental lab work.
Short, careful definitions of the materials, file formats and platform terms you will meet when sending scans to a lab.
- Zirconia
- A high-strength ceramic (zirconium dioxide) milled from a pre-sintered block and then fired in a furnace, where it shrinks to its final size. It is the usual choice for posterior crowns and bridges because it resists fracture far better than glass ceramics, although the strongest grades are more opaque and need careful shading for front teeth. Multilayer and translucent grades trade some strength for a more natural appearance.
- E.max (lithium disilicate)
- A glass-ceramic made of lithium disilicate, sold by Ivoclar as IPS e.max. It is valued for translucency and is a common choice for anterior crowns, veneers, inlays and onlays. It is pressed or milled and is less strong than zirconia, so it is usually avoided for long-span bridges or heavy grinders.
- Ti-base
- A titanium bonding base that sits on an implant and carries a ceramic crown or abutment cemented onto it. It gives the precision of a factory-made connection with the aesthetics of a ceramic restoration. The lab needs to know the implant system, platform size and gingival height, so those details must be on the prescription.
- STL
- A surface-mesh file format that stores only geometry as triangles, with no colour or texture data. Almost every lab system can read it, which makes it the safe default for sending intraoral scans. Because it carries no shade information, shade must be communicated separately.
- PLY
- A mesh file format that can carry colour as well as geometry. Some scanners export PLY so the lab can see soft tissue and tooth colour, which helps with shade matching and margin identification. File sizes are larger than STL.
- OBJ
- A mesh format that stores geometry together with texture mapping. It is used by some scanners when a coloured, textured model is wanted, and is generally accepted by lab design software.
- Intraoral scanner
- A handheld camera that captures the shape of teeth and gums digitally, replacing physical impressions. Scans are exported as files, or sent through the scanner manufacturer cloud, to the lab. Examples include 3Shape TRIOS, iTero, Dentsply Sirona Primescan and Medit.
- Turnaround time
- The number of working days between a lab receiving a valid case and delivering the finished work. Complex restorations, try-ins and shade matching take longer. On ExoLink the due date you set is one of the inputs used when a case is allocated, so an unrealistic date narrows the choice of labs.
- Remake
- A restoration produced again because the first one did not fit, matched poorly or failed. Remakes cost time and chair time, so remake rate is one of the most telling quality measures for any lab. ExoLink ratings feed into allocation so persistently poor labs receive fewer cases.
- Price cap
- The maximum a clinic is willing to pay for a given product, set once in advance. A case is only allocated to a lab whose price sits within the cap, which keeps lab costs predictable without negotiating case by case.
- Allocation
- The automatic matching of a case to a lab. ExoLink weighs the lab price against the clinic cap, the lab quality record and the requested due date, so the clinic does not have to choose or chase a lab for each case.
- Margin line
- The edge on the prepared tooth where the crown finishes. It must be clearly captured in the scan, free of blood, saliva or retraction cord shadows, or the lab cannot design an accurate fit. Unclear margins are the single most common reason for a scan being returned.
- Prescription
- The written instructions that travel with a case: tooth numbers, material, shade, occlusal scheme and any special requirements. A complete prescription prevents queries and delays.
- CAD/CAM
- Computer-aided design and manufacturing. The lab designs the restoration in software, then mills it from a block or prints it. Most crowns and bridges now follow this route from a digital scan.
Keep reading
See resources, how ExoLink works or the lab services page for your area.
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