Two ways to retain an implant crown
An implant crown is either screwed directly to the implant (usually via a Ti-base) or cemented onto an abutment. The choice is clinical, made by the dentist, but it changes almost every decision in the CAD design — so the designer needs to know it before starting.
Designing a screw-retained crown
The crown and its interface are designed as one piece bonded to a Ti-base. Key points:
- Screw channel position: ideally exiting through the occlusal or lingual surface, never the buccal of an anterior tooth.
- Angled screw channels, when the implant system supports them, to move the access hole away from visible areas.
- Correct Ti-base selection from the implant library, matching system, platform and gingival height.
- Enough material around the access hole to avoid thin walls that can chip.
Designing a cement-retained crown
Here two parts are designed: a custom (or stock) abutment and the crown that sits on it.
- Abutment margin placed close to the gingiva so excess cement can be removed.
- Abutment height and taper that give retention without compromising crown thickness.
- A defined cement gap on the crown, as for a natural preparation.
- No visible access hole, which can help aesthetics when the implant angle is unfavourable.
Common to both: emergence profile
Whichever option is chosen, the emergence profile shapes the soft tissue. The scan body scan and a clear gingiva scan let the designer create a profile that supports the tissue without excessive pressure.
What to send your designer
With this information we can deliver the crown, and where needed the custom abutment, ready for milling. See our crown and custom abutment services for details.
- Implant system, platform and the Ti-base or abutment you plan to use
- Retention type: screw-retained or cement-retained
- Scan body scan, antagonist and bite registration
- Material (zirconia, lithium disilicate, PMMA) and any shade or anatomy notes