Screw-retained and cement-retained implant crowns need different design briefs. Screw-retained cases depend on accurate implant position and angulation so the access channel exits correctly; cement-retained cases depend on the margin and cement gap. Tell your designer which you need, and send accurate implant position data, before the case starts.
"Screw-retained or cement-retained?" isn't a box to check on a case form — it changes what a CAD designer actually needs from you before they can start, and what can go wrong if that information is missing.
Screw-retained: it's all about the access channel
A screw-retained crown needs an access channel angled precisely enough to reach the screw without breaking through the facial surface or compromising the occlusal table. That angle depends entirely on the implant's true 3D position and angulation — which means the design is only as accurate as the scan data describing that angulation. Vague or incomplete implant position data is where screw-retained cases go wrong, not the design step itself.
What the designer needs from you
- Accurate implant scan body data reflecting true angulation, not an approximation
- Any preference on access channel positioning relative to the occlusal anatomy
- Whether the crown is screw-retained only or a hybrid screw/cement design
Cement-retained: it's all about the margin and gap
A cement-retained design shifts the critical variables to margin placement relative to the gingival margin, and cement gap thickness — too tight and the crown won't fully seat, too loose and retention suffers along with a higher risk of excess cement, which has its own well-documented complications.
What the designer needs from you
- Clear soft-tissue and margin data from the scan
- Your lab's standard cement gap preference, since defaults vary between labs
- Any concern about excess cement retrievability for that specific case
The fixation method isn't a detail you can leave implied. It determines which variables the designer is optimizing for from the very first step — getting it wrong midway through means starting over, not adjusting.
Hybrid cases: when you need both
Some cases call for a screw-retained substructure with a cemented final restoration on top — combining both sets of requirements. This is exactly the kind of case where a design partner needs to ask clarifying questions rather than guess, and where flagging ambiguity before designing (not after) protects your turnaround time.