Screw loosening remains the number one mechanical complication in screw-retained multi-unit restorations. Studies report incidence rates between 12% and 28% within the first year—especially in full-arch and All-on-X cases where cantilever forces concentrate on posterior screws.For dental labs seeking a reliable Rosen Type Screw solution, this widespread issue represents a major operational challenge
However,for dental labs and technicians, a loose screw means one thing: the case comes back. And it always comes back at the worst time.
What causes screw loosening in the first place?
The primary culprit is micro-movement at the abutment-screw interface. Every time a patient chews, occlusal forces create microscopic gaps between the screw head and the driving instrument seat. Over time, these gaps widen. Torque fades. The screw backs out.
Traditional fixes—retorquing, anti-rotation washers, switching to gold screws—help temporarily but do not address the root geometry problem.
The conical head solution
A Rosen-type conical head screw takes a different approach. Instead of relying on axial clamping force alone, the conical profile wedges into the MUA driver seat and self-locks under load.
Key advantages over standard flat-head screws:
1.Self-locking geometry: The conical interface converts lateral occlusal forces into radial compression, actively resisting back-out.
2.Direct to fixture: Eliminates the Ti-Base step. Fewer components mean fewer interfaces, fewer failure points.
3.Consistent torque retention: Because the conical seat does not rely on surface friction alone, torque values remain stable across thermocycling and mechanical loading.
Benefits of Rosen Type screws
1.Full-arch screw-retained bridges (All-on-4, All-on-6)
2.Multi-unit restorations with posterior cantilevers
3.Cases where previous screw loosening has occurred
Laboratories producing batch MUA frameworks and needing a standardized screw spec
Available specifications
Our CNC-machined Rosen-type screws are produced in medical-grade Titanium Grade 5 (Ti-6Al-4V ELI) with three drive options:
M1.4 × 8mm — T5 driver
M1.6 × 8mm — 1.25 Hex driver
M1.72 × 8mm — T6 driver
Custom lengths and thread pitches available upon request. All components are machined in-house at our Dongguan facility with tolerance control under ±0.01mm.
Why this matters for your workflow,If you are currently using standard abutment screws with separate Ti-Bases, switching to a conical head system reduces:
Component count per case (no Ti-Base)
Inventory SKU proliferation
Remake rate from screw-related failures
Chairside adjustment time
For labs running Exocad, our screw specifications integrate directly into your digital workflow. Export your framework, specify the screw path, and machine the complete assembly in one cycle.
Need a sample batch?
We support low-volume trial orders for labs evaluating the conical head system. Submit your implant system specifications or STL/Exocad files and we will confirm compatibility within one business day.