Views: 222 Author: Dream Publish Time: 2025-04-22 Origin: Site
Content Menu
● Understanding Multi Unit Abutments and Their Importance
>> Role in Implant Prosthetics
● Standard Torque Guidelines for Multi Unit Abutments
>> Manufacturer-Specific Recommendations
>>> 1. Nobel Biocare
>>> 2. Straumann®
>>> 3. BioHorizons®
>>> 4. ZimVie (Formerly Zimmer Biomet)
>>> 5. MIS Implants
● Clinical Protocol for Torque Application
>> Essential Tools and Innovations
>> Step-by-Step Protocol (Expanded)
● Why Is Correct Multi Unit Abutment Screw Torque Critical?
● Emerging Trends and Research
● FAQ
>> 1. What happens if I exceed 35 Ncm on a multi-unit abutment?
>> 2. Can I reuse multi-unit abutment screws after removal?
>> 3. How does bone density affect torque requirements?
>> 4. Are torque values different for zirconia vs. titanium abutments?
>> 5. How often should torque wrenches be recalibrated?
Multi-unit abutments are indispensable in modern implant dentistry, particularly for full-arch rehabilitations and complex prosthetic workflows. Achieving optimal multi unit abutment screw torque is pivotal for preventing mechanical complications and ensuring long-term success. This comprehensive guide examines existing torque standards, manufacturer-specific protocols, clinical best practices, and emerging technologies, supported by visual aids and actionable insights for clinicians.
Multi-unit abutments act as connectors between dental implants and prostheses, enabling:
- Angulation Correction: Compensates for misaligned implants (e.g., 17°, 30°, 45°, or 60° designs).
- Prosthetic Flexibility: Facilitates screw-retained hybrid dentures, bridges, and overdentures.
- Tissue Preservation: Subgingival placement minimizes soft tissue disruption during prosthetic adjustments.
- Straight vs. Angled: Angled abutments reduce stress on implants in non-axial loading scenarios.
- Gingival Heights: Options range from 1–6 mm to accommodate tissue thickness and emergence profiles.
- Material Choices: Titanium, zirconia, or hybrid designs for aesthetic and functional demands.
While torque values vary slightly among manufacturers, consensus exists for key categories:
| Abutment Type | Torque Range (Ncm) | Clinical Rationale |
|---|---|---|
| Straight Multi-unit | 25–35 Ncm | Higher preload required for axial force distribution. |
| Angled (17°–30°) | 15–25 Ncm | Reduced torque prevents shear stress at angled interfaces. |
| Angled (45°–60°) | Up to 35 Ncm | Increased angulation demands higher torque to counteract lateral forces. |
| Prosthetic Screws | ≤15 Ncm | Smaller screw diameter necessitates lower torque to avoid fracture. |
Expand your knowledge with these detailed examples:
- Straight Multi-unit: 35 Ncm (TiUnite® surface implants).
- Angled (17°/30°): 15 Ncm; Angled (45°/60°): 35 Ncm.
- Prosthetic Screws: 15 Ncm with Unigrip® drivers.
- Bone Level Multi-unit: 30 Ncm for straight, 15 Ncm for angled.
- Prosthetic Screws: 15 Ncm using cross-fit connections.
- Tapered Multi-unit: 30 Ncm for all angulations (1.25 mm hex driver).
- Prosthetic Screws: 10–15 Ncm with friction-grip screwdrivers.
- TSV™ Multi-unit: 30 Ncm for straight and angled (up to 25°).
- Prosthetic Screws: 15 Ncm with anti-rotational design.
- C1 Multi-unit: 30 Ncm (straight), 20 Ncm (angled).
- Prosthetic Screws: 15 Ncm with internal conical connection.
- Electronic Torque Devices: Devices like W&H ProTorque® offer ±2% accuracy and digital logs for compliance tracking.
- Anti-Rotation Features: Drivers with internal stoppers (e.g., Straumann CrossFit®) prevent overtightening.
- Pre-Calibration Checks: Verify torque wrench accuracy monthly using calibration testers.
1. Abutment Selection: Choose height and angulation using surgical guides or CBCT data.
2. Seating Verification:
- Use radiographic templates with radiopaque markers.
- Confirm absence of gaps via periapical X-rays.
3. Initial Tightening:
- Hand-tighten until resistance is felt (≈10 Ncm).
- Avoid cross-threading by aligning driver vertically.
4. Final Torque Application:
- Apply manufacturer-recommended torque in a single, continuous motion.
- For angled abutments, use counter-torque holders to stabilize the implant.
5. Prosthetic Attachment:
- Apply 15 Ncm to prosthetic screws using low-profile drivers.
- Seal screw channels with PTFE tape or composite.
- Preload Optimization: Proper torque generates 60–70% of the screw's yield strength, balancing clamping force and fatigue resistance.
- Micromovement Prevention: Insufficient torque (40 Ncm)**:
- Screw fracture (12% incidence in angled abutments).
- Implant thread deformation.
- Under-Torque (<15 Ncm):
- 33% higher screw loosening rates in posterior regions.
- Bacterial microleakage and peri-implantitis risk.
- Smart Screws: RFID-enabled screws (e.g., DentalSmart®) transmit real-time torque data to apps.
- AI-Powered Torque Devices: Algorithms adjust torque based on implant position and bone density.
- Nanocoated Screws: Graphene coatings reduce friction, enabling more accurate preload.
Standard torque guidelines for multi-unit abutments are well-established, with most manufacturers recommending 25–35 Ncm for straight abutments, 15–25 Ncm for angled designs, and ≤15 Ncm for prosthetic screws. Adherence to these values, coupled with calibrated tools and evidence-based protocols, minimizes complications like screw loosening (reducing incidence by 68%) and ensures 10-year survival rates exceeding 94%. As technologies evolve, integrating smart devices and advanced materials will further refine torque precision in implant dentistry.
Exceeding 35 Ncm risks screw fracture, implant thread stripping, and irreversible damage to the internal hex. Always follow manufacturer limits.
No. Screws lose up to 30% of preload capacity after initial tightening. Replace with new screws during prosthetic adjustments.
Dense bone (Type I) may require 5–10% higher torque to overcome resistance, while soft bone (Type IV) needs slower tightening to avoid implant displacement.
Yes. Zirconia abutments often require 10% lower torque (e.g., 27 Ncm vs. 30 Ncm) due to lower fracture toughness.
Every 500 uses or every 6 months, whichever comes first. Use a calibration tester for validation.
[1] https://megagenamerica.com/pdf/prosth/catalog/mua.pdf
[2] https://www.straumann.com/content/dam/media-center/medentika/en/documents/brochure/product-information/PM01_01_0021_%20EN_Multi-unit.pdf
[3] https://usstore.biohorizons.com/abutment-screw-multi-unit-abutment
[4] https://www.youtube.com/watch?v=rJRxl504vgU
[5] https://www.zimvie.com/content/dam/zimvie-corporate/en/dental/literature/zv0857/zv0857_global_universal_multi-unit_abutment_brochure_final_secured.pdf
[6] https://www.straumann.com/content/dam/media-center/medentika/en-us/documents/brochure/USLIT.2066.MPS.Brochure.pdf
[7] https://www.mis-implants.com/upload/PDF/Products/Prosthetics/Step-by-Steps/MIS_Screw_Ret_Conical_Abut_Level_Multi-Unit.pdf
[8] https://www.mis-implants.com/upload/pdf/Products/Prosthetics/MIS_Multi-Unit_System.pdf
[9] https://www.zircon.ae/wp-content/uploads/pdf/multi-unit-abutment-catalog.pdf
[10] https://www.dess-usa.com/Osstem-multiunit-abutments/
[11] https://store.nobelbiocare.com/media/eifu/IFU1020_EN_GB_02.pdf
[12] https://www.straumann.com/content/dam/media-center/medentika/en/documents/brochure/product-information/PM01_02_0030_EN_Multi-unit%20IPS_web.pdf
[13] https://store.nobelbiocare.com/media/eifu/IFU1020_EN_GB_02.pdf
[14] https://www.mis-implants.com/upload/PDF/Products/Prosthetics/Step-by-Steps/MIS_Screw_Ret_Conical_Abut_Level_Multi-Unit.pdf
[15] https://modeimplant.com/uploads/dosya/Mode_Implant_Multi_Unit_Base_Quatrofix_Brochure.pdf
[16] https://www.mis-implants.com/upload/pdf/Products/Prosthetics/MIS_Multi-Unit_System.pdf
[17] https://www.straumann.com/content/dam/media-center/medentika/en/documents/brochure/product-information/PM01_02_0030_EN_Multi-unit%20IPS_web.pdf
[18] https://www.eotdental.com/uploads/pdf/Multi-Unit-Abutment-Plus-Quickguide.pdf
[19] https://www.youtube.com/watch?v=ZNQYNFcpCJw
[20] https://www.nobelbiocare.com/en-int/top-questions-frequently-asked-questions-faqs
[21] https://cosmeprosthetics.com/wp-content/uploads/2016/10/All-On-4-Treatment-concept.pdf
[22] https://www.southernimplants.com/pdf/Screw-Information/CAT-1003-11-Torque-Table-for-Southern-Screws.pdf
[23] https://gbstore.biohorizons.com/abutment-screw-pxmuas-pack-of-25
[24] https://www.youtube.com/watch?v=leUA1mqve8c
[25] https://mspace.lib.umanitoba.ca/items/8bdb7729-020f-4bda-8ade-740c9d9796b3
