Abutment Screw Torque and Driver
There are many designs of prosthesis screws in Implantology. The screwing torque will depend on the material but also on the way the parts will fit together. Screwing with the right torque is essential to ensure the durability of the implant rehabilitation. Spotimplant has listed the main systems with the screwdriver and the torque recommended by the manufacturer.
In implant dentistry, there are many different designs of prosthesis screws. Dentists must understand how they work to avoid mistakes that could lead to implant restoration failure, as they are often the weakest part of the prosthetic restoration. Screws are used to secure an abutment to the implant body, and their mechanism of action can be explained by the fact that they increase the force that is transmitted into the implant when it is screwed in. When a certain torque is applied to the screw, the screw is stretched (or deformed) inside the implant, resulting in a precise connection between them that prevents further loosening of the screw and the prosthesis.
The screw torque depends on the material, but also on how the parts fit together. The different titanium grades and alloys used to manufacture these parts are relevant as they determine the subsequent torque. For this reason, the manufacturer's specifications must be observed, as they have different resistance properties and therefore the required torque is different.
Precise adjustment between the abutment parts and the implant connection is extremely important, as it reduces the force absorbed by the prosthesis screw and also helps to create a biological seal around the implant and the surrounding tissue. Using original parts made with the same metal composition and machinery as the implant is extremely important, and if the implant was placed by another clinician, the brand and model must be identified to find the most appropriate parts. Even components of the same brand may be mismatched as the dimensions may be slightly different due to the manufacturing process.
Another factor that affects this implant-abutment connection is the design of the screw head. They are usually flat, which determines the even distribution of forces between the implant and the restoration. They also have a shape for the screwdriver, which can be deformed by repeated use. Screws with slotted, triangular or square features are less prone to deformation than the more common hex screwdriver shapes. Size is another factor, as a larger diameter can withstand higher forces, so wider screws are stronger than smaller ones.
Proper torque is also critical to the durability of the implant restoration. Torque is measured in Newton-centimeters (N-cm), and professionals must use the torque recommended by the implant manufacturer. Excessive screw torque can lead to permanent deformation of the screw material and its fracture with associated clinical complications. Hand screwdrivers are not recommended as the required torque cannot be applied by hand. The use of a torque wrench is mandatory, acting through a lever that increases the torque up to 100 N-cm. Torque wrenches can be damaged by sterilization and must be recalibrated periodically as they can reach excessive torque, posing a risk to the implant and its restoration. Most implant manufacturers recommend a torque of 20 to 35 N-cm. Spotimplant has listed the most important systems with the screwdriver and the torque recommended by the manufacturer.
Astra 3.0: 15 N-cm Titanium Screw 0.050”- 1.27mm hex
Astra 3.5-4.0: 20 N-cm Titanium Screw 0.050”- 1.27mm hex
Astra 4.5-5.0: 25 N-cm Titanium Screw 0.050”- 1.27mm hex
Astra EV 3.0, 3.6, 4.2, 4.8, 5.4: 25 N-cm Titanium Screw 0.050”- 1.27mm hex
BioHorizons® External, Internal, Internal Tapered: 30 N-cm Titanium Screw 0.050”- 1.27mm hex
Biomet 3i™ External Hex: 35 N-cm Titanium Screw 0.048"- 1.22mm hex Gold Screw Square
Biomet 3i™ Certain® *: 20 N-cm Titanium Screw 0.048"- 1.22mm hex
BlueSkyBio One Stage: 30 N-cm Titanium Screw Star & 0.048" hex
BlueSkyBio Trilobe: 30 N-cm Titanium Screw Unigrip & 0.048" hex
BlueSkyBio Internal Hex & Molar: 30 N-cm Titanium Screw 0.050"- 1.27mm hex
BlueSkyBio Conus 12 & Three: 30 N-cm Titanium Screw 0.050"- 1.27mm hex
BlueSkyBio Max: 30 N-cm Titanium Screw 0.048"-1.22mm hex
BlueSkyBio Quatro: 30 N-cm Titanium Screw 0.048"-1.22mm hex
Brånemark (Nobel Biocare): 35 N-cm Titanium Screw Unigrip Gold Screw Square
Camlog™ & Conelog®: 20 N-cm Titanium Screw 0.050”- 1.27mm hex
Dentium Super Line & Implantium: 30 N-cm Titanium Screw 0.050”- 1.27mm hex
Dentsply Friadent/Frialit & Xive: 24 N-cm Titanium Screw 0.048"-1.22mm hex
Dentsply Ankylos® C/X: 15 N-cm Titanium Screw 0.039"-1mm hex
Glidewell iNCLUSiVE® Tapered 3.7, 4.7, 5.2: 35 N-cm Titanium Screw 0.050"- 1.27mm hex
Hiossen/Osstem HG mini (3.5): 20 N-cm Titanium Screw 0.048"-1.22mm hex
Hiossen/Osstem HG standard (4.0, 4.5, 5.0): 30 N-cm Titanium Screw 0.048"-1.22mm hex
Imtec® 3M Endure™: 35 N-cm Titanium Screw 0.050”- 1.27mm hex
Implant Direct™: 30 N-cm Titanium Screw 0.050"-1.27mm hex
Keystone/Lifecore Genesis* & Prima™ *: 30 N-cm Titanium Screw Square
Keystone/Lifecore Renova®: 30 N-cm Titanium Screw 0.048"-1.22mm hex
Keystone/Lifecore Restore®: 30 N-cm Titanium Screw 0.048"-1.22mm hex Gold Screw Square
Mega'Gen EZ Plus: 35 N-cm Titanium Screw 0.048"-1.22mm hex
Mega'Gen Rescue: 45 N-cm Titanium Screw 0.048"-1.22mm hex
Mega'Gen ExFeel internal (3.5): 25 N-cm Titanium Screw 0.048"-1.22mm hex
Mega'Gen ExFeel internal (4.1, 4.8, 5.5): 35 N-cm Titanium Screw 0.048"-1.22mm hex
Mega'Gen ExFeel external (3.3): 25 N-cm Titanium Screw 0.048"-1.22mm hex
Mega'Gen ExFeel external (3.75, 4.0,4.5, 5.0, 5.5): 35 N-cm Titanium Screw 0.048"- 1.22mm hex
MIS® Biocom & Seven: 30 N-cm Titanium Screw 0.050"-1.27mm hex
NEODENT® CM: 15 N-cm Titanium Screw 0.035"- 0.9mm hex
NEODENT® CM: 32 N-cm Titanium Screw 0.048"-1.22mm hex
NEODENT® CM: 32 N-cm Titanium Screw 0.063"-1.6mm hex
Neoss: 30 N-cm Titanium Screw Unigrip (not compatible with Nobel)
NobelActive™ & Replace™: 35 N-cm Titanium Screw Unigrip
NobelActive™ 3.0: 15 N-cm Titanium Screw Unigrip
OCO Biomedical: 30 N-cm Titanium Screw 0.050"-1.27mm hex
Southern Implant External: 32 N-cm Titanium Screw 0.048"-1.22mm hex Gold Screw Square & Unigrip
Southern Implant Tri Nex: 32 N-cm Titanium Screw Unigrip
Southern Implant Octa: 32 N-cm Titanium Screw Star/Torx
Straumann® Bone & Tissue Level: 35 N-cm Titanium Screw Star/Torx
Sybron Pitt Easy: 25 N-cm Titanium Screw 0.067"-1.7mm hex
Thommen SPI® 3.5: 15 N-cm Titanium Screw Four lobe
Thommen SPI® 4.0, 4.5, 5.0, 6.0: 25 N-cm Titanium Screw Four lobe
Thommen SPI® zirconia abutment: 20 N-cm Titanium Screw Four lobe
Zimmer®: 30 N-cm Titanium Screw 0.050”- 1.27mm hex
* Biomet 3i™ Certain® screws are gold plated only. Keystone Genesis and Prima™ abutment screws are made of titanium and have a titanium nitride coating.
