What Is a Dental Implant Screw?
A dental implant screw is the part of the implant that is surgically placed into the jawbone. It is a small, threaded post, usually 3mm to 6mm wide and 6mm to 16mm long. Most implant screws are made from commercially pure titanium or titanium alloy, which is biocompatible and integrates with bone through a process called osseointegration.
Once the implant screw has fused with the jawbone (typically over 3 to 6 months), an abutment is attached to the top of the screw. The abutment connects the implant to the visible crown, bridge, or denture that replaces the missing tooth. The screw itself remains completely beneath the gumline and is not visible.
Dental Implant Screw Diameters
The diameter of an implant screw is one of the most important factors in implant selection. A wider implant has more surface area in contact with bone, which generally provides more stability. However, the width of the available bone at the implant site limits which diameter can be used safely.
Narrow-Diameter Implants (3mm to 3.5mm)
Narrow-diameter implants are used when the available bone ridge is too thin for a standard implant. Common placement sites include the lower front teeth (incisors), upper lateral incisors, and areas where bone has been lost due to long-term tooth absence. They are also used in tight spaces where neighboring tooth roots are close together.
While narrow implants can be successful in the right situation, they are subject to higher stress per unit area than wider implants. Your specialist will evaluate whether a narrow implant is appropriate or whether bone grafting to widen the ridge would be a better long-term solution.
Standard-Diameter Implants (3.5mm to 4.5mm)
Standard-diameter implants are the most commonly placed size for single-tooth replacements. They are used for premolars, canines, and many molar sites where bone width is adequate. A 4.0mm or 4.5mm implant provides a good balance between surface area for osseointegration and compatibility with most jaw anatomy.
Most major implant systems offer their widest selection of prosthetic components (abutments, healing caps, impression copings) in standard diameters, which gives the restorative dentist or prosthodontist the most flexibility when designing the final crown.
Wide-Diameter Implants (5mm to 6mm)
Wide-diameter implants are primarily used for molar sites, where chewing forces are highest and the jawbone is typically wider. A 5mm or 6mm implant distributes biting force over a larger area of bone, which can improve long-term stability in the posterior jaw.
Wide implants may also be selected when an immediately placed implant needs to fill a larger extraction socket, or when a previous implant has failed and the existing bone hole is wider than standard. Sufficient bone width must be confirmed with a 3D scan before a wide implant is chosen.
Dental Implant Screw Lengths
Implant length refers to how deep the screw extends into the jawbone. Lengths typically range from 6mm to 16mm, with 10mm to 13mm being the most commonly used. The available bone height at the implant site determines which length is appropriate.
Short Implants (6mm to 8mm)
Short implants are used when bone height is limited. This is common in the back of the lower jaw, where the inferior alveolar nerve runs through the bone, and in the upper jaw, where the maxillary sinus limits how deep an implant can go. Short implants have become more reliable in recent years, and research shows favorable survival rates when placed in dense bone with appropriate prosthetic design.
Standard-Length Implants (10mm to 13mm)
Standard-length implants offer the most bone contact and are the default choice when bone height permits. They provide excellent primary stability and have the longest track record of clinical success. Most clinical studies on implant survival rates are based on standard-length implants.
Long Implants (14mm to 16mm)
Long implants are used less frequently but can be appropriate in specific situations, such as when maximum bone engagement is needed for immediate loading (placing a temporary crown the same day as surgery) or when anchoring a full-arch prosthesis. The upper front jaw, which typically has ample bone height, is one area where longer implants may be placed.
One-Piece vs. Two-Piece Implant Systems
Dental implant systems come in two fundamental designs: one-piece and two-piece. The distinction refers to whether the implant body and the abutment (the connector between the screw and the crown) are a single unit or separate components.
Two-Piece Implants
Two-piece implants are the most widely used design in modern implant dentistry. The implant screw is placed into the bone first and allowed to heal beneath the gumline. After osseointegration is complete, the gum is reopened and a separate abutment is attached to the top of the implant. This design allows the implant to heal in a protected environment and gives the restorative dentist flexibility to choose the abutment angle and type.
One-Piece Implants
In a one-piece implant, the screw body and abutment are manufactured as a single unit. This eliminates the connection point between the two components, which some clinicians view as a potential weak point. One-piece implants are simpler surgically because there is no second procedure to attach the abutment. They are sometimes used for narrow-ridge cases or temporary implants. However, one-piece designs offer less prosthetic flexibility since the abutment angle is fixed.
Platform Switching and Connection Types
Platform switching is a design concept where the abutment is slightly narrower than the top of the implant screw. This offset shifts the junction between the implant and abutment inward, away from the surrounding bone. Research suggests that platform switching may help preserve the bone around the top of the implant over time.
The connection between the implant screw and the abutment also varies by manufacturer. Common connection types include external hex, internal hex, and conical (Morse taper) connections. Internal connections, particularly conical designs, tend to provide a tighter seal and more resistance to loosening. Your implant specialist and prosthodontist select a system with a connection type suited to the clinical situation.
Major Dental Implant Brand Systems
Several manufacturers produce dental implant systems, each with proprietary screw designs, surface treatments, and prosthetic component libraries. Your implant specialist typically works with one or two systems they know well.
- Straumann (Basel, Switzerland): One of the most widely researched implant systems globally. Known for their SLActive surface treatment and Bone Level Tapered (BLT) implant line.
- Nobel Biocare (Zurich, Switzerland): Pioneered the original Branemark implant system. Current product lines include NobelActive and NobelParallel, with a large prosthetic component library.
- Zimmer Biomet (Warsaw, Indiana, USA): Offers the Tapered Screw-Vent system, widely used in the United States. Known for versatility across a range of clinical situations.
- BioHorizons (Birmingham, Alabama, USA): Known for the Tapered Internal implant with a laser-microtextured surface designed to promote soft tissue attachment.
- Dentsply Sirona (Charlotte, North Carolina, USA): Produces the Astra Tech implant system, recognized for its MicroThread design at the implant neck.
Why the Brand Matters for Future Maintenance
The abutments, screws, and prosthetic parts used with your implant are specific to the brand and model. If you move to a new city or change dentists, your new provider needs to know which implant system was placed so they can order compatible components. Ask your implant specialist for a record of the implant brand, model, diameter, and length, and keep this information with your dental records.
How Your Implant Specialist Selects the Right Size
Implant size selection is not a one-size-fits-all decision. Your specialist uses several factors to determine the optimal diameter and length for your case.
- 3D imaging (CBCT scan): A cone-beam CT scan provides a three-dimensional view of your jawbone, showing the exact width, height, and density of bone at the implant site. This is the primary tool for size selection.
- Tooth position: Front teeth, premolars, and molars each require different implant sizes. Molars need wider implants to handle greater chewing forces, while front teeth often require narrower implants due to limited bone width.
- Bone density: Dense bone (common in the front lower jaw) provides more grip for the implant threads. Softer bone (common in the back upper jaw) may require a wider or longer implant to achieve adequate stability.
- Adjacent anatomy: The location of nerves, sinuses, and neighboring tooth roots limits where and how deep an implant can be placed. Your specialist measures these distances on the CBCT scan before selecting the implant size.
- Prosthetic plan: The type of restoration (single crown, bridge, or full-arch denture) influences implant diameter and positioning. A prosthodontist and surgeon often collaborate on the plan.
When to See a Prosthodontist or Oral Surgeon
Dental implants involve both a surgical phase (placing the screw) and a restorative phase (designing and attaching the crown or prosthesis). An oral surgeon or periodontist typically handles the surgical placement, while a prosthodontist designs the final restoration and ensures the implant, abutment, and crown work together as a functional unit.
If you are considering dental implants, a prosthodontist can evaluate your overall situation, coordinate with the surgeon on implant size and positioning, and ensure the final result looks natural and functions properly. This is especially important for complex cases involving multiple missing teeth, limited bone, or teeth in the visible smile zone.
Find a Prosthodontist Near You
Every prosthodontist on My Specialty Dentist has verified specialty credentials. Search by location to find a prosthodontist who can evaluate your implant options and design a restoration plan.
Search Prosthodontists in Your Area