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What Are All-on-4 Dental Implants? How They Work and Who They're For

Dr. Igor Kaplansky, DDS · April 18, 2026 · 5 min read

Medically reviewed by Dr. Igor Kaplansky, DDS — April 18, 2026

All-on-4 is a full-arch implant system that replaces every tooth in one jaw using four strategically positioned titanium implants. Two are placed vertically in the front of the arch; two are tilted posteriorly at 30–45 degrees to reach denser bone and avoid the sinus cavity. A fixed prosthetic arch is attached, and provisional teeth are delivered within hours of surgery. For many patients with full-arch tooth loss, it eliminates the need for bone grafting.

How the Angled Implant Design Works

The standard objection to full-arch implants in patients with bone loss has historically been that there isn’t enough bone volume — especially in the posterior maxilla, where the sinus sits close to where implants would need to go.

All-on-4 addresses this by tilting the two rear implants. At a 30–45 degree angle, they can reach the denser, well-vascularized bone anterior to the sinus rather than requiring the posterior bone that may have resorbed. This geometry often allows placement without grafting, which shortens the overall treatment timeline.

The four implant positions:

• Two anterior implants: placed vertically in the densest front-jaw bone (symphysis and canine regions in the lower arch; anterior maxilla in the upper)
• Two posterior implants: angled to engage bone anterior to critical anatomy (sinus in the upper jaw; inferior alveolar nerve in the lower)

The Procedure Step by Step

Consultation and 3D planning: A CBCT scan evaluates bone density and maps nerve and sinus positions. Custom surgical guides are fabricated from this imaging to direct implant placement precisely.

Surgery: Any remaining teeth requiring extraction are removed. The four implants are placed using the surgical guide. In the same appointment or within 24 hours, a provisional fixed arch is attached.

Healing period: The provisional arch provides function and aesthetics while osseointegration occurs over three to six months. Chewing forces load the implants, which is normal — the provisional is designed to distribute load appropriately.

Final prosthesis: After osseointegration is confirmed, the provisional is replaced with the permanent screw-retained restoration. Material options include zirconia or high-strength acrylic.

All-on-4 vs. More Implants

All-on-4 uses four implants per arch. Systems using six to eight implants distribute forces more broadly and offer additional redundancy. At this practice, the TeethNow system uses six to eight zirconia implants and a full zirconia prosthesis — a higher-implant-count, metal-free alternative.

The right choice depends on your bone distribution, anatomy, and clinical needs. Some cases are best served by four implants; others benefit from more. That determination requires imaging and clinical evaluation — not a blanket recommendation.

Who Is a Good Candidate

Ideal All-on-4 candidates:

• Have full or near-full arch tooth loss, or failing teeth requiring extraction
• Have adequate anterior bone for implant anchorage (the most common situation)
• Are in good general health with controlled chronic conditions
• Do not smoke, or are willing to comply with cessation protocols
• Are committed to post-surgical maintenance

Patients with severe upper jaw bone loss who have extensive posterior atrophy may not have enough bone even for angled posterior implants. For those patients, zygomatic implants are an alternative that anchors in the cheekbone rather than the jaw. Dr. Igor Kaplansky, DDS — Diplomate ABOI/ID, Fellow AAID/FICOI/FAGD, ZAGA Center certified — is one of only 11 ZAGA-certified zygomatic specialists in the United States and can evaluate whether that pathway applies.

Long-Term Performance

All-on-4 has a well-documented clinical record. Implant survival rates in published studies run in the 95–98% range at five to ten years. The prosthesis itself may require maintenance — occlusal adjustments, screw tightening, or eventual replacement of the acrylic or zirconia components — but the fixtures are designed to last decades.

Consultations at Dentistry by Dr. Kaplansky in Gasport, NY are offered at no charge. Serving Lockport, Niagara Falls, Buffalo, and Western New York. Schedule a consultation to find out which full-arch approach is right for your anatomy.

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Related: Dental Implants Overview · TeethNow Full-Arch System · Zygomatic Implants · Dental Implant Cost Guide