Reviving a Pioneering Technique in Modern Dentistry
Subperiosteal implants, a type of dental implant placed under the gum tissue but on top of the jawbone, have undergone a remarkable resurgence in recent years. Originally developed to address severe jawbone atrophy where traditional endosseous implants—screw-like fixtures drilled directly into the bone—are not feasible without extensive grafting, these custom frameworks offer a graftless alternative. As dental science evolves, university-led research is at the forefront, leveraging advanced imaging and manufacturing to improve outcomes for patients with compromised bone volume.
Historical Foundations: From Early Experiments to Widespread Use
The story of subperiosteal implants begins in the 1940s when Swedish dentist Gustav Dahl introduced the concept for edentulous patients with atrophic mandibles. By the 1950s, Dr. Leonard Linkow refined the design, creating prefabricated frameworks cast from vitalium or gold alloys, popularized in the United States. These implants featured a metal mesh or bar structure contoured to the bone surface, with posts emerging through the mucosa to support dentures. Early adoption was rapid, with thousands placed by the 1960s and 1970s, particularly at institutions like the University of Southern California, where long-term studies tracked survival.
Initial success stemmed from their ability to bypass bone drilling, ideal for elderly patients or those with systemic conditions precluding major surgery. Case reports from the era documented functional lifespans exceeding 20 years in select patients, sparking optimism in academic circles focused on prosthetic rehabilitation.
The Decline: Challenges and Shift to Osseointegration
Despite early promise, subperiosteal implants faced scrutiny by the 1980s. Complications like framework exposure, peri-implant infection, bone resorption, and prosthetic instability—known as the 'degenerative triad'—led to failure rates climbing to 40-50% over 10-15 years. Historical survival statistics revealed 92% at 5 years dropping to 82% at 10 years for mandibular cases. The rise of endosseous implants, championed by Per-Ingvar Brånemark's osseointegration discovery in the 1960s at Göteborg University, offered superior long-term predictability (95%+ survival), rendering subperiosteal designs obsolete for most clinicians.
Academic reviews from this period, including those from New York University, highlighted design flaws: imprecise casting from mucosal impressions caused micromotion, promoting bacterial ingress. By the 1990s, usage plummeted, confined to niche cases.
Technological Renaissance: CAD/CAM and 3D Printing
The turning point came around 2015 with digital dentistry's ascent. Cone-beam computed tomography (CBCT) enables precise bone mapping, while computer-aided design/computer-aided manufacturing (CAD/CAM) and direct metal laser sintering (DMLS) produce patient-specific titanium frameworks. These modern subperiosteal implants feature multivectorial anchorage via mini-screws into residual bone, polished surfaces for hygiene, and optimized post geometry to minimize soft tissue trauma.
Institutions like Hannover Medical School and the University of the Basque Country have pioneered prototypes, reporting fitting accuracy exceeding 95%. The process involves CBCT scanning, digital modeling, 3D printing surgical guides and frameworks, and single-stage surgery—reducing morbidity compared to historical two-stage methods.
Step-by-Step: How Subperiosteal Implants Are Placed Today
- Diagnosis and Planning: CBCT assesses bone morphology (Cawood-Howell class V-VI atrophy). Software simulates framework fit.
- Design and Fabrication: CAD creates custom titanium structure with 20+ screws for anchorage and 4-8 posts. DMLS prints in 1-2 days.
- Surgery: Full-thickness flap elevation exposes bone; framework secured with screws; flap closed over it. Posts protrude transmucosally.
- Prosthetics: Healing abutments or immediate provisional denture; final prosthesis after 3-6 months.
- Follow-up: Monitor plaque, inflammation; hygiene protocols essential.
This streamlined workflow, refined in university clinics, contrasts sharply with past techniques reliant on plaster casts.
Clinical Evidence: Success Rates from Recent Studies
Contemporary research validates the revival. A 2025 meta-analysis reported 97.8% short-term survival (mean 21 months) across 227 patients, with complications mainly soft-tissue (25.6% partial exposure). Long-term data: 91.6% success at 2 years, 89.4% survival at 8.9 years in multivectorial designs.
| Study | Follow-up | Survival Rate |
|---|---|---|
| Anitua et al. (2024) | 21 months | 97.8% |
| Zielinski et al. (2025) | 5 years | 97.1% |
| Pott et al. (2025) | 8.9 years | 89.4% |
A five-year comparison with zygomatic implants showed comparable survival (96.3% vs. 97.1%) but fewer sinus complications with subperiosteal (5.6% peri-implantitis vs. higher sinusitis).Read the full study
Photo by Mansi Telharkar on Unsplash
Comparing Subperiosteal to Endosteal and Zygomatic Implants
- Endosteal: Gold standard (95-98% 10-year survival), but requires 10mm+ bone height. Grafting often needed for atrophy.
- Zygomatic: Anchors in cheekbone; immediate load; 96% survival but sinus/orbital risks.
- Subperiosteal: Graftless for extreme atrophy; custom fit; similar survival but better soft tissue stability; longer surgery (177 vs. 123 min).
Biomechanical finite element analyses from universities like those in Italy confirm optimized stress distribution in modern designs.
Real-World Case Studies: Success Stories from Clinics
In a 2025 Polish study, 150 atrophic maxilla patients received subperiosteal implants, achieving 97.1% survival with restored function. A Romanian pilot (2021-2022) using DMLS titanium reported no major complications in custom cases. Long-term: A 41-year mandibular case from 2000 persists, though exceptional. University-affiliated centers report high satisfaction due to preserved bone height and aesthetics.
Patient profile: Elderly (mean age 62), comorbidities; full-arch rehab common.
Advantages and Patient Benefits
- Graftless: Avoids donor site morbidity, shorter recovery.
- Custom precision: Perfect fit via digital workflow.
- High initial success: 95-99% short-term.
- Versatile: Maxilla/mandible, partial/full arches.
- Cost-effective long-term vs. grafting failures.
Ideal for non-compliant patients or those rejecting sinus lifts.
Potential Risks and Management Strategies
Primary issues: Soft-tissue inflammation (18-25%), exposure (up to 37%), plaque accumulation at posts. Risk factors: Close spacing (<10mm), tooth proximity, poor hygiene. Mitigation: Keratinized mucosa grafts, polished titanium, rigorous recall. Modern rates lower than historical (5-10% major). Detailed complication analysis
The Role of Academia in Advancing Subperiosteal Implants
Universities drive innovation: Hannover's CAD prototypes, Basque Country's survival studies, Italian FEA models. Training programs at Pikos Institute, Subperiosteal Institute offer hands-on courses, bridging research to practice. Dentistry departments integrate into implantology curricula, fostering expertise in digital workflows.
Market Growth and Future Innovations
Global market: USD 645M in 2026, CAGR 6.6% to $1.07B by 2034, fueled by aging populations and 3D printing. Outlook: Bioactive coatings, resorbable scaffolds, AI-optimized designs. Hybrid endosseous-subperiosteal emerging. Research focuses on osseopromotion for longevity.
Photo by Shahid Hafiz on Unsplash
Implications for Dental Education and Practice
As subperiosteal implants gain traction, dental schools must update curricula with digital implantology modules. Collaboration between academia and industry promises broader access, enhancing patient outcomes worldwide.
