Single tooth replacement — required following extraction of a non-restorable tooth — represents one of the most common treatment planning decisions in dental practice, with the choice typically centering on a dental implant (titanium fixture + crown) versus a 3-unit fixed dental prosthesis (bridge) supported by adjacent teeth. Two decades of comparative outcome data now provide a clear clinical picture of relative advantages and limitations, though cost and patient-specific factors continue to make bridges the appropriate choice in a significant subset of cases.
10-Year Survival Data
A landmark 2015 systematic review in the International Journal of Oral and Maxillofacial Implants synthesized 10-year outcome data: implant-supported crowns demonstrate 96.4% 10-year survival versus 89.2% for 3-unit bridges. More significantly, complication profiles differ: bridge complications predominantly involve caries on abutment teeth (affecting 18% of bridges over 10 years), endodontic complications in abutments (6%), and decementation. Implant complications include peri-implantitis (occurring in 10–15% of implants), technical complications (screw loosening, crown fracture), and occasional osseointegration failure (approximately 3–5% in healthy patients). The 2024 updated European Association for Osseointegration guidelines place 20-year implant survival at approximately 90% in healthy patients with good oral hygiene — substantially superior to bridge longevity over equivalent follow-up periods.
Bone Preservation: The Invisible Advantage
The most underappreciated difference between implants and bridges is the effect on alveolar bone. Following tooth extraction, alveolar bone undergoes progressive resorption: without a functional root (or implant), bone volume reduces approximately 25% at 12 months and 40–60% at 3 years. An implant provides functional loading that maintains bone volume and ridge width — preserving esthetics and enabling future implant placement in adjacent sites if needed. A bridge, by contrast, allows continued bone resorption beneath the pontic — creating an esthetic "ledge" effect that becomes increasingly visible over time, particularly in the esthetic zone.
Adjacent Tooth Considerations
Bridge preparation requires removal of 60–75% of adjacent tooth structure to create retainer cores — a permanent irreversible reduction in natural tooth substance even if the bridge eventually fails. Studies show that bridge abutment teeth undergo endodontic complications at rates 2–4× higher than un-prepared teeth of equivalent pre-existing condition. For posterior teeth with existing large restorations (where significant tooth structure is already compromised), this consideration is less impactful. For anterior teeth with intact or minimally restored adjacent teeth, the tooth tissue loss from bridge preparation is a compelling argument for implant treatment.
When Bridges Are the Right Choice
Implants are contraindicated or relatively contraindicated in: active uncontrolled diabetes (HbA1c >8%), recent radiotherapy to the jaw (osseointegration failure rate 2–4× higher), active smoking (relative contraindication, failure rate 1.5–2×), bisphosphonate therapy for osteoporosis (MRONJ risk, though current evidence suggests risk with oral bisphosphonates is low at standard doses), and patients younger than 18 with growing alveolar ridges. In these situations, bridges remain the primary fixed prosthetic option. The treatment time advantage of bridges — immediate restoration possible after extraction, versus 4–6 months for implant healing before final crown — also favors bridges when patient time constraints are significant. Dental facilities providing restorative and implant dentistry should stock comprehensive dental supplies including surgical materials, impression materials, and post-operative wound care products.
