In dental implant restoration, the screw acts as the critical connector between the implant and restoration, and its stability directly dictates treatment success.Clinically, screw fracture not only results in restoration failure but can also trigger peri-implant inflammation and even necessitate secondary surgery.While fractures may seem accidental, they’re actually driven by a combination of material properties, structural design, and clinical technique—with material mechanical performance standing as the decisive factor.
What Causes Screw Fracture? Multiple Factors, But Material Leads the Way
Among mainstream titanium alloys, the key distinction between Ti-6Al-4V and Ti-6Al-4V ELI (Extra Low Interstitial) lies in interstitial element control—a factor that directly defines fracture resistance limits. See the table below for detailed comparisons:
|
Comparison Metric |
Standard Ti-6Al-4V |
Ti-6Al-4V ELI (Extra Low Interstitial) |
Fracture Resistance Relevance |
|
Interstitial Parameters |
O≤0.20%, N≤0.05% |
O≤0.13% (≤0.10% for premium grades), N≤0.03% |
★★★★★ |
|
Fatigue Strength (500,000 cycles) |
Prone to microcracks |
No damage; strength improved by 10%-15% |
★★★★★ |
|
Toughness (Energy absorption pre-fracture) |
Baseline level |
Increased by 20%-30% |
★★★★☆ |
|
Manufacturing Precision (Thread Tolerance) |
±0.03mm, burr-prone |
±0.01mm, smooth surface |
★★★☆☆ |
|
Key Clinical Outcomes |
Fracture rate: 1.6%; Bone resorption: 0.8-1.0mm |
Fracture rate: 0.2%; Bone resorption: 0.3-0.5mm |
★★★★★ |
(I) Choose High-Quality Materials
Leading international manufacturers prioritize Ti-6Al-4V ELI: For instance, Zapp’s 3.7165 MG material meets ASTM F136 and ISO 5832-3 standards, with oxygen (≤0.10%) and hydrogen (≤0.012%) tightly controlled via vacuum arc remelting—resulting in a 5-year restoration screw fracture rate of just 0.2%. Sandvik’s bars use electron beam cold hearth melting for micron-level precision, while ATI’s products offer 15% higher fatigue strength than standard grades, ensuring performance from the start.
Lighter: α phase
Darker: β phase.
Deep black spots are typically small oxides or inclusions.
(II) Implement Full-Cycle Quality Control
Dentists should standardize torque application (20-35N・cm) and occlusal adjustment, with regular follow-ups. Technicians must maintain strict restoration precision to avoid uneven stress distribution. Distributors should prioritize products with comprehensive material certifications and advanced manufacturing processes.
Dental restoration screw fracture is no accident—it’s a "comprehensive litmus test" of material performance and clinical management. Opting for extra low interstitial materials like Ti-6Al-4V ELI, paired with full-cycle quality control, creates a "fracture-proof shield" for dental implants, ensuring long-term, stable restoration results.
