Stress distribution in bone simulation model with pre-angled implants

Area of Science:

• Biomaterials Science
• Dental Implantology
• Biomechanics

Background:

• External hexagon implants are widely used in dental restorations.
• Understanding the biomechanical behavior of angled implants is crucial for long-term prosthesis success.
• Photoelastic analysis offers a visual method to assess stress distribution in dental materials.

Purpose of the Study:

• To evaluate the biomechanical behavior of prostheses attached to conventional and pre-angled external hexagon implants.
• To compare stress distribution in single-unit and three-unit prostheses under varying implant angulations (0°, 8°, 12°, 20°).

Main Methods:

• Photoelastic analysis was used on eight resin casts of external hexagon implants (13 × 4 mm).
• Casts were configured as single crowns or three-unit bridges and subjected to axial and oblique (45°) 100 N loads.
• Stress patterns were recorded photographically and analyzed qualitatively.

Main Results:

• For single-unit prostheses, higher implant angulation led to increased high-stress fringes.
• In three-unit prostheses, stress distribution was similar across angles, except for the 12° implant showing higher stress.
• Pre-angulation generally increased stress concentration in single prostheses but had a similar effect in three-unit fixed prostheses.

Conclusions:

• Implant angulation significantly affects stress distribution in single-unit restorations.
• Angled implants may offer comparable biomechanical performance to conventional implants in multi-unit fixed prostheses.
• Further research is needed to optimize implant angulation for specific prosthetic designs.