Strain Assessment Around Two Short Implants Retaining a Mandibular Overdenture with Different Attachment Systems: In...

Area of Science:

• Dental Implantology
• Biomaterials Science
• Biomechanics

Background:

• Mandibular overdentures are a common prosthetic solution for edentulous patients.
• Implant-retained overdentures offer improved stability and function.
• Attachment systems and implant length are critical factors influencing stress distribution.

Purpose of the Study:

• To compare strain distribution around long and short implants in mandibular overdentures.
• To evaluate the effect of ball versus Positioner attachments on strain.
• To determine the optimal implant characteristics for mandibular overdenture stability.

Main Methods:

• Two epoxy resin mandibular models with either long or short implants were used.
• Overdentures were retained by ball or Positioner attachments.
• Strain gauges measured microstrain under vertical loads; data analyzed using ANOVA and t-tests.

Main Results:

• Positioner attachments generated significantly higher microstrain than ball attachments (P <0.001).
• No significant difference in microstrain was observed between long and short implants under bilateral or unilateral loading.
• Implant length did not influence strain distribution.

Conclusions:

• Positioner attachments lead to greater strain around implants compared to ball attachments, irrespective of implant length.
• Increasing implant length offers no biomechanical advantage.
• Short implants are a practical alternative for retaining mandibular overdentures.