Human ex vivo bone tissue strains around immediately-loaded implants supporting mandibular fixed prostheses

Area of Science:

• Dental Implantology
• Biomechanics
• Biomaterials

Background:

• Immediately-loaded dental implants are crucial for restoring function in edentulous patients.
• Understanding bone strain is vital for predicting implant success and longevity.
• The number of implants used in fixed prostheses can influence stress distribution.

Purpose of the Study:

• To quantify and qualify bone strains around dental implants supporting mandibular fixed prostheses.
• To investigate the effect of the number of implant supports (3, 4, or 5 implants) on bone strain.
• To assess the biomechanical implications of different implant configurations for immediate loading.

Main Methods:

• Strain gauges were placed on the labial bone surrounding 5 Straumann implants in human cadaver mandibles.
• Installation torque and resonance frequency analyses measured initial implant stability.
• Controlled loading experiments were conducted on 3-, 4-, and 5-implant supported full-arch prostheses.

Main Results:

• Installation torque values ranged from 42.12 to 145.67 N cm, and implant stability quotient values were between 61 and 80.
• The 3-implant configuration exhibited the highest bone strain magnitudes.
• Bone strain tended to be similar between the 4- and 5-implant designs (P < 0.05).

Conclusions:

• A 3-implant design generates significantly higher bone strain compared to 4- or 5-implant designs.
• Increased bone strain with fewer implants may elevate the risk of supporting implant failure.
• 4- and 5-implant configurations may offer comparable clinical outcomes regarding bone strain distribution.