The Insertion Torque-Depth Curve Integral and Implant Micromotion: A Study on Polyurethane Foam Blocks

Area of Science:

• Biomaterials Science
• Dental Implantology
• Biomechanics

Background:

• Primary stability is crucial for successful dental implant osseointegration.
• The torque-depth integral (I) is a parameter used to assess primary implant stability.
• Understanding the relationship between insertion parameters and implant stability is vital for clinical success.

Purpose of the Study:

• To investigate the relationship between the torque-depth integral (I) and implant micromotion in an in vitro setting.
• To evaluate the torque-depth integral (I) as a primary stability-measuring parameter for dental implants.

Main Methods:

• Cylindrical and tapered-cylindrical implants were inserted into polyurethane foam blocks of varying densities using different preparation protocols (undersized, standard, oversized).
• Insertion torque (IT) and torque-depth integral (I) were measured using a torque-measuring micromotor.
• Implant micromotion was assessed by applying a lateral load and measuring displacement via a tensile testing machine.

Main Results:

• Significant inverse nonlinear relationships were found between the torque-depth integral (I) and micromotion (p<0.001).
• A similar inverse relationship was observed between insertion torque (IT) and micromotion.
• No statistically significant differences were noted between the slopes of the (I)-micromotion and IT-micromotion curves.

Conclusions:

• The torque-depth integral (I) is a reliable parameter for measuring primary dental implant stability.
• Further research is recommended using bone-like materials and applying axial loads to validate these findings.