Biomechanical Effect of an Exposed Dental Implant's First Thread: A Three-Dimensional Finite Element Analysis Study

Area of Science:

• Biomaterials Science
• Biomechanics
• Dental Implantology

Background:

• Understanding the biomechanical behavior of dental implants is crucial for successful osseointegration.
• The extent of the first implant thread exposure can influence stress distribution in the surrounding alveolar bone.

Purpose of the Study:

• To evaluate the impact of varying first thread exposure levels of dental implants on adjacent bone stress and strain.
• To utilize finite element analysis (FEA) to simulate and quantify these biomechanical effects.

Main Methods:

• Developed 3D finite element models of threaded implants and mandibular bone segments.
• Simulated four distinct first thread exposure levels (Upper Flank, Thread Crest, Lower Flank, Thread Root) and a covered control model.
• Applied oblique forces to the models and analyzed stress and strain distributions in the adjacent bone.

Main Results:

• Peak stress magnitudes varied with exposed thread profiles, ranging from 136 MPa (Thread Crest) to 197 MPa (Lower Flank), compared to 141 MPa in the covered model.
• Stress concentration occurred at the mid-lingual crestal region for Lower Flank, Upper Flank, and covered models, shifting distally for Thread Crest and Thread Root models.
• Alveolar bone volumes within physiological microstrain windows for bone maintenance were comparable across all tested models.

Conclusions:

• The specific profile of an exposed dental implant thread influences stress and strain in the immediate vicinity of the bone.
• This influence is confined to a localized area around the exposed thread, suggesting limited widespread impact on bone remodeling.