Comparative Evaluation of Stress Distribution Around Mandibular Overdentures Surrounded by Three and Four Implants: A Three?Dimensional Finite Element Analysis

Abstract

Background and objectives: Placement of more than two implants in the interforaminal area may create
a greater implant-to-bone contact area that allows for better stress distribution and minimizes crestal bone
loss. The purpose of this study was to analyze and compare the stress distribution around implants of the
three or four implant?retained mandibular overdenture.
Methodology: Two finite element models comprising an edentulous mandible with three and four implant
supported mandibular overdenture with bar and clip attachment was used. A vertical load of 30 pounds was
applied bilaterally to the first molar. Maximum and minimum von Mises stress values in the bone around
the implants were evaluated.
Results: The highest stress value was observed in the bone around the distal implants and lowest stress
value was concentrated in the middle implant in the molar region in three implant supported overdenture.
The highest stress value was concentrated in the bone around the distal implants and lowest stress value was
concentrated in the anterior implants in four implant supported overdenture. Stress values were more on four
implant supported overdenture than three implant supported overdenture.
Conclusion: Within the limitation of the study, three implant supported overdentures demonstrated lesser
stress in comparison to the four implant supported overdentures. The stresses generated were higher in the
bone around the distal implants and lowest in the middle and anterior implants.