[Stress analysis of the staggered and straight placement of implants in the mandibular posterior region under the localized load].

Objective: To compare the stress distribution of the staggered and straight placement of implants in the mandibular posterior region.

Methods: Using three-dimensional finite element approach to analyze the stress distribution and variance regularity under the localized load.

Results: Under vertical load, the stress peak value reduced when wide implant was placed straight (min: 3.70 MPa), but slightly increased when normal implant was placed staggered (max: 8.32 MPa); under the inclined load from buccal to lingual direction, the stress peak value reduced when the wide implant was placed in straight line (min: 12.29 MPa) or normal implant was placed staggered with buccal offset configuration (min: 15.48 MPa), but increased with lingual offset configuration (max: 23.60 MPa).

Conclusions: Wide implant (> or = 4 mm) with straight placement should be adopted to reduce the stress peak value and improve stress distribution, when the buccolingual diameter of the alveolar ridge in the mandibular posterior region was wide.