Evaluation of the Effects of Implants with Different Geometries on the Inferior Alveolar Nerve Under Occlusal Stresses

Dental implant placement in the posterior mandible can be challenging due to the presence of the inferior alveolar nerve (IAN). Biomechanical factors related to implant design and loading may also influence nerve compression. This study aimed to investigate the influence of implant geometry, diameter, length, and implant–canal distance on IAN pressure. Dental implants with two geometries (tapered and cylindrical), two lengths (8 and 12 mm), and two diameters (3.3 and 4.1 mm) were virtually positioned at three implant–canal distances (0.5, 1.0, and 1.5 mm). A total of 24 finite element models were generated. Functional occlusal loading was simulated using a 300 N vertical force and a 100 N oblique force applied at a 45° angle. The resulting IAN pressure values were determined. The implant diameter affected IAN pressure, with 3.3 mm implants yielding higher values than 4.1 mm implants. Longer implants exhibited lower pressure values than shorter implants. Cylindrical implants generated higher pressure than tapered implants. Increasing the implant–canal distance from 0.5 to 1.5 mm reduced nerve pressure. Vertical loading yielded higher pressure values than oblique loading. The implant–canal distance was the primary factor influencing IAN pressure. Implant diameter and geometry had secondary effects, whereas implant length had a limited influence. These findings highlight the importance of implant planning and design selection to reduce load transfer to the IAN.