Abstract
Due to its simplicity and patient satisfaction, an implant-retained overdenture has become the most preferred treatment for edentulous patients. Due to the presence of an attachment system at mandibular anterior region, however, base fracture is the most common complication of overdenture. This study aimed to evaluate the stress distribution and deformation on a symphyseal single implant retained mandibular overdenture using a three-dimensional finite element. Zirconia versus acrylic overdenture was investigated. Acrylic overdentures reinforced with short (over inter-canine distance) or long (extending between first molars) zirconia, cobalt-chromium alloy or polyetherketoneketone framework were also investigated. A load of 100 N was applied to the incisal edge of mandibular central incisors at a 30 degrees angle. Results showed that zirconia overdenture had lower von Mises stress and deformation in its components than acrylic. Reinforcement of an acrylic overdenture with cobalt chromium or zirconia short frameworks reduced von Mises stress and deformation on its components. Reinforcement of an acrylic overdenture with polyetherketoneketone framework did not show any significant reduction in von Mises stress and deformation. Therefore, it can be concluded that using zirconia overdenture or reinforcing an acrylic overdenture with cobalt chromium or zirconia framework could increase the longevity of the prosthesis.