RESUMEN
Available bone is one of the important factors in implant treatments. Due to concerns about complications caused by less bone implant contact area, researchers have focused on biomechanical properties of implants and methods to promote them. We investigated stress distribution around bone of different implant diameters and vertical cantilever length. Computed tomography (CT) images obtained of human mandible were used in this study. An SPI implant (Alpha Bio Tech, Simplantology) of two different lengths (10.5 mm and 8.5 mm) and two different widths (3.5 mm and 4.5 mm) were placed into two different groups of bone samples (with and without osteoplasty). Vertical and lateral forces of 100N and 30N at 45° were applied simultaneously in two models. The stress was analyzed using the finite element method. Maximum stress areas were located around the implant neck. Lower stress values in the loaded implants were observed in the shorter group related to the increase in crown height space, when compared to the other group. A wider implant may be better to dissipate force, thus reducing stress on the bone surrounding the implant. Additionally, the use of shorter and wider implants might be a reasonable alternative in sites limited by the height of the residual ridge.
Asunto(s)
Proceso Alveolar , Implantes Dentales , Diseño de Prótesis Dental , Mandíbula , Estrés Mecánico , Proceso Alveolar/diagnóstico por imagen , Fenómenos Biomecánicos , Simulación por Computador , Módulo de Elasticidad , Análisis de Elementos Finitos , Humanos , Mandíbula/diagnóstico por imagen , Tomografía Computarizada por Rayos XRESUMEN
The objective of the current study is to investigate the relative effect of splinted and nonsplinted implants on stress and strain in the supporting tissue around implants in two-implant-supported mandibular overdentures. Two models of mandibular overdentures using locators (nonsplinted implants) and bar locators (splinted implants) were constructed, and a vertical load of 100 N was placed on the central fossa of the mandibular first molar. Stress and strain values were obtained using three-dimensional finite-element analysis (ANSYS R18.0). Splinting reduced stress in peri-implant bone in the ipsilateral implant by half and in the contralateral implant by a quarter. Greater stress and a rise in strain from 59 to 79 µÎµ in the posterior ridge were also observed with splinting. The model with splinted implants showed more favorable stress distribution in peri-implant bone, perhaps due to better distribution through the bar and the posterior ridge. These findings should be corroborated with clinical studies.