Influence of microthreads and platform switching on stress distribution in bone using angled abutments

Abstract

Purpose: To evaluate the stress distribution in peri-implant bone by simulating the effect of an implant with microthreads and platform switching on angled abutments through tridimensional finite element analysis. The postulated hypothesis was that the presence of microthreads and platform switching would reduce the stress concentration in the cortical bone. Methods: Four mathematical models of a central incisor supported by an implant (5.0 mm  13 mm) were created in which the type of thread surface in the neck portion (microthreaded or smooth) and the diameter of the angled abutment connection (5.0 and 4.1 mm) were varied. These models included the RM (regular platform and microthreads), the RS (regular platform and smooth neck surface), the SM (platform switching and microthreads), and the SS (platform switching and smooth neck). The analysis was performed using ANSYS Workbench 10.0 (Swanson Analysis System). An oblique load (100 N) was applied to the palatine surface of the central incisor. The bone/implant interface was considered to be perfectly integrated. Values for the maximum (s max ) and minimum (s min ) principal stress, the equivalent von Mises stress (s vM ), and the maximum principal elastic strain (e max ) for cortical and trabecular bone were obtained. Results: For the cortical bone, the highest s max (MPa) were observed for the RM (55.1), the RS (51.0), the SM (49.5), and the SS (44.8) models. The highest s vM (MPa) were found for the RM (45.4), the SM (42.1), the RS (38.7), and the SS models (37). The highest values for s min were found for the RM, SM, RS and SS models. For the trabecular bone, the highest s max values (MPa) were observed in the RS model (6.55), followed by the RM (6.37), SS (5.6), and SM (5.2) models. Conclusion: The hypothesis that the presence of microthreads and a switching platform would reduce the stress concentration in the cortical bone was partially rejected, mainly because the microthreads increased the stress concentration in cortical bone. Only platform switching reduced the stress in cortical bone.

Impact of platform switching on marginal peri‐implant bone‐level changes. A systematic review and meta‐analysis

“…; Ferraz et al. ), and clinical experiences with this treatment were gained during the last decade (Lazzara & Porter ; Canullo & Rasperini ). Briefly, platform switching is defined as an “act of changing an implant abutment to one with a smaller diameter, so as to place the implant‐abutment interface medial to the edge of the implant platform” (Laney ).…”

“…As introduction of the platform switching concept into construction of implant systems and abutment configurations, their experimental impact on peri-implant bone-level alterations was studied in various finite-element and in vivo studies as well (Becker et al 2007(Becker et al , 2009Jung et al 2008;Cochran et al 2009;Ferraz et al 2012), and clinical experiences with this treatment were gained during the last decade (Lazzara & Porter 2006;Canullo & Rasperini 2007). Briefly, platform switching is defined as an "act of changing an implant abutment to one with a smaller diameter, so as to place the implantabutment interface medial to the edge of the implant platform" (Laney 2007).…”

Influencia del Diseño Micro y Macroscópico de la Región Cervical del Implante en la Preservación de Hueso Marginal Perimplantario: Una Revisión Sistemática

“…Esta circunstancia podría deberse a un mayor cerclaje del implante alrededor de la cresta ósea cortical, lo que aseguraría un menor nivel de micromovimientos durante la fase de osteointegración o a una mejora de las transferencias de carga al terreno de soporte. Sin embargo, los estudios de elementos finitos no presentan consenso a este respecto (Ferraz et al, 2012;Rahimi et al, 2009).…”

Value of platform switching on marginal peri-implant bone loss reduction : A summary review

“…Since introduction of platform switching (PS) concept, there are many fi nite-element and in vivo studies on its eff ect on the MBL were conducted. [1][2][3][4][5] However, most studies that aiming on the eff ect of PS on MBL compared to platform matching (PM) implant-abutment have relatively short follow-up periods and diff erent sample sizes in addition to heterogeneity and possible publication bias, which led to diff erent conclusions even in systematic reviews, ranging from not revealing any clinical superiority for any particular implant design in maintaining marginal bone levels to recognizing the PS technique as appearing useful in limiting bone resorption. So that long term, well-conducted RCT to validate eff ect of PS is conceded even in most recently publishing review.…”