Journal of Oral Implantology October 2012 - (Page 587)

RESEARCH Stress Analysis in Platform-Switching Implants: A 3-Dimensional Finite Element Study Eduardo Piza Pellizzer, DDS, PhD, MSc1* Fellippo Ramos Verri, DDS, PhD, MSc1 ´ Rosse Mary Falcon-Antenucci, DDS, MSc1 ´ Joel Ferreira Santiago Junior, DDS1 ´rgio Perri de Carvalho, DDS, PhD, MSc2 Paulo Se ´ Sandra Lucia Dantas de Moraes, DDS, MSc1 Pedro Yoshito Noritomi, PhD, MSc3 The aim of this study was to evaluate the influence of the platform-switching technique on stress distribution in implant, abutment, and peri-implant tissues, through a 3-dimensional finite element study. Three 3-dimensional mandibular models were fabricated using the SolidWorks 2006 and InVesalius software. Each model was composed of a bone block with one implant 10 mm long and of different diameters (3.75 and 5.00 mm). The UCLA abutments also ranged in diameter from 5.00 mm to 4.1 mm. After obtaining the geometries, the models were transferred to the software FEMAP 10.0 for pre- and postprocessing of finite elements to generate the mesh, loading, and boundary conditions. A total load of 200 N was applied in axial (08), oblique (458), and lateral (908) directions. The models were solved by the software NeiNastran 9.0 and transferred to the software FEMAP 10.0 to obtain the results that were visualized through von Mises and maximum principal stress maps. Model A (implants with 3.75 mm/abutment with 4.1 mm) exhibited the highest area of stress concentration with all loadings (axial, oblique, and lateral) for the implant and the abutment. All models presented the stress areas at the abutment level and at the implant/abutment interface. Models B (implant with 5.0 mm/abutment with 5.0 mm) and C (implant with 5.0 mm/abutment with 4.1 mm) presented minor areas of stress concentration and similar distribution pattern. For the cortical bone, low stress concentration was observed in the peri-implant region for models B and C in comparison to model A. The trabecular bone exhibited low stress that was well distributed in models B and C. Model A presented the highest stress concentration. Model B exhibited better stress distribution. There was no significant difference between the large-diameter implants (models B and C). INTRODUCTION one remodeling surrounding osseointegrated implants has been used for decades as a parameter to assess the predictability of prosthetic rehabilitation.1 Bone loss of 1.5 mm during the first year of loading and 0.1 mm in the subsequent years is considered acceptable.1–3 Recently, the platform-switching technique has decreased the Department of Dental Materials and Prosthodontics, Aracatuba ¸ ˜ School of Dentistry, Sao Paulo State University-UNESP, Brazil. 2 Department of Surgery and Integrated Clinic, Aracatuba School ¸ ˜o of Dentistry, Sa Paulo State University-UNESP, Brazil. 3 ˜ Renato Archer Information Technology Center, Sao Paulo, Brazil. * Corresponding author, e-mail: ed.pl@uol.com.br DOI: 10.1563/AAID-JOI-D-10-00041 1 B possibility of bone loss in the peri-implant region.4–11 The platform-switching technique consists of using an implant with a large diameter and an abutment with small diameter. The resorption pattern was not exhibited in patients with the platform-switching technique after a 5-year followup according to radiographic examinations.12 Lazzara and Porter12 stated that this phenomenon occurs because of the displacement of the implantabutment junction to the central axis of the implant and transferring of microgap at the implantabutment interface that may exhibit bacterial leakage, which avoids inflammation in the bone crest. Clinical, retrospective, and histomorphometric studies demonstrated preservation of bone ridge Journal of Oral Implantology 587

Table of Contents for the Digital Edition of Journal of Oral Implantology October 2012

Should the Implant Fit the Patient or Should the Patient Fit the Implant?
Histologic and Biomechanical Evaluation of Alumina-Blasted/Acid-Etched and Resorbable Blasting Media Surfaces
Impact of Dental and Zygomatic Implants on Stress Distribution in Maxillary Defects: A 3-Dimensional Finite Element Analysis Study
Precision of Implant Placement With Stereolithographic Templates: A Pilot In Vitro Study
An Evaluation of Biocompatibility of Indigenously Produced Pure Titanium: An Experimental Study in Rabbits
Relationship Between Smoking and Bleeding on Probing
Stress Analysis in Platform-Switching Implants: A 3-Dimensional Finite Element Study
Acrylic Resin Polymerization in Direct Contact to the Abutment and the Temperature at Bone-Implant Interface: A Pilot In Vitro Study
Clinical Application of Stereolithographic Surgical Guide With a Handpiece Guidance Apparatus: A Case Report
Fixed Rehabilitation of Severely Atrophic Jaws Using Immediately Loaded Basal Disk Implants After In Situ Bone Activation
A Functional Open-Tray Impression Technique for Implant-Retained Overdenture Prostheses
Use of Plasma Rich in Growth Factor for Schneiderian Membrane Management During Maxillary Sinus Augmentation Procedure
A Technique to Facilitate the Fabrication of Provisional Restorations for ITI Solid Abutments
Influence of Etiologic Factors in Peri-Implantitis: Literature Review and Case Report
Simplistic Partially Limiting Surgical Guide for Flapless Implant Placement: A Case Report
Types of Implant Surgical Guides in Dentistry: A Review
Rehabilitation of Atrophic Posterior Maxilla With Zygomatic Implants: Review

Journal of Oral Implantology October 2012