Journal of Oral Implantology October 2013 - (Page 575)

RESEARCH Influence of Different Soft Liners on Stress Distribution in Peri-Implant Bone Tissue During Healing Period. A 3D Finite Element Analysis Mateus Bertolini Fernandes dos Santos, PhD* Rafael Leonardo Xediek Consani, PhD Marcelo Ferraz Mesquita, PhD The aim of this study was to evaluate the stress distribution in the bone adjacent to submerged implants during masticatory function in conventional complete dentures with different soft liners through finite element analysis. Three-dimensional models of a severely resorbed mandible with 2 and 4 submerged implants in the anterior region were created and divided into the following situations: (1) conventional complete dentures (control group); and conventional complete dentures with different soft liner materials, (2) Coe-Comfort, (3) Softliner, and (4) Molteno Hard. The models were exported to mechanical simulation software and 2 simulations were done with the load in the inferior right canine (35 N) and the inferior right first molar (50 N). The data were qualitatively evaluated using the maximum principal stress and microstrain values given by the software. The use of soft liners provides decreased levels of stress and microstrains in peri-implant bone when the load was applied to canine teeth. Considering all of the values obtained in this study, the use of softer materials is the most suitable for use during the period of osseointegration. Key Words: biomechanics, finite element analysis, healing period, microstrain, prosthodontics, soft liner INTRODUCTION S ince their introduction, dental implants have become a successful restorative modality in clinical dentistry, with a reported success rate of over 90%.1 Nowadays, oral rehabilitation with dental implants has become the best choice for treatment because it solves many problems of treatment with conventional dentures,2 exceeding the pretreatment expectations for both esthetics and function.3 The first studies related to implantology advocated that after the placement of an implant, it has to be maintained undisturbed for 3 to 6 months of healing to obtain osseointegration without major problems4; this is because the micromotion caused by loading it earlier may induce fibrous encapsulaPiracicaba Dental School, University of Campinas. * Corresponding author, e-mail: DOI: 10.1563/AAID-JOI-D-11-00049 tion instead of a direct bone-implant interface.5,6 At this time, it is safe to say that completely undisturbed healing of the implant-bone interface is not necessary for successful osseointegration to occur,7 and according to an experimental work, the healing of peri-implant bone under a load seems to be beneficial.8 However, these findings do not imply that the protocol of delayed loading is no longer needed9 since the literature reports that the success of immediately loaded implants is dependent on several factors. Among them, primary stability is the key factor: micromotions at the bone-implant interface beyond 150 lm may result in fibrous encapsulation instead of osseointegration.10 Thus, when primary stability cannot be achieved (30 N/ cm),11 it is recommended to opt for adequate healing time before loading.9 During the healing time, the patient needs to wear a conventional prosthesis on a provisional basis to maintain proper function and esthetics until Journal of Oral Implantology 575

Table of Contents for the Digital Edition of Journal of Oral Implantology October 2013

Food and Drug Administration: Reclassification of Blade Form Dental Implants
Optimizing Platelet-Rich Plasma Gel Formation by Varying Time and Gravitational Forces During Centrifugation
Effect of Surface Roughness and Low-Level Laser Therapy on Removal Torque of Implants Placed in Rat Femurs
Impression Techniques for Multiple Implants: A Photoelastic Analysis. Part I: Comparison of Three Direct Methods
Impression Techniques for Multiple Implants: A Photoelastic Analysis. Part II: Comparison of Four Acrylic Resins
A Pig Model for the Histomorphometric Evaluation of Hard Tissue Around Dental Implants
In Situ Tooth Replica Custom Implant: A 3-Dimensional Finite Element Stress and Strain Analysis
Influence of Different Soft Liners on Stress Distribution in Peri-Implant Bone Tissue During Healing Period. A 3D Finite Element Analysis
Influence of Surface Nano-Roughness on Osseointegration of Zirconia Implants in Rabbit Femur Heads Using Selective Infiltration Etching Technique
Modified Titanium Surfaces Alter Osteogenic Differentiation: A Comparative Microarray- Based Analysis of Human Mesenchymal Cell Response to Commercial Titanium Surfaces
Hemorrhage Secondary to Interforaminal Implant Surgery: Anatomical Considerations and Report of a Case
Rehabilitation of a Patient With Mandibular Resection Using Osteointegrated Implants: A Case Report
Two-Stage Bone Expansion Technique Using Spear-Shaped Implants Associated With Overlapped Flap: A Case Report
Implant Esthetic Restoration in Ridge Deficiencies in Cases of Trauma: A Case Report
Rehabilitation of the Atrophic Maxilla With Tilted Implants: Review of the Literature

Journal of Oral Implantology October 2013