Journal of Oral Implantology October 2013 - (Page 539)

RESEARCH Impression Techniques for Multiple Implants: A Photoelastic Analysis. Part I: Comparison of Three Direct Methods ´ Itamar Lopes-Junior, MSc* Barbara de Lima Lucas, MSc Henner Alberto Gomide, PhD Vanderlei Luiz Gomes, PhD The purpose of this article was to compare through photoelastic analysis the stress distribution in 3 direct transfer techniques for implants with splinting. Three photoelastic resin blocks were made with 2 implants placed parallel to each other and 2 square transfer copings splinted. Both transfers were splinted with acrylic resin chemically activated in 3 different techniques: metallic sticks (T1), prefabricated acrylic bars (T2), or dental floss (T3). A circular polariscope was used, and the distortion energy (E) was calculated in 4 periods: 20 minutes and 3, 24, and 36 hours. Statistically significant differences were found among the 3 techniques (P , .05). The dental floss presented the greatest distortion energy values (T3 ¼ 0.469 Kgf/mm2) and the metallic sticks the lowest values (T1 ¼ 0.0 Kgf/mm2). Thus, the metallic sticks technique (T1) appears to be the most accurate protocol to be used for implant-supported prosthesis with multiple abutments. Key Words: dental implant, impression, photoelasticity, implant-supported prostheses INTRODUCTION I mplantology currently consists of a reliable oral treatment that follows scientific and clinical evidence.1,2 Despite the proven success of rehabilitations with implants throughout a long period of time,1,2 many difficulties still persist without solution. Among them, the lack of passivity of implant-supported dentures may cause biological complications of the surrounding tissues or mechanical failures of the dentures and implant systems, and thus receives great attention from researchers.3–10 Attention in all stages of prostheses manufacturing can contribute to avoiding the absence of passivity, and a fundamental stage to be observed is the impression procedure. The objective of the impression procedure in implantology is to obtain Faculty of Dentistry, Federal University of Uberlandia, Uberlandia, Minas Gerais, Brazil. * Corresponding author, e-mail: itamar_ljr@yahoo.com.br DOI: 10.1563/AAID-JOI-D-11-00040 the most accurate copy of the implant analogues and the surrounding oral tissues,11 avoiding instabilities in the prosthetic device.4–7 The most commonly used transfer techniques for implant-supported prostheses with multiple abutments are indirect, direct, and direct splinted.12 Some authors have noted that the impression made by the direct transfer technique for implants with splinting is more accurate than that of other techniques.8,13 Chemically activated acrylic resin is frequently used to fabricate intraoral splinting to join impression copings during the open-tray implant impression technique. However, some splinting methods can be used, each with advantages and disadvantages. The technique that uses dental floss as a framework for chemically activated acrylic resin is used thoroughly and demands longer clinical time for application.3,14–17 Other splinting forms are prefabricated bars5,18 and metal sticks,8,16 which use a smaller amount of acrylic resin and need less time for their conclusion. The search for accuracy during the impression Journal of Oral Implantology 539

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