Journal of Oral Implantology April 2012 - (Page 125)

RESEARCH Deformation of Implant Abutments After Framework Connection Using Strain Gauges Henrique Hollweg, DDS, MSc, PhD1 ´ Letıcia Borges Jacques, DDS, MSc, PhD1 ´ Marcio da Silva Moura, MEng2 ´ Vinıcius Cappo Bianco, DDS, MSc3 Edson Antonio Capello Souza, MEng, PhD4 ´ Jose Henrique Rubo, DDS, MSc, PhD3* When a cylinder is connected to an abutment it is expected that abutment and cylinder will be subjected to compression forces throughout their periphery because of the clamping force exerted by the screw. The deformation resultant of this compression should be measurable and uniform along the periphery of the abutment. Considering that multiple retainers connected to each other can affect the fit of a framework, as well as the use of different alloys, it is expected that the abutments will present different levels of deformation as a result of framework connection. The aim of this study was to evaluate the deformation of implant abutments after frameworks, cast either in cobalt-chromium (CoCr) or silverpalladium (AgPd) alloys, were connected. Samples (n 5 5) simulating a typical mandibular cantilevered implant-supported prosthesis framework were fabricated in cobalt-chromium and silver-palladium alloys and screwed onto standard abutments positioned on a mastercast containing 5 implant replicas. Two linear strain gauges were fixed on the mesial and distal aspects of each abutment to capture deformation as the retention screws were tightened. A combination of compressive and tensile forces was observed on the abutments for both CoCr and AgPd frameworks. There was no evidence of significant differences in median abutment deformation levels for 9 of the 10 abutment aspects. Visually well-fit frameworks do not necessarily transmit load uniformly to abutments. The use of CoCr alloy for implant-supported prostheses frameworks may be as clinically acceptable as AgPd alloy. Key Words: implant frameworks, prosthesis fit, strain gauges INTRODUCTION Department of Restorative Dentistry, School of Dentistry, Federal University of Santa Maria, Santa Maria, RS, Brazil. 2 ˜ Sao Paulo State University, Bauru, SP, Brazil. 3 Department of Prosthodontics, Bauru School of ˜ Dentistry, University of Sao Paulo, Bauru, SP, Brazil. 4 Department of Mechanical Engineering, School of ˜o Engineering, Sa Paulo State University, Bauru, SP, Brazil. * Corresponding author, e-mail: jrubo@fob.usp.br DOI: 10.1563/AAID-JOI-D-10-00068 1 ne of the objectives in fabricating implant-supported restorations is the production of frameworks that exhibit passive fit when connected to multiple abutments.1–3 The term ‘‘passive fit,’’ with regard to the relationship of a prosthetic framework to its underlying Journal of Oral Implantology 125 O

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

Research Letters: A New Editorial Format for the Rapid Disclosure of Innovative Data and Concepts, Didactic Demonstrations, and Scientific Discussions
Effect of Defective Collagen Synthesis on Epithelial Implant Interface: Lathyritic Model in Dogs. An Experimental Preliminary Study
Presence of Aspartate Aminotransferase in Peri-Implant Crevicular Fluid With and Without Mucositis
Deformation of Implant Abutments After Framework Connection Using Strain Gauges
Implant-Retained Mandibular Bar-Supported Overlay Dentures: A Finite Element Stress Analysis of Four Different Bar Heights
The Efficacy of Mylohyoid Nerve Anesthesia in Dental Implant Placement at the Edetulous Posterior Mandibular Ridge
Metal-Ceramic Screw-Retained Implant Fixed Partial Denture With Intraoral Luted Framework to Improve Passive Fit
A Relaxed Implant Bed: Implants Placed After Two Weeks of Osteotomy With Immediate Loading: A One Year Clinical Trial
A Modified Technique for Removing a Failed Abutment Screw From an Implant With a Custom Guide Tube
Therapy for Missing Lower Medial Incisor by Means of Reduced Diameter Implants
Simplifying the Implant Treatment Plan for an Elderly Patient
The Use of Leukocyte- and Platelet-Rich Fibrin During Immediate Postextractive Implantation and Loading for the Esthetic Replacement of a Fractured Maxillary Central Incisor
Atraumatic Removal of an Asymptomatic Migrated Dental Implant Into the Maxillary Sinus: A Case Report
Tooth-Implant Connection: A Review

Journal of Oral Implantology April 2012