Journal of Oral Implantology June 2012 - (Page 221)

RESEARCH Microstrains Around Standard and Mini Implants Supporting Different Bridge Designs Hanaa Sallam, PhD1 Lamia Sayed Kheiralla, PhD1* Alzahra Aldawakly, PhD1 The purpose of the study was to analyze microstrains around small- versus standarddiameter implants used in restoration of thin wiry ridge through different bridge designs. Additionally, influence of the site of occlusal vertical loading was evaluated using strain gauges. Two models simulating mandibular unilateral free-end saddle were fabricated. Two standard-size implants (3.75 3 13 mm) were inserted in one model in the position of the second premolar and first molar to support 2 3-unit cantilever bridges (NiCr alloy). On the other model, a standard implant and a mini implant (3.0 3 13 mm) were inserted in the position of the second premolar and second molar, respectively, to support 2 fixed-fixed 3unit NiCr bridges. Four strain gauges were mounted buccally, lingually, mesially, and distally adjacent to each implant. The prostheses were temporarily cemented. A 300 N vertical load was applied on the middle of the horizontal runner bar connecting the prosthetic units and on the center of the pontics. Microstrains were recorded and analyzed. Cantilever bridges recorded higher microstrains than fixed-fixed bridges for both loading conditions. Yet, for both designs, loading on the horizontal runner bars, which apply an equal load on all bridge units simultaneously, resulted in significantly lower microstrain values than applying the load only on the pontics. Mini implant revealed greater strain values than standard implant supporting the same fixed partial denture. The best treatment option that produced the least microstrains was the fixed-fixed bridge with a mini implant as a terminal abutment. Mini implants induced higher microstrains than standard implants. Key Words: oral implantology, prosthodontics, implants, strain development INTRODUCTION mplant dentistry represents a reliable solution to situations that cannot be treated with conventional techniques, such as free-end saddles and long-span edentulous ridges. Today, the continued high rate of success 1 I Fixed Prosthodontics Department, Oral and Dental Medicine, Cairo University, Cairo, Egypt. * Corresponding author, e-mail: lamiask@yahoo.com DOI: 10.1563/AAID-JOI-D-10-00020 achieved with osseointegrated dental implants allows a greater number of patients to enjoy the benefits of fixed rather than removable restorations.1,2 Osseointegration and prognosis are greatly influenced by the biomechanical environment. The internal stresses that develop in an implant system and surrounding biological tissue under an imposed load have a significant influence on the long-term longevity of the implant.3,4 These stresses may induce Journal of Oral Implantology 221

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

Editorial
Relationships Between the Gonial Angle and Mandibular Ramus Morphology in Dentate Subjects: A Panoramic Radiophotometric Study
A Comparison of Peripheral Marginal Bone Loss at Dental Implants Measured With Conventional Intraoral Film and Digitized Radiographs
Microstrains Around Standard and Mini Implants Supporting Different Bridge Designs
Surface and Biomechanical Study of Titanium Implants Modified by Laser With and Without Hydroxyapatite Coating, in Rabbits
Survival and Success Rates of Immediately and Early Loaded Implants: 12-Month Results From a Multicentric Randomized Clinical Study
Posttreatment Quantification of Patient Experiences With Full-Arch Implant Treatment Using a Modification of the OHIP-14 Questionnaire
Correlation Between Occlusal Forces and Marginal Bone Levels Around Implant- Retained Restorations: A Clinico-Radiological Study
The Influence of Maximum Bite Force on Patient Satisfaction and Quality of Life of Patients Wearing Mandibular Implant Overdentures
Guided Flapless Surgery With Immediate Loading for the High Narrow Ridge Without Grafting
Estimation of the Safe Distance Between the Implant and an Adjacent Tilted Implant Using Trigonometry
Chair-Side Fabrication of a Fixed Implant-Supported Prosthesis in an Edentulous Mandible From A Diagnostic Wax-Up: A Clinical Report
A Comparison Between Screw- and Cement-Retained Implant Prostheses. A Literature Review

Journal of Oral Implantology June 2012