Journal of Oral Implantology April 2013 - (Page 140)

RESEARCH Retention of Implant-Supported Overdenture With Bar/Clip and Stud Attachment Designs Omid Savabi, DDS, MS1 Farahnaz Nejatidanesh, DDS, MS2* Forough Yordshahian, DDS3 The degree of retention for overdenture attachments depends on design, location, and alignment of supporting dental implants and the type of attachments. The aim of this study was to evaluate the retention of an implantsupported overdenture with different attachment designs. An overdenture was made on an edentulous mandibular model with 2 ITI implants (4.1 3 10 mm) in the symphyseal region. Five specimens of 8 attachment designs with corresponding abutments and superstructures were used: ITI regular Dolder bar with 1 metal clip, ITI regular Dolder bar with cantilever and 3 metal clips, Hader bar with 1 plastic clip, Hader bar with cantilever and 3 plastic clips, Sphero block abutment with Rhein plastic caps (green, white, and pink), and retentive anchor with ITI elliptical matrix. The attachments’ housings were interchangeable and fixed into the overdenture through nut and screw. The overdenture attachments were subjected to 8 consecutive pulls on a universal testing machine with a crosshead speed of 50.8 mm/min in the vertical and posteroanterior directions. Analysis of variance and Duncan tests were used to determine differences between mean retention values (a ¼ .05). The highest average value retention was recorded for the ITI Dolder bar with cantilever and 3 metal clips in both the vertical and posteroanterior directions, respectively (P , .05). The Rhein pink caps had the lowest retention in the posteroanterior direction (P , .05). Retention decreased over the course of consecutive pulls for all attachments in both directions. The type, number, and placement of attachments affect the retention of implant-supported mandibular overdentures. Key Words: dental implants, denture precision attachment, denture retention, denture design INTRODUCTION T here are some problems in the treatment of fully edentulous patients such as residual ridge resorbtion, excess salivary flow, muscle tone reduction, and other factors that affect the retention quality of complete dentures. These patients need greater retention for chewing and psychological reasons.1,2 1 Torabinejad Dental Research Center, Department of Prosthodontics, School of Dentistry, Isfahan University of Medical Sciences; Biomaterials Research Group, Isfahan University of Technology Isfahan, Iran. 2 Dental Materials Research Center, Department of Prosthodontics, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran. 3 School of Dentistry, Isfahan Islamic Azad University, Isfahan, Iran. * Corresponding author, e-mail: DOI: 10.1563/AAID-JOI-D-11-00016 140 Vol. XXXIX /No. Two / 2013 Implant prostheses are a great improvement over conventional dentures. Implant-supported overdentures increase patient satisfaction and quality of life. It has been suggested that an overdenture with 2 implants is the first choice of treatment in the edentulous mandible.3 Retention is one of the most important factors for determining patient satisfaction with removable prostheses.4–6 A clinically acceptable degree of retention depends on the amount of dislodging forces, the behavior of the prosthesis during function, and the patient’s ability to place and remove the prosthesis. Implants and attachments provide retention and support for the removable denture. This can improve patient satisfaction, psychologic profile, and emotional status.7 There are many different attachment systems for retaining overdentures.

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

Evidence-Based Practice or Practice-Based Evidence?
Evaluation of Optimal Taper of Immediately Loaded Wide-Diameter Implants: A Finite Element Analysis
A Prospective, Randomized Controlled Preclinical Trial to Evaluate Different Formulations of Biphasic Calcium Phosphate in Combination With a Hydroxyapatite Collagen Membrane to Reconstruct Deficient Alveolar Ridges
Retention of Implant-Supported Overdenture With Bar/Clip and Stud Attachment Designs
The Clinical and Histologic Outcome of Dental Implant in Large Ridge Defect Regenerated With Alloplast: A Randomized Controlled Preclinical Trial
Fluoride-Treated Bio-Resorbable Synthetic Hydroxyapatite Promotes Proliferation and Differentiation of Human Osteoblastic MG-63 Cells
Resonance Frequency Analysis of 208 Straumann Dental Implants During the Healing Period
A Simplified Technique for Solving the Transfer Problem of Implant-Supported Fixed Partial Dentures for Patients With Microstomia
Esthetic Evaluation of Single-Tooth Morse Taper Connection Implants Placed in Fresh Extraction Sockets or Healed Sites
A Technique for Improving the Retention of Dentures Retained by Ramus Frame Implants
Treatment of Congenitally Missing Maxillary Lateral Incisors: An Interdisciplinary Approach
Use of Titanium Mesh in Lieu of a Fixation Screw to Stabilize an Autogenous Block Graft: A Case Report
A Novel Approach to Preserve the Buccal Wall in Immediate Implant Cases: A Clinical Report
Implant Failure Associated With Actinomycosis in a Medically Compromised Patient
Replacement of Mandibular Posterior Teeth With Implants in a Postmandibular Resection Case: A Case Report
Zygomatic Implants/Fixture: A Systematic Review
An Overview of Immediate Root Analogue Zirconia Implants
Letter to the Editor
Reviews of Current Literature

Journal of Oral Implantology April 2013