Influence of rigid bar and nonrigid double crown attachments on maxillary implant overdentures: An in vitro study with differential bone quality
Journal
International Journal of Oral and Maxillofacial Implants
Journal Volume
33
Journal Issue
4
Pages
764-769
Date Issued
2018
Author(s)
Abstract
Purpose: To evaluate the bending strain exerted on a maxillary implant overdenture supported by rigid bar and nonrigid double crown connectors in models of high- and low-quality bone. Materials and Methods: Four implants were embedded in acrylic resin models of an edentulous maxilla simulating good- and poor-quality bone at the canine and second premolar regions bilaterally. A bar (cross-section dimension: 5 × 5 mm; bilateral distal extension: 10 mm) and double crown connectors with a metal framework (same morphology as the bar) were attached to these implants and placed under a constant 49 N vertical load at the anterior and cantilever regions of both superstructures. The bending strain on the implants was measured by strain gauges attached to the implant surfaces. Results: In good-quality bone with cantilever loading, the strain-which was highest near the load for both attachment systems-was highly concentrated in the rigid bar system but dissipated through the double crown connector. The directionality of the bending moment was homogenous on the two attachments. In poor-quality bone, strains were significantly lower and more variable, especially for double crown connectors, and there was heterogeneity in the directions of the bending moment. Conclusion: Within the limitations of this study, bar and double crown connectors have identical biomechanical features in good-quality edentulous maxillary bone, but have divergent properties in poor-quality bone. ? 2018 by Quintessence Publishing Co Inc.
Subjects
Bar attachment; Bending strain; Bone quality; Double crown connectors; Implant overdenture
Other Subjects
anatomic model; denture; human; implant-supported denture; maxilla; mechanical stress; mouth disease; overlay denture; procedures; tooth crown; tooth implant; Crowns; Dental Implants; Dental Prosthesis, Implant-Supported; Denture Retention; Denture, Overlay; Humans; Maxilla; Models, Anatomic; Mouth, Edentulous; Stress, Mechanical
Publisher
Quintessence Publishing Co. Inc.
Type
journal article