Journal of Oral Implantology February 2014 - (Page 42)

RESEARCH Peri-Implant Biomechanical Responses to Standard, Short-Wide, and Mini Implants Supporting Single Crowns Under Axial and Off-Axial Loading (an In Vitro Study) Lamia Sayed Kheiralla, PhD1* Jihan Farouk Younis, PhD2 This study compared the biomechanical responses of 3 single crowns supported by 3 different implants under axial and off-axial loading. A standard implant (3.75 mm diameter, 13 mm length), a mini implant (3 mm diameter, 13 mm length), and a short-wide implant (5.7 mm diameter, 8 mm length) were embedded in epoxy resin by the aid of a surveyor to ensure their parallelism. Each implant supported a full metal crown made of NiCr alloy with standardized dimensions. Strain gauges and finite element analysis (FEA) were used to measure the strain induced under axial and off-axial functional loads of 300 N. Results showed that mini implants recorded the highest microstrains, under both axial and off-axial loading. All implants showed a considerable increase in strain values under off-axial loading. Standard and short-wide implants proved to be preferable in supporting crowns, as the standard implant showed the lowest strains under axial and off-axial loading using FEA simulation, while the short-wide implant showed the lowest strains under nonaxial loading using strain gauge analysis. Key Words: mini implants, short-wide implants, standard implants, axial and off-axial loading, strain gauge analysis, finite element analysis INTRODUCTION I mplant selection is generally based on the maximum amount of available bone. This is based on the fact that favorable load distributions exist when the greatest surface area of bone is contacted by the implant to facilitate the transfer of occlusal forces.1 Yet, in the presence of limited alveolar bone height or diminished alveolar ridge buccolingually, the use of a standard diameter implant with adequate length and diameter is not an option. The quantity of bone in the vertical direction and the distance between the teeth adjacent to a 1 Faculty of Oral and Dental Medicine, Cairo University, Cairo, Egypt. 2 Faculty of Oral and Dental Medicine, Ain Shams University, Cairo, Egypt. * Corresponding author, e-mail: lamiask@yahoo.com DOI: 10.1563/AAID-JOI-D-11-00102 42 Vol. XL /No. One /2014 missing tooth are the main criteria when selecting the length and diameter of an implant.2,3 It has been shown that the distance between an implant and natural teeth must not be less than 1.25 mm in order to leave a sufficient distance for bone and periodontal membrane for implants placed between 2 natural teeth, as a proper blood supply is necessary for osseointegration.3 Moreover, the existence of 0.5-mm-thick bone around the implants is advocated for long-term implant success.3 When there is insufficient bone around the implants or in the presence of severe bone atrophy, the volume of bone can be increased by bone augmentation, followed by insertion of a standard size implant.4,5 Yet, as an alternative to bone grafting and to avoid subjecting patients to multiple surgical procedures, mini implants were suggested to be inserted in thin wiry ridges and in the presence of the narrow space between 2 natural teeth. Short implants with a wide diameter were

Table of Contents for the Digital Edition of Journal of Oral Implantology February 2014

Evolution of Bone Grafting for Improved Predictability
Electrochemical Behavior of Titanium in Artificial Saliva: Influence of pH
Efficacy of Antibacterial Sealing Gel and O-Ring to Prevent Microleakage at the Implant
Wired/Classic and Wireless/Periotest ‘‘M’’ Instruments: An In Vitro Assessment of
Altered Position of the Medial Lingual Nutritional Foramina at Different Stages of Alveolar
Genotoxicity of Endosseous Implants Using Two Cellular Lineages In Vitro
Implants With Internal Hexagon and Conical Implant-Abutment Connections: An In Vitro
Stress Distribution Around Maxillary Anterior Implants as a Factor of Labial Bone Thickness
Peri-Implant Biomechanical Responses to Standard, Short-Wide, and Mini Implants
Removal Torque Analysis of Implants in Rabbit Tibia After Topical Application of
Nonprocessed Adipose Tissue Graft in the Treatment of Peri-Implant Osseous Defects in
Assessment of the Effect of Two Occlusal Concepts for Implant-Supported Fixed
Nerve Damage Assessment Following Implant Placement in Human Cadaver Jaws:
Dental Implants: Early Versus Standard Two-Stage Loading (Animal Study)
Intravenous Sedation for Implant Surgery: Midazolam, Butorphanol, and
Nanocrystalline Hydroxyapatite-Based Material Already Contributes to Implant Stability
Two Neglected Biologic Risk Factors in Bone Grafting and Implantology: High Low-Density

Journal of Oral Implantology February 2014