Journal of Oral Implantology August 2014 - (Page 432)

RESEARCH The Effect of Dynamic Loading on Bacterial Colonization of the Dental Implant Fixture-Abutment Interface: An In Vitro Study Theofilos Koutouzis, DDS, MS* Ruben Mesia, DDS, MS Nadia Calderon Fong Wong, DDS, MS Shannon Wallet, PhD Bacterial colonization of the fixture-abutment interface (FAI) microgap may contribute to increased marginal bone loss. The contribution of loading on bacterial colonization has not been thoroughly evaluated with in vitro experiments. The aim of this study was to evaluate the effect of dynamic loading on the colonization of oral microorganisms in the FAI microgap of dental implants with internal Morse-taper connection. Forty implants were divided into two groups (n ¼ 20/group) based on subjection to dynamic loading conditions. Both Group 1 and 2 were comprised of fixtures that connected to standard abutments and allowed to incubate in a bacterial solution of Escherichia coli. The specimens of Group 2 were loaded with 500 000 cycles of 50 N using a chewing simulator. Following disconnection of fixtures and abutments, microbial samples were taken from the threaded portion of the abutment, plated and cultured under appropriate conditions. One of the 20 implants of Group 1 and 4 of the 20 implants of Group 2 had FAI microgaps colonized by E coli. With the limits of this study, it indicates that implants with internal Morse-taper connection exhibited minimal bacterial penetration down to the threaded part of the FAI and that dynamic loading increases the potential for such bacterial penetration. Key Words: dental implants, bacterial leakage, in vitro, bacterial counts, titanium INTRODUCTION T he importance of the position, size, and geometry of the fixture-abutment interface (FAI) microgap on marginal bone levels has been a subject of various studies1-4 demonstrating that bacterial colonization of the FAI microgap may contribute to the observed increased marginal bone loss. Microorganisms may grow into this FAI microgap5-7 and establish a bacterial reservoir, resulting in an area of inflamed soft tissue facing the fixture-abutment junction.8 In addition, the close proximity FAI Department of Periodontology, University of Florida, College of Dentistry, Gainesville, Fl. * Corresponding author, e-mail: tkoutouzis@dental.ufl.edu DOI: 10.1563/AAID-JOI-D-11-00207 432 Vol. XL /No. Four / 2014 microgap to bone may have a role in the development of peri-implant inflammation and bone loss.1-3,9 Therefore, prevention of microbial leakage at the FAI is a major challenge for the construction of two-piece implant systems to minimize inflammatory reactions and to maximize peri-implant bone stability. Several in vitro studies have evaluated the potential microbial leakage at the FAI, utilizing either non-loading10-15 or loading conditions.16,17 Despite the fact that these types of in vitro studies poorly mimic the biologic reality, they can be useful for understanding the dynamics of the FAI and thus contribute to the improvement of the FAI design. For instance, in vitro studies have demonstrated that the design of the FAI can impact the amount of microbial penetration into the internal part of the

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

Helping, Rather Than Criticizing, a Colleague May Lead to a Lifetime of Referrals
Utilization of Ethyl Cyanoacrylate and 2-Octyl Cyanoacrylate Adhesives for Autogenous Bone Graft Fixation: Histomorphometric Study in Rats
Conventional Versus Implant-Retained Overlay Dentures: A Pilot Study of Masseter and Anterior Temporalis Electromyography
Axial Relationship Between Dental Implants and Teeth/Implants: A Radiographic Study
The Effect of Dynamic Loading on Bacterial Colonization of the Dental Implant Fixture–Abutment Interface: An In Vitro Study
Longitudinal Implant Stability Measurements Based on Resonance Frequency Analysis After Placement in Healed or Regenerated Bone
A Clinical Report on the Use of Closed-Tray, Hex-Lock-Friction-Fit Implant Impression Copings
Immediate Restoration of NobelActive Implants Placed Into Fresh Extraction Sites in the Anterior Maxilla
Clinical Study of Flap Design to Increase the Keratinized Gingiva Around Implants: 4-Year Follow-Up
Use of Subepithelial Connective Tissue Graft as a Biological Barrier: A Human Clinical and Histologic Case Report
Calvarial Autogenous Bone Graft for Maxillary Ridge and Sinus Reconstruction for Rehabilitation With Dental Implants
Staged Ridge Splitting Technique for Horizontal Expansion in Mandible: A Case Report
An Overview of Zirconia Dental Implants: Basic Properties and Clinical Application of Three Cases
Dental Gypsum Verification Jig to Verify Implant Positions: A Clinical Report
Platelet-Rich Preparations to Improve Healing. Part I: Workable Options for Every Size Practice
Platelet-Rich Preparations to Improve Healing. Part II: Platelet Activation and Enrichment, Leukocyte Inclusion, and Other Selection Criteria

Journal of Oral Implantology August 2014