Biomechanical Implant Treatment Complications: A Systematic Review of Clinical Studies of Implants with at Least 1 Year of Functional Loading

Purpose: The aim of this article is to discuss the current literature available on the etiology and management of biomechanical complications of dental implant treatment. Materials and Methods: An electronic search of the PubMed database for English-language articles published before May 31, 2011, was performed based on a focus question: "How can biomechanical implant treatment complications be managed and identified?" The key words used were "dental implant", "etiology", "management", "excessive occlusal forces", "occlusal forces", "occlusion", "parafunctional habits", "biomechanical failure", "biomechanical complications", and "occlusal overloading". Clinical trials with a minimum of 10 implants followed for at least 1 year after functional loading were included. Results: The initial electronic search identified 2,087 publications, most of which were eliminated, as they were animal studies, finite element analyses, bench-top studies, case reports, and literature reviews. After the titles, abstracts, and full text of 39 potentially eligible publications were reviewed, 15 studies were found to fulfill the inclusion criteria. Conclusion: Occlusal overloading was thought to be the primary etiologic factor in biomechanical implant treatment complications, which commonly included marginal bone loss, fracture of resin/ceramic veneers and porcelain, retention device or denture base fracture of implant-supported overdentures, loosening or fracture of abutment screws, and even implant failure. Occlusal overloading was positively associated with parafunctional habits such as bruxism. An appreciation of the intricacy of implant occlusion would allow clinicians to take a more preventive approach when performing implant treatment planning, as avoidance of implant overloading helps to ensure the long-term stability of implant-supported prostheses. Keywords: biomechanics, dental implants, implant complications, implant prosthesis, overload