title: The implant infection paradox: why do some succeed when others fail? Opinion and discussion paper.
abstract: Biomaterial-implants are frequently used to restore function and form of human anatomy. However, the presence of implanted biomaterials dramatically elevates infection risk. Paradoxically, dental-implants placed in a bacteria-laden milieu experience moderate failure-rates, due to infection (0.0-1.1%), similar to the ones of joint-arthroplasties placed in a near-sterile environment (0.1-1.3%). Transcutaneous bone-fixation pins breach the immune-barrier of the epidermis, exposing underlying sterile-tissue to an unsterile external environment. In contrast to dental-implants, also placed in a highly unsterile environment, these pins give rise to relatively high infection-associated failure-rates of up to 23.0%. Herein, we attempt to identify causes as to why dental-implants so often succeed, where others fail. The major part of all implants considered are metal-made, with similar surface-finishes. Material choice was therefore discarded as underlying the paradox. Antimicrobial activity of saliva has also been suggested as a cause for the success of dental-implants, but was discarded because saliva is the implant-site-fluid from which viable bacteria adhere. Crevicular fluid was discarded as it is largely analogous to serum. Instead, we attribute the relative success of dental-implants to (1) ability of oral tissues to heal rapidly in the continuous presence of commensal bacteria and opportunistic pathogens, and (2) tolerance of the oral immune-system. Inability of local tissue to adhere, spread and grow in presence of bacteria and an intolerant immune-system are identified as the likely main causes explaining the susceptibility of other implants to infection-associated failure. In conclusion, it is the authors' belief that new anti-infection strategies for a wide range of biomaterial-implants may be derived from the relative success of dental-implants.
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Biomedical Engineering, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands.e.rochford@umcg.nl.
authors.forename: C
authors.initials: C
authors.lastname: Yue
authors.forename: B
authors.initials: B
authors.lastname: Zhao
authors.forename: Y
authors.initials: Y
authors.lastname: Ren
authors.forename: R
authors.initials: R
authors.lastname: Kuijer
authors.forename: H C
authors.initials: HC
authors.lastname: van der Mei
authors.forename: H J
authors.initials: HJ
authors.lastname: Busscher
authors.forename: E T J
authors.initials: ET
authors.lastname: Rochford
mesh_terms: D001419:Bacteria / Q000145:classification / Q000187:drug effects / Q000254:growth & development*; D001672:Biocompatible Materials / Q000737:chemistry / Q000627:therapeutic use; D003757:Dental Implantation / Q000379:methods; D015921:Dental Implants / Q000592:standards*; D006801:Humans; D018928:Immunity, Mucosal / Q000276:immunology; D008954:Models, Biological; D009061:Mouth Mucosa / Q000276:immunology / Q000382:microbiology; D019736:Prostheses and Implants / Q000145:classification / Q000592:standards*; D016459:Prosthesis-Related Infections / Q000276:immunology / Q000382:microbiology* / Q000517:prevention & control
chemical_list: D001672:Biocompatible Materials; D015921:Dental Implants