The XXXX paradox: why do some succeed when others fail? Opinion and discussion paper.

@entity1 @entity2121 @entity177 @entity281 @entity4500
UNASSIGNED: Biomaterial-implants are frequently used to restore function and form of @entity1 anatomy. However, the presence of implanted biomaterials dramatically elevates @entity281 risk. @entity2121 , @entity4500 placed in a bacteria-laden milieu experience moderate failure-rates, due to @entity281 (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 @entity4500 , also placed in a highly unsterile environment, these pins give rise to relatively high @entity177 -rates of up to 23.0  %. Herein, we attempt to identify causes as to why @entity4500 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 @entity4500 , 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 @entity4500 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 @entity177 . In conclusion, it is the authors' belief that new anti- @entity281 strategies for a wide range of biomaterial-implants may be derived from the relative success of @entity4500 .
