Risk factors associated with early failure of dental implants. A literature review.

The aim of the study was to examine articles published on risk factors associated with early failure of dental implants. We conducted a search on PubMed for articles published between January 2000 and December 2009 using the keywords 'dental implants' and 'early failure'. Seven studies that specified the number of early failed implants and studied the associated risk factors were included. Early failures are caused by the inability of tissue to establish osseointegration prior to prosthetic restoration; however the causal factors and mechanisms are unclear. In the reviewed literature there was a higher percentage of early than late failures; nevertheless, few articles were found that analyzed risk factors associated with early implant failure. In the majority of studies, statistically significant factors associated with early implant failure were smoking, quantity and quality of bone, and posterior implant location. The low number of studies in the literature does not allow definitive conclusions to be drawn.