Clinical and microbiologic findings that may contribute to dental implant failure

Clinical and DNA probe analysis were used to evaluate 36 failing implant sites in 13 patients. Failing implants showed evidence of increased mobility and a high incidence of peri-implant radiolucencies in radiographs. The probing depth was greater than 6 mm in 58% of the sites measured. Moderate levels of Actinobacillus actinomycetemcomitans, Bacteroides intermedius, and Bacteroides gingivalis were detected with DNA probe analysis.