Incidence of Endodontic Implantitis and Implant Endodontitis Occurring with Single-tooth Implants: A Retrospective Study

The purposes of this study were to determine success and survival rates for implants and teeth adjacent to implants and the incidence of endodontic implantitis (E-I) (endodontic involvement in adjacent teeth causing implant failure) and implant endodontitis (I-E) (implant placement causing endodontic failure). The data were from 233 single-tooth implants placed in 116 subjects by postgraduate periodontal students with recall radiographs taken ≥9 months after implant placement. Three groups were analyzed: group A, implants with no adjacent teeth (n = 90); group B, implants with nonendodontically treated adjacent teeth (n = 123); and group C, implants with endodontically treated adjacent teeth (n = 20). The success and survival rates for implants were both 92.2% in group A, 98.4% and 99.2% for group B, and 85% and 95% for group C, respectively. For adjacent teeth, they were both 99.4% in group B compared with 75% and 90% in group C. However, after case review, none of the implants or adjacent teeth in group B were considered to have E-I or I-E, and one (5%) of the implants in group C had E-I and two (10%) of the adjacent teeth may have had I-E. The results of the present study agree with previous research, which suggests that endodontically treated teeth adjacent to single-tooth implants are usually successful and should be maintained.