Implant Survival Rates at the University of Texas Health Science Center: A Retrospective Analyses on Implants From 1985-2012

Objectives: As the population ages, the need for dental implants has become a standard of care for the edentulous patient. Nonetheless, there is still controversy regarding dental implant success rates when various surgical protocols are performed. This study aims to measure dental implant survival rates including fixtures placed at a university setting and compare their success rates when placed in native bone as compared to grafted sites. Additionally, we will identify risk factors associated with dental implants loss.
Methods: A retrospective chart review was conducted for patients receiving dental implants at the University of Texas, School of Dentistry (UTSOD) from 1985 to 2012. Patients with genetic diseases, radiation and chemotherapy were excluded. Data was mined for age, gender, ethnicity, tobacco use, diabetes, anatomic location of implant, implant length and width, bone graft, barrier membrane, and maintenance. Cumulative survival rates were calculated and illustrated by a Kaplan-Meier survival curve. Log rank test was used to compare the survival rate between surgical protocols and across categories of other variables. Multivariate analysis using Cox regression with shared frailty was conducted to determine if bone graft affected implant survival
Results: 2,732 implants were included. Overall, the cumulative survival rate at the 6 month, 1-, 5-, and 10- years were 97.6%, 96.8%, 90.8%, and 85.1%, respectively. Results from multivariate analysis (Cox regression) indicated no statistically significant difference in success rate between implants placed in native versus grafted bone (hazard ratio: p=0.3). Non-Hispanic, tobacco use, and having maintenance care are significantly related to implant loss; the hazard ratios were 3.1, 1.9, and 0.2, respectively.
Conclusions: There is no difference in the implant survival rate when fixtures are placed in native bone or bone grafted sites. Non-Hispanic, tobacco use, and lack of maintenance care are significantly related to implant loss.