Survival Rate of Dental Implants in Patients with History of Periodontal Disease: A Retrospective Cohort Study

Purpose: To evaluate the differences between the survival rates of implants placed in patients with no history of periodontal disease (NP) and in patients with a history of chronic periodontal disease (CP). Materials and Methods: A retrospective cohort study was conducted in which all consenting patients treated with dental implants in a private clinic in Oporto, Portugal, from November 2, 2002 through February 11, 2011 were included. All patients were treated consecutively by the same experimental operator. This study aimed to analyze how the primary outcomes (presence of disease, time of placement, and time of loading) and the secondary outcomes (severity-generalized periodontitis, brand, implant length, prosthesis type, prosthesis metal-ceramic extension) influence the survival rate of dental implants. The survival analysis was performed through the Kaplan-Meier method, and the equality of survival distributions for all groups was tested with the log-rank test with a significance level of .05 for all comparisons. Results: The sample consisted of 202 patients (47% NP and 53% CP) and 689 implants (31% NP and 69% CP). The survival rate in the NP and CP groups showed no statistically significant differences (95.8% versus 93.1%; P ≥ .05). Implants were lost before loading in 54.9% of the cases. The majority of the implants were lost in the first year and stabilized after the second year. Survival rates in the NP and CP patients showed no statistically significant differences when comparing the following factors: subclassification of the disease, implant brands, implant length (short/ standard), type of prosthesis, extension of the prosthesis metal-ceramic, and time of placement and loading (P ≥ .05). Conclusion: This work disclosed no statistically significant differences in terms of survival rates when compared with the control group. Placing implants in patients with a history of periodontal disease appears to be viable and safe. Keywords: cohort studies, dental implants, periodontal diseases, survival rate