Failing Factors and Clusterization in Dental Implant Loss

Dental implants are currently the esthetic and functional alternative of choice for tooth absence. Despite the high success rate shown by longitudinal studies, failures do occur, even in patients who present appropriate clinical conditions. Objectives: The aim of the present study was to identify factors related to or determinant of dental implant loss in patients of the Latin-American Dental Research Institute (ILAPEO), Curitiba, PR. Methods: Retrospective analysis was performed in 3,578 records of patients who had placed implants in this institute from 1996 to 2006 was performed. Beyond records, panoramic and periapical X-rays were analyzed. Patient sex and age, number of present teeths, number of placed implants, main detectable failure causes, duration of the implants, implant position, bone quality and quantity, and the primary stability were evaluated. Results: Out of 3,578 individuals implant treated, failures occurred in 126 (3.5%) patients (mean age 52.2 ± 10.6 years). Men lost more implants (4.5%) than women (3.1%) (p=0.05). Early failure represented the majority of failure cases (88.2%). Most implant losses (75%) did not present apparent clinical cause. Identified causes were: 17.5% iatrogenic conditions (surgical technique, contamination and/or oclusal trauma); poor bone quality and quantity (3%); peri-implantitis (1%), and 3.5% were misregistrations. Failure was more frequent when the implant was installed in the posterior jaw. Within the group of pacients who presented implant loss, failure rates increased from 3.5% to 24.2%. Conclusion: It was observed the first evidence of clusterization in an osseointegrated dental implant treated population. These results suggest that host factors may contribute to increasing risk for implant loss. Genetic studies might be proposed in order to better understand host response to implant failure.