Survival of Single Immediate Implants and Reasons for Loss: A Systematic Review

Background: Immediate implant placement (IIP) or Type I implants have become more attractive than conventional implant placements as it reduces the number of surgical procedures and allows faster delivery of the final restoration compared to conventional implant placements. However, the survival of Type I implants varies depending on multiple factors. Purpose: To evaluate the survival rate of Type I implants, and to describe the factors influencing their failure. Materials and methods: A developed search strategy was applied to identify randomised controlled trials on single-unit immediate implants including at least six human participants with a minimum follow-up time of 12 months and published between 1 January 1999 and 1 January 2020 in several databases. The data were extracted independently using validated data extraction forms. Information on survival rates, number of implants placed, loading protocols, setting of the study, location of implants in the jaw, antibiotic protocol, grafting methods, and implant geometry were obtained and assessed. Results: Twenty-six randomised controlled trials with an average follow-up time of 24 months (range = 12–120 months) were included and analysed to give a survival rate ranging between 83.7 and 100%. Fifteen studies reported implant failures, of which twelve reported early losses (loss before definitive restoration). Nine early losses were due to lack of osseointegration, two did not report the reason for implant failure, and one was reported as iatrogenic. Of the eleven studies with 100% survival rates, the common trend observed was the use of titanium implants and an antibiotic regimen using amoxicillin. Conclusions: The survival rate for immediate single implant placement ranged from 83.7 to 100%. Implant failure was not consistently reported and when reported, failure due to lack of osseointegration prior to placement of the definitive restoration was the most common descriptor. Other attributed reasons included infection abscess, mobility after immediate loading, and iatrogenic complications.