Effect of the lack of primary stability in the survival of dental implants.

Background: The survival of dental implants has been linked to primary stability. The aim of this study is to analyse the factors that influence the survival of dental implants placed without primary stability.

Material and Methods: A cohort study of implants placed without primary stability was carried out between September 2011 and July 2016. All cases with registered information on the patient and surgical intervention were used. Cases that did not have a 12-month follow-up after implant placement were excluded.

Results: Out of 2,400 analysed implants, 92 were placed without primary stability. The absence of primary stability was classified as B in 49 cases, C in 38 cases and D in 5 cases. No statistically significant influence of the patient's age, primary stability, brand, or implant size in terms of implant survival was established. A tendency towards greater early implant loss was observed in implants whose absence of primary stability was classified as C.

Conclusions: Poor primary stability is not statistically significant in the loss of dental implants of the characteristics studied. Any of the factors studied are related with early implant loss as a main factor. Key words: Primary stability, survival, dental implants.