Does Primary Stability Is Mandatory For Dental Implant Success? A Systematic Review Of Literature

Background: Implant primary stability is considered a prerequisite of implant osseointegration and ultimately, implant success. The prognosis of dental implants installed with low or without primary stability is still unclear. The aim of this systematic review was to assess the survival rate of implants placed with low/without primary stability and to diagnose risk factors that might affect outcomes of such implants. Material and methods: Electronic search in the National Library of Medicine (MEDLINE-PubMed) was performed on articles published in English up to September 2020. The terms (MeSH words) used in the search were ‘Dental’ OR ‘Oral’ AND ‘Implant’ AND ‘Survival’ OR ‘Success’ AND ‘Stability’ OR ‘Low stability’ AND ‘Insertion torque’. In addition to the online databases of selected journals. Randomized and controlled clinical trials, cohort studies, case-control studies, and prospective or retrospective case series were included. Results: Of the retrieved 386 publications, 24 studies met the inclusion criteria, with a total of 1632 implants, giving a survival rate of 96.32%. No statistically significant influence of the type and site of implantation on implant survival was recorded. A significant higher failure rate of immediately loaded implants that than those with delayed loading protocols. Conclusion: Poor primary stability might not negatively affect the survival rates of non-immediately loaded dental implants.