Factors affecting dental implant success in partially edentulous patients: an overview of systematic reviews

Different dental implant surgical techniques, protocols and properties could variably impact dental implant treatment outcomes. To date, no gold standard in dental implant treatment exists despite many systematic reviews. Therefore, this overview summarises evidence from systematic reviews (SRs) of randomised controlled trials (RCTs), to determine the effect of different dental implant surgical techniques, protocols, and properties on the success of dental implant treatment in partially edentulous patients. Methodology: PubMed, SCOPUS, Web of Science, EBSCOhost, Cochrane Library and CRD databases were searched without time or language restrictions. Eligible SRs reporting on comparators of dental implant surgical techniques, protocols and properties and outcomes of marginal bone loss (MBL) as well as the success, survival, and failure rates were included. Meta-analyses were conducted on RCTs reporting the same outcomes when not done in the SRs. Heterogeneity was explored through subgroup analyses and the methodological quality was appraised by the AMSTAR 2 tool. Results: Sixty-two eligible SRs were included. Meta-analyses revealed statistically greater MBL in immediate implant placement compared to delayed placement [p= 0.001, MD: -0.06; 95% CI: -0.10, -0.03]. MBL is statistically greater in longer implants compared to short implants [p< 0.01, MD= -0.11mm; 95% CI= -0.16, -0.07], while in platform-switched implants the MBL in 0.85mm [p<0.01, MD= 0.89mm; 95% CI= 0.69, 1.10] and 0.20-0.25mm implant-abutment mismatch [p<0.01, MD= 0.51mm; 95% CI= 0.41, 0.61] is statistically significantly lower than platform-matched implants. The methodological quality of the SRs was found ‘low’ in four SRs and ‘critically low’ in fifty-eight. Conclusion: Different dental implant surgeries and properties may variably impact treatment success in partially edentulous patients. Short implants with rough collars and platform-switching with mismatch of 0.85mm and 0.20-0.25mm endure less MBL. Nonetheless, more high-quality RCTs are needed in this field of study.