Do Super-hydrophilic Surfaces Affect Implant Primary Stability in the Early Healing Phase of Osseointegration? A Systematic Review with Metanalysis

PURPOSE: Implant stability, related to mechanical (primary) and biological (secondary) bone-to-implant interactions, is essential for osseointegration. Implant surface bioactivation is a process designed to accelerate and enhance surface-cell interaction.The purpose of this systematic review was to determine whether a beneficial effect of bioactive (BS) over traditional surfaces (TS) can be identified. MATERIALS AND METHODS: An electronic search of Pubmed, Scopus, and CENTRAL databases was performed to identify randomized (RCT) and non-randomized controlled trials comparing BS and TS implants. Risk of bias was assessed using the Cochrane Collaboration tool for RCTs and the Joanna Briggs Institute tool for non-RCTs. Outcome variables were implant stability quotient (ISQ) measured through resonance frequency analysis from placement to prosthetic loading, one-year implant survival rate, and marginal bone loss (MBL). Meta-analysis was performed where possible. RESULTS: Of the 6920 records identified, 13 RCTs and two non-RCTs were included, reporting on 1256 implants (49.8% TS and 50.2% BS) in 596 patients. Four of the studies had a low risk of bias, three had a moderate risk and eight had a high risk. The meta-analysis showed no evidence of an effect of implant surface on survival rate (p = 0.99, 10 studies) and MBL (p = 0.86, 5 studies). At baseline (10 studies) and at one month (9 studies) the ISQ did not differ statistically significantly different between groups. A statistically significantly greater increase in ISQ was found for the BS implants compared to the TS implants (p = 0.04) at three months after placement (9 studies). CONCLUSION: An advantage of BS over TS during the early osseointegration phase could not be demonstrated, but a positive effect on implant stability seems to occur after three months of placement. The statement that bioactive surfaces may safely allow early and immediate implant loading is insufficiently supported by the current evidence.