Clinical, Immunological and Microbiological Improvements With Zinc-Coated Healing Abutments During the Healing Phase

The aim of this study was to evaluate the clinical, immunological, and microbiological effects of zinc-coated healing abutments (Zn-TiO₂ abutments) on peri-implant soft tissue as compared with the commercially used ones (Ti abutments).

The study was a prospective, non-randomised, single-centre, open-label, proof-of-concept clinical trial. The Ti and Zn-TiO₂ abutments were non-randomly connected to 2 neighbouring implants in the posterior region in each eligible patient. The bleeding-on-probing proportion (BOP%), probing pocket depth (PPD), the concentration of the pro-inflammatory cytokine (TNF-α, IL-6) in the peri-implant crevicular fluid (PICF), and the early microbial communities assessed by 16S rRNA sequencing were recorded.

Eleven patients with 22 implants attended the 8-week examination. The BOP% was significantly lower in the Zn-TiO₂ abutments than that in the Ti abutments (24.23% ± 13.67% versus 42.42% ± 29.22%, P = .019). The concentration of TNF-α in PICF was significantly lower in the Zn-TiO₂ abutments than that in the Ti abutments (22.86 ± 11.21 versus 32.05 ± 16.28, P = .022). No significant differences in PPD and IL-6 were found between the two groups. Based on the microbiome assessments, higher microbial richness and lower presence of Lancefieldella were also observed in the Zn-TiO₂ abutments as compared with the Ti abutments.

Within the limitations of the study, the zinc-coated healing abutments improved early peri-implant soft tissue health clinically and immunologically. However, further studies are still needed to exclude the interference of soft tissue phenotype and confirm the relationship between microbial and clinical findings.