IADR Abstract Archives
Clinical Implants Differentially Activate Macrophages In Vitro and In Vivo
Objectives: Peri-implant bone formation is affected by the design and physico-chemical surface properties of the implant. Surface modifications like roughness and hydrophilicity are commonly used in clinical implants. While the success of dental implants has been assessed mostly by osseointegration and force-to-failure, the inflammatory response to commercially-available implants is overlooked. Our aim was to characterize the macrophage inflammatory response to clinical implants with varying compositions and surface characteristics.
Methods: Eleven commercial dental implants with different compositions (titanium or titanium-alloys) and different surface roughness and hydrophilicity were examined. Implant surfaces were characterized by surface roughness, dynamic contact angle, and X-ray photoelectron spectroscopy. Primary human macrophages were seeded directly on clinical implants and cultured in custom vials. Secreted protein levels of pro- and anti- inflammatory cytokines and chemokines were measured after 24 hours. The inflammatory response was evaluated in vivo by placing clinical implants subcutaneously and measuring macrophage M1/M2 polarization by flow cytometry (n=6/variable, ANOVA, post-hoc TUKEY HSD, α=0.05).
Results: Macrophages cultured on TiUnite, MDI, OsseoSpeed, and Alvim-Acqua produced the highest levels of pro-inflammatory cytokines and chemokines. The highest levels of anti-inflammatory cytokines and chemokines were produced by macrophages on Roxolid-SLActive, Ti-SLActive, and Ti-SLA. M1 polarization was predominant on OsseoSpeed, TiUnite, Alvim-Acqua, and Facility-Acqua, while M2 polarization was predominant on Roxolid-SLActive and Ti-SLActive.
Conclusions: Macrophage polarization was not clearly driven by any single implant composition, roughness or hydrophilicity in this study. While hydrophilic modifications are associated with reduced inflammatory response independent of implant composition, our results suggest that multiple parameters beyond implant composition and hydrophilicity control macrophage polarization. These results demonstrate that our in vitro evaluation model for clinical implants may be a powerful predictor of in vivo outcomes.
Methods: Eleven commercial dental implants with different compositions (titanium or titanium-alloys) and different surface roughness and hydrophilicity were examined. Implant surfaces were characterized by surface roughness, dynamic contact angle, and X-ray photoelectron spectroscopy. Primary human macrophages were seeded directly on clinical implants and cultured in custom vials. Secreted protein levels of pro- and anti- inflammatory cytokines and chemokines were measured after 24 hours. The inflammatory response was evaluated in vivo by placing clinical implants subcutaneously and measuring macrophage M1/M2 polarization by flow cytometry (n=6/variable, ANOVA, post-hoc TUKEY HSD, α=0.05).
Results: Macrophages cultured on TiUnite, MDI, OsseoSpeed, and Alvim-Acqua produced the highest levels of pro-inflammatory cytokines and chemokines. The highest levels of anti-inflammatory cytokines and chemokines were produced by macrophages on Roxolid-SLActive, Ti-SLActive, and Ti-SLA. M1 polarization was predominant on OsseoSpeed, TiUnite, Alvim-Acqua, and Facility-Acqua, while M2 polarization was predominant on Roxolid-SLActive and Ti-SLActive.
Conclusions: Macrophage polarization was not clearly driven by any single implant composition, roughness or hydrophilicity in this study. While hydrophilic modifications are associated with reduced inflammatory response independent of implant composition, our results suggest that multiple parameters beyond implant composition and hydrophilicity control macrophage polarization. These results demonstrate that our in vitro evaluation model for clinical implants may be a powerful predictor of in vivo outcomes.