Phosphorylated Pullulan Coating Enhances Titanium Implant Osseointegration in a Pig Model

Purpose: To investigate the effect of coating a titanium implant surface with a phosphorylated exopolysaccharide, pullulan, on the peri-implant bone formation and implant osseointegration. Materials and Methods: Implants were placed in the skull bone of 12 domestic pigs and healed for 1 or 3 months. Osseointegration of (un)coated implants was evaluated by quantitative histology (peri-implant bone fraction [BF] and bone-to-implant-contact [BIC]). The Wilcoxon-Mann-Whitney test with α = .05 was used to statistically compare BF and BIC of the coated and uncoated implants. Results: Significantly more BF was observed surrounding pullulan-coated implants compared with uncoated implants (P .05) and for both healing periods (P .05). BIC was positively affected by the exopolysaccharide coating, with significantly more BIC after the 3-month healing period compared with the uncoated implant (P .05). Furthermore, BIC remained stable over time for the coated implants, while it significantly decreased for the uncoated ones (P .05). Conclusion: These findings reveal the capacity of functionalizing the titanium implant surface with phosphorylated pullulan to improve the mineralization of the implant-bone interface. Schlagwörter: bone, organic coating, osseointegration, pullulan, titanium implant