Mussel byssus-inspired dual-functionalization of zirconia dental implants for improved bone integration.

Zirconia faces challenges in dental implant applications due to its inherent biological inertness, which compromises osseointegration, a critical factor for the long-term success of implants that rely heavily on specific cell adhesion and enhanced osteogenic activity. Here, we fabricated a dual-functional coating that incorporates strontium ions, aimed at enhancing osteogenic activity, along with an integrin-targeting sequence to improve cell adhesion by mussel byssus-inspired surface chemistry. The results indicated that although the integrin-targeting sequence at the interface solely enhances osteoblast adhesion without directly increasing osteogenic activity, its synergistic interaction with the continuously released strontium ions from the coating, as compared to the release of strontium ions alone, significantly enhances the overall osteogenic effect. More importantly, compared to traditional polydopamine surface chemistry, the coating surface is enriched with amino groups capable of undergoing various chemical reactions and exhibits enhanced stability and aesthetic appeal. Therefore, the synergistic interplay between strontium and the functionally customizable surface offers considerable potential to improve the success of zirconia implantation.

[Effect of gradually induced disordered occlusion on the expression of osteoprotegerin and receptor activator of nuclear factor-kappaB ligand in mandibular condylar cartilage of rats].

OBJECTIVE: To investigate the effect of gradually induced disordered occlusion (GIDO) on the expression of osteoprotegerin (OPG) and receptor activator of nuclear factor-kappaB ligand (RANKL) in mandibular condylar cartilage of rats. METHODS: Totally 48 rats, aged 8 weeks were included, and were divided into experimental and control groups randomly at 4 time points, with same gender distribution (n=3). By inserting elastic rubber band the right side mandibular first molar and the left side maxillary first molar were moved mesially. Four weeks later, the right side mandibular third molar and the left side maxillary third molar were moved distally with same method. In this way, the GIDO was established in rats. The rats were sacrificed at the end of 2th, 4th, 6th and 8th week respectively after the application of the GIDO. The expression of OPG and RANKL in condylar cartilage was examined with immunohistochemical method and calculated by the area of positive cell percentage. RESULTS: OPG and RANKL expressed predominantly in condylar cartilage hypertrophic layer. The rats in experimental group expressed a higher OPG level in all of the 4 time points than their age-matched controls (P<0.05), while RANKL were higher in 2, 6, 8 weeks subgroups (P<0.05), but not in 4 weeks subgroup. No differences were found between male and female subgroups. CONCLUSION: The present results suggest that both OPG and RANKL take part in the condylar cartilage remodeling procedure in the present rat model.