Biofunctionalization of onplants to enhance their osseointegration
A pilot study in domestic pigs
Background: Onplants are skeletal orthodontic anchorage devices that serve as alternatives to the frequently used miniscrews and palatal implants. Since onplants are not placed in bone, immediate loading is not possible and treatment may be prolonged. The purpose of this study was to improve the onplant surface by nanocrystalline diamond (NCD) coating and bone morphogenetic protein-2 (BMP-2) biofunctionalization to enhance osseointegration.
Materials and methods: Forty-eight onplants were placed on the palate and the mandible of three domestic pigs. The onplants were divided into three groups of the same size: (1) uncoated, (2) coated with NCD, (3) coated with NCD and functionalized with BMP-2. After 6 weeks, the pigs were sacrificed and the samples were subjected to radiographic, histologic, and histomorphometric analyses.
Results: Ten of the 48 onplants were lost. There was no significant difference between the samples in the upper and the lower jaw. The BMP-2 functionalized onplants showed higher bone-to-implant contact than the other groups albeit without significance.
Conclusion: The results of this pilot study show that BMP-2 biofunctionalization of NCD-coated onplants improves osseointegration and may suggest its clinical use in orthodontics. Due to the high loss rate, more investigations are required to confirm the beneficial effects and the current data should be interpreted with caution.