Researchers at the University of Toronto Faculty of Dentistry have examined the healing process around dental implants at the cellular level for the first time. Using a multiphoton microscope, they observed the components of tissue regeneration around metallic implants with both smooth and rough surfaces.
“We were able to look at healing at the implant site while it’s happening,” said first author Niloufar Khosravi, PhD. “The resolution is down to a single-cell level, which means you can see the cells while they’re alive and moving. This approach is quite novel in the field of implant dentistry.”
The researchers observed progenitor cells, which heal tissues, work to heal the wound, and trigger the creation of new blood vessels. The rough implants experienced what professor John Davies called a “proliferative bloom” of progenitor cells.
“What was surprising was not only the number of these cells changing with the surface properties of the implant, the rougher implant had a far greater number of these essential cells. But they also arrived at the wound site earlier,” said Davies, who also is a professor with the university’s Institute of Biomedical Engineering.
Smooth implants also caused the creation of these cells, but they came later and in lower volumes, without the dramatic bloom of their rough counterparts.
“When blood vessels start growing in a wound, at some point they have to stop, mature, and start remodeling,” said Khosravi. “You don’t want overgrowth of blood vessels and ongoing inflammation.”
Rough implants and their proliferative bloom had this important ability to switch off at the right time and pivot to a more mature, calmer state to allow for full wound healing without any overgrowth of blood vessels or continued inflammation.
Since this study has tracked many key wound-healing cellular processes, the researchers said, it offers many possibilities for future research. This cellular change from generating new blood vessels to a more mature healing state is still a mystery and merits more investigation, Davies added.
“Very little is known about this switch,” Davies said.
The study was conducted in healthy conditions, Khosravi said. Understanding how the healing process changes for some disease states could improve the care of patients in the future, the researchers added.
“From a clinical standpoint, you could personalize the approach for different patients with different healing conditions,” Khosravi said. “Once you know enough about the condition of the cells involved in healing, you could understand why an implant is failing in some patients.”