Advances in Bone Grafting Protocols

Alexandre-Amir Aalam, DDS (AA): I believe that some of the most impactful innovations are those involving the use of biologics. In the 1990s and early 2000s, when evaluating the bone grafting materials that were available, everyone was looking at the mechanical attributes. The focus was on how the bone graft was composed-the mineral composition, the architecture of the bone, and the trabecular aspect of the bone-with the goal of seeing which material would be able to best mimic the anatomy of human bone. For that reason, we had many types of graft materials available in the allograft, xenograft, and synthetic categories. With time, we realized that although those materials were good, they were missing an ingredient: the biologic factor. The main difference in today's grafting protocols is the addition of biologics. Biologics, which include growth factors, cytokines, stem cells, healing proteins, and other components, are used in conjunction with bone graft materials to create composite graft materials that not only behave more properly mechanically but also heal faster, integrate better, turn over better, achieve neoangiogenesis and revascularization better, and provide tissue that is more stable for the patient.

ID: Do these biologic composite graft materials behave similarly to bioactive fluoride-releasing composites?

AA: I guess you could say that the idea is similar in that we are charging the bone graft with stem cells and growth factors that are released over time and help the bone graft incorporate faster into the body.

ID: What effect do biologic graft materials have on what is possible in implant dentistry?

AA: The primary advantages of this technology are that patients experience far fewer complications and that the rate of success of the graft is much higher, so the procedures are much more reliable. Better success rates lead to higher case acceptance rates. Furthermore, patients are served faster; they no longer need to wait 9 to 12 months to completely heal like in the past. Now, in less than 4 months, they can get their dental implants and move on with their prostheses. Everything is fast-forwarded in terms of the healing, but the use of biologics also results in better quality. It is not only the wound healing that is improved but also the integration of the bone graft and the turnover of this bone to become the patient's own bone that is improved, so the quality of the bone that we get is better, and the long-term maintenance with the patient is better. With the addition of biologics, there is no risk of encapsulation, rejection, or immune responses related to this foreign body that at times in the past would remain in place for a long time, but people would still develop a reaction to it. Because of biologics, bone graft turns over much faster and incorporates faster, and the body recognizes it much faster, so the success rate increases. Those are the main advantages that we get from biologics today: speed and quality.

ID: Are there any other new material technologies on the horizon with the potential to improve implant treatment?

AA: There are some new material technologies that are emerging from the field of orthopedic surgery. I would call them bone cements or bone adhesives. The concept is basically based on the mechanical properties of bone. These materials are almost like a biologic orthopedic glue that orthopedic surgeons can use when they have patients with fractures that require instant healing. They have special bone cements that set into moisture, which you can apply to the edges of the bone, and then use pins and screws to hold the edges together. I believe that there are some clinical trials being conducted right now, and the US Food and Drug Administration is putting protocols in place regarding how we can use bone cements that are derived from orthopedic surgery in oral surgery. So, that is one new trend that is developing. Of course, because it is so new, we do not have any clinical data or any histology yet.

ID: Are there any other materials impacting your ability to develop bone for implant placement?

AA: The bone graft itself is just one aspect of regenerative dentistry in terms of building back the hard tissues. There are membranes that we use that basically serve as covers that help to stabilize the graft and keep it in place. Remember, the more complex the defect, the more help you need from biologics and other materials to be able to stabilize your graft materials. Therefore, we have a lot of innovations related to the utilization of partially enhanced membranes that help to calcify. These new membranes mineralize and densify and become a hard matrix, not soft like in the past, so they help to maintain the space of the bone graft long term. Moreover, they allow the bone graft to express itself, blocking the pressure coming from the flap or the environment, and in return, promote better healing. This is one example of how many of the tools and the adjuncts that we have are being improved upon to help us achieve better outcomes for patients.

ID: Will any of these innovations make bone grafting simpler or reduce its learning curve?

AA: Possibly. For example, one of the orthopedic bone cements currently in clinical trials that I mentioned earlier is called Tetranite^®. This seems to be the simplest material ever. It's like a paste that you score into the socket after extracting the tooth. You can put the implant inside the cement at that time, and the implant, the cement, and the bone all fuse together. I don't think it can get any simpler than that. Today, all of the material manufacturers are trying to simplify delivery. Almost everything comes in preloaded syringes and individual packages. So, that is an overall trend-simplification-and this follows that.

ID: If approved, would this development be a panacea for bone grafting? Are there any specific frontiers left to cross?

AA: I really hope this is not the end because practicing would become boring. I believe that there will be more innovations. As a periodontist, I look at some of the implant treatments that were done in the past, especially cases involving those blade implants and subperiosteal implants, and I think, "I cannot believe that dentists used to perform these kinds of treatments and that patients were accepting of them." But back in the day, that was the standard of care. Of course, with time, things become obsolete, and better technology is introduced that enables us to be faster, more successful, and less invasive. So, I hope that in 10 to 15 years, whatever we have today will be obsolete, and we will have things that are easier, faster, and cheaper for our patients.

ID: Is there anything specific that you can envision?

AA: There will certainly be advances in the area of biologics and in anything else that helps with integration. Mechanically, I believe that we are coming to a plateau regarding innovation. The future will be about how we can speed integration and healing.