Going to the dentist is usually not anyone’s idea of fun. In particular, root canals are no fun. However, if you have an abscessed tooth that hurts like the dickens, then a root canal may be your best bet for resuming normalcy.
In younger patients, the innermost part of the tooth, the pulp, may die off for a variety of reasons. This phenomenon, known as “pulp necrosis” arrests root development and may result in tooth loss. Injury to the pulp as a result of trauma, inflammation, tooth decay, or infection can result in the irreversible loss of teeth.
Regenerating dental pulp has proven to be a bear. Getting the mass of blood vessels and nerves to regrow is not straight forward. However, teeth, fortunately, are blessed with a host of stem cell populations. This includes the pulp, which contains “human deciduous pulp stem cells” or hDPSCs. These cells can be extracted from baby teeth. Can they be tamed to regenerate the pulp?
A new paper from Science Translational Medicine by Kun Xuan and others have used hDPSCs to regenerate the pulp in two different animals. However, this Chinese team did not stop there, since they turned around and tried hDPSCs in human patients.
In their animal model, implantation of hDPSCs into damaged teeth regenerated dental pulp with blood vessels and nerves. However, it also with a layer that deposited dentine. In short, the regenerated pulp saved the damaged teeth.
On the strength of these results, Xuan and others enrolled 40 patients with pulp necrosis after traumatic dental injuries in a randomized, controlled clinical trial. In this trial, Xuan and his colleagues randomly assigned 30 patients to the hDPSC group and 10 to the group that received a traditional dental treatment called apexification. Apexification materials like calcium hydroxide and mineral trioxide aggregates to form a calcified barrier in the lower parts of the tooth root to seal it and prevent it from further degradation.
They lost four patients, whose teeth experienced new trauma and were lost. In the 26 patients they examined after hDPSC implantation and 10 patients (10 teeth) after apexification treatment, Xuan and others found that hDPSC implantation, but not apexification treatment, regenerated the pulp tissue complete with blood vessels and sensory nerves at 12 months after treatment. hDPSC implantation also led to regeneration of sensory nerves in the pulp.
They further followed 20 of the hDPSC-implanted patients for 24 months to determine safety risks. In these observations Xuan and others did not observe any adverse events.
This is a small study, but it is a very encouraging study. It suggests that hDPSCs can regenerate whole dental pulp and may potentially revolutionize the treatment of tooth injuries due to trauma. Larger studies are needed and all of this must be verified before commercialization of this treatment is possible, but it seems like a great start.