Researchers have developed a reliable, biodegradable gel filling that promotes healing and regeneration. The filling, say scientists, releases nitric oxide and antibiotics inside the treated tooth, boosting the potential for tooth regeneration.
Gel Instead of Blood Clots
As we know, when the pulp of a tooth, its blood vessels and nerves, is infected, root canal treatment becomes necessary. This can happen when the pulp is exposed following damage caused by caries or mechanical injury. In such cases, the infected tissue inside the tooth is removed, the area is disinfected, medicine and canal filling material are placed in the cavity and the crown is restored.
Currently, blood clots are used as a canal filling material. The composition of these blood clots cannot be controlled and the procedure, while mostly successful, can have negative effects like discoloration or tooth fractures. Also, the procedure can damage the tooth’s stem cells, which are needed for regeneration. The research team consequently set out to develop a better canal filling material.
The new gel is made from peptide amphiphiles, molecules that self-assemble into gel-like structures based on their charge. To add the nitric oxide, the researchers reacted the amphiphiles with poly-lysine as a nitric oxide donor before heat-induced polymerization. The antibiotics ciprofloxacin and metronidazole were encapsulated in the gel during polymerization.
Blood Pressure and Now Teeth
The discovery that nitric oxide is a signalling molecule in the body has allowed the development of drugs such as Viagra and drugs to treat high blood pressure. But it seems that nitric oxide signalling, along with its antibacterial effects, can be beneficial for pulp regeneration in teeth too.
The researchers found that nitric oxide-releasing gel had antibacterial effects. Also, nitric oxide helps wound healing and blood vessel growth by preventing death of blood vessel cells (vascular endothelial cells) and by regulating vascular endothelial growth factor. This allows the interior of the treated tooth to regenerate.
The antibacterial effect of nitric oxide that the authors observed in their study might actually allow them to leave out the conventional antibiotics completely in the future. This would be ideal for preventing antibiotic resistance.
In the future, the authors want to supplement the gel with growth factors, to support the growth factors naturally present in the treated tooth.