Preliminary dental research reported a recent synthetic protein, Dentonin, assists to grow back damaged dentin. The information was presented on Thursday at the 84th general session of the International Association for Dental Research, in Brisbane, Australia.

The investigators from Acologix, the University of California, San Francisco and the University of Connecticut examined 35 patients. These patients had been recommended for extraction of at least two of third molars. When Dentonin was placed on some of these to-be-extracted teeth, they found that Dentonin stimulated creation of new dentin from the dental pulp.

Dentin regeneration will eliminate the necessity for root canal treatment for tooth with extensive cavity because dentin is the tooth structure near the dental pulp.

The human tooth is composed of three separate tissues. The outermost layer is the enamel, the middle layer is dentin, and at the core, the dental pulp. A dental cavity starts by breaking down the enamel layer. Enamel, the tooth’s most most-protective cover, is “nonliving,” about 2-3 mm thick, having no communication with the nerves in the dental pulp. Unlike enamel, dentin is a “living” tissue, holds specialized cells (odontoblasts), about 3-4 mm thick, and connects with the nerves in the dental pulp via the dentinal tubules. The pulp is the central core of the tooth and houses the nerves and the vascular bundles.

A dental cavity starts by breaking down the enamel. When it enters the dentin, it may occasionally induce some sensitivity and require a dental filling. If the cavity is not restored, it will advance toward the pulp and eventually penetrate the pulp. Once the pulp is infected, the dentist needs to initiate a root canal therapy in order to save the tooth.

Comparing to a dental filling, which restores the carious dentin with a “nonliving” substance, Dentonin stimulates the odontoblasts to make new “living” dentin. This new treatment approach has several advantages over the conventional method. They include:

• Fewer breakage of the restored tooth and filling: The restored dental filling dehydrates the tooth and renders it more likely to break.
• Less post-operative sensitivity: Tooth sensitivity after dental filling is common. This is due to the difficulty of sealing the dentinal tubules. New dentin that is made from Dentonin stimulation fixes this issue
• Less need for root canal treatment: Sometimes when a dental cavity is closed to pulp and it is questionable whether the tooth would need a root canal. A dentist would put some sedative filling on the tooth and “watch.” Typically, the “watched” tooth has pulpal inflammation (pulpitis). If the pulpitis is reversible (healing on its own), then the tooth would only need a permanent filling. If the pulpitis is irreversible (not able to heal on its own), then the tooth basically requires a root canal. Since Dentonin can regrow the decayed dentin, the pulpitis will always be reversible and the root canal treatment will not be needed.

It is important to note that the root canal treatment is often performed in three conditions: (1) irreversible pulpitis; (2) pulpal necrosis; and (3) pulpal abscess. Dentonin is only effective in term of reducing the demand of the root canal for the pulpitis cases. For situation of pulpal necrosis or pulpal abscess, the root canal therapy is still needed.

Dr. Dan Meyer, an associated executive director of ADA (American Dental Association), said Dentonin “shows promise” of an innovative method to restore carious teeth. Nevertheless, more researches will be needed before the FDA can approve it for dental treatment in US.