How Pulp Testing Can Benefit Restorative Dentistry

Pulp testing is a quick, easy, and predictable way to assess the health of a tooth's pulp. Although it is commonly utilized in endodontics, pulp testing is an underutilized tool that can help ensure more predictable results for restorative dentistry.

The Pulp Testing Process

Pulp testing is the process of assessing the health of a nerve within a tooth. Although historically this process was called vitality testing, this phrase is a misnomer. A pulp oxygen tension test indicates if pulp tissue is vital. Currently, there is no clinically viable way to perform a pulp oxygen tension test. Thus, the actual vitality status of the nerve cannot be definitively determined. However, the sensibility of the nerve (i.e., whether it responds to a stimulus) can be accessed to make a diagnosis on the status of the nerve.

A pulp test is performed by applying a stimulus to the tooth and evaluating its response. Multiple studies discuss the most predictable way to perform pulp testing. Both electric stimuli, in the form of an electron pulp test device, and a cold stimulus, in the form of a refrigerant such as Endo Ice, have been found to produce an accurate sensibility response reliably. Heat stimuli, such as hot water, will not produce as accurate of a sensibility response and should be avoided for pulp testing.

Pulp Testing Using a Cold Stimulus

A cold stimulus is a common and efficient way to assess the pulpal status. When a refrigerant is utilized as a cold stimulus, the refrigerant can be sprayed directly on a cotton pellet or sprayed into a cup to make a bath that cotton pellets can be bathed in before being applied to the tooth.

How a cold stimulus is applied to the tooth can affect the test result. When a dense material, such as a cotton tip applicator, is utilized to apply the cold stimulus to the tooth, there is a higher probability of false positive or false negative results. However, when a large cotton pellet is utilized to apply the refrigerant to the tooth, the probability of a false positive or false negative result decreases significantly. Thus, a large cotton pellet is considered the most reliable way to determine pulp sensibility when using a cold stimulus.

Pulp Testing for Restorative Dentistry

Endodontists commonly perform pulp testing to establish a pulpal diagnosis. After pulp testing, a pulpal diagnosis of a normal pulp, symptomatic reversible pulpitis, symptomatic irreversible pulpitis, or pulpal necrosis can be established. Based on the pulpal diagnosis, endodontic therapy may or may not be indicated.

Endodontic therapy is typically not pursued when a normal pulp or symptomatic reversible pulpitis is diagnosed. However, for symptomatic irreversible pulpitis or pulpal necrosis cases, damage to the pulp tissue has occurred and may warrant root canal therapy.

Pulp testing also has benefits in restorative dentistry. Before administering anesthesia, a pulp test can be performed on teeth that clinically and radiographically show signs of deep carious lesions or deep existing restorations.

The sensibility of the pulp tissue will enable the clinician to determine the status of the pulp before starting treatment. If the tooth has a cold response that dissipates within 10 seconds, restorative treatment can be pursued, knowing that the pulp is likely healthy. However, if the tooth has a lingering, intense response that lasts more than 30 seconds or does not respond to the cold or electric stimulus, there is likely an unhealthy pulp that may require endodontic therapy before restorative treatment can be completed.

Pulp testing is commonly utilized in endodontics but also has benefits in restorative dentistry. This diagnostic procedure helps determine the health of the pulp, and provides more predictable results for all patients.

Andy Janiga, D.M.D., practices at the Center for Dental Excellence in Nashua, N.H., and is a contributor to Spear Digest.

References

1. Chen, E., & Abbott, P. V. (2009). Dental pulp testing: a review. International Journal of Dentistry, 2009.
2. American Association of Endodontists. (2021). AAE position statement on vital pulp therapy. Journal of Endodontics, 47(9), 1340-1344.
3. Peterson, K., Söderström, C., Kiani‐Anaraki, M., & Levy, G. (1999). Evaluation of the ability of thermal and electrical tests to register pulp vitality. Dental Traumatology, 15(3), 127-131.
4. Jones, D. M. (1999). Effect of the type carrier used on the results of dichlorodifluoromethane application to teeth. Journal of Endodontics, 25(10), 692-694.
5. “Endodontic Diagnosis.” AAE, Colleagues for Excellence, Newsletter, Fall, 2013