Dr. Christensen’s advice on how to avoid pulpal death during fixed prosthodontic procedures failed to address a relevant and important aspect of pulpal devitalization ("Avoiding Pulpal Death During Fixed Prosthodontic Procedures," November JADA).
Research from the past two decades has given rise to the paradigm that, with few exceptions, pulpal death and necrosis are invariably caused by microbial invasion.
Exposed dentinal tubules, while partially sealed by the smear layer and protected by positive pulpal hydrostatic pressure, cannot be ascertained to prevent microbes from invading the pulp. Consequently, actions that help reduce the possibility of microbes reaching the pulp should also diminish the chance of needing endodontic treatment.
Actions such as thorough cleansing and disinfecting prior to cementation, removal of infected dentin and adequate sealing of the tubules, especially those near the pulp, should be beneficial. The longer dentinal tubules are exposed to the microbe-infested oral environment, the greater the chance for infection. Hence, minimizing the waiting time for final restoration placement should also help.
Temporization must adequately shield the dentinal tubules from the oral environment. During mastication, temporaries that leak can create a pumping action that facilitates the invasion of microbes into the tubules by overcoming the positive hydrostatic pressure of the pulp. Moreover, the pumping action–induced fluid flow may deliver nutrients to microbes in confined areas for rapid growth, much as a cracked amalgam can result in the onset of rapid decay.
Understanding the pivotal role microbes play in pulpal death should allow clinicians to implement steps that help protect the pulp and alleviate the problem of pulpal infection during fixed prosthodontic procedures.
