Dr. Stephen Porter’s November JADA article, "Prion Disease: Possible Implications for Oral Health Care," was interesting and timely, but I wonder if his conclusion that these diseases are unlikely to be transmitted in a dental environment is always true.
Since their discovery by Dr. Stanley B. Prusiner several years ago, a discovery that won him the 1997 Nobel Prize in Physiology or Medicine, prions have proved to be notoriously difficult to study or even culture. Having no DNA, they exist in a nether world between living and nonliving organisms, and they do not follow normal biologic laws. There is no test that can detect them, and they are not killed by normal sterilization methods. Their long incubation period, which could be several years or decades long, makes it almost impossible to determine how or when a patient was infected.
As a periodontist, I use a variety of allografts and xenografts to regenerate lost periodontal tissues. Substances such as human freeze-dried bone, human dura and deproteinized bovine bone are commonly obtained from tissue banks, where they are carefully screened and sterilized to eliminate any potentially infectious substances. Yet, I am left with the uneasy feeling that some organism or other infectious substance, such as prions, might have slipped through undetected.
It is essential that we continue to monitor developments in the field of prion research, and I hope the ADA continues to publish articles on this important topic.
