Introduction

Microbial Chemotherapy, Resistance, and Metastasis

Thomas J. Pallasch, DDS, MS

Copyright 2000 Journal of the California Dental Association.

"The great tragedy of science: The slaying of a beautiful hypothesis by an ugly fact." -- Thomas Henry Huxley

"When everyone is thinking the same, no one is thinking." -- John Wooden

Judging from the lay media, programmed dental conferences, and selective readings of the scientific literature, it would appear that a new age of dentistry is upon us: We will now treat caries, pulpal disorders, periodontal diseases, and possibly even occlusions not only for the basic pathology they present but to prevent or ameliorate coronary heart disease and infant preterm births. We will possibly no longer treat periodontal disease mechanically but will have a plethora of chemicals to manage this disorder that presently demands dedicated faculty teaching skills and avid practitioners to control its progress. Surely heaven has blessed us with the resurgence of the focal infection theory of diseases with the mouth as once again its central character. No more voids in the appointment books.

Until now, the proponents of these hypotheses have held the field of play. This is so because of the time required to review and critically analyze all of the past and current studies that either support or negate these proposals, prepare them in an objective scientific manner, and pursue the long process of manuscript preparation, peer review, manuscript revision, and eventual publication. Now this process has been completed, and another side of the story can be told.

The focus of this issue of the Journal is to address three central themes: the role of antimicrobials in the management of periodontal disease, the influence that the world epidemic of microbial resistance to antibiotics may have on our clinical judgment as to when and how antimicrobials should be employed in dentistry, and what factual evidence is extant to justify the return of the focal infection theory of disease. As corollaries to these themes, information is presented regarding the influence of antimicrobial misuse in our daily personal lives; how we may gain critical judgment in determining the veracity of claims of epidemiological "associations" or "causations" that may affect patient care or our personal health decisions; and, not insignificantly, the medicolegal dangers inherent in promoting the oral cavity as a source of systemic disease.

To these ends, Drs. Michael Jorgensen and Jørgen Slots have prepared an expert discussion of the role of antimicrobials in periodontal therapy with a clearly formulated decision tree as a clinical blueprint for patient periodontal management. Dr. Slots has also added his expertise in the evaluation of both the medical and dental studies on the role of microorganisms in the etiology of cardiovascular disease. Dr. Michael Wahl is virtually unique in that he has published several papers in medical journals on dental metastatic infections. These efforts have substantially altered the attitudes of our medical colleagues regarding just how often dental professionals are truly responsible for metastatic infections. Dr. Wahl’s experience in this regard and his fascination with 19th century dental literature aided greatly in the analysis of the theory of the focal infection of disease. Finally a concise guide to the evaluation of epidemiological studies was deemed appropriate.

Some may disagree with our interpretations of the literature, our personal insights, and ultimate conclusions. This is everyone’s prerogative as the essence of science is open discussion, re-evaluation of opinions, and presentations of new hypotheses as our data and insight increase. However, it is hoped that such dissent is reasoned and based upon facts and not hopes. The authors collectively researched more than 3,000 journal papers to gain our conclusions, with a fifth or so listed as references. Hopefully, this type of effort will form the basis for future discussions.

The authors wish to thank the information sources that were so valuable to us, including the library resources of the American Dental Association and the University of Southern California School of Dentistry, and in particular Ms. Sylvia Flores at USC who was unfailingly cheerful and professional in gathering the printed word, particularly from more than a century ago.

Contributing Editor

Thomas J. Pallasch, DDS, MS, is a professor of pharmacology and periodontics at the University of Southern California School of Dentistry.