Faculty Bibliography

Periodontal disease is the consequence of a mixed Gram-negative infection in the gingival sulcus and has been associated with deficits in the neutrophil response. A novel, and heretofore untested, alternative approach to therapy is the use of biological-response modulators that enhance the neutrophil response. Poly-beta1-6-glucotriosyl-beta1-3-glucopyranose glucan (PGG-glucan) is an immunomodulator, derived from yeast, which specifically enhances neutrophil priming, phagocytosis and bacterial killing while failing to induce inflammatory cytokine expression. The hypothesis tested was that PGG-glucan could enhance host resistance to a Gram-negative periodontal pathogen, Porphyromonas gingivalis. Chambers were implanted subcutaneously in the dorsolumbar region of C57BL/6J mice and allowed to heal for 14 days. PGG-glucan was administered subcutaneously to one-half of the animals and saline to the other half. In the first set of experiments the chambers were inoculated with P. gingivalis (A7436) at 4 x 10 (6), 4 x 10 (7), and 4 x 10 (8) colony-forming units (CFU). In the second set of experiments the chambers were inoculated with 5 x 10 (8) CFU of either P. gingivalis or Streptococcus sanguis, a Gram-positive oral microbe that is not periodontopathic. Chambers were sampled over the following 2 weeks. The results demonstrated that: (1). bacterial CFU and neutrophils increased with increasing bacterial inoculum (P<0.02); (2). bacterial CFU were lower in the PGG-glucan-treated animals than in the saline controls (P<0.02); and (3). neutrophil counts were higher in the PGG-glucan-treated animals than in the saline controls (P<0.01). These results indicate that PGG-glucan significantly enhances neutrophil emigration and bacterial killing, thus decreasing the bacterial infection in this model system.

The purpose of this study was to determine the number of randomized controlled trials in children from 1990-2000 in seven dental disciplines. Sensitive and specific MEDLINE search methodologies were used for upper and lower estimates, capture-recapture corrected those estimates, and hand evaluation refined the estimates. The data indicate that between 602 and 1737 trials were published, and the number per year doubled from 1990 to 2000. These results have implications for clinical decision making, the development of systematic reviews, insurance reimbursement, and teaching.

PURPOSE: The purpose of this study was to estimate the availability of dental literature between 1989 and 1998 in seven disciplines within pediatric dentistry by using a bibliometric analysis on MEDLINE and to compare the results to that for adolescents and adults. METHODS: A search strategy was developed for each discipline incorporating dental vocabulary obtained from the MEDLINE Medical Subject Heading (MeSH) index. The number of articles retrieved from MEDLINE for adolescents and adults (> 13 yo) was compared to those for children (< 12 yo) in seven dental disciplines: dental implants, endodontics, oral medicine/radiology, oral surgery, orthodontics, periodontics, and restorative dentistry. RESULTS: There was an average of 8,097 dental articles published each year for the combined seven disciplines studied with an eight-fold range from 327 articles/year for endodontics to 2,765 articles/year for oral medicine/radiology. Of the mean number of articles published each year, 1,273 (16%) were limited to children, while the remaining 6,824 (84%) were on adolescents and adults. The number and percentage of children articles relative to the total number of publications on children ranged from 7 articles/year (1%) for dental implants to 528 articles/year (42%) for oral medicine/radiology. Implant dentistry publications increased the fastest, growing at an average yearly rate of 25%, followed by restorative dentistry (9%), endodontics (9%), oral surgery (6%), orthodontics (6%), periodontics (3%), and oral medicine/radiology (2%). CONCLUSIONS: There is a substantial amount of literature in pediatric dentistry upon which to base clinical decisions. Within this large body of literature, there is a significant amount of variation between the various dental disciplines examined. To stay current, one would need to read and absorb approximately 24 articles each week over 52 weeks per year in more than 75 different journals. Furthermore, the volume of literature is increasing each year, making access even more difficult. These trends suggest the need for computer systems that will facilitate access and retrieval of clinically useful literature.

The purpose of this study was to identify and quantify the endodontic literature available for clinical decision making. A search strategy based on Medical Subject Headings for endodontics was developed to examine MEDLINE. The identified articles were limited to human subjects and English. Sensitive and specific methodological search filters identified four categories of information: etiology, diagnosis, therapy, and prognosis. The results were then subdivided by year to identify trends. Between 1990 and 1998 MEDLINE identified 3,152 articles published in English on endodontics in humans. The number of articles per year (mean +/- SD) for sensitive and specific searches was etiology (28+/-10, 1+/-2), diagnosis (38+/-11, 1+/-1), therapy (59+/-15, 3+/-3), and prognosis (40+/-13, 10+/-5), respectively. The number of articles in each category increased by 1 to 3% each year. There were 150 articles/yr in endodontics in at least 120 journals cited on MEDLINE on which to base clinical decisions.

BACKGROUND: Retrospective and correlation studies suggest that early-onset periodontal disease may be due to a deficiency in phagocyte function, a pathogenic oral biofilm, and/or dysregulated gingival cytokine expression. Increased susceptibility to periodontal disease is therefore thought to result from multiple risk factors. METHODS: We tested this hypothesis prospectively using P/E-selectin adhesion molecule deficient mice that mimic the human syndrome leukocyte adhesion deficiency II. RESULTS: Our studies demonstrate that, in comparison to wild type animals, P/E-/- mice exhibit: spontaneous, early onset alveolar bone loss which is significant by 6 weeks of age; a 10-fold elevation in bacterial colonization of their oral cavities; and elevated gingival tissue levels of the bone resorptive cytokine IL-1alpha. Alveolar bone loss is completely prevented by prophylactic antibiotic therapy. CONCLUSIONS: These experiments provide the first prospective evidence for the multiple risk factor hypothesis of periodontal disease, and validate the first animal model for early onset periodontitis in which both the microbiota and host response can be systematically manipulated. P/E-/- animals should be useful in testing the virulence of putative periodontal pathogens, in determining the role of host resistance factors in periodontitis, in exploring the proposed relationship(s) between infection mediated alveolar bone loss and systemic health disorders, and exploring their genetic relationships.

Variation in health care, and more particularly in dental care, was recently chronicled in a Readers Digest investigative report. The conclusions of this report are consistent with sound scientific studies conducted in various areas of health care, including dental care, which demonstrate substantial variation in the care provided to patients. This variation in care parallels the certainty with which clinicians and faculty members often articulate strongly held, but very different opinions. Using a case-based dental scenario, we present systematic evidence-based methods for accessing dental health care information, evaluating this information for validity and importance, and using this information to make informed curricular and clinical decisions. We also discuss barriers inhibiting these systematic approaches to evidence-based clinical decision making and methods for effectively promoting behavior change in health care professionals.