Faculty Bibliography

The molecular and cellular mechanisms responsible for the etiology and pathogenesis of Alzheimer's disease (AD) have not been defined; however, inflammation within the brain is thought to play a pivotal role. Studies suggest that peripheral infection/inflammation might affect the inflammatory state of the central nervous system. Chronic periodontitis is a prevalent peripheral infection that is associated with gram-negative anaerobic bacteria and the elevation of serum inflammatory markers including C-reactive protein. Recently, chronic periodontitis has been associated with several systemic diseases including AD. In this article we review the pathogenesis of chronic periodontitis and the role of inflammation in AD. In addition, we propose several potential mechanisms through which chronic periodontitis can possibly contribute to the clinical onset and progression of AD. Because chronic periodontitis is a treatable infection, it might be a readily modifiable risk factor for AD.

INTRODUCTION: Treponema denticola inhabits the oral subgingival environment and is part of a proteolytic benzoyl-dl-arginine-naphthylamide-positive 'red complex' associated with active periodontal disease. Spirochetes have a unique form of chemotactic motility that may contribute to their virulence. Chemotaxis is essential for efficient nutrient-directed translocation. METHODS: We examined the effect of glucose on T. denticola cell velocity, expression of periplasmic flagella proteins, and chemotaxis, e.g. translocation into capillary tubes. RESULTS: The presence of glucose did not significantly effect T. denticola cell velocity in high viscosity conditions nor did it alter periplasmic flagella protein expression. The addition of glucose to capillary tubes resulted in greater numbers of T. denticola cells in tubes containing glucose. A non-motile mutant did not migrate into capillary tubes containing glucose. CONCLUSION: These results are consistent with a chemotactic response to glucose that is motility dependent.

Alzheimer's disease (AD) affects approximately 4.5 million people in the U.S. and this number will increase as the population ages and the life-span increases. Therefore, of paramount importance is identifying mechanisms and factors that affect the risk of developing AD. The etiology and pathogenic mechanisms for AD have not been defined, although inflammation within the brain is thought to play a role. Consistent with this hypothesis, studies suggest that peripheral infections contribute to the inflammatory state of the central nervous system. Periodontitis is a prevalent, persistent peripheral infection associated with gram negative, anaerobic bacteria that are capable of exhibiting localized and systemic infections in the host. This review offers a hypothetical link between periodontitis and AD and will present possible mechanistic links between periodontitis related inflammation and AD. It will review the pathogenesis of periodontitis and the mechanisms by which periodontal infections may affect the onset and progression of AD. Since periodontitis is a treatable condition, it may be a readily modifiable risk factor for AD.

In previous cross-sectional or case-control studies, clinical periodontal disease has been associated with gestational diabetes mellitus. To test the hypothesis that, in comparison with women who do not develop gestational diabetes mellitus, those who do develop it will have had a greater exposure to clinical and other periodontal parameters, we measured clinical, bacteriological (in plaque and cervico-vaginal samples), immunological, and inflammatory mediator parameters 7 weeks before the diagnosis of gestational diabetes mellitus in 265 predominantly Hispanic (83%) women in New York. Twenty-two cases of gestational diabetes mellitus emerged from the cohort (8.3%). When the cases were compared with healthy control individuals, higher pre-pregnancy body mass index (p=0.004), vaginal levels of Tannerella forsythia (p=0.01), serum C-reactive protein (p=0.01), and prior gestational diabetes mellitus (p=0.006) emerged as risk factors, even though the clinical periodontal disease failed to reach statistical significance (50% in those with gestational diabetes mellitus vs. 37.3% in the healthy group; p=0.38).

The purpose of this article is to review the current literature on the association between maternal periodontal disease and poor pregnancy and neonatal outcomes and outline the role nurses can play in improving the oral health of pregnant women. Maternal periodontal disease is linked to preterm birth, low birthweight, and preterm low birthweight, but treatment of periodontal disease during pregnancy has been shown to be safe and effective. Nurses, nurse practitioners, and nurse-midwives are in a position to educate pregnant women on the benefits of good oral health and identify and refer women who are in need of dental care for treatment.

Deaths of children due to neglected dental diseases have put the issue of access to care by minorities at the forefront of dental public health discussions. We evaluated the trends in dental service utilization in relation to racial disparities and other factors using Medicaid enrollment and claims data from 1990 to 1997 for Alabama children 19 years of age and younger (N=512,049). Alabama Medicaid children visited the dentist at a low and declining rate. The number of participating providers gradually declined over time and the racial disparities in service utilization were related to the availability of a local provider. Lower service utilization, however, was not a simple function of race, but a complex interaction of race with age and gender. Identification of these complex interactions and removal of barriers to service utilization in race, age, and gender sub-groups will help the U.S. meet the year 2010 oral health objectives

A survey was conducted within a practice-based dental research network to determine dentists' treatment methods for deep caries lesions and whether the dentists' intended treatment approaches were influenced by their expectations for pulpal exposure. The survey further examined how general dentistry practices have adopted scientific evidence of caries classification, excavation, and capping techniques. Dentists were queried regarding liner use, hypersensitivity considerations, point of endodontic therapy, and anticipated vitality outcomes from Class I resin-based composite restorations over three to five years. Of the 93 practitioner-investigators who were in the network at the time of the survey, 85 (92%) completed it. Of those who responded, 62% said that they would remove all caries when presented with a case in which one would expect pulpal exposure, while 18% would partially remove caries and 21% would initiate endodontic treatment; 17% reported that they would utilize an antimicrobial agent before a liner or bonding agent during restoration. The outcomes projected for tooth vitality over the next three to five years were equivalent regardless of the caries removal approach or the use of a liner/bonding agent. When beginning the preparation, the method of treatment did not change if a pulpal exposure was anticipated, other than a threefold increase in immediate endodontic treatment. When dentists were given a direct pulp cap scenario, the projected use of a liner/bonding agent changed little while the vitality projections decreased. Overall survey findings indicate that approximately 20% of network dentists favor partial caries removal techniques and that deep caries treatment outcome studies are warranted, given the various treatments employed.

For nearly a century, lactobacilli (LB) in the oral cavity have been generally associated with dental caries. Here, we characterized the LB isolated from the saliva of 6 women with active caries using genetic-based taxonomical identification methods. From each subject, 30 isolates growing on Rogosa medium and presumed to be LB were analyzed. Of the 180 isolates, 176 were further characterized by biotyping, DNA melting points, DNA chromosomal fingerprinting, genotyping, and phylogenetic cluster assessment. We found a total of 30 unique genotypes of LB in the saliva of caries-active women, with each woman harboring between 2 and 8 distinct genotypes. Although Lactobacillus vaginalis, L. fermentum, and L. salivarius were found in 4 of 6 of the subjects, results from other studies using comparable methods show an entirely different array of LB associated with caries. These collective observations lead us to surmise that LB associated with dental caries are likely exogenous and opportunistic colonizers, arising from food or other reservoirs outside the oral cavity.