Faculty Bibliography

BACKGROUND, AIMS: Destructive periodontal diseases have been reported disproportionately more prevalent and severe in African-Americans relative to other American populations. Differences in subgingival microbiota and host immune response have also been reported for African-Americans, implying that risk factors for disease progression may also differ for these populations. Since it is not clear whether these differences are truly genetic or due to confounding variables such as social economic status, we examined a series of clinical, environmental, demographic, and microbiologic features associated with periodontal disease status in a group of 185 urban minority subjects resident within the greater New York metropolitan area. METHODS: The study population consisted of 56 Asian-American, 71 African-American and 58 Hispanic subjects. Clinical data recorded included pocket depth, attachment level, gingival erythema, bleeding upon probing, suppuration, and the presence of supragingival plaque. Environmental and demographic data recorded included smoking history, years resident in the United States, whether the subject reported a private dentist and occupational status. Subgingival plaque was sampled from the mesial aspect of all teeth exclusive of third molars and the levels of 40 subgingival species enumerated using checkerboard DNA-DNA hybridization. RESULTS: The African-American group had more missing teeth, deeper periodontal pocket depth and more attachment loss than the Asian-American or Hispanic groups. However, the African-American group were less likely to report having a private dentist, had a greater proportion of smokers and a greater proportion of unskilled individuals. The profile of subgingival species differed among the three ethnic/racial groups with A. actinomycetemcomitans, N. mucosa, S. noxia and T. socranskii significantly elevated in the Asian-American group and P. micros significantly elevated in the African-American group. When subset by occupational status, numbers of missing teeth, pocket depth, attachment level and prior disease activity were all found increased in the unskilled relative to the professional group. Local factors including the mean % of sites with plaque, marginal gingival erythema, bleeding upon probing and suppuration were also elevated in the unskilled group. The microbial profile differed among the 3 occupational groups with the unskilled group having elevated numbers of species associated with destructive periodontal diseases. CONCLUSIONS: Although greater destructive periodontal disease prevalence and severity were found in the African-American group, these results suggest that environmental and demographic variables, such as occupational status, may have a greater influence on risk indicators associated with disease prevalence and progression in these populations

Dentists can be effective in helping their patients achieve smoking cessation. To plan a didactic program, we explored the smoking cessation attitudes and practices of dental students and identified barriers to service provision in the dental setting. We assessed 244 fourth-year dental students at New York University College of Dentistry through a self-report survey. The instrument included a twenty-nine-item measure assessing attitudes towards tobacco-use counseling and adherence to National Cancer Institute tobacco cessation guidelines. The survey also assessed demographics, tobacco use history, and level of preparation to provide services. Generally, students endorsed tobacco prevention practices, but perceived barriers to service provision. Students provided counseling inconsistently, with 69 percent asking about smoking, 58 percent advising cessation, 24 percent offering assistance, and 22 percent providing followup on a routine basis. Those who provided more counseling were more likely to have undergone formal training in smoking cessation, did not feel time was a barrier to counseling, and had more favorable beliefs about dentists' role in promoting smoking cessation. Study findings indicate great receptivity among students as well as a critical need and opportunity to include comprehensive cessation counseling training in the dental curriculum

PURPOSE: To compare the effect on in vivo plaque pH of rinsing with an aqueous solution of sucralose (alone or in combination with maltodextrin or maltodextrin and dextrose) to the effect of rinsing with an aqueous solution of sucrose. MATERIALS AND METHODS: Each solution (four in total) had a sweetness equivalent to two teaspoons of sucrose in 6 oz. of water. The four test solutions were administered randomly over four test visits (one solution per visit) to 10 subjects presenting 2-day resting plaque. Before, and at specified time intervals over 60 minutes following the rinse, in vivo plaque pH was monitored at six designated sites using a Beckman 3500 digital pH meter. Data were analyzed by ANOVA. RESULTS: The mean pH minimum for the sucralose rinse (6.56) was significantly higher than the sucralose/maltodextrin (SM), sucralose/maltodextrin/dextrose (SMD), and sucrose rinses (6.15, 5.84, and 5.29, respectively). The mean delta pH (difference between resting and minimum pH) for the sucralose rinse (0.45) was significantly lower when compared to the SM (0.79), SMD (1.14), and sucrose (1.69) rinses. The differences seen in mean pH minimum and mean delta pH for the SM and SMD groups vs. the sucrose group were also statistically significant. Mean areas under the pH vs. time curve for the sucralose, SM and SMD rinses were all significantly less compared to the sucrose rinse. Rinsing with aqueous solutions of sucralose, or of sucralose in combination with maltodextrin and/or dextrose (commercially available formulations, of sucralose) was less acidogenic than rinsing with a sucrose solution of equivalent sweetness.

The first example of conjugal transfer of DNA from Escherichia coli to the periodontal pathogen Actinobacillus actinomycetemcomitans is presented. Derivatives of the incompatibility group P (IncP) plasmid RK2 successfully transferred from an E. coli donor to an A. actinomycetemcomitans recipient. The resulting A. actinomycetemcomitans transconjugants transferred the plasmids back to E. coli recipients. The IncP transfer functions were also used in trans to mobilize the IncQ plasmid pBK1 from E. coli to A. actinomycetemcomitans. The IncP and IncQ plasmids both transferred into A. actinomycetemcomitans at high frequencies (0.3 to 0.5 transconjugants per donor) and showed no gross deletions, insertions, or rearrangements. Determinations of MICs of various antibiotics for the A. actinomycetemcomitans transconjugant strains demonstrated the expression of ampicillin, chloramphenicol, and kanamycin resistance determinants.

This study, using a simulated office visit model, showed that the pre-procedural use of an antimicrobial mouthrinse produces a significant reduction in number of viable bacteria in a dental aerosol.