Abstracts from the 85th General Session of the IADR: March 21-24, 2007, New Orleans, Louisiana.

These abstracts were among those presented at the 85th General Session of the International Association for Dental Research in New Orleans from March 21-24, 2007. The IADR has given us permission to publish a selection of abstracts in the Canadian Journal of Dental Hygiene.

CLINICAL MICROBIOLOGY

1127 DIVERSE AND NOVEL ORAL BACTERIA IN BLOOD FOLLOWING DENTAL PROCEDURES

F.K. BAHRANI-MOUGEOT, (1) B. PASTER, (2) S. COLEMAN, (1) J. ASHER, (1) S. BARBUTO, (2) and P.B. LOCKHART, (1) (1)Carolinas Medical Center, Charlotte, NC, USA, (2) Forsyth Institute, Boston, MA, USA

It has been estimated that over 700 bacterial species colonize the human oral cavity. Some of these bacteria are associated with periodontal disease and dental caries, and some gain entrance to the circulation and are associated with systemic disease. Objectives: The purpose of this study was to identify oral bacteria in the blood of patients undergoing either a single tooth extraction, with or without antibiotic prophylaxis, or tooth brushing. Methods: Blood samples were taken at timed intervals before, during and following these two procedures and cultured in BACTEC media. Positive cultures were subcultured on differential media for isolation of both aerobic and anaerobic bacteria. Bacterial identification was based on sequence analysis of 16S rRNA genes. Genomic DNA was isolated and 16S rRNA genes were amplified by PCR. The sequences of the amplified genes were determined and compared with known sequences. Results: In the analysis of 410 isolates from 149 subjects, 119 different bacterial species belonging to 33 different genera were recovered including many known species of Streptococcus, Peptostreptococcus, Neisseria, and Prevotella. Species not often detected in the oral cavity were also isolated including Haemophilus aphrophilus, Solobacterium moorei, Shuttleworthia satelles and Acinetobacter sp. Of interest, 48 of the isolates were representing 24 novel species of Prevotella, Fusobacterium, Streptococcus, Actinomyces, Capnocytophaga and Veillonella. Conclusions: By using conventional culture techniques and 16S sequence analysis, a diverse bacterial population including novel species can be isolated from bacteremia following routine or invasive dental procedures. This work was supported by NIDCR grant R01-DE13559-01 A2.

2285 MOLECULAR ANALYSIS OF MICROBIAL DIVERSITY IN CARIES AND HEALTH

K.M. ASNANI, (1) E.L. GROSS, (1) B.J. PASTER, (2) E.J. LEYS, (1) and A.L. GRIFFEN, (1) (1) Ohio State University, Columbus, USA, (2) Forsyth Institute, Boston, MA, USA

The microbiology of dental caries has been described as an ecological disruption and loss of biodiversity that consists of overgrowth of a small number of pathogenic species and elimination of protective species. Clear, quantitative microbiologic data that demonstrate this shift are needed. Objective: To measure the diversity of microbial communities in childhood caries and health by quantitative rDNA 16S cloning and sequencing. Methods: Plaque from children with incipient caries in the primary dentition (n=21), rampant caries of the primary dentition (n=16), severe caries in the permanent dentition (n=12) and age-matched healthy controls (n=50) was sampled. Samples were collected from healthy enamel, whitespots, cavitated lesions and dentinal caries. DNA was isolated and amplified by PCR with universal bacterial 16S rDNA primers, and amplicons were cloned and sequenced for bacterial identification. Results: Plaque from healthy children contained an average of 18.2 species, and plaque from children with caries from healthy enamel, whitespots, cavitated lesions and dentin contained an average of 14.7, 13.4, 11.7 and 12.9 species respectively. Differences between healthy subjects and all types of samples from subjects with caries were significant (P<0.0001), all paired post hoc tests significant). The Shannon-Weiner diversity index was calculated, and differences were highly significant as well (healthy children 2.4, children with caries intact enamel 2.1, whitespots 2.0, cavitated lesions 1.8 and dentin 1.8, P<0.0001). These relationships were similar in incipient and established caries of the primary dentition and in caries of the young permanent dentition. Conclusions: Microbial biofilm community diversity is greater in healthy children than in children with caries by quantitative 16S cloning and sequencing, supporting the concept that dental caries is an ecological disruption and a loss of microbial community biodiversity. Supported by NIH DE16125.

INFECTION CONTROL

1139 EFFECT OF LUBRICATION ON STERILIZATION OF DENTAL HANDPIECES

P. KANG, K. VOGT, K. ARAVAMUDHAN, S.E. GRUNINGER, J. KUEHNE, C. SIEW, and D. MEYER, American Dental Association, Chicago, IL, USA

Many of the devices sterilized in health care facilities contain lumens and other areas that are difficult to penetrate by sterilization processes. It is generally accepted that in steam sterilization, the dental handpiece provides the most difficult challenge to sterilant penetration (ANSI/AAMI ST55:2003 5.5.5.1 Handpiece selection). However, current standard methods do not specify a standard handpiece for testing nor a requirement to lubricate the handpiece turbine prior to steam sterilization. Objectives: In this study we evaluated the efficacy of the steam sterilization of dental high speed handpieces in the presence or absence of handpiece lubricant as specified by the handpiece manufacturer. Methods: Three different brands of handpieces were used. Sterilization tests for handpieces were performed by inoculating lubricated or non-lubricated turbines with spore suspension in blood containing 1.0 x 106 Geobacillus stearothermophilus. After steam sterilization of handpieces, turbines were aseptically transferred and incubated in tryptic soy broth (TSB) for 7 days at 55[degrees]C. Results: According to ANSI/AAMI ST55:2003 4.5 Biological performance of sterilizers, biological indicators processed in half cycles shall show no growth of the test spores. In this study, no live spore growth was observed from lubricated handpiece turbines sterilized by three commercially available tabletop steam sterilizers. Spore germination occurred in all non-sterilized positive controls, and no growth was detected in negative controls (sterile TSB). However, 18.5 [+ or -] 7.4 (SEM) % of non-lubricated handpiece turbines demonstrated spore growth. Conclusions: This study demonstrates that the lubrication of handpiece turbines with the manufacturer's recommended lubricant enhances the sterilization efficacy. Specification of handpiece turbine lubrication should be considered for any standard method used for testing the efficacy of steam sterilizers used in dentistry. More research is needed to identify the cause or causes of this lubricating effect. This study was funded by ADA.

1142 EVALUATION OF HAND HYGIENE AGENTS IN DENTISTRY FOR ANTIMICROBIAL EFFECTIVENESS

I. PLIANRUNGSI, University of Detroit Mercy, MI, USA

As waterless hand hygiene products began to be widespread accepted within the medical community in recent years, introducing and evaluating an alcohol-based waterless agent using in dentistry was considered to be a worthwhile undertaking. The waterless agent could shorten times and the number of steps while maintaining appropriate antisepsis. The importance of efficacy in choosing right hand hygiene product is recommended in new CDC guideline 2002 on hand hygiene. Objective: To evaluate the effectiveness of traditional hand soap and others antiseptics agents used in dentistry comparing with no hand hygiene (control). Materials and Method: The study was conducted among 90 healthy volunteers from dental students, dental hygiene students and faculties at University of Detroit Mercy, School of dentistry. The standard test method for evaluation of the effectiveness of health care professional handwash formulations was used. Subjects were divided to 3 groups, using various hand hygiene products (Nonantiseptics Soap, Parachlorometaxylenol-PCMX, and Waterless Alcohol-Based Spray) at wash times of 30 seconds. (No hand hygiene procedure as control in every group) The samples were collected from middle of palm, between fingers and fingertips. They were cultured in blood agar at 37 [degrees]C for 24 hours, 48 hours and 72 hours respectively. Result: The use of liquid preparations-PCMX and waterless alcohol based spray reduced and eliminated bacterial contamination. There was no difference in bacterial activity between PCMX and Waterless Alcohol-Based spray at any culture time, while there was bacterial activity found at 48 and 72 hours for nonantiseptics soap. Conclusion: According to this study, hand washing with traditional soap and water can reduce some transient bacterial contamination but not eliminate. The Waterless Alcohol-Based Spray can be used as reliable antiseptic agent in dental clinics, owing to its favorable antiseptic effect and convenience.

PERIODONTOLOGY 

2321 RISK OF EARLY ATHEROSCLEROSIS IN WOMEN AND MEN WITH PERIODONTITIS

B. SODER, (1) P.-O. SODER, (1) M. YAKOB, (1) J. MEURMAN, (2) T. JOGESTRAND, (3) and J. NOWAK, (1) (1) Karolinska Institutet, Huddinge, Sweden, (2) University of Helsinki, Finland, (3) Karolinska University Hospital, Huddinge, Sweden

Objectives: Periodontal disease has been implicated as a proatherogenic risk factor and the present study addresses the issue of possible gender differences in this association. Methods: In randomly chosen patients with periodontitis (46 women and 47 men), and 41 age-matched periodontally healthy subjects (21 women and 20 men) that underwent dental examination in 1985, carotid ultrasonography was performed during reexamination 16 years later. Common carotid artery intima-media thickness (IMT) and lumen diameter were measured, and intima-media area (cIMA) was calculated. The relationship between IMT and cIMA, and periodontal disease, age, body mass index, heredity for atherosclerosis, diabetes mellitus, hypertension, plasma cholesterol, smoking, and education was evaluated in a multiple logistic regression model in both gender groups. Results: While the mean values of left-sided IMT and cIMA was significantly greater in patients than in controls in both gender groups, the female patients presented also significantly greater right-sided cIMA. When the means of the bilateral IMT and cIMA values were tested in both gender groups, multiple logistic regression analysis identified periodontitis as an independent predictor of increased IMT (odds ratio [OR]=3.39, p=0.038 in women, and OR=4.15, p=0.023 in men), and cIMA (OR=5.41, p=0.0280 in women, and OR=3.88, p=0.028 in men). In addition, IMT and cIMA values related strongly to BMI in men, and to age and heredity in women. Conclusion: Periodontal disease appears to be a risk factor for the development of early carotid atherosclerosis colluding together with BMI in men, and with age and heredity in women.