Abstracts.

The International Association for Dental Research (IADR), in association with the American Association for Dental Research (AADR), Canadian Association for Dental Research (CADR), and American Dental Educators Association (ADEA) held a combined meeting and exhibition March 8-11, 2006, in Orlando, Florida. Scientists and researchers from around the world present their research findings for discussion. The IADR has given us permission to publish a selection of abstracts presented at that meeting.

CARIES 

0153 DENTAL CARIES AND FLUOROSIS IN RELATION TO WATER FLUORIDE LEVELS

L. HONG (1), S.M. LEVY (2), J. WARREN (2), and B. BROFFITT (2), (1) University of Missouri-Kansas City, USA, (2) University of Iowa, Iowa City, USA

Objectives: This study assessed the relationship between dental caries and fluorosis at varying fluoride levels in drinking water. Methods: Subjects were followed from birth with questionnaires every 3-4 months to gather information on fluoride intake. 420 study subjects received dental examinations at age 5 on primary teeth and at age 9 on early-erupting permanent teeth. Composite fluoride levels in drinking water at home and childcare were determined from public, private well, and/or bottled water sources at 24 months of age for individual participants. Permanent tooth fluorosis cases were defined as subjects having definitive/severe fluorosis on 2+ teeth. Caries prevalence rates were calculated at age ~5 and ~9 on primary teeth. The linear trends between fluorosis or caries and fluoride levels in drinking water were assessed by Cochran-Armitage tests. Results: Fluorosis prevalence rates on early-erupting permanent teeth were 21.0%, 41.1% and 46.3% for composite water fluoride levels of <0.7, 0.7-1.2, and >1.2 ppm (P<0.001). Caries prevalence rates on all primary teeth at ~age 5 were 23.8%, 22.9%, and 24.4% for water levels of <0.7, 0.7-1.2, and >1.2 ppm (p=0.970). Specifically on primary second molars, the corresponding caries prevalence rates were 18.2%, 15.3%, and 17.0% at ~age 5 (p=0.631) and 37.1%, 34.3%, and 34.1% at ~age 9 (p=0.612), respectively. Similar relationships were found between fluorosis/caries and water fluoride levels at 12 months and 36 months. Conclusions: Fluorosis prevalence increased significantly with higher water fluoride levels; however, caries prevalence did not decline significantly. Supported in part by R01-DE09551, R01-DE12101, and M01-RR00059.

1532 SITE-SPECIFICITY OF ACID PRODUCTION IN DENTAL PLAQUE 

S. YAHATA, M. HIROSE, D. MATSUMOTO, A. FUKUDA, and S. IGARASHI, Health Sciences University of Hokkaido, Japan

Objectives: We have been studying the site-specificity of dental plaque cariogenecity that would be related to the caries status of associated tooth surfaces. Our previous study of plaque buffer capacity showed that the highest was the lower-anterior-lingual (LAL) and the lowest was the upper-anterior-buccal (UAB) when we compared the 8 different sites. The aim of this study was to clarify the two different sites of acid production in dental plaque by determining the plaque pH curves following sucrose exposure. Methods: Two-day plaque samples were collected from UAB and LAL in each of 9 adult subjects. Wet plaque samples were transferred to plastic sticks and immediately put into pre-weighed plastic tubes. The samples were weighed and 0.85% KC1 solution (1mg wet plaque/100[micro]l) was added. A stir bar was then added to the plastic tubes. A micro pH electrode was then inserted and the pH was determined. After 5 minutes, 10% sucrose (1mg wet plaque/30[micro]l) was added, plaque pH was then measured at 60 different time points (1-60 min), and the plaque pH curves were recorded. After plotting the curves, the area under each curve (AUC) was calculated. Mean pH values are reported as the log of the mean hydrogen ion activity (i.e., 10[.sup.-P.sup.H]), and all statistical comparisons were made based on the hydrogen ion activities. Statistical analyses between 2 different sites were carried out using the Mann-Whitney U test. Results: Initial pH (without acid) of plaque in the LAL (mean[+ or -]S.D.: 7.18[+ or -]0.36) was significantly higher than in the UAB (6.12[+ or -]0.36) (p<0.01). As for the AUC, the UAB (mean[+ or -]S.D.: 8.02[+ or -]7.06 (mmol/L x min)) was significantly larger than the LAL (0.52[+ or -]0.64 (mmol/L x min)) (p<0.01). Conclusion: Plaque in the UAB is more cariogenic than in the LAL.

1613 ASSOCIATION BETWEEN BMI AND CARIES FREQUENCY IN ELEMENTARY SCHOOL CHILDREN

B. WILLERSHAUSEN, M. BLETTNER, G. HAAS, and K. IIOIIENFELL-NER, Johannes Gutenberg Universitat Mainz, Germany

Objectives: Within the last 10 years an enormous increase in overweight adults as well as adolescents and children could be observed. Besides well-known risk factors, it may be postulated that a higher frequency of caries can also occur in overweight or obese people as eating habit may contribute to both. Methods: A total of 1290 elementary school children (50% boys, 49.8% girls; age 6 to 11 years) were examined. The dental examination included the determination of caries frequency (DF-T-/df-t-values). The medical evaluation assessed the pupils' general health and the body mass index (BMI). Results: The study showed that 3.6% of the children were underweight, 74.8% had a normal weight, 11.9% were overweight and 9.7% obese. Naturally healthy teeth were found in 38.8 % of all children. Children with underweight showed healthy teeth in 44.7%, those with normal weight showed natural teeth in 40.7%, while children with high weight and obese children showed healthy teeth in 30.5% resp. 31.7 %. A significant correlation between high weight and caries frequency in the first dentition (p= 0.0067 for df-t distribution) and in the permanent dentition (p= 0.0002 for DF-T distribution) could be observed. The association remains statistically significant after adjusting for age. The number of healthy teeth decreased with the age (p=0.001), BMI (p=0.0061) and was different between girls and boys (p=0.0334. Conclusions: This study demonstrated a significant association between dental caries and weight in children of elementary schools. In future preventive programs the importance of nutrition should not only be emphasized with respect to general diseases but also with regard to carious lesions

1997 USE OF TELEDENTISTRY FOR DETECTION OF CARIES IN PRESCHOOL CHILDREN

D. KOPYCKA-KEDZIERAWSKI (1), M. LANTZY (2), S. COYLE (2), and R. BILLINGS (2), (1) University of Rochester, Eastman Department of Dentistry, Rochester, NY, USA, (2) University of Rochester, NY, USA

Objectives: To assess caries prevalence in 12-60 month old children enrolled in six Early Head Start inner-city childcare centers by means of Teledentistry and to evaluate the use of Teledentistry as an oral examination screening tool. Methods: Images of the deciduous dentition were obtained by trained Telehealth Assistants using an intraoral camera. Images were entered into a web-based storage and retrieval program maintained by Health-e-Access, University of Rochester, Department of Pediatrics and the sponsor of the Teledentistry initiative. Images were transmitted to a secure remote-site computer and evaluated by a calibrated pediatric dentist. Results: Of 121 children screened, 55 (approximately 45%) were caries active. The mean dfs score was 2.34 (SD= 4.73) with a range of 0 to 32 carious surfaces. African-American children (n=78) had the highest mean dfs score of 3.05, followed by Caucasian children (n=3, dfs= 1.67) and Hispanic children (n=39, dfs= 1.03). Males had a higher mean dfs score (dfs=2.35, SD= 5.76) than females (dfs= 2.33, SD=4.10). 2.48% of children had diagnostically unacceptable images. These children were re-imaged until diagnostically acceptable images were obtained. Referrals for preventive or restorative care were provided for all children participating in the study. Conclusion: The results of this study suggest that (1) an intraoral camera can be used successfully for diagnostic purposes; (2) may reduce costs and enhance oral health screening programs; (3) images can be obtained as often as necessary to achieve an acceptable diagnostic standard or to follow-up on children referred for treatment and (4) very young children who often are not seen by a dentist can be screened and referred for care. Supported by NIH/NIDCR R21 DE08946 and the Aetna Foundation.

1998 ELECTRICAL CONDUCTANCE MEASUREMENT IN HIDDEN OCCLUSAL CARIES DETECTION

R. CHATTERJEE, F. CONFESSORE, and I. KLEINBERG, State University of New York--Stony Brook, USA

Introduction and Objective: Intact enamel of occlusal surfaces of posterior teeth is non-conducting electrically. With enamel mineral loss especially in caries vulnerable sites (e.g. pits and fissures), electrical conductivity (EC) rises. However, EC for detecting caries has met limited success. Here we re-examined this question in vitro using a newly developed EC device developed in our laboratory. Method: In 20 extracted third molars with no restorations, non-cavitated caries lesions or visible defects, 6-8 occlusal sites were tested for EC before crowns were sectioned horizontally using an Isomet 11-1180 low-speed saw. Sections were 630[micro]m thick and spaced at 150[micro]m (thickness of diamond blade). Our EC instrument is comprised of a current source with a 3[micro]A current output to which reference and indicator electrodes are connected. To simulate oral cavity conditions, a special apparatus was constructed to enable tooth and electrode positioning. Three measurements were made in triplicate at each site. Before each measurement, each tooth site was dried with air-blowing for 10 sec. Results: A total of 81 potential caries and 69 potential non-caries sites were identified from the conductance data. The former sites showed EC values ranging from 1.0 to 3.0[micro]A, except for one site which was 0.3[micro]A. EC for the potential non-caries sites were all 0.0[micro]A. Visual examination of the first group sections overwhelmingly showed demineralization. Scoring them on a 0 to 4 scale and determining their degree of agreement with EC showed a correlation coefficient of 0.895. In contrast, the non-conducting tooth sites showed no mineral loss visually and scores of 0. Conclusion: Results of this evaluation suggest that the detection of dental caries in occlusal pits and fissures by EC with the new EC device is highly reliable and reproducible. If proven in vivo, it could be a valuable instrument for early hidden caries detection.

1008 INEVITABILITY OF DENTAL DISEASE: BELIEFS OF YOUNG MOTHERS

R.D. JACKSON, M. FONTANA, M. TORO, S. KELLY, and G. ECKERT, Indiana University School of Dentistry, Indianapolis, USA

The dental beliefs of parents may impact on the resultant oral health of their children. If it is believed that the development of dental caries or tooth loss are inevitable, parents may be less receptive to the initiation of preventive care. As a result, the caries experience of their children may be increased. Objective: These data were derived from a larger study designed to determine associations between caries risk behaviors, dental knowledge and perceptions of health of primary caregivers (PCG) and their toddlers, with their level of caries incidence. These data summarize the dental health beliefs of the PCGs based on self-reported race/ethnicity related to caries development and tooth loss. Methods: 375 white, black and Hispanic PCGs of 396 young children (26.4[+ or -]5.6 months-of-age) were interviewed. Six questions were formulated to measure their dental health beliefs; two to gauge perceptions concerning the development of dental disease as related to dental caries and tooth loss. The first question was "Most young children will get cavities". The second was "Most adults will lose all their teeth as they get older". Answers of True, False or Do Not Know were recorded. Results: For the first question, 66% of Hispanic mothers answered affirmatively followed by 51% and 45% of black and white mothers, respectively. Hispanic mothers were most likely to answer "True" to the second question (49%) followed by black (37%) and finally white mothers (22%). Analyses of the data indicated significant differences between groups for both questions. Conclusion: Preliminary analyses indicated that the belief in the inevitability of the development of dental disease and resultant tooth loss was found to differ significantly based on race/ethnicity. Comparative analyses of these data to the collected caries examination data of the children are being performed. This study was supported by NIH R21 48-745-00

0152 ASSESSING THE CARIES PREVENTIVE EFFECT OF PREVENTIVE PUBLIC SCHOOL PROGRAM

J. VERONNEAU, Jr., McGill University, Montreal, Quebec, Canada, and P. ALLISON, McGill University, Montreal, VA, Canada

The Quebec Preventive Dental Services Public Program (PDSPP) has a recurring annual budget of $12 M. Its main component is a school program (PDIIPSP) having as its major objective the prevention of dental caries in primary school children. Objective: Evaluate the association between exposure to the PDHPSP and dental caries prevalence among Quebec children aged nine years. The hypothesis tested was that nine year old children found at risk for dental caries at age five years and who did not benefit from any preventive intervention (the control group) had an average d3efs + D3EFS greater by three units or more than children of the same age and caries risk but who received preventive interventions (the intervention group). Method: A retrospective cohort design with cross-sectional data collection was used. A convenience and non-representative sample of 1185 nine year-old children was used. Of these 142 were at high risk of caries and received the PDHPSP, 103 were at high risk and did not receive the PDHPSP and 940 were at low risk for caries and did not receive the PDHPSP. Data were collected directly from the children in a school environment by three dental hygienists, and by mail from their parents and their private dentist. Questionnaires were used to collect data concerning knowledge and behavior associated with dental caries incidence. The study primary dependent variable was the average d3efs + D3EFS. Results: The mean d3efs + D3EFS of children in the control group was 17.03, while that of children from the intervention group was 17.02. There was no difference in these mean caries experiences between the two groups. Conclusion: The results suggest that there is no evidence of association between dental caries prevalence and PDHPSP exposure after four years (i.e. at nine years old).

0456 FACTORS ASSOCIATED WITH SEVERE EARLY CHILDHOOD CARIES AMONG ABORIGINAL CHILDREN

S. PERESSINI (1), J.L. LEAKE (2), and J. MAYHALL (2), (1) University of Toronto, Canada, (2) University of Toronto-, Canada

Objectives: To identify the factors associated with Severe Early Childhood Caries (S-ECC) among three and five year-old Aboriginal children residing in seven Aboriginal communities in the District of Manitoulin, Ontario, Canada. Methods: Using a case-control study design factors were identified using a standardized interview questionnaire given to 68 primary caregivers. A S-ECC case was defined as a child with caries on two or more deciduous maxillary incisors or canines presenting as active or filled lesions or teeth missing due to caries, or they had a total decayed, missing (because of caries), filled primary teeth score (dmft) greater than 3. Data were analyzed using manual, forward, stepwise multiple logistic regression. Results: The following familial, infant/child feeding and oral hygiene factors were statistically associated with the development of S-ECC (P<0.1): father's education level OR 14.2 90% CI (4.1,49.2); child using a bedtime bottle containing sweet liquids after the child began walking (approximately 12 months of age) OR 6.6 90% CI (1.2, 36.4); mother's education level OR 0.2 90% CI (0.03, 0.4); primary caregiver initiating child's brushing of teeth after the age of 24 months OR 6.1 90% CI (1.5, 25.7); and the child eating four or more between-meal snacks per day OR 4.9 90% CI (1.4, 17.1). Conclusion: These results will assist community health care workers in identifying those children at greatest risk for S-ECC. It may also help in the redirection of limited resources to plan and implement effective preventive oral health interventions.

DEMINERALIZATION / REMINERALIZATION 

0497 INFLUENCE OF FLUORIDATED CARBAMIDE PEROXIDE BLEACHING GEL ON ENAMEL DEMINERALIZATION

L.M. CLARK, N. BARGHI, J.B. SUMMITT, and B.T. AMAECHI, University of Texas--San Antonio / Health Science Ctr, USA

Objective: Some brands of 10% carbamide peroxide bleaching (CP) gels are now fluoridated to limit bleaching-induced tooth sensitivity experienced by some individuals. Fluoride application on tooth surface induces increase resistant of the surface to demineralization. The aim of this study was to determine the effect of fluoridated CP gel application to tooth surface on enamel demineralization, comparing it with non-fluoridated CP gel and fluoridated toothpaste. Method: 4 enamel blocks were cut from each of twenty extracted human molars. The 4 blocks from each tooth were randomly assigned to four experimental groups: A (control), B (treated with non-fluoridated CP gel), C and D (treated respectively with CP gel and toothpaste both containing 0.11% fluoride). The blocks were subjected to 8-hour treatment each day with their respective agent for 14 days to simulate manufacturer's bleaching instruction. Following treatment, a tooth section was cut from each block. Sections were microradiographed and the images were analyzed for quantification of lesion parameters (mineral loss ([DELTA]z) and lesion depth (LD)) using transverse microradiography. Data was analyzed statistically using paired t-test (n=20, [alpha]=0.05) to test for differences in degree of demineralization (as measured by the lesion parameters) among the four groups. Result: Significantly greater [DELTA]z was observed in group A when compared with B(p<0.05), C(p<0.001) and D(p<0.01), and in B when compared with C(p<0.05). No significant difference in [DELTA]z between B and D, and between C and D. LD was significantly greater in group A when compared with C(p<0.001) and D(p<0.01), and in B when compared with C(p<0.001) and D(p<0.05). No significant difference in LD between A and B, and between C and D. Conclusion: Application of fluoridated 10% carbamide peroxide gel resulted in enamel demineralization inhibition comparable to toothpaste of similar fluoride concentration. Supported in parts by NIDCR, Grant #DE14318 for COSTAR Program and Ultradent Products.

2070 TOPICAL FLUORIDE TREATMENT AND ENAMEL DISSOLUTION IN CITRUS-CONTAINING BEVERAGES

E.E. JACOBSEN, G.B. SMITH, and J.A. VON FRAUNHOFER, University of Maryland at Baltimore, USA

Objectives: Previous studies have demonstrated that exposure of dental enamel to soft drinks, particularly those containing citrus flavoring, causes dissolution. It is well-known that topical fluoride treatment reduces the rate of carious lesion development. No data is available, however, on the effect of topical fluoride on enamel erosion by citric acid-containing beverages. Methods: Enamel was sectioned in thin slices from extracted human molars and premolars with care being taken to yield enamel-only slices. The dimensions and weights were recorded for each enamel slice. Three sets of enamel slices (N=6) were then immersed in Mountain Dew, Fresca, Red Bull and lemon juice for a total of 8 days, with solutions being changed daily. The solutions were stored in an incubator at 37[degrees]C. One set of slices were left untreated prior to immersion. A second set of slices was treated with APF and the 3rd set was treated with neutral pH Nupro fluoride treatment. Results: It was noted that enamel dissolution was low for up to 5 days but thereafter the rate of enamel dissolution increased. Topical fluoride treatment markedly reduced enamel dissolution in the beverages compared to that for untreated enamel, and while a second topical F- treatment initially reduced the rate of attack, eventually both treated and untreated enamel exhibited similar rates of dissolution. It was found that successive F- treatments reduced enamel dissolution until there was marked enamel loss; thereafter, the rate of attack increased regardless of F treatment. Conclusions: Citrus-containing beverages are very aggressive towards dental enamel and while topical fluoride treatment delays the onset and rate of enamel dissolution, it does not prevent attack.

0474 ENAMEL AND ROOT SURFACE EROSION DUE TO POPULAR U.S. BEVERAGES

L. EHLEN, T.A. MARSHALL, F. QIAN, J.J. WARREN, J.S. WEFEL, M.M. HOGAN, and J.D. HARLESS, University of Iowa, Iowa City, USA

Our earlier work has demonstrated the effect of acidic beverages on dental enamel but the susceptibility of root surfaces to a similar acidic insult has not been investigated. Objective: This study measured erosion depths in root surfaces following beverage exposure, and compared erosion depths between enamel and root surfaces. Methods: Representative beverages were chosen from regular sodas, diet sodas, 100% juices, and sports drinks categories. Extracted teeth were painted with fingernail polish exposing a small window (1x4 mm) of enamel or root surface. Teeth (n=4/per group) were randomly assigned and submerged in the beverages for 25 hours; beverages were changed every 5 hours. Teeth were sectioned into thin slices using a microtome, erosion depths were viewed using a polarized light microscope and measured with Image Pro Plus. Data were analyzed using one-way ANOVA and two-sample t-test (p<0.05). Results: Mean enamel erosion depths following exposure to Gatorade[R] (131[+ or -]8[micro]m) were greater (p<0.05) than Red Bull[R] (100[+ or -]5[micro]m) and Coke[R] (92[+ or -]6[micro]m); these three depths were greater (p < 0.05) than Diet Coke[R] (61[+ or -]4[micro]m) and apple juice (57[+ or -][micro]m). Mean root surface erosion depths differed between each possible pair of beverage comparisons (p<0.05) following exposure; Gatorade[R] (118[+ or -]5[micro]m), Red Bull[R] (111[+ or -]4[micro]m), Coke[R] (101[+ or -]3[micro]m), apple juice (77[+ or -]3[micro]m) and Diet Coke[R] (66[+ or -]2[micro]m). Erosion depths were greater in root than in enamel surfaces following exposure to Red Bull[R], Coke[R], and apple juice (p<0.05 in all instances). Erosion depths were greater in enamel than in root surfaces following exposure to Gatorade[R] (p<0.05). Enamel and root surface erosion depths did not differ following exposure to Diet Coke[R]. Conclusion: Exposure of root surfaces to acidic beverages resulted in significant erosion. The susceptibility of enamel and root surfaces to erosion was not consistent between beverages and warrants further investigation.

PERIODONTOLOGY 

2152 THE ASSOCIATION BETWEEN METABOLIC SYNDROME AND PERIODONTAL DISEASE

O.M. ANDRIANKAJA, R. DUNFORD, and E. DENARDIN, State University of New York--Buffalo, USA

Objectives: Obesity, hypertension, hyperglycemia and dyslipidemia, collectively referred to as "metabolic syndrome", have been associated with cardiovascular disease and have been suggested as potential independent risk factors for periodontal disease (PD). To confirm the latter, using data from the NHANES III that included 7431 subjects aged 20 years or older, we analyzed the association between metabolic syndrome and PD, and identified which components of metabolic syndrome may play a role in this association. We also examined the possibility that subjects with PD may be at higher risk to develop metabolic syndrome. Methods: Clinical criteria for metabolic syndrome included: 1. Abdominal obesity; 2. High triglyceride levels; 3. Low HDL cholesterol levels; 4. High blood pressure or current use of blood pressure medication; and 5. High fasting plasma glucose concentration. PD was evaluated by probing pocket depth (PPD) at four sites per tooth on the two randomly selected quadrants, one upper and one lower. Periodontal disease was defined as mean PPD [greater than or equal to] 2.5mm. Results: There was a 39% increase (OR= 1.39 95%CI; 1.20- 1.62) in the odds of having PD in women having indicators of metabolic syndrome; no difference was seen for men [OR=0.98 (0.84-1.14)]. Using a minimum of 3 out of 5 criteria for metabolic syndrome, the adjusted OR were 1.02 (0.65-1.61) for men and 1.88 (1.05-3.35) for women. Abdominal obesity [OR= 1.50 (0.98-2.29) for men, 3.38 (1.81-6.32) for women] was the largest contributory factor. In addition, there was a significant increase in the odds of having metabolic syndrome in periodontal patients [OR = 1.33 (1.17-1.51)]. Conclusions: The present study suggested that individuals with metabolic syndrome were more likely to develop periodontal disease. The association was statistically significant for women. Further studies are needed to determine the nature of the association between metabolic syndrome and PD. Supported by USPHS-NIH T32 DE07034.

0209 CONTROLLING PERIODONTAL INFECTION REDUCES SEVERITY OF ACTIVE RHEUMATOID ARTHRITIS

M.K. AL-KATMA (1), N.F. BISSADA (2), J.M. BORDEAUX (2), and A.D. ASKARI (3), (1) Case Western Reserve University, School of Dental Medicine, Cleveland, OH, USA, (2) Case Western Reserve University, Cleveland, OH, USA, (3) University Hospitals of Cleveland, OH, USA

Objective: To determine if eliminating periodontal infection and gingival inflammation has an effect on the severity of active rheumatoid arthritis (ARA) in patients with chronic inflammatory periodontal disease (CPD). Methods: 29 patients with a confirmed diagnosis of ARA as well as mild-to-moderate CPD for at least three years participated in the study. Activity of RA was assessed using the disease activity score test (DAS28) and the erythrocyte sedimentation rate (ESR). CPD is defined by 30% or more of the present teeth having 1 to 4 mm of clinical attachment loss. 17 out of the 29 patients were randomly selected to receive periodontal treatment consisting of scaling/root planing and oral hygiene instructions, whereas the other 12 received no treatment. All participants continued with their usual medications for RA during the study period. DAS28, ESR, and periodontal evaluations including plaque index, gingival index, probing depth, and bleeding on probing were recorded at base line and at 8 weeks thereafter for all the participants. Mann-Whitney U and chi-square tests were used to test if there is a significant difference in ARA severity in the periodon-tally-treated group than in the untreated group. Results: 10 out of the 17 subjects (58.8%) in the treated group showed improvement in the RA score indices whereas only 2 out of 12 (16.7%) in the untreated group showed slight improvement. There was a statistically significant difference (p>.05) in DAS28 and ESR between the treated and the control groups (40.1[+ or -]20.4 vs. 43.7[+ or -]16.1) and 30.5[+ or -]20.4 vs. 39.4[+ or -]22) respectively. Conclusion: Control of periodontal infection and gingival inflammation by scaling/root planing and plaque control in subjects with periodontal disease may lessen the severity of ARA. This finding supports the notion that there is an association between these two chronic inflammatory disease conditions.

GERIATRIC ORAL RESEARCH

0184 ORAL HEALTH CARE PERCEPTIONS IN U.S. NURSING FACILITIES

D. BERKEY, University of Colorado at Denver and Health Sciences Center, Total Longterm Care, Aurora, USA, R. BERG, University of Colorado at Denver and Health Sciences Center, Aurora, USA, and B. SMITH, University of Michigan, School of Dentistry, Ann Arbor, USA A variety of factors may substantially influence the oral health status of nursing home residents. Objectives: Explore perceptions of Directors of Nursing (DoNs) regarding access to dental care and related issues. Methods: Questionnaires sent to random sample of DoNs in 9 regionally representative U.S. states (n=1333). Results: Response rate was 50% (n=664); mean facility 109 residents; 82% were of "white" ethnicity; and less than 25% were private pay; 51% were located in rural areas; and 59% of facilities were proprietary. DoNs and social workers most likely to coordinate dental care; nearly 30% of facilities did not have a written plan of care for oral health; 8% had on-site dental equipment; nearly half of residents were reported to be examined annually by dental professional; only 28% were likely to have received dental care beyond an exam and 25% of these visits were related to dental emergencies. Only 15% of respondents were dissatisfied with their facilities capacity to adequately address dental emergencies. Barriers to care with the highest mean level of significance were DDS willingness to treat residents and financial concerns of the resident/family. A 5 point "access" indicator scale was created and logistic regression model constructed to assess key variables; significant factors (p<.05) in decreasing strength of association were availability of dental equipment, having a written dental care plan, and having the dental care plan coordinated by the unit charge nurse. A variety of state-based study differences were evident; when compared to those in NY facilities residents in AZ and TX faced much greater barriers due to financial constraints (OR 19.6, 18.3), transportation of resident for care (OR 10.6, 11.6), and willingness of DDS to treat at facility (OR 7.7, 7.9). Conclusions: Findings confirm that there are substantial barriers to care and they appear to vary considerably by region.

2071 AGING CONTRIBUTES TO THE FATIGUE CRACK GROWTH RESISTANCE OF DENTIN 

D. BAJAJ, N. SUNDARAM, A. NAZARI, and D.D. AROLA, University of Maryland at Baltimore County, USA

With rise in the number of seniors that are fully dentate, it is becoming increasingly important to understand the changes in structure of tooth tissues with age and the corresponding influence on their mechanical behavior. Objectives: To quantify the influence of patient age on the fatigue crack growth properties of human dentin. Methods: Compact Tension (CT) fatigue specimens were sectioned from the coronal dentin of extracted molars and subjected to high cycle fatigue loading (105<N<106) while fully hydrated (HBSS) at 22[degrees]C. The specimens were categorized young (18" Age " 35; N=9) or old (50" Age; N=8). All specimens were prepared to achieve crack growth perpendicular to the dentin tubules and then were subjected to Mode I loads with stress ratio (R) and frequency of 0.1 and 5Hz, respectively. Fatigue crack growth rates corresponding to steady-state growth were quantified according to the Paris Law in terms of the crack growth exponent (m) and coefficient (C). In addition, Electron Dispersive X-ray Analysis (EDXA) was performed to study the changes in chemistry and structure of dentin with age. Results: Overall, the fatigue crack growth rates ranged from 4E-7 to 5E-2 mm/cycle over a stress intensity range from 0.5 to 1.2 MPa x m^0.5. The average fatigue crack growth exponent for the young dentin (m= 13.3[+ or -]1.1) was significantly lower than that of the old dentin (m = 21.6[+ or -]5.2; p<0.003). Fatigue cracks in the old dentin underwent initiation and propagation at a much lower stress intensity range than that for the young dentin. Results from the EDXA showed that the Ca:P ratio in young dentin was 3.14[+ or -]0.053 whereas in old dentin was 2.55[+ or -]0.072. Conclusion: The fatigue crack growth resistance of dentin decreases with patient age. (Supported by an individual investigator grant, Whitaker Foundation)

ORAL HEALTH

2049 ADVANTAGES OF BRUSHING TWICE-PER-DAY COMPARED TO ONCE-PER-DAY

S.E. ADAMS (1), V.J. CROMWELL (2), A.J. THEOBALD (2), M.G. BRADING (2), A.K. GREEN3, T.F. COX (2), M. MCGRADY (4), and D. SAVAGE (4), (1) Unilever R & D Port Sunlight, Wirral, United Kingdom, (2) Unilever R & D Port Sunlight, Wirral, England, Uk, (3) Unilever R & D Port Sunlight, Wirral, (4) 4-Front Research Ltd, Capenhurst, United Kingdom

Objectives: To compare the effects of brushing once-per-day (morning) with brushing twice-per-day (morning and evening) on fluoride levels in saliva and total viable bacteria (TVC) in plaque. Methods: 32 healthy adult volunteers completed a single-blind, randomised crossover design study. Before Test Day 1, subjects had all visible plaque removed and used non-fluoride toothpaste for 1-week. Having refrained from brushing for 12hours, subjects provided a baseline saliva sample on the morning of Test Day 1 then brushed with 1.5g of silica toothpaste containing 0.32% NaF (Close-Up, Unilever). Saliva samples were collected 1 and 2hours after brushing. Subjects allocated to twice-per-day brushing were given the test toothpaste to use on the evening of Test Day 1, while those allocated to once-per-day regime did not brush. The following morning (Test Day 2) all subjects provided a saliva sample on waking then returned to the test site where a plaque sample was collected. The subjects completed a further week on non-fluoride toothpaste prior to repeating the procedures for the second brushing regime. Saliva samples were analysed for total fluoride by ion selective electrode. Aerobic and anaerobic TVCs were determined in the plaque samples. Results: Overall Mean (s.e.) Salivary fluoride concentrations (ppm):

                               1 hour    2 hours
Brushing regime      Baseline  post-use  post-use  Morning

Once-per-day          0.035     0.556     0.195     0.046
(morning only)       (0.009)   (0.067)   (0.024)   (0.006)
Twice-per-day         0.027     0.537     0.213     0.292
(morning & evening)  (0.002)   (0.077)   (0.034)   (0.057)
Significance                                       p>0.0001

When brushing twice-per-day the fluoride levels in the morning saliva samples were similar to the levels found 2hours after brushing. When brushing once-per-day the fluoride levels in the morning saliva samples had returned to baseline. Significantly fewer aerobic(p<0.0001) and anaerobic(p=0.0003) bacteria were found in plaque for twice-per-day brushing compared to once-per-day. Conclusion: Brushing twice-per-day with the test product gave significant increases in overnight salivary fluoride levels and reductions in total viable bacteria compared to once-per-day brushing.

RESEARCH METHODOLOGY

0920 EVALUATION OF DENTAL SYSTEMATIC REVIEW SEARCH AND SELECTION METHODS

M.P. MAJOR (1), P.W. MAJOR (2), and C. FLORES-MIR (2), (1) Boston University, Craniofacial & Oral-health Evidence-based Practice Group (COEPG), MA, USA, (2) University of Alberta, Cranio-facial & Oral-health Evidence-based Practice Group (COEPG), Edmonton, Canada

Objectives: Despite the large increase in evidence-based knowledge in dentistry, there has been little done to evaluate the quality of dental systematic reviews and meta-analyses. The aim was to evaluate search and selection of studies in these systematic reviews. Methods: Dental systematic reviews published between January 1, 2000 and July 14, 2005 were searched for systematically utilizing multiple electronic databases and secondary searches. Search and selection methods of identified reviews meeting the definition of a "systematic" were evaluated against the guidelines in Cochrane Handbook for Systematic Reviews of Interventions. Systematic reviews were evaluated for 1) documentation of database name and date range of search, 2) electronic searches preformed in at least two databases, 3) electronic-searches followed-up with secondary searches, 4) search terms were clearly presented 5) Boolean operators for combining terms were presented, 6) clear and reproducible inclusion-exclusion criteria were presented, 7) included articles were selected by a team of two or more researchers, and 8) all languages were included. Results: 220 unique dental systematic reviews were identified. All aspects of search and selection methodology have improved. In 2005, most systematic reviews documented database names and search dates (90%), electronic search terms (95%), inclusion-exclusion criteria (95%), and employed secondary searching (100%). However, any still fail to search more than MEDLINE (20%), document the search strategy (20%), use multiple reviewers for selecting studies (25%), and include all languages (39%). Conclusions: Readers of systematic reviews can become increasingly confident of the reviews conclusions. But though systematic review methodology is improving, key components are still frequently absent. Each component identified as frequently missing has been quantitatively tied to the validity of systematic review conclusions. Therefore researchers, clinicians, and all other interested parties should always read systematic reviews critically constantly considering the potential for bias from methodological flaws.

0876 VALIDATION OF THE CHILD PERCEPTIONS QUESTIONNAIRE IN CHILDREN WITH MALOCCLUSION 

S. AGOU (1), D. LOCKER (2), B. TOMPSON (2), and D. STREINER (3), (1) University of Toronto, King AbdulAziz University, Canada, (2) University of Toronto, Canada, (3) University of Toronto, Kunin-Lunenfeld Applied Research Unit, Canada

The Child Perceptions Questionnaire for 11-14-year-olds (CPQ11-14) is an oral-health-related quality of life measure encompassing the domains of oral symptoms, functional limitations, emotional well-being and social well-being. The Child Health Questionnaire (CHQ-87) is an established measure of self-perceived physical and psychosocial child well being. Objective: To test the cross-sectional convergent validity of the CPQ11-14 against the CHQ-87 in orthodontic patients. Methods: The CPQ11-14 and the CHQ-87 were completed by orthodontic patients at the Faculty of Dentistry, University of Toronto prior to the commencement of their treatment. CPQ11-14 total scores were calculated by summing the domain subscale scores. Two domains of the CHQ-87 were tested against CPQ11-14 total score and socio-emotional domains scores: self esteem (SE) and general mental health (GMH) domains. Convergent validity was tested by means of Spearman's correlation. Results: Data were collected from 211 children. Mean age of the sample was 12.5 (SD = 1.2). Mean SE and MH scores for children with malocclusion were 0.85, 0.79 respectively, compared to school based population norms of 0.89 and 0.82. There were significant negative correlations between the CPQ11-14 scores and the CHQ-87 domain scores. High CPQ11-14 total scores indicating poor oral health quality of life were associated with low self esteem CHQ scores (rs = -0.46; p<0.01) and low general mental well being (rs = -0.47; p<0.01). A similar pattern was observed for the subscale scores, with the most pronounced gradient in the emotional well-being domain. Conclusions: The study provided evidence of the cross-sectional convergent validity of the CPQ11-14, supporting its application in clinical orthodontics settings.

0878 THE MEANING OF SELF-RATINGS OF ORAL HEALTH

D. LOCKER, J. MAGGIRIAS, and E. WEXLER, University of Toronto, Canada

Objectives: To assess variations in the frames of reference underlying self-ratings of oral health. Method: Interviews were undertaken with a convenience sample of adults. Subjects were asked to rate their oral health on a scale ranging from excellent to poor and then to give the reasons for their ratings. The interviews were tape-recorded, transcribed and content analyzed. Up to four numerical codes were allocated to reflect the reasons given in support of the self-ratings. Quantitative analysis was undertaken to determine if there were systematic differences in the frames of reference used according to gender, age and education. Results: Data were obtained from 80 subjects, ranging in age from 22 to 97 years. 55% were female. 13.8% rated their oral health as excellent, 36.3% as very good, 30.0% as good, 15.0% as fair and 5.0% as poor. Sixty-two codes were needed in order to characterize the frames of reference underlying these ratings. Some rationales were simple, others complex and multi-layered. There were variations in the biophysical and behavioural characteristics invoked and whether those characteristics were present or absent. Some were based on the present and some on the past. For quantitative purposes these codes were reduced to six major groups. Current and past dental problems, treatment needs and histories were referred to by 59% and health behaviours by 51%; 25% referred to tooth loss and 16.2% to pain and other outcomes. For 6%, ratings were based on temporal or social comparisons. There were some differences by gender, age and education in the referents invoked to account for self-ratings in predictable ways. This may be because quantification of the qualitative data reduced and misrepresented its complexity. Conclusions: There are considerable variations in the frames of reference underlying self-ratings of oral health that are masked by the requirements of quantitative analysis.

1505 SCHOOL PERFORMANCE INDICATORS AS PROXY MEASURES OF SCHOOL DENTAL NEEDS

V. MUIRHEAD, D. LOCKER, and C. QUINONEZ, University of Toronto, Canada

Concerns about the cost-effectiveness of universal school dental screening programs have spurred the hunt for alternative approaches to identify individuals or schools at oral health risk. This pilot study assessed the feasibility of using readily available educational and social determinants as proxy measures of school-based dental treatment need. Objective: To test the ability of school performance indicators to predict school dental treatment needs in York Region elementary schools, Ontario, Canada. Methods: An ecological study using school aggregated data. Data sources included York Region Dental Health Unit dental screening data (2003-2004); area-based income data from Statistics Canada (2001) based on school address postcodes and grade three and grade six school performance results in reading, writing mathematics and English as a second language (ESL) data (2003-2004) obtained from publicly accessible educational websites. Results: Data were extracted for 219 elementary schools. Simple linear regression analyses showed that the percentage of children requiring urgent dental treatment was positively associated with all six school performance variables representing the percentage of grade three and six children scoring below the provincial standard in reading, writing and mathematics (P<0.001). Hierarchical stepwise multiple linear regression analysis showed that two school performance variables remained in the model after controlling for area-based median family income and ESL variables: the percentage of grade 6 pupils scoring below the provincial average in writing (P<0.001) and the percentage of grade 3 pupils scoring below the provincial average in reading (P=0.02). Conclusions: Grade three and six school performance results are good predictors of urgent school dental treatment in York Region elementary schools. Further studies need to be carried out using age corresponding data sources and data from other Ontario health regions.

CANCER

0748 ALVEOLAR RIDGE KERATOSIS: A CLINICOPATHOLOGIC STUDY

P.R. LAMBERT (1), L. VO (2), E. EDWARDS (2), B.W. NEVILLE (2), and A.C. CHI (2), (1) The Citadel, Medical University of South Carolina, Charleston, SC, USA, (2) Medical University of South Carolina, Charleston, USA

Alveolar ridge keratosis (ARK) is a white lesion of the retromolar pad (RP) or edentulous alveolar ridge (EAR) believed to represent a response to chronic frictional trauma. ARK is not widely recognized and often is included in studies of oral leukoplakia (OL), thereby implying premalignant potential. Objectives: 1)To characterize the clinicopathologic features of ARK. 2)To determine whether removal of ARK from the OL category could have a significant impact on prevalence of dysplasia or carcinoma in OL. Methods: We conducted a retrospective study of all ARK cases submitted to our biopsy service from 1995-2004. We defined ARK as a white patch or plaque without erythema and limited to RP or EAR. Results: 421 ARK cases were identified, comprising 17% of all OL specimens. The mean age was 54years (range 16-87years). The male:female ratio was 1.8:1. Microscopically, ARK cases exhibited hyperkeratosis and the following features: 95.25%(n=401) without dysplasia, 2.85%(n=12) mild reactive atypia, 1.43%(n=6) mild-to-moderate dysplasia, 0.48%(n=2) severe dysplasia, 0%(n=0) carcinoma. All dysplastic cases were associated with one or more of the following: verrucous appearance, tobacco use, history of multiple OL lesions (not involving RP or EAR), previous oral carcinoma. Removing ARK from the OL group increased the percentage of OL cases exhibiting dysplasia or carcinoma from 19 to 23%. Including versus excluding ARK from OL resulted in a marked difference regarding the OL microscopic diagnostic profile (kappa=0.18). Conclusions: The majority of ARK cases represent benign hyperkeratoses, although prospective studies are needed to confirm a lack of premalignant potential. Certain features of the patient history and clinical examination might suggest true OL mimicking ARK and may provide guidelines regarding indications for biopsy. Excluding ARK from OL yielded a small but significant increase in the proportion of OL cases with dysplasia or carcinoma. Investigators should consider not classifying ARK as OL.