Scientific Abstracts Submitted

Preliminary Assessment Strategies for Implementing Guidelines International Salt Fluoridation
Herman A., DMD, MScD, Miller M., DMD, MPH, Griffiths J., MD, MPH, TM
Navidomskis M., MPH - Tufts University, Maryland

OBJECTIVES: The program objective is to vigorously evaluate strategies to implement international salt fluoridation program guidelines in El Salvador.  Oral disease is a critical element in overall health status in Central American, Latin American, and Caribbean regions. In San Salvador, the majority of the population resides in rural areas without access to community fluoridated water.  In particular, dental caries remain at a high prevalence and severity. Additionally, the prevalence and severity of dental caries is greater in low-income and poorly-educated population segments.  METHODS: A systematic, comprehensive feasibility analysis of an international salt fluoridation project will be performed by accomplishing each of the following goals: (a) analyze existing community water fluoridation data collected throughout El Salvador (including both rural and urban areas from 728 unique collection sites) to identify potential salt fluoridation sites; (b) coordinate a comprehensive network of project partners (domestically and abroad) to further the goal of ‘global oral health'; (c) establish realistic and beneficial partnerships with relevant governmental and non-governmental organizations (NGO's); (d) identify specific contacts (e.g. names/roles/contact information) within each partner organization; and (e) establish personal contact (e.g. face-to-face meeting / telephone / email) with each individual contact (e.g. PAHO representatives in Washington, D.C. and El Salvador) to solicit insights about bio-ethical concerns, barriers to policy implementation, and other potential issues (e.g. financial, social, cultural) based upon existing water fluoridation data in El Salvador. RESULTS / CONCLUSIONS: A feasibility assessment using existing fluoridation data will be performed and subsequently utilized to implement a program as follows: (a) Coordinate a comprehensive network of project partners (domestically and abroad) to further the goal of ‘global oral health'; (b) Identify and evaluate specific barriers; (c) Policy analysis; and (d) "Salt Fluoridation Health Campaign" in collaboration with the Ministry of Health in El Salvador.

Flexural Bond Strength of Two Adhesive Systems to Dentin
J Mariscal, JL Drummond, AKB Bedran-Russo - University of Illinois at Chicago College of Dentistry, Illinois

HYPOTHESIS: A major field of interest in dentistry is the performance of adhesive bonding materials used for several dental bonding procedures. We have tested the null hypothesis that the adhesive systems tested on this study would present similar flexural bond strength (FBS) values, regardless of the mechanism of bonding.

OBJECTIVES: The study was conducted to investigated the FBS of two adhesives systems, total-etch 2 step Adper Single Bond Plus (3M ESPE) and self-etching Adper Prompt L-Pop (3M ESPE).

METHODS: Ten human sound molars had the occlusal dentin exposed and polished using #180, 320, and 600 grit carbimet paper discs in sequence in order to simulate clinical restorative preparations. The teeth were randomly assigned into 2 groups according to the bonding mechanism: total-etch 2 step Adper Single Bond Plus (3M ESPE) and self-etching Adper Prompt L-Pop (3M ESPE). The adhesive systems were used according to manufacturers' instructions. After the adhesive systems application, a composite resin crown was built up to allow for sample preparation. After 24 hours the specimens were sectioned into beams with approximately 1 mm² (1.0 mm x 1.0 mm) cross sectional area for testing. Specimens were tested in 3-point bending flexural at a crosshead speed of 1mm/min until failure. Data were calculated and statistical analysis was performed using ANOVA and Fisher's PLSD test (p < 0.05).  RESULTS: Flexural bond strength values [Mean (Standard deviation)] were as follow:

Statistical analysis indicated a significant difference between the groups evaluated (p < 0.0001).

CONCLUSION: The use of a total-etch adhesive system resulted in statistically significant higher FBS values in dentin when compared a self-etching system; therefore the null hypothesis was rejected.

Crown Shape and Professional Judgment of Ethnic Background
Amy Rodriguez, Emike Usman-Aliu, Nanci De Felippe DDS, MS - University of Illinois at Chicago College of Dentistry, Illinois

General Dentists (GD) and Orthodontists often judge a patients' ethnicity by dental pictures and casts. They also tend to believe that certain malocclusions are more prevalent in one specific race due to dental shape and size. Although some studies have estabilished norms for tooth size among ethnic groups like:  Asians, African Americans (AA), Caucasians, and Hispanics, no study has yet assessed marginal crest thickenss (MCT) and crown shape in relation to professional judgement of ethnic background (EB).  OBJECTIVES:  The specific aims of this research are: to assess the anatomy of the upper right central incisor (URCI) in different ethnic groups; to compare these measurements and to assess the judgment of GD and Orthodontists in relation to crown shape and patient's EB.  METHODS: 400 subjects had their URCI crown's height, width, and MCT measured by a digital caliper.  20 GD and 20 Orthodontists responded to a structured survey.  RESULTS:

37.5% of GD were able to identify the EB of the subject by looking at a picture of study models, while only 12.5% of Orthodontists were able to do so.  

CONCLUSIONS:  The following are conclusions that can be drawn from this study: there was no statistical significant difference on the anatomical variables tested among the ethnicities studied (p≥0.05); GD and Orthodontists were not able to identify the ethnicity of the subject by judging their study models; there were no statistically significant correlations between the ethnicity of the panelists (GD or Orthodontists) and their answer choice. URCI crown shape varied considerably therefore proving not to be a scientifically legitimate tool when judging EB. 

Family History of Recurrent Aphthous Stomatitis
M. Gertsen, D.W. Theriaque, J.J. Shuster, N.C. Martino, and L. Baccaglini - University of Florida College of Dentistry, Florida

Recurrent aphthous stomatitis (RAS), also known as canker sores, is a common disorder characterized by painful recurrent intraoral ulcers of unknown cause.  It has been reported that over 40% of RAS cases had a positive family history, although reports vary and family history in controls is unclear.  OBJECTIVES:  To determine whether idiopathic RAS is associated with a positive family history.  METHODS:  This is an ongoing unmatched case-control study conducted at the University of Florida.  Data were collected through standardized questionnaires (June 2006-August 2007).  Participants with (cases) or without (controls) a lifetime history of RAS were asked whether their blood relatives (parents and/or siblings) ever had RAS. Data were analyzed using crude odds ratios (OR; 95% CI), Mantel-Haenszel chi-square test, two-sided alpha=0.05 and SAS v9.1.  RESULTS: A total of 234 participants were screened, 12 were excluded, 25 withdrew, and 197 completed the study (123 cases, 74 controls). Participants were 17-66 years old (mean 25 years for both groups), 56% females, 14% Hispanic, 63% White, 17% Asian, 11% Black and 9% other/mixed race. Overall, 79% of cases had a positive family history of RAS (≥1 affected relative) vs. 13% of controls (OR=25.6; 95%CI=11.2-58.6; p<0.0001). Specifically, a higher proportion of cases vs. controls had an affected mother (80% vs. 12%), father (75% vs. 5%), or both parents (66% vs. 5%). On average, cases reported that 80% of their siblings were affected (vs. 12% reported by controls). CONCLUSION:  Cases were more likely than controls to report a positive family history. These results suggest that familial/genetic factors are likely to be involved in the etiopathogenesis of RAS. A potential limitation of case-control studies is some degree of differential recall bias by case status.  This research was supported by NIH grants R03DE016356, 5U24DE016509, and M01RR00082, and the contribution of GCRC personnel, research assistants, and study participants.

Recurrent Aphthous Stomatitis and Dietary Factors
N. C. Martino*, D. W. Theriaque, J. J. Shuster, and L. Baccaglini - University of Florida College of Dentistry, Florida

Recurrent aphthous stomatitis (RAS) or canker sores is a common inflammatory condition characterized by painful recurrent oral ulcerations. Although genetic and environmental factors, including dietary factors, have been suggested as risk factors, the etiology of RAS is still unidentified. OBJECTIVE: Investigate the association between 12 dietary factors and idiopathic RAS. METHODS: Participants recruited using an unmatched case-control design (University of Florida campus, June 2006-August 2007) completed a questionnaire and an oral examination. Questionnaire items included socio-demographic factors, RAS history, and diet in the past 30 days. We compared diet in active (RAS episode ≤1 month earlier) vs. inactive status (RAS ≥6 months earlier up to never in life) using the Mantel-Haenszel test, two-sided alpha=0.05 and SAS v9.1. RESULTS: Overall, 234 participants were screened with 12 excluded, 25 withdrawn, and 197 completing the study. Cases with RAS 1-6 months ago (n=35) and current smokers (n=26) were also excluded from these analyses (final n=136, 43 active and 93 inactive). Participants were 17 and older (mean age: inactive 25.8, active 24.2 years), 56% females, 13% Hispanics (including mixed), 63% Whites, 14% Asians, 13% Blacks, and 10% other/mixed race.  Daily intake of sugar (p=0.036) chocolate (p=0.015), canned foods (p=0.010) and minerals (p=0.004) was higher in the active group. Furthermore, intake was higher for vitamins, preserved meat, fried foods and alcohol, similar for salt, nuts and caffeine, and slightly lower for fruits/vegetables (all p>0.05; n.s.). CONCLUSION: The positive association between sugar and chocolate (typically high in sugar) intake and RAS raises the possibility that sugar may trigger RAS episodes. The higher minerals/vitamins supplements intake may in part reflect attempts to self-medicate or differential health awareness. These findings require further investigation and independent confirmation. This research was supported by NIH grants R03DE016356, 5U24DE016509, and M01RR00082, and the contribution of GCRC personnel, research assistants, and study participants.

Shortened telomeres and increased metastasis in telomerase deficient oral cancer
B. Bojovic, and D. L. Crowe - University of Illinois at Chicago College of Dentistry, Illinois

Telomerase is a ribonucleoprotein which maintains chromosomal ends (telomeres) and is overexpressed in many cancers. Oral cancer arises from the telomerase-positive basal cell layer of oral stratified squamous epithelium. Telomerase activity is repressed as basal cells differentiate but continues to be expressed in oral cancer cells. Telomerase is considered an important molecular target for cancer therapy. OBJECTIVES: To determine the effects of telomere length on oral carcinogenesis, we developed a new mouse oral cancer model in which the telomerase RNA component Terc was disrupted by homologous recombination. METHODS: Following institutional guidelines, first (G1, long telomeres) and fifth (G5, short telomeres) generation Terc -/- mice were orally dosed with 25 ug of the carcinogen 9,10-dimethyl-1,2- benzanthracene twice weekly. Terc +/+ animals were used as a control group. Complete necropsy was performed on all mice. Tumor tissue was processed for histopathologic and immunohistochemical analysis. Total RNA was extracted from microdissected tumor tissue for gene expression analysis (Affymetrix GeneChip mouse genome 430 2.0 microarray). RESULTS: Compared to Terc +/+ mice, G1 Terc -/- animals developed significantly fewer metastatic cervical lymph nodes (p < 0.001). However, G5 Terc -/-mice with shortened telomeres showed no significant differences in the number of metastatic lymph nodes compared to Terc +/+ animals (p < 0.09). Transcriptional profiling showed distinct gene expression signatures between metastatic tumors in wild type and Terc -/- mice. In primary tumors, there were no significant differences in latency period or histopathologic grade between wild type and Terc -/- animals. Primary tumors recapitulated gene expression changes frequently observed in human oral cancer (epidermal growth factor receptor overexpression, loss of cyclin dependent kinase inhibitor p16INK4A expression). CONCLUSION: We concluded that telomere length and telomerase activity were important regulators of cervical lymph node metastasis in a novel mouse model of oral carcinogenesis. Supported by NIH grant DE14283.

Assessment of Children's Oral Health-related Quality of Life
Hillary L. Broder, Maureen Wilson-Genderson, Rosa Chaviano-Moran - University of Medicine and Dentistry New Jersey, New Jersey

OBJECTIVE: To evaluate children's oral health-related quality of life among children seeking orthodontic and pediatric care as well as a community-based sample.

METHODS: Children were recruited from pediatric and orthodontic clinical settings in the US and Canada. A comparison group of children not seeking dental treatment was recruited from two US elementary schools. Participants included 157 pediatric, 152 orthodontic and 104 community-based participants. Each participant completed the recently validated Child Oral Health Impact Profile (COHIP) as per IRB approval. Comparisons of groups were completed by ANOVA.  RESULTS: The children averaged 11.6 years (s.d.=1.60); 51.6 % were female; and represented diverse ethnicities (black= 22.4%, Latino= 32.1%, white=35.1%, other 10.4%). Overall COHIP scores ranged from 28 to 135 (mean ± SD, 99.0 ± 19.2) for the children.  (Higher scores reflect higher quality of life). For Whites, Blacks, and Latinos respectively, COHIP scores for Functional Well-being were: 19.5, 17.0, 18.2;  Emotional Well-being were: 26.1, 22.9, 22.9; School Environment were: 14.3, 12.8, 13.0; and Overall OHRQoL were: 101.7, 93.9, 93.9.  CONCLUSION: The overall COHIP quality of life scores revealed lower OHRQoL among Latino and African American children compared to white children.

A Spanish Curriculum for Dental Personnel Developed: A Student Initiative
Benjamin Baptist*, Carla Delafuente, Gandy Garcia, Esther Lopez Mario Serrano, Dalila Valdez - University of Illinois at Chicago College of Dentistry, Illinois

OBJECTIVES:  To develop a standardized course and supplemental textual material that will facilitate basic Spanish proficiency for dental staff and students with emphasis on conversational proficiency, non-verbal communication, and cultural values.  METHODS:  Spanish is the first language of the fastest growing immigrant population in the U.S., yet there is a significant deficit in students, staff, and practicing dental professionals confident and proficient in this language.  Students and staff in U.S. dental schools often feel overburdened, and may be hesitant to pursue an ‘extra' initiative. Consistency of ‘out-of-class' practice is another challenge without additional resources.  Most published texts tend to have unnecessary material and an emphasis on "Spain-ish Spanish" colloquialisms.  To combat this growing deficit, a committee was formed from students and foreign trained dentists with varied backgrounds in language, culture, and clinical experience.  This committee was charged with compiling a list of subjects to be included in the course as well as to format this material into chapters following a logical progression. These were then homogenized and integrated into a single congruent text by a single author before they were redistributed and cross-edited by the rest of committee.  The course was taught by student and staff volunteers based on the developed curriculum and text.  RESULTS:  A supplemental text and a series of lectures was developed and administered.  The course has been positively received by students and faculty at our university, who have been able to integrate this material into their clinical practice.  We have also been able to establish course continuity that can be maintained after the students who developed the course leave, due to the formal curriculum and fabricated materials.   CONCLUSIONS:  We were able to successfully develop and administer an efficient course in clinically-relevant dental Spanish and nurture a growing interest in improved service to a critically underserved population.

Assessing the Hispanic Population Attendance of the Saturday Morning Clinic at the University of Kentucky
Michael Bauman, Matt Yazerski, Juan F. Yepes, DDS, MD, MPH - University of Kentucky College of Dentistry, Kentucky

The University of Kentucky College of Dentistry has had the wonderful opportunity to provide a free clinic for underprivileged children ages 12 and under of the Lexington/Fayette county area for over 25 years.  The clinic specifically targets those children who do not qualify for Medicaid and cannot afford private dental insurance.  A survey was conducted of the parents of the children attending the clinic in order identify the characteristics of the children we are treating.  OBJECTIVES: The Survey was designed to assess certain characteristics of the population attending the SMC.  One was the percentage of SMC patients that speak Spanish and would benefit from a translator at the clinic.  The main objective is to determine the main demographic characteristics of the SMC population and assess if there is a need to provide special considerations (such as translators) for the Hispanic community.  METHODS: A two page survey was given to parents of children attending the clinic during three clinic sessions held in the spring of 2007.  Each parent was asked to complete one survey per child attending the clinic.  RESULTS: There were 25 families that completed the Spanish survey and 18 that completed the survey in English.  Of the Hispanic families surveyed, 20 responded that the parents of the patients would benefit from a translator while only 3 responded that they would not need one.  The Hispanic families' incomes were all under $20,000/year except one while those filling out the English surveys varied from under $20,000 up to $40,000/year.

CONCLUSIONS: Over 50 percent of the surveys were completed in Spanish.  The Hispanic families reported having difficulty communicating.  There would be a strong benefit to providing translators at the SMC for each of the patients.