Iowa Section of the American Association for Dental Research

67th Annual Meeting

Moving Oral Health Research Forward Through Collaboration Our Keynote Speaker —

Dr. Mary L. Marazita is professor and vice chair of the Department of Oral Biology in the University of Pittsburgh School of Dental Medicine and the Director of the Center for Craniofacial and Den- tal Genetics. With over 400 publications and almost 35 years of continuous NIH-funding, Dr. Marazita is a world leader in the use of statistical genetics and genetic epidemiology for understanding craniofacial birth defects and oral-facial development.

In 1980, Dr. Marazita earned a Ph.D. in Genetics from the University of North Carolina, and in 1982, she completed post-doctoral training in craniofacial biology at the University of Southern California. Before coming to Pittsburg, Dr. Marazita had faculty appointments at UCLA and the Medical College of Virginia. She is also a diplo- mate of the American Board of Medical Genetics and a Founding Fellow of the American College of Medical Genetics.

At the University of Pittsburgh, Dr. Marazita has held numerous other appointments in the School of Dental Medicine, including assistant dean, associate dean for research, head of the Division of Mary L Marazita, Ph.D. Oral Biology, and chair of the Department of Oral Biology.

Given her international reputation and commitment to the oral sci- ences, Dr. Marazita has held important roles in the National Institutes of Health (NIH), including the National Institute of Dental and Craniofacial Research (NIDCR), and the National Human Genome Research Institute (NHGRI).

Dr. Marazita exemplifies the collaborative nature of scientific research, and embodies the theme of this conference. She has conducted research with colleagues across the United States and in more than 15 other countries, including working with and mentoring several here at the University of Iowa.

Keynote Address: The Long and Winding Road Leading to Today’s Pittsburgh Center for Craniofacial and Dental Genetics (CCDG)

This talk will provide a perspective on Dr. Marazita’s long and winding road from her B.S. in Animal Husbandry (i.e. Agriculture) to her current position as Director of the University of Pittsburgh Center for Craniofacial and Dental Genetics (CCDG). In large part her destination was due to mentorship and collaborations at key career points, as well as a fair amount of serendipity, and, notably, extensive influences from the University of Iowa. Learn about her many generous and influential mentors, plus her valued collaborations from individuals of diverse expertise (genetics and genomics of course, but also anthropology, computer science, nutrition, microbial ecology, virtually every clinical specialty in dentistry and medicine, and many more), and from every continent except Antarctica.

Dental research images for the cover were selected from poster presentations by University of Iowa students, faculty, and staff in 2019. Thanks for these images go to Daniah Alhazmi, Casey Goetz, Cameron Gray, Hyunok Jo, Jay Leer, Tarin Piangsuk, Natalia Restrepo-Kennedy, Moamen Sheba, and Erica Teixeira. Table of Contents Research at our College

Improving Dental Public Health in Early Childhood...... 2

Using Dental Public Health Research to Improve Access to Care in Iowa...... 3

Dr. Isabelle Denry: World-Renowned Researcher in Ceramics and Bioglasses for Dental Applications...... 4

Maximizing Bone Preservation...... 6

Research Day 2020

Letter from Dean David Johnsen...... 8

Letter from Interim Associate Dean for Research, Galen Schneider and Director of the Iowa Insitute for Oral Health Research, Kim Brogden...... 9

Letter from Officers of the Iowa Section of the AADR...... 10

Welcoming our Guests from the Chongqing Medical University School of Stomatology...... 11

Program...... 12

Presentation Assignments...... 13

Abstracts...... 22

Author/Abstract-Number Index...... 66

Iowa Section of AADR — Presidents...... 67

Acknowledgments...... 68

1 Improving Dental Public Health in Early Childhood

Pediatric dentistry is Dr. Karin Weber-Gasparoni’s profession, but it is also deeply personal for her.

“If we can keep a child caries-free in the first three years of life, it will increase the opportunity for this child to enjoy better oral health for their lifetime.”

As a young dentist and teacher in Brazil, Weber-Gasparoni’s academic interests focused on early childhood oral health and preventive care. Weber-Gasparoni’s daughter, Nathália, was born with Smith-Magenis syndrome, which is a developmental disorder that affects various parts of the body. For Nathália, it resulted in significant acid reflux and early childhood caries. As a low-income, single mother of a child with special health care needs, Weber- Gasparoni was taken aback by the lack of resources and support available for children with special Karin Weber-Gasparoni with her daughter, Nathália who is now 34 years old, in the Pediatric Dentistry clinic at the College of Dentistry. needs. This experience sparked her interest in pediatric dentistry and Dr. Michael Kanellis founded an Infant Oral and a passion for early preventive dental care, Health Program in collaboration with the lo- particularly for underprivileged children. cal Special Supplemental Food Program for Weber-Gasparoni’s research draws from this Women, Infants and Children (WIC) through the passion and is closely tied to her clinical work. Johnson County Department of Public Health designed to provide care to this group. In the Professionally, Weber-Gasparoni’s mentor in program, University of Iowa dental students, pe- Brazil used and promoted a model for pediatric diatric dentistry residents, and pediatric medi- dentistry that had been developed at Iowa— cine residents provide free dental screenings, namely that children should be seen by a den- preventive care, and education to low-income tist before they turn one-year old. The American children up to age three every Thursday. Academy of Pediatric Dentistry (AAPD) recommends that infants should visit a dentist as soon “Health professionals have an obligation to pro- as their first tooth erupts and no later than 12 vide low-income and underprivileged patients months of age. the same access to care as more affluent patients,” Weber-Gasparoni said. “Preventive care, particularly for infants, is one of the most cost-effective ways to improve oral Weber-Gasparoni’s research team has used this health,” Weber-Gasparoni said. program to study how it can improve oral health for children. Although the AAPD recommends Low-income children are an underserved group in dentistry. For this reason, Weber-Gasparoni Continued on page 63 — see 'Pediatric Dentistry' >>

2 Using Dental Public Health Research to Improve Access to Care in Iowa

Although Dr. Susan McKernan was awarded a “I knew I needed to go to Iowa,” McKernan $300,000, two-year grant from the National explained, “since it was the best dental public Institutes of Health in June, the seeds for the health program in the country.” award were planted and cultivated much earlier.

The seed: As a dental student at the University “We need to know which levers make it of Florida, McKernan had an extramural rota- more likely that a dentist will follow tion in southern Florida providing dental care to preventive recommendations seasonal farm workers without insurance. on the use of fluoride and sealants, and successfully implement those “There were 4-year olds that needed every single tooth extracted,” McKernan said. “And recommendations with buy-in every night, I went home and cried.” from the entire clinic"

The experience opened McKernan’s eyes to the great impact that preventive dental care can As a student, McKernan was an active partici- have. Fast-forward a few years as she was in pant in the college’s research training grant, private practice in well-to-do area of Tampa, and it helped her become the researcher she is and she realized that no matter how much she today—exposing her to high-quality research did in this practice, it would never have the im- projects and strategies, improving her critical pact that a rigorous preventive oral health care thinking skills, and teaching her to conduct her routine would have for those who lack access to own research projects. these services. The fruit: McKernan is now assistant professor The growth: That’s when McKernan decided it in Iowa’s Department of Preventive and Com- was time for her to address larger issues in ac- munity Dentistry and a researcher in the Health cess to care as she earned an M.S. and a Ph.D. Policy Research Program as part of the Public specializing in dental public health at the Uni- Policy Center at Iowa. versity of Iowa. Continued on page 63 — see 'Access to Care' >>

Collaborating with Jennifer Sukalski (PhD candidate, Oral Science) on a study about barriers to dental care for Iowa Dental Wellness Plan members

3 Dr. Isabelle Denry: World-Renowned Researcher in Ceramics and Bioglasses for Dental Applications

Dr. Isabelle Denry is an internationally-recog- So, what sets Denry apart from others? nized expert whose research focuses on developing, characterizing, and understanding As their careers develop, many scientists slowly the relationship between structure and clinical part from the research program of their men- performance of ceramics for use in dentistry. tor as they develop their own research profile through a series of incremental improvements At the 2019 International Association for Dental within that research general direction. Research (IADR) annual meeting in Vancouver, she received the Wilmer Souder Award—an Denry’s methodology, however, is more explor- IADR Distinguished Scientist Award—recogniz- atory and entrepreneurial. She’s always looking ing excellence in the field of Dental Materials. for new angles and possibilities, potential applications of novel materials, as well as innovative “Looking at the list of past award recipients, I experimental approaches. felt very honored to receive this award and to have my name added to this list of highly re- “I like to think outside the box and I am excited garded researchers,“ Denry stated. to try high risk/high reward experiments. Often

4 the results are inconclusive; but scientists need agents, but they all have significant drawbacks. to explore new possibilities—I was trained to be Some produce strong exothermic reactions that rigorous but audacious at the University of Paris cause serious burns, others are made from shell- and that’s really what science is about,” Denry fish and can cause allergic reactions, still others said. leave behind residue that can be harmful.

Ceramics are an important material used in Denry, however, invented an effective blood dental restorations. For dental restorations, clotting agent that has none of these draw- ceramics closely mimic the aesthetics of teeth backs. Although initially designed to stop oral in terms of shade and translucency. Ceramics bleeding, this discovery has been so revolution- are also chemically inert and biocompatible, and ary that several companies are interested in de- thus, they don’t have some of the drawbacks as- veloping it for triage and emergency situations, sociated with the use of metals. as a replacement for current blood clotting agents. Because of these possible applications, Unfortunately, ceramics are brittle, and can be the University of Iowa has applied for interna- less reliable. Denry has studied ways to predict tional and US patents on the technology. the performance of ceramics based on both their chemical and structural properties. The Since 2011, Iowa has been privileged to have information has been used to find materials that Denry’s unique scientific expertise. Already an have the optimum balance of strength and reli- excellent researcher and recognized leader in ability for dental restorations. the field when she arrived, the UI College of Dentistry’s former Associate Dean for Research, "I like to think outside the box and I am Dr. Clark Stanford, recruited Denry from The excited to try high risk/high reward Ohio State University. experiments " “Iowa had the technology and infrastructure that I needed to conduct my research, and I was excited for the opportunity,” Denry said. “It’s im- Although this line of research is important in its portant that we maintain and reinvest in our in- own right, her research also opened up a new frastructure so that we can continue conducting area of exploration: bone regeneration. Using innovative and important research,” she added. her prior research on the chemical and structural properties of ceramics, Denry began to As Denry continues conducting her own re- invent new kinds of ceramic scaffolds that can search, she also sees how important it is to pass promote bone growth. For these scaffolds, the along what she’s learned. And that’s why her relative amount of calcium and phosphate and exploratory approach to science is an essential their physical architecture determined how ef- part of her mentoring and teaching. fective the scaffold was. Whereas strength and reliability were important for dental restorations, “I want my students to be rigorous but also these ceramics needed to be resorbable so that come up with new ideas and try new things. I they could break down and be absorbed to train my students in the same way I was taught,” most effectively promote bone growth. she said. “Sometimes that isn’t easy for them, and it can be a cultural challenge; but in the But perhaps the best example of Denry’s ex- end, it’s worth it.” ploratory approach is when she discovered a self-assembled gallo-silicate microsphere material with some unique properties. Presently, there are a number of emergency blood clotting

Photo, top left: Dr. Denry processing castable ceramics in a high temperature furnace. Photos, bottom left: Scanning Electron Micrographs showing the microstructure of a variety of ceramics developed in Dr. Denry’s laboratory, from zirconias (left) to bioactive scaffolds (right). Photo, right: Dr. Rena D'Souza, president of the IADR, presents the Wilmer Sounder Award to Dr. Denry.

5 Maximizing Bone Preservation

For each month spent on the International which may make it difficult to replace a missing Space Station, an astronaut will lose approxi- tooth with a dental implant,” he added. mately one to two perce nt of bone mass. Since the skeleton is not being used to support the Avila-Ortiz has been researching how full weight of the body, the bones weaken, and different biomaterials can preserve the lose mass and density. When a bone is not being properly stimulated, it usually undergoes natural architecture of the bone after an disuse atrophy and subsequently shrinks. When extraction, minimize the detrimental a tooth is removed from its socket, this resorp- effects of tooth loss, shorten the healing tive phenomenon also occurs with the alveolar time between extraction and placing an bone—the bone that provides direct support to implant, and reduce the need for addi- the teeth. tional bone grafting to allow for implant Just as scientists have found ways for astro- placement. nauts to maintain and strengthen bones while living in space, Dr. Gustavo Avila-Ortiz is explor- In the late 1990s and early 2000s, clinicians ing new therapies to preserve the alveolar bone. began to explore various ways to preserve the It is common to lose a significant amount of alveolar bone. “Over the years different bone alveolar ridge volume in the first three to six substitutes, like bovine-derived xenograft or a months after a tooth extraction. “Without a human-derived allograft, typically applied in tooth there to stimulate the bone, the alveolar a particulate form, have been used to fill the ridge volume will decrease,” Avila-Ortiz ex- tooth socket after tooth extraction in an at- plained. “Bone loss can lead to an intense re- tempt to reduce alveolar bone resorption. It has modeling of the contour of the alveolar ridge, also been shown that sealing the socket orifice

Illustration showing alveolar bone contour changes that typically follow unassisted extraction socket healing (upper row) and alveolar ridge preservation via socket grafting after tooth extraction (lower row).

6 Comparison of the clinical and 3D bone radiographic outcomes following unassisted socket healing (Left - Control) and alveolar ridge preservation (Right - ARP) after 14 weeks of healing from the time of tooth extraction. These images were generated as part of a clinical trial that has been submitted for publication.

with a barrier material, such as a biocompatible One of the main goals of Avila-Ortiz’s research membrane, is important to protect the underly- in this area is to discover both new therapies ing bone during the healing process. This ap- and the influence that patient-specific factors proach, known as alveolar ridge preservation, is (i.e local and systemic) have on the outcomes a widely used therapy in contemporary practice. of treatment. “One size does not fit all. One of But it is not the only available option” Avila- our objectives is to deliver individualized care to Ortiz commented. each of our patients,” Avila-Ortiz explained.

Another alveolar ridge preservation treatment involves intentionally leaving part of the tooth in the socket to stimulate the bone. “Although it can work, this treatment is technically hard, it isn’t always possible, and it may increase the risk of infections and failure of implant integra- tion,” Avila-Ortiz said.

Although he admits that there is no single fix- it-all solution, Avila-Ortiz has been researching how different biomaterials can preserve the natural architecture of the bone after an extraction, minimize the detrimental effects of tooth loss, shorten the healing time between extraction and placing an implant, and reduce the need for additional bone grafting to allow for implant placement. Dr. Avila-Ortiz

7 Dear Colleagues:

Thank you for your participation in the 67th Anniversary of the University of Iowa College of Den- tistry’s Local Research Day on February 7, 2020. Research is central to our mission and is important in itself and for the culture of inquiry that it supports. This day is one of the highlights of our life as an academic community. The event’s planning committee and research presenters are to be heartily commended for their hard work.

We are honored to host Dr. Mary Marazita as our keynote speaker. Dr. Marazita is professor of oral biology at the University of Pittsburgh School of Dental Medicine and director of the Center for Craniofacial and Dental Genetics. As an outstanding researcher and leader in our profession, she is an expert in the field of craniofacial genetic development and orofacial clefts with hundreds of peer- reviewed publications and continuous NIH funding since 1985. She has held and continues to hold many prominent positions at her university and in the National Institute of Dental and Craniofacial Research and National Human Genome Research Institute, and she has worked directly with a number of our researchers. We are excited to continue building our relationship with Dr. Marazita.

Over the past several years, our college has been successful in recruiting bright and talented faculty. This includes faculty with significant interests in tissue engineering, ceramics, genetics, malocclu- sion, health policy, and translational and clinical research. This infusion of new ideas has brought new avenues of research and mentoring opportunities across the pre-doctoral, clinical post-doctoral, and graduate programs. It is an exciting time for the college’s future!

Local Research Day shows the people and the spirit of discovery that have always made possible outstanding education, service, research, and patient care within our college.

Local Research Day and this research abstract book offer many opportunities to learn about fasci- nating research within our College. Thank you for being a part of this important event.

Best wishes,

David C. Johnsen, DDS, MS Dean

8 Dental Research participants and Iowa Section of the American Association of Dental Research (AADR):

The University of Iowa College of Dentistry and Dental Clinics (CoD) and the Iowa Institute for Oral Health Research (IIOHR) are committed to advancing science in our laboratories and clinics. Science in the clinics and research laboratories is focused on several thematic areas for the improvement of oral health and patient care. Interdisciplinary collaboration between CoD scientists and other Uni- versity of Iowa researchers is essential to the training of future dentists and dental researchers.

The Iowa AADR symposium represents a commitment to recognize the current research programs that exist at the CoD and all of the great research that has been accomplished in the last year. Our students, post-doctoral associates, residents, faculty and staff have worked together in the discovery of new and novel scientific paradigms. Dental research covers all aspects of basic, clinical and evidenced-based research studies, often combining multiple disciplines.

In 2019, the CoD successfully recruited several new faculty members whose expertise covers craniofacial genetic and molecular biology and the oral microbiome and periodontal health. These new faculty advance the mission and priority research areas for the college. The goal is to provide the resources needed to continually improve research at the college and develop new partnerships and collaboration across the university research community. We are grateful for the continuation of the College’s NIH T90/R90 training program, which has been funded for over 30 years, and the support of our Biostatistics and Computational Biology faculty.

This year we are honored to have Dr. Mary Marazita, Ph.D., as our keynote speaker. Dr. Marazita is a global leader in genetics and dental research and has had a long and productive partnership with the CoD. Dr. Jeff Murray, Dr. Lina Moreno, and Dr. Azeez Butali have multiyear, on-going projects with Dr. Marazita that are focused on understanding nonsyndromic orofacial clefts. Dr. Marazita is also a co-mentor for Dr. Aline Petrin’s career-development K-award, “A Twin Approach for Genome- Wide Differential DNA Methylation in Orofacial Clefting.” The college greatly values the opportunity we have to continue this collaboration both during this conference and beyond.

Warmest Regards,

Galen B. Schneider, DDS, PhD Kim Brogden PhD Interim Associate Dean for Research Director, IIOHR

9 Dear Colleagues,

On behalf of the Iowa Section of the American Association for Dental Research (AADR), we are very pleased to welcome you to our 67th Annual Meeting—“Moving Oral Health Research Forward through Collaboration.” This event provides an open forum for presenting exciting research while strengthening and creating new opportunities for collaboration.

We are honored to have Dr. Mary Marazita as the keynote speaker. Dr. Marazita’s innovative research illustrates how to bring together diverse scientific areas from all over the world to improve human health and patient care. At the University of Pittsburgh, she was instrumental for the establishment of the Center for Craniofacial and Dental Genetics (CCDG), which serves as a home base for her research team and collaborators. Moreover, through the CCDG, she has established a multidisciplinary team that encompasses diverse fields such as statistical genetics, molecular genetics, cell and developmental biology, dentistry, medicine, microbiology, anthropology, morphometrics, psychology, and computational modeling.

Dr. Marazita’s research group has contributed to improvements in the standard of care for individuals with craniofacial and dental disorders, with publications of groundbreaking studies in genomics and phenotypes in non-syndromic orofacial cleft families from many ethnicities; genetic studies of oral and dental diseases; multidisciplinary studies of oral health disparities incorporating the meta- genome, host genome, behaviors and environment; and genetic studies of normal facial development. Dr. Marazita is now focusing on revealing molecular mechanisms related to genetic variants that cause oral and craniofacial traits in different populations. She also leverages multiple “omics” approaches and is expanding her human datasets to connect oral and craniofacial traits with other aspects of human health and disease.

We are excited to welcome Dr. Marazita and thank her for being our keynote speaker. We would also like to thank all of our sponsors who have generously contributed to the Iowa Section of AADR and are essential for the success of this event.

Sincerely,

Cristina Vidal, DDS, MS, PhD Brian J. Howe, DDS, MS, FICD President, Iowa Section of the AADR Vice-President, Iowa Section of the AADR Assistant Professor Assistant Professor Department of Operative Dentistry Department of Family Dentistry

Sara E. Miller Secretary/Treasurer, Iowa Section of the AADR Research Associate/Coordinator

10 The University of Iowa, College of Dentistry and Dental Clinics welcomes our visitors from Chongqing Medical University, School of Stomatology, Chongqing, China for the 2020 Annual Meeting of the Iowa Section of the AADR.

Milestones of Achievement Between Iowa and Chongqing • The University of Iowa College of Dentistry (UICOD) established a Memorandum of Agreement with Chongqing Medical University School of Stomatology (CMUSS) — To collaborate for the Advancement of Oral Health Research and Scholarship in Oral, Craniofacial and General Health—September 2016. • Faculty and colleagues from CMUSS presented their research at the 2018 and 2019 Annual Meetings of the Iowa Section of the AADR. This partnership helped strengthen our commitment to the exchange of ideas, research, teaching and training opportunities for all of our faculty and students—February 2018 and February 2019. • Faculty from the University of Iowa attended the 1st Sino-U.S.Summit Forum of Dental Hospitals for Faculty-to-Faculty Cooperative Exchange. This formal summit included presentations from UICOD and CMUSS faculty—May 2018. • Since 2018, the UICOD and CMUSS faculty have several joint research projects and collaborations including: 1. A joint research project on microRNA-based craniofacial bone regeneration, with Chongqing researchers performing animal experiments that demonstrated the enhanced mandibular bone regeneration using plasmid microRNA-incorporated in modified collagen plugs. Iowa researchers participating in the project came from the labs of Drs. Brad Amendt, Liu Hong and Hongli Sun. 2. Dr. Yi Shu, D.D.S., Ph.D., is a visiting scholar from Chongqing who is conducting research in Dr. Liu Hong’s lab. Dr. Shu is an assistant professor of endodontics at Chongqing Medical University. 3. Dr. Jin Xie is advising Dr. Tao Chen on clinical research infrastructure as Chongqing Medical University School of Somatology develops its clinical research center. We are pleased to welcome our Chongqing collaborators to the Annual Meeting of the Iowa Section of the AADR held on February 7, 2020. We are advancing our exchange of ideas, research and education, which strengthens oral health global initiatives here and abroad.

11 Program Iowa Section of the American Association for Dental Research (AADR) 67th Annual Meeting, Friday, February 7th, 2020

7:30 a.m. Reception with Coffee and Rolls (1st Floor)

8:00 a.m. Welcome Address (Galagan A/B/C) Dr. David Johnsen

Keynote Speaker Introduction Dr. Cristina Vidal

8:20 a.m. Keynote Address Dr. Mary L. Marazita "The Long and Winding Road Leading to Today’s Pittsburgh Center for Craniofacial and Dental Genetics (CCDG)"

9:20 a.m. Break

9:30 a.m. - 11:30 a.m. Oral Presentations Session One (Galagan A) Session Two (Galagan B) Session Three (Galagan C) Session Four (Oral-B Classroom N212) Session Five (Margeas Seminar Room W205)

11:45 a.m. – 12:45 p.m. Poster & Table Clinic Presentations (Iowa Institute for Oral Health Research, W220 A/B)

4:00 p.m. - 6:00 p.m. Awards Reception (Galagan B/C and First Floor Link)

12 Presentation Assignments Presenters are underlined. Oral Session 1 Mentors are italicized. 9:30 a.m. - 11:30 a.m., Galagan A

(b) Max Smith Oral Health Science Graduate Competition (q) Basic Science Post-Doctoral Award (v) International/Visiting Student or Faculty Basic Research Award ▼

1. b,q Tadkamol Krongbaramee, M. Zhu, M.E. Sweat, H. Cao, B. Cavalcanti, B.A. Amendt, F.B. Teixeira, L. Hong A Novel Therapeutic Approach Using miRNA-200c in Regenerative Endodontics

2. b,q Yan Y. Sweat, M.E. Sweat, W. Yu, Z. Sun, S. Eliason, B.A. Amendt Oral Adhesions, Missing Periderm and Rugae Disrupt Tooth and Palate Development in Sox2 Null Mice

3. b,q Mason E. Sweat, Y.Y. Sweat, W. Yu, S. Eliason, H. Cao, B.A. Amendt miR-200 Regulates Dental Epithelial Stem Cell Factors to Promote Differentiation

4. v Duanjing Chen LIPUS Enhances Osteogenic Differentiation Via miR-182/FOXO1 in hPDLCs

5. x Yoshiaki Nagumo, M.T. Remy, M.E. Sweat, S. Eliason, B.A. Amendt, L. Hong MicroRNA-200c Promotes Bone Regeneration of Synthetic Bone Grafts

6. x Steven Eliason, L. Hong, H. Cao, Y.Y. Sweat, C. Chalkley, Q. Liu, H. Qi, H. Xu, F. Zhan, B.A. Amendt Inhibition of Colorectal Tumor Formation Using a New miR-210 Therapeutic Inhibitor That Targets the Lnc RNA Xist and Nme1

7. v Guangyue Li The Effects of Angiotensin II on Mitochondrial Functions and Apoptosis-Related Signal Transduction Pathway in Mouse Osteoblasts

8. b,q Matthew T. Remy, Y. Nagumo, B.A. Amendt, L. Hong Bone Regeneration Induced by Gelatin-Coated 3D-Printed PCL Incorporated With miR-200c

13 Oral Session 2 9:30 a.m. - 11:30 a.m., Galagan B

(a) Max Smith Pre-Doctoral Competition (b) Max Smith Oral Health Science Graduate Competition (f) Endodontic Michel Fuller Post-Doctoral Award (h) Iowa Society for Periodontology Post-Doctoral Award (i) Operative Dentistry Post-Doctoral Award (p) Prosthodontics Post-Doctoral Award (x) International/Visiting Student or Faculty Clinical Research Award ▼

9. b,h Emilio Couso-Queiruga, U. Ahmad, H. Elgendy, G. Avila Ortiz Characterization of Extraction Sockets by Indirect Digital Root Analysis

10. b,f Elliott Glenn, F.B. Teixeira, A.E. Williamson, X. Xie Retrospective Evaluation of Apical Barriers With Cone Beam Computed Tomography

11. b,p Hyunok Jo, T. El Kerdani, D.V. Dawson, T. Lindquist Correlation Between Patient Satisfaction and the Location of Incisive Papilla as a Guide to Anterior Tooth Position on Maxillary Complete Denture

12. x E. Couso-Queiruga, Mustafa Tattan, U. Ahmad, G. Avila Ortiz Assessment of Soft Tissue Thickness Using STL-CBCT Superimposition Versus Convention- al Clinical Measurement Methods: A Cross-Sectional Study

13. x Qian Jiang The Oral Microbiome in the Elderly With Root and Coronal Caries

14. x Emma L. Thayer, J. Harless, K.A. Morio, K.A. Brogden UVC Light Emitting Diode (LED) Kills Microorganisms in an Instrumented Model of Root Canals

15. a Alexandria C. Cashmore, X. Chen, J. Madiloggovit, N.L. Denburg Development of a Cognitive Screening Assessment for Dental Practitioners

16. b,i Amal Aljeshi, J.L. Kolker, M.R. McQuistan, T.A. Marshall, S. Guzman-Armstrong, E. Zeng, C.L. Comnick, Y.M. Alyousef Saudi Physicians’ Knowledge About Diet in Relation to Dental Caries and Their Behaviors Toward Oral Health

14 Oral Session 3 9:30 a.m. - 11:30 a.m., Galagan C

(a) Max Smith Pre-Doctoral Competition (b) Max Smith Oral Health Science Graduate Competition (i) Operative Dentistry Post-Doctoral Award (v) International/Visiting Student or Faculty Basic Research Award (y) AADR Student Research Day Award ▼

17. x Sara E. Miller, T. Busch, K. Shin, L.M. Moreno Uribe, X. Xie, K.A. Brogden, B.A. Amendt, A. Butali Implementing Effective Iowa Biorepository Recruitment Strategies to Facilitate Personal- ized Medicine

18. x Amira Elgreatly, A. Mahrous Enhancing Student Learning in Dental Anatomy by Using Virtual Three-Dimensional Models

19. a,y Jacob N. Lensing, E.C. Teixeira Bond Strength and Leakage Patterns of Intraorifice Barrier Materials

20. x Chukwuebuka E. Ogwo, S.M. Levy, J.J. Warren, A.M. Curtis Modeling Dental Caries Trajectories Over a Life-Course Using Machine Learning Technique

21. a Katelyn Stine, C.L. Comnick, X. Xie, M. Carrilho, C. Vidal Comparison of MMPs Extraction Assays and Their Roles in Studying Caries Lesion Progres- sion

22. b,i Sundes A. Elfagih, L.R. Jaidev, C.L. Comnick, E.C. Teixeira, S.R. Armstrong, A. Guymon, X. Xie, A. Salem, C. Vidal Dentin Bond Strength of a Dental Adhesive System Containing Proanthocyanidin-Loaded Mesoporous Silica Nanoparticles

23. v Liang Chen Effect of PAMAM Dendrimer on the Dentin Matrix Metalloproteinases Activities

24. a,y Caroline LaRoy, B. Voy, F. Qian, A. Bedran-Russo, C. Vidal Hydroxyacids for Etching: Long-term Bonding Performance and Dentin Biodegradation

15 Oral Session 4 9:30 a.m. - 11:30 a.m., Oral-B Classroom N212

(a) Max Smith Pre-Doctoral Competition (b) Max Smith Oral Health Science Graduate Competition (h) Iowa Society for Periodontology Post-Doctoral Award (j) Oral and Maxillofacial Pathology Post-Doctoral Award (q) Basic Science Post-Doctoral Award ▼

25. x Sydney E. Arlis, L.A. Lansdon, H. Liu, G. Bonde, A. Polyak, K. Mohlke, S. Girirajan, B.W. Darbro, R.A. Cornell, D.W. Houston, J.C. Murray, J.R. Manak Copy Number Variation Analysis of Cleft Lip and Palate Cases Reveals Novel Craniofacial Patterning Genes

26. x K. Duncan, W.L. Adeyemo, W.O. Awotoye, T. Busch, S.E. Miller, C. Adeleke, A. Alade1 M. Li, M. Hassan, L.J.J. Gowans, M.A. Eshete, J.C. Murray, M.L. Marazita, R. Cornell, Azeez Butali Functional and Sequencing Studies Identify ZNF750 as CPO Candidate Gene

27. a Logan W. Sardzinski, C. Pendleton, T. Peter, X. Xie, J.T. Hecht, C. Padilla, F.A. Poletta, I.M. Orioli, C.J. Buxó-Martínez, F. Deleyiannis, A. Butali, C. Valencia-Ramirez, C.R. Mu—Eton, G.L. Wehby, S. Weinberg, M.L. Marazita, L.M. Moreno Uribe, B.J. Howe Phenotypic Spectrum of Enamel Defects in Nonsyndromic Orofacial Clefting

28. x Eric Van Otterloo, H. Li, T. Williams Identification of the Transcription Factor AP-2 (TFAP2) as a Functionally Relevant Key- stone of Craniofacial Ectodermal Enhancers

29. x Aline L. Petrin, X. Xie, E. Zeng, R. Cornell, R. Philibert, A. Butali, G.L. Wehby, V. Willour, R.T. Lie, M.L. Marazita, J.C. Murray, L.M. Moreno Uribe DNA Methylation Profiles of Monozygotic Twins Discordant for Orofacial Clefts

30. b,j Azeez Alade, C.J. Buxó-Martínez, W.L. Adeyemo, T. Naicker, W.O. Awotoye, C. Adeleke, T. Busch, M.Y. Li, J. Olotu, M. Mohamed, J. Pape, O. Adeniyan, O. Olatosi, S.E. Miller, L.J. Gowans, A. Butali Non-Random Mutations in IRF6 Are Associated With Van Der Woude Syndrome

31. x Michaela Schotanus, F. Smith, C. Carey, E. Van Otterloo Finding MEMO—Identifying an Oral Epithelial Specific Requirement for MEMO1 During Am- eloblast Development

32. b,h,q Waheed O. Awotoye, P. Ayanbadejo, K. Umeizudike, F. Ajayi, O. Olagundoye, A. Akinshipo, O. Ayodele, T. Busch, M.Y. Li, M.A. Musa, M. Hassan, C. Adeleke, O. Olatosi, J. Pape, A. Alade, S.E. Miller, O. Adeniyan, W.L. Adeyemo, A. Butali A Novel IGSF3 Variant Is Associated With Hereditary Gingival Fibromatosis

16 Oral Session 5 9:30 a.m. - 11:30 a.m., Margeas Seminar Room W205

(a) Max Smith Pre-Doctoral Competition (b) Max Smith Oral Health Science Graduate Competition (h) Iowa Society for Periodontology Post-Doctoral Award (p) Prosthodontics Post-Doctoral Award (q) Basic Science Post-Doctoral Award (v) International/Visiting Student or Faculty Basic Research Award ▼

33. v Yao He Proliferation of Condylar Chondrocytes in Physiology or After Partial Cells Death Induced

34. v Yi Shu, M. Zhu, E. Van Otterloo, L. Hong Memo1, a Novel Therapeutic Target for Craniosynostosis

35. x Fan Shao, M.E. Sweat, Y. Guo, A. Phan, B.A. Amendt, H. Cao The Mechanism of Branched Incisors Formation in Dicer-Deficient Mice

36. q Yuwei Guo, M.E. Sweat, F. Shao, Y.Y. Sweat, S. Eliason, B.A. Amendt, H. Cao Profiling Gene Expression in the Epithelial and Mesenchymal Compartments of Developing Rodent Incisor

37. b,p,q Kan Wongkamhaeng, J.A. Banas, D.V. Dawson, J.A. Holloway, A.J. Haes, I. Denry Antimicrobial Efficacy of Platinum-doped Silver Nanoparticles Against P. aeruginosa

38. v Yangyingfan Feng, L. Chen Entanglement-Driven Adhesion, Self-Healing, and High Stretchability of Double-Network PEG-Based Hydrogels

39. b,h Andrew Shelby, G.K. Johnson, X. Xie, E.L. Thayer, C. Pendleton, K.A. Brogden PD-L1 Correlates With the Presence of Chemokines and Cytokines in Gingival Crevicular Fluid From Healthy and Diseased Sites in Smoking and Non-Smoking Subjects With Peri- odontitis

40. a Emily E. Starman, M.P. Gomez Hernandez, A.B. Davis, E. Zeng, S.M. Lieberman, K.A. Brogden, E.A. Lanzel Biomarker Profiles in the Saliva of Children With Sjögren Syndrome Suggest Inflammation Trending Towards a Strong Lymphocyte-Mediated Immune Response

17 Posters 11:45 a.m. - 12:45 p.m., Iowa Institute for Oral Health Research, W220 A/B

(c) Procter & Gamble Competition (d) ADA Posters and Table Clinics Pre-Doctoral Competition (e) ADA Posters and Table Clinics Post-Doctoral Competition (g) Iowa Society for Periodontology Pre-Doctoral Award (i) Operative Dentistry Post-Doctoral Award (j) Oral and Maxillofacial Pathology Post-Doctoral Competition (m) Orthodontics Post-Doctoral Award (o) Preventive & Community Dentistry Post-Doctoral Award (q) Basic Science Post-Doctoral Award (u) James S. Wefel Pediatric Pre-Doctoral Award (y) AADR Student Research Day Award ▼

41. e,i Wafaa Kattan, E.C. Teixeira, O. Urquhart, S. Guzman-Armstrong, J.L. Kolker, M.R. McQuistan, T. Peter, C.L. Comnick Acceptance and Factors Influencing Dental Restoration Repairs Among US Dentists

42. x Garrett P. Schultz, C. Cucco, A.E. Williamson, C.L. Comnick, X. Xie Rubber Dam Usage in Clinical Dentistry

43. d,c,y Allison M. Schollmeyer, T. Peter, X. Xie, S. Anamali, A. Jain Survival Analysis of Crown Margin Repair, A Retrospective Study

44. d,c Bradyn Ellis, K. Stine, C.L. Comnick, X. Xie, C. Vidal Comparison of Dentin Endogenous Proteolytic Activity After Protein Extraction With Dif- ferent Assays

45. e,i Alshimaa Alghamdi, S.R. Armstrong, C. Vidal, E.C. Teixeira, F. Qian, R.R. Maia Effect of Dental Composite Marginal Repair Techniques on Enamel Bonding

46. d,c,u,y Andrew J Carlson, M.C. Skotowski, F. Qian Caries Risk Factors Associated With Early Childhood Caries

47. x Ryan. M. Hemsley, M. Zhu, J.A. Banas Inhibitory Properties of Non-Mutans Low pH Streptococci in the Caries Disease Process

48. d,c Daniel H. Soh, C.L. Comnick, C. Vidal, R.R. Maia, K. Shin, C.A. Barwacz Incorporation of Fluorophore Molecule for Enhanced Visualization of Dental Adhesive Resin

49. x Steven M. Levy, A.M. Curtis, J.J. Warren, J.E. Cavanaugh, J.L. Kolker, K. Weber-Gasparoni Changes in Mean Fluorosis Scores from Age 9 to 23

50. x Abigail M. Wieland, J.A. Banas Examining Dental Plaque Isolates of Streptococcus for Potential Probiotic Activity

51. x Kelsey R. Wenger, C. Pendleton, X. Xie, D.J. Caplan, D.R. Drake, L. Marchini Predictors for the Counts of Selected Oral Pathogens in an Institutionalized Elderly Popula- tion

18 52. x Connor A. Dang, C.L. Comnick, M. Tabrizi, L. Kaufman, A. Soto, B. Smith, A. Ribeiro, T. Tobey, O.R. Capin, D. Prince, X. Xie, L. Marchini Willingness to Use Silver Diamine Fluoride Among US Dental Students

53. c,u Erika Takanami, M. Zhu, J.A. Banas Speciation and Properties of Potential Probiotic Strains of Oral Streptococci

54. x Kyle Barry, C. Cucco, A.E. Williamson, X. Xie, C.L. Comnick Antibiotic Usage in Endodontics: A Survey of Fourth-Year Dental Students

55. d,c Sheng H. Lu, K. Leary, M.R. McQuistan, F. Qian Impact of a Poverty Simulation on Dental Students’ Attitudes Towards Low-Income Populations

56. x Charlie A. Rupp, P.C. Damiano Investigating Critical Access Hospital’s Role in Rural Iowa Dental Care

57. x McKenna J. Woodward, J. Reynolds, M. Kelly Iowa Dental Hygienists under Public Health Supervision: Employment and Dentist Referral Patterns

58. d,c Trevor W. Craig, D. Johnsen, J. Hartshorn, H. Cowen, A. Sato, L. Thompson, C. Pendleton, X. Xie, L. Marchini Teaching Rapid Oral Health Deterioration Risk Assessment: A 5-year Report

59. d,c Erin D. Kallsen, F. Qian, T.A. Marshall, M.K. Geneser, K. Leary, K. Weber-Gasparoni Do Modifiable Oral Hygiene and Dietary Habits Differ by Birth Order?

60. d,c Zachary W. Prouty, J.C. Reynolds Motivations for Rural Practice: A Qualitative Study of Iowa Dentists

61. x Tanner T. Brolsma, K. Leary, K. Flick, F. Qian Patient Failure Rates and Characteristics of Patients at the University of Iowa Pediatric Den- tal Clinics in Muscatine, Iowa

62. d,c David J. Strabala, J.C. Reynolds, S.C. McKernan, P.C. Damiano Member Awareness of Iowa Medicaid Healthy Behavior Requirements

63. x Luke T. Veenstra, P. Barlow, A.E. Kossioni, S. Mihaela Popescu, V. Mercut, M. Jana Tuculina, M. Scrieciu, A. Stanusi, L. Marchini Preliminary Validation of an Ageism Scale for Dental Students in Romania

64. d,c Bobby L. LeWarne, D.J. Caplan, L. Marchini, S. Sasser, C. Russell Transportation Dependency and Oral Pain Among Community-Dwelling Older Iowans

65. x Madison M. Kasparek, T.A. Marshall Use of Social Media by Dental Students and Recent Alumni

66. e Susana J. Calderon, J.A. Banas, D.R. Drake, X. Xie, C.L. Comnick A Social Media Intervention for Improving Dental Health in Adolescents

19 67. e,o Aparna Ingleshwar, J.C. Reynolds, S.C. McKernan, P.C. Damiano Structural and Cognitive Barriers to Completion of a Healthy Dental Behavior in Iowa’s Medicaid Program

68. d,c,y Kane M. Louscher, H. Chen, K. Shin, K. Kluesner, C. Pendleton, X. Xie TMD and General Health Symptoms in Adolescent Orthodontic Patients

69. e,m Samantha Marti, C. West, F. Qian, S. Rengasamy Venugopalan, S. Marshall, T.E. Southard, K. Shin Comparison Between TAD-Supported RME vs. Conventional RME for Palatal Expansion

70. d,c,y Nicole E. Youd, V. Allareddy, A. Figueroa, K. Shin A Pilot Study on Post-Surgical Change in Condylar Position

71. d,c,y Benjamin Phan, T. Ling, T. Peter, P. Fan, K. Shin Performance of Machine Learning Algorithms on Premolar Extraction Pattern

72. d,c Jasmine A. Butler, F. Qian, A. Lesch, M. O’Malley, K. Leary Evaluating Reasons for Failed General Anesthesia and Procedural Sedation Visits

73. x Robert Staley, F. Qian Effect of Different Forces on Inclination When Torqueing Upper Incisors

74. x Bethany Doolittle, L. Rhea, M. Dunnwald Arhgap29 in Oral Epithelial Cells Is Required for Palate Shelf Elevation

75. e,q Dan Su, F. Shao, S. Eliason, H. Cao, B.A. Amendt Identification and Characterization of Wolf-Hirschhorn Syndrome Candidate 1 (Whsc1) in miR-23-Cluster-Mediated Tooth Development

76. d,c,y Chinyere Adeleke, T. Naicker, T. Busch, W.O. Awotoye, M.Y. Li, J. Olotu, M. Hassan, J. Pape, A. Alade, O. Adeniyan, O. Olatosi, S.E. Miller, A. Butali GRHL3 Variants are Associated with South African Cleft Palate Only

77. d,c Grant L. Gullion, M.S. Campos Possible interaction between VEGF, fl-catenin and Cardiac Hormones on Oral Squamous Cell Carcinoma

78. c,g,y Flora Y. Yen, L. Sun, M. Girnary, Y. Jiao, S. Zhang IL-10 Protects Periodontal Bone Loss through Reducing Neutrophil Recruitment

79. e,j,q Wattawan Wongpattaraworakul, R. Anand, K.N. Gibson-Corley, G. Ofori-Amanfo, A. Simons Potential Prognostic Role of Combined EGFR and T cell markers in Oral Squamous Cell Carcinoma

80. q F. Shao, M. Li, M.E. Sweat, Q. Qian, Y. Guo, An-Vi D. Phan, B.A. Amendt, L. Yang, H. Cao A Novel Endoplasmic Reticula Micropeptide BGRM1 Promotes Insulin Secretion in Pancreas

81. x Dongrim Seol, I. Song, J. Marks, A. Tiwari, S. Chinnathambi, E. Sander, J. Martin, K. Shin Anti-Fibrotic Effects of Sulfasalazine and Blebbistatin on Synovial Myofibroblasts

20 82. q Mary Y. Li, J. Olotu, T. Busch, T. Naicker, C. Adeleke, V. Bravo, M. Musa, M. Hassan, S. Huang, W.O. Awotoye, J. Pape, A. Alade, S.E. Miller, A. Butali Variant Analyses of Catenin Alpha-2, Sonic Hedgehog, Activin A Receptor Type I, and Growth Differentiation Factor 11 genes in Orofacial Clefts in African and Puerto Rican Populations

83. e,m,q Ino Song, D. Seol, E. Kim, T. Lim, J. Martin, K. Shin Therapeutic Effects of MSC-Exosomes on Fibroblasts and Synoviocytes in TMJ

84. e,q Timothy M. Acri, N.Z. Laird, L.R. Jaidev, A.K. Salem, K. Shin Non-Viral Gene Delivery Using Biomimetically-Mineralized Matrices for Bone Tissue Engi- neering

85. x Jue Hu, J. Miszuk, H. Sun Nanoclay-Mediated Osteoinductive Factors Sustained Release for Bone Tissue Engineering

86. x Kyle J. Mercer, S. Zhang ACT1-Mediated IL-17 Signaling in a Ligature-induced Alveolar Bone Loss Model

87. x Jacob Miszuk, J. Hu, H. Sun Press-Fit 3D Electrospun Porous Nanofibrous Scaffolds for Bone Tissue Engineering

88. x Hongwei Dai Effects of Human Urine-Derived Stem Cells on the Cementogenic Differentiation of Indi- rectly-Cocultured Periodontal Ligament Stem Cells

21 Abstracts 2. Oral Adhesions, Missing Periderm and Rugae Disrupt Tooth and Palate Develop- ment in Sox2 Null Mice 1. A Novel Therapeutic Approach Using miRNA-200c in Regenerative Endodontics Yan Y. Sweat1, M.E. Sweat1, W. Yu1, Z. Sun1, S. Eliason1, B.A. Amendt1 1, M. Zhu1, Tadkamol Krongbaramee 1 M.E. Sweat1, H. Cao1, B. Cavalcanti1, University of Iowa, Iowa City, IA 1 1 1 B.A. Amendt , F.B. Teixeira , L. Hong Objective: In humans, ankyloglossia 1University of Iowa, Iowa City, IA and cleft palate are common congenital craniofacial anomalies, regulated by a MicroRNAs (miRs) play important post- complex gene regulatory network. The transcriptional regulators in inflammation periderm is a transient structure that prevents abnormal and regeneration, and have emerged as innovative tools oral adhesions during development. Understanding the for the diagnosis of diseases and treatment. miR-200c, genetic underpinnings of ankyloglossia and cleft palate a member of the miR-200 family, has previously been will aid in understanding the etiology of these genetic demonstrated to potently regulate tooth development, anomalies. modulate inflammation, and promote osteogenesis, Methods: We inactivated the Sry (Sex determining and could also be a candidate to assist in regenerative region Y)-box 2 (Sox2) gene in the developing oral endodontics procedures. epithelium, which resulted in ankyloglossia and cleft Objective: To characterize miR-200c in pulpitis and palate with 100% penetrance in embryos examined after determine its potential in attenuating inflammation E14.5. and promoting odontogenesis in dental pulp stem cells Results: In the conditional Sox2 null embryos, the oral (DPSCs). epithelium failed to differentiate as demonstrated by the Methods: We quantitated the level of miR-200c and lack of keratin 6, a marker for the periderm structure. proinflammatory cytokines (IL-6 and IL-8) in human Further examination revealed that an epithelial adhesion dental pulp tissues diagnosed with irreversible pulpitis of the tongue and mandible expressed the oral epithelial and compared them to healthy pulps. In addition, markers E-Cad and P63 in an expanded layer of the we used PEI nanoparticles to transfect plasmid oral epithelium. The expanded oral epithelia are Sox9, DNA encoding miR-200c into human DPSCs and Pitx2 and Tbx1 positive cells, and we show for the first measured the transcript and protein level of IL-6 time that the dental epithelium contributes to the and IL-8 in the cells after they were exposed to P. development of oral adhesions. Furthermore, we have gingivalis lipopolysaccharide (PG-LPS). Finally, we found that Sox2 is required for palatal shelf extension, evaluated the proliferation (MTT assay) and the level and for the formation of palatal rugae, which are of odontogenic differentiation markers (RUNX2, OCN, signaling centers that regulate palatogenesis. DMP1, DSPP and DSP by qPCR, Western blotting Conclusion: Loss-of-function of Sox2 in oral epithelium and Immunofluorescence staining) in the miR-200c disrupts palatal shelf extension, palatal rugae formation, overexpressed DPSCs. tooth development and more importantly periderm Results: We observed the downregulation of miR-200c formation. The periderm is required to inhibit oral (50.08±25.259-fold) in human pulpitis tissues, while IL-6 adhesions and ankyloglossia, which we show for the and IL-8 were significantly upregulated (3.066±0.77, first time is regulated by Sox2. 4.062±1.763 Log10-fold, respectively) (n=6). PEI Supported by: NIH R43DE027569, NIH R01DE026433, nanoparticles efficiently transfected plasmid miR-200c NIH R03EB025873, NIH R21DE025328 in human DPSCs and the overexpression of miR-200c downregulated the level of IL-6 and IL-8 under PG-LPS challenge. In addition, the overexpression of miR- 200c significantly increased the level of odontogenic differentiation markers in the human DPSCs, including the transcripts of RUNX2 (2.6±0.39-fold), OCN (4.0±1.48-fold), DMP1 (22±7.023-fold), DSPP (6.55±2.94- fold). Conclusion: Our findings revealed that plasmid DNA encoding miR-200c using non-viral transfection may potentially be used as therapeutic approaches for vital pulp therapy and endodontic regeneration by attenuating inflammation and promoting odontogenic differentiation. Supported by: NIDCR R01 DE026433, Endodontic department, Thailand government scholarship

22 3. miR-200 Regulates Dental Epithelial 4. LIPUS Enhances Osteogenic Differentia- Stem Cell Factors to Promote Differentiation tion Via miR-182/FOXO1 in hPDLCs

Mason E. Sweat1, Y.Y. Swe at 1, W. Yu1, Duanjing Chen101 1 1 1 S. Eliason , H. Cao , B.A. Amendt 101Chongqing Medical University, 1University of Iowa, Iowa City, IA Chongqing, China

Objective: MicroRNAs (miRs) have been Objective: Low intensity pulsed implicated in dental development by ultrasound (LIPUS) promotes bone studies that have deleted them from oral fracture healing in clinical therapy. epithelial tissue in early development. Transcription factor Forkhead box However, the specific miR families that are involved with O1 (FOXO1) is crucial for bone differentiation. But odontogenesis have yet to be determined, and their whether FOXO1 is involved in LIPUS-promoted bone functions remain largely uninvestigated. Previously, differentiation is largely unknown. we have profiled miR expression in developing teeth Methods: Human periodontal ligament cells (hPDLCs) and found that the miR-200 family is upregulated in were isolated to and treated with LIPUS. Cell viability differentiated dental tissues compared with immature and apoptosis were detected by CCK-8 assay and progenitor and stem cells, suggesting that the family flow cytometry. Osteogenic differentiation of hPDLCs functions to promote epithelial differentiation. was assessed by Alkaline phosphatase (ALP) and Objectives: To determine the function and mechanisms Alizarin red S staining. qPCR and western blot were by which the miR-200 family regulates tooth used to analyze the expression of miR-182, FOXO1 and development. runt-related transcription factor 2 (Runx2), and the phosphorylation of Akt. The binding of miR-182 with Methods: We have developed a Plasmid based miR mRNA of FOXO1 was presented by the luciferase assay. Inhibitor System (PMIS) that allows for the inhibition of specific miR functional groups, which are targeted by Results: LIPUS promoted total and nucleus FOXO1 seed sequence homology. We constructed mouse lines protein accumulation in hPDLCs. LIPUS-induced expressing the PMIS-miR-200a and PMIS-miR-200c activation of FOXO1 further lead to higher ALP and constructs. By crossing these lines, we obtain embryos Runx2 expression and matrix mineralization. LIPUS with inhibition of the complete miR-200 family which inhibited miR-182 expression, which function as a can be used to examine odontogenesis. repressor of FOXO1 through post-transcriptional regulation. Overexpression of miR-182 reversed the Results: PMIS-miR-200a/c double inhibitor embryos LIPUS-enhanced FOXO1 expression and osteogenic have reduced levels of miR-200a and miR-200b, and differentiation. Moreover, LIPUS enhanced Akt are embryonic lethal past E16.5. Odontoblasts and phosphorylation, which function in preventing active ameloblasts, which begin to differentiate at E16.5, are FOXO1 excessive accumulation via inducing the not present in double inhibitor lower incisors and have cytoplasm translocation of nucleus FOXO1. reduced expression of lineage-specific markers in single inhibitor embryos. We found that the dental epithelial Conclusion: Our study revealed that FOXO1, which was tissue was maintained in a proliferative state when the a target gene of miR-182, played an essential role in miR-200 family was inhibited, and the proliferative LIPUS-promoted osteogenic differentiation. This new cells expressed transcription factors that are normally molecular insight throws light upon the application of compartmentalized in the epithelial stem cell niche, LIPUS therapy on periodontal bone defect. including Sox2 and Tbx1. The poorly differentiated lower incisors of the double inhibitor embryos and PMIS-miR-200c embryos were shorter than WT lower incisors, due to the activation of a Cleaved Caspase independent cell death program resulting from high levels of autophagy. Conclusion: Overall, we demonstrate a role for the miR- 200 family in promoting the maturation of the dental epithelium, which is essential for the production of mineralized enamel at later stages of development. Supported by: NIH R43DE027569, NIH R01DE026433, NIH R03EB025873, NIH R21DE025328, 2T90DE023520-06; T90 training grant

23 5. MicroRNA-200c Promotes Bone 6. Inhibition of Colorectal Tumor Formation Regeneration of Synthetic Bone Grafts Using a New miR-210 Therapeutic Inhibitor That Targets the Lnc RNA Xist and Nme1 Yoshiaki Nagumo1, M.T. Remy1, M.E. Sweat1, S. Eliason1, B.A. Amendt1, Steven Eliason1, L. Hong1, H. Cao1, L. Hong1 Y.Y. Swe at 1, C. Chalkley1, Q. Liu1, H. Qi1, 1 1 1 1University of Iowa, Iowa City, IA H. Xu , F. Zhan , B.A. Amendt 1University of Iowa, Iowa City, IA Objective: We previously reported that plasmid DNA encoding miR-200c Objective: In several recent reports, it enhances osteogenic differentiation of human bone has been shown that many genes are marrow mesenchymal stem cells (hBMSCs) and involved in both tooth agenesis and the progression promote bone regeneration. The goal of this study is to of colorectal cancer (CRC). In clinical studies, miR-210 investigate the enhancement efficacy of miR-200c in has been shown to correlate with poor CRC outcomes. bone regeneration by combining synthetic bone grafts In this report we investigate the role of microRNA-210 composited by octacalcium phosphate and collagen (miR-210) in the etiology of CRC using both cell-based (OCP/Col). and xenograft mouse models. Methods: The OCP/Col discs loaded with pDNA Methods: In vitro cell based assays including encoding miR-200c (1 and 10 µg) or empty vector (EV transfection, qPCR, ChIP and confocal microscopy. In 10 µg) were implanted into 9 mm in diameter calvarial vivo assays including Xenograft tumor implant, live defect sites in Sprague Dawley rats. The new bone bioluminescence imaging, tissue fixation and processing formation was assessed after 6 weeks using micro-CT and IHC/IHF. and histology. In addition, we conducted an in vitro assay to test the osteogenic differentiation of hBMSCs Results: We show that miR-210 expression is higher after seeded into OCP/Col discs loaded miR-200c at in SW620 (colon cancer cell line) versus normal different concentrations. colon epithelium, consistent with its association with decreased cancer survival rates. Stable expression of Results: In the rat calvarial defect model, the micro-CT our new miR-210 inhibitor changes the morphology, and histology analysis revealed that miR-200c-loaded proliferation and gene expression in both SW620 OCP/Col had stronger osteogenic capability compared cells and tumors. RNA-seq identified potential targets to controls. Additionally, miR-200c expression was of miR-210 and qPCR has verified several of these significantly increased in hBMSCs seeded in miR-200c/ targets. We find that inhibition of miR-210 can act as a OCP/Col. The mRNA of RUNX-2, ALP and OCN were tumor suppressor and reduce colon tumor formation also up-regulated in the hBMSCs. in xenograft mouse models. Direct comparison with Conclusion: pDNA encoding miR-200c effectively Capecitabine treatments demonstrates the improved promoted osteogenic differentiation and bone effectiveness of the miR-210 inhibitor treatment. The formation of OCP/Col, indicating that it may potentially direct administration of the miR-210 inhibitor (PMIS- be used in clinical application to improve current miR-210) to existing tumors can inhibit tumor growth technologies for bone healing and regeneration. in both NSG and Foxnu/j mouse models. The inhibition of miR-210 can cause alterations in hypoxia responses Supported by: NIH 1R01DE026433. and upregulation of several tumor suppressor genes, including Nme1. We demonstrate that the long non- coding (LNC) transcript XIST is regulated by miR-210 and XIST expression is decreased in colon tumors. We show that increased XIST expression correlates with the expression of the tumor suppressor gene Nme1. Furthermore, the inhibition of miR-210 and the OE of XIST effects epigenetic marks of the NME1 loci, with increases in H3K4me3 and H3K27ac chromatin marks near the transcription start site (TSS). Lastly, we show that the PMIS-miR-210 inhibitor is present in exosomes and can be transferred to donor cells in vitro. Conclusion: We show that our new miR-210 inhibitor can be used as an effective colorectal cancer therapeutic treatment. Supported by: NIH NIDCR; University of Iowa College of Dentistry and Carver College of Medicine

24 7. The Effects of Angiotensin II on Mito- 8. Bone Regeneration Induced by Gelatin- chondrial Functions and Apoptosis-Related Coated 3D-Printed PCL Incorporated Signal Transduction Pathway in Mouse With miR-200c Osteoblasts Matthew T. Remy1, Y. Nagumo1, Guangyue Li101 B.A. Amendt1, L. Hong1 101Chongqing Medical University, 1University of Iowa, Iowa City, IA Chongqing, China 3D-printed, tissue-engineered bone Objective: As the essential effector grafts provide an alternative option in the rennin-angiotensin system, to overcome the limitations of natural Angiotensin II (AngII) plays a vital grafts. As synthetic substitutes degrade, role in the pathogenesis of primary they release entrapped molecules that stimulate bone hypertension. Recent studies suggest the relation formation. The sustained release of osteo-inductive between hypertension and bone metabolism disorders. agents, such as miR-200c, from these constructs may Given the critical role of osteoblast in bone formation, prolong the regenerative capacity of synthetic grafts we detected the effects of AngII on cell proliferation, and enhance bone formation toward the treatment of osteogenic differentiation, apoptosis, and mitochondrial large bone defects. functions in mouse osteoblasts. Objective: The aim of our study is to develop a Methods: We cultured primary osteoblasts from mouse 3D-printable scaffold capable of sustaining the release calvaria, and treated with different concentrations of of miR-200c in order to create a therapeutic and AngII (10-8M, 10-7M, 10-6M). The effects of AngII on cell clinically-translatable synthetic bone graft to restore proliferation, osteogenic differentiation were detected large bone defects. -6 in vitro. We also assessed the impacts of 10 M AngII Methods: Poly(caprolactone) (PCL) scaffolds were on generations of reactive oxygen species (ROS), fabricated using fused deposition modeling (FDM). The enzymatic activities of mitochondrial respiratory chain, scaffolds were coated with different concentrations mitochondrial membrane potentials and ATP content of gelatin and varying dosages of empty vector (EV) in osteoblasts. The molecular mechanism of AngII- or miR-200c, and then freeze-dried. For the in vitro induced apoptosis in osteoblast was elucidated as study, scaffolds were seeded with human bone marrow well by assaying the activations of Mitogen-Activated mesenchymal stem cells (hBMSCs) and cultured for up Protein Kinase (MAPK) and apoptosis-related cell signal to 7 days. We evaluated scaffold/coating topography transduction pathways. via SEM imaging. Osteogenic differentiation markers Results: Osteoblast proliferation and osteogenic were quantified using qRT-PCR. For the in vivo study, differentiation were inhibited upon the treatment of PCL-Gel-miR scaffolds were implanted into critical- Ang II .10-6M AngII treatment could induce great amount sized calvarial defects in rats for 6-weeks and bone of ROS generations, decreased enzymatic activities of regeneration was assessed using micro-CT imaging complexes, lowered mitochondrial membrane potentials (µCT). and impaired ATP synthesis within osteoblasts. Results: Scaffolds coated with low concentration Apoptosis could be induced upon activation of SAPK/ gelatin demonstrated thinner coatings compared to JNK and via mitochondria-related apoptosis pathway, scaffolds with high concentration gelatin. Osteogenic indicated by decreased levels of Bcl-2 and increased differentiation markers were up-regulated for scaffolds translocation of Bax from cytosol into mitochondria coated with miR-200c in comparison to control and caspase-3 activities, with augmented release of samples. µCT images showed PCL-Gel-miR implants cytochrome C from mitochondria into cytosol. The with more bone formation than other treatments. above changes could be at least partially inhibited by the pretreatment of SAPK/JNK inhibitor SP600125. Conclusion: PCL scaffolds coated withmiR-200c incorporated gelatin increased the transfection Conclusion: The present study suggests negative efficiency of miR-200c, which lead to increased -6 effects of 10 M AngII on cell proliferation, osteogenic osteogenic differentiation and bone formation. differentiation and mitochondrial functions. Also Sustained release of miR-200c from gelatin coatings cell apoptosis could be induced via SAPK/JNK and allowed for the prolonged regenerative signaling mitochondria-related apoptotic pathway. The study of miR-200c, which effectively enhanced bone could pave the way for further delineating the potential regeneration in critical-sized bone defects. mechanisms about the relations between primary hypertension and bone resorption. Supported by: NIH NIDCR T90DEO23520; NIH NIDCR 1R01DE026433-01A1

25 9. Characterization of Extraction Sockets 10. Retrospective Evaluation of Apical Barri- by Indirect Digital Root Analysis ers With Cone Beam Computed Tomography

Emilio Couso-Queiruga1, U. Ahmad1, Elliott Glenn1, F.B. Teixeira1, H. Elgendy8, G. Avila Ortiz1 A.E. Williamson1, X. Xie1 1University of Iowa, Iowa City, IA; 1University of Iowa, Iowa City, IA 8East Carolina University, Greenville, NC Objective: Apical barriers are commonly Objective: Alveolar ridge preservation used in endodontic treatment for cases of (ARP) via socket grafting and sealing is a necrotic teeth with open apices either due commonly indicated interceptive therapy to stage of development or resorption. aimed at attenuating the resorptive events that typically Current research indicates that the procedure has high affect the alveolar bone after tooth extraction with success rates, but the studies lack the use of cone- the goal of facilitating tooth replacement using dental beam computed tomography (CBCT) in the evaluation implants. Determining the volume of bone grafting of healing of apical periodontitis. Our objective was material and the approximate dimensions of the sealing to evaluate two-year post-treatment healing of apical element required to perform ARP is critical to maximize barrier cases completed in the Endodontic Clinic at the efficiency and suitability of this surgical intervention. the University of Iowa College of Dentistry using CBCT To the best of our knowledge, there is limited evidence interpretation. The goal was to produce an accurate regarding the association between root morphology long-term prognosis as well as identify variables that and its potential use in the planning of ARP procedures. affect prognoses such as the material used, 1 or 2 visit Furthermore, the objective of this study is to determine root canal therapy, presence of definitive restoration, the amount of bone grafting material and approximate tooth type, and age of the patient. dimensions of the barrier membrane employed in Methods: Patients who had received an apical barrier ARP therapy based on root morphology and the as a part of endodontic treatment more than two years corresponding socket orifice dimensions. ago at the University of Iowa were recalled. At the Methods: Four hundred and twenty extracted recall appointment, clinical signs of apical periodontitis permanent teeth were screened. Third molars and were evaluated, and limited view CBCT was made and teeth with anatomical abnormalities, extensive caries or interpreted. Each tooth was assigned a score based on undetectable cemento-enamel junctions were excluded. the Cone Beam Computed Tomography Periapical Index Teeth were decontaminated and any residual tissue Score. The results were statistically analyzed. was removed. An expert in dental anatomy grouped Results: Images were collected and interpreted and the teeth, which were digitally scanned to obtain STL statistically analyzed. files. Each tooth was analyzed using an image analysis software. After digitally sectioning each root at 2mm Conclusion: There were no statistically significant apical to the CEJ, root volume was measured in mm3 results between the different groups. and converted into cc. Subsequently, a section plane Supported by: American Association of Endodontics was drawn at the level of the CEJ and the surface Foundation area in mm2, as well as bucco-lingual and mesio-distal linear measurements in mm of the socket orifice, were obtained. Results: A total of 15 complete sets of maxillary and mandibular adult teeth, from second molar to second molar, were analyzed. Maxillary first molars had the largest mean root volume (0.451 cc ± 0.096 cc) followed by mandibular second molars (0.400 cc ± 0.094 cc). Surface area analysis demonstrated that mandibular first molars exhibited the largest socket orifice area (78.56 mm2 ± 10.44 mm2) followed by maxillary first molars (77.71 mm2 ± 8.303 mm2). Maxillary molars showed the greatest mean socket orifice distances in the bucco- lingual dimension (First: 11.08 mm ± 0.6006 mm; Second:11.08 mm ± 0.5965 mm), whereas mandibular molars showed the greatest mean mesio-distal socket orifice distances (First: 9.731 mm ± 0.846 mm; Second: 9.399 mm ± 0.6925 mm). Conclusion: Data obtained from this study could be used to efficiently plan ARP procedures and provides information that can be utilized to enhance and design new biomaterials for extraction site management purposes.

26 11. Correlation Between Patient Satisfac- 12. Assessment of Soft Tissue Thickness tion and the Location of Incisive Papilla as a Using STL-CBCT Superimposition Versus Guide to Anterior Tooth Position on Maxillary Conventional Clinical Measurement Methods: Complete Denture A Cross-Sectional Study

Hyunok Jo1, T. El Kerdani1, E. Couso-Queiruga1, Mustafa Tattan1, D.V. Dawson1, T. Lindquist1 U. Ahmad1, G. Avila Ortiz1 1University of Iowa, Iowa City, IA 1University of Iowa, Iowa City, IA

Introduction: Clinical evaluation of Objective: Sufficient evidence portrays maxillary complete denture is subjective that the conventional dichotomic for both patient and clinician. There periodontal phenotype classification, of are several factors affecting patient’ thick flat and thin scalloped, is no longer satisfaction with maxillary complete denture such as adequate in describing the compounded, dynamic maxillary central incisor (MCI) position, the mold or nature of periodontal tissues. Consequently, there contours, shade, lip support, and phonation. Clinicians remains a lack of consensus regarding a universal use a guideline to locate the preliminary position of approach to classifying periodontal phenotype within MCI. In most cases, clinicians use generalized horizontal the context of clinically relevant implication. The values of 8-10mm which is the average distance from aim of this study was to evaluate the accuracy and the labial incisal surface of the MCI to the center of reproducibility of quantifying gingival thickness using the incisive papilla (IP). This guideline is based on the the superimposition of an STL file (representing the biometric analysis of the IP in the dentate population or overlying soft tissue) onto a cone beam computed measurements from immediate complete dentures. tomography (CBCT) acquired DICOM file (representing the underlying hard tissue) compared with two direct, Objective: The purpose of this study was to evaluate an average distance between center of IP to the MCI of clinical modalities, namely using an endodontic file as a complete dentures for edentulous patients by using the transgingival probe or a spring caliper. “Alma gauge” (Denture gauge) when patient-perceived Methods: A total of thirty patients presenting subjective analysis could be highly achieved before with clinical indications for an anterior maxillary or processing a dental prosthesis and examine associations mandibular single tooth extraction were included. with patient characteristics and satisfaction ratings. These were equally divided into two groups, according to the method of clinical supracrestal soft tissue/ Methods: Each subject completed satisfaction questionnaires used visual analogue scales (VAS) to mucosal thickness measurement. In the first group rate satisfaction rate with the wax denture regarding lip (SC), the mucosal thickness at the mid-facial (FMT) support, phonation, and esthetics. Following completion and mid-lingual (LMT) gingiva was measured using a of the satisfaction questionnaires, the researcher spring caliper, while in the second group (EF) the same examined each patient’s mouth intraorally and measurements were performed using an endodontic file. evaluated PDI classification of the maxillary arch. Then, Subsequently, for all patients, intra-oral and CBCT scans the center of incisive papilla was defined in the patient’s were obtained and superimposed for corresponding mouth and marked with indelible marker. A maxillary digital measurements of mucosal thickness. The inter- wax denture was placed in the patient’s mouth and the rater reliability of digital measurements, as well as center of IP was recorded on the intaglio surface of wax agreement between the digital and two modalities of denture. Horizontal and vertical distances between the clinical measurements were assessed using inter-class center of IP and the MCI of wax denture was measured correlation coefficients (ICC). by using the Alma gauge. Results: Overall, excellent inter-rater reliability agreement was demonstrated for all study parameters. Results: The current study suggests that the previous studied horizontal value of 8-10mm for dentate The comparison between the endodontic file and the population may not provide an effective guideline to digital superimposition method of soft tissue thickness edentulous population especially for those with the measurement demonstrated excellent agreement highest PDI classification (IV) on complete edentulism. and a clinically significant outcome, with ICCs of 0.85 (FMT) to 0.87 (LMT) and mean differences of 0.05 and Conclusion: The clinical evaluation of complete denture 0.25mm for FMT and LMT, respectively. Meanwhile, on lip support, esthetics, and phonation is extremely the comparison between the spring caliper and the subjective, especially by patients. Therefore, it is digital superimposition method of soft tissue thickness imperative for clinicians to understand the differences measurement demonstrated poor agreement, with ICCs between dentate and edentulous populations before of 0.16 (FMT) to 0.22 (LMT) and mean differences of adapting previously studied general guideline of -0.66 and -0.65mm for FMT and LMT, respectively. denture tooth set-up. Conclusion: Digital measurements of soft tissue thickness demonstrate an accurate and reliable method of assessment compared with direct measurements performed with an endodontic file.

27 13. The Oral Microbiome in the Elderly With 14. UVC Light Emitting Diode (LED) Kills Root and Coronal Caries Microorganisms in an Instrumented Model of Root Canals Qian Jiang101 1 1 101Chongqing Medical University, Emma L. Thayer , J. Harless , Chongqing, China R.H. Sternowski152, K.A. Morio153, K.A. Brogden1 With the aging of the Objective: 1 population, dental caries in the elderly has University of Iowa, Iowa City, IA; 153 received increasing attention. This study Softronics, Ltd., Marion, IA; 154 aims to gain thorough knowledge of the Apex Endodontics, Hiawatha, IA bacterial and fungal community structures of the elderly Objective: Successful treatment of infected or with root and coronal caries. inflamed endodontic tissues require chemo-mechanical Methods: Subjects were recruited after a debridement of the canal spaces. Unfortunately, comprehensive oral examination. Samples were infections can reoccur. In this study, we assessed the collected from dental plaque and carious lesion of killing capabilities of UVC light-emitting diode (LED) coronal and root caries patients and healthy controls. on a variety of microorganisms that are associated with The bacterial 16S rDNA and fungal ITS DNA were canal infections. respectively amplified using PCR and sequenced by Methods: We developed an instrumented model of Illumina MiSeq high-throughput sequencing. root canals and assessed the effects of 3 prototype Results: 1. The bacterial community: The compositions units emitting 265 nm and 280 nm LED on killing of were largely consistent in different groups, but different Candida albicans, Enterococcus faecalis, Staphylococcus relative abundances could be observed. The Venn aureus, methicillin-resistant S. aureus (MRSA #7), and diagram showed 306 unique species in root carious Streptococcus sanguinis at 0, 30, 60, and 90 second lesion, while 247 species shared among groups. Alpha exposure times. Results were compared to the same diversity showed decreased diversity in root caries. microorganisms placed on cellulose discs and treated Beta diversity showed gradually diffuse trend in caries similarly. Differences were assessed with a one-way process and a quite different distribution in root carious fixed-effect ANOVA model and Tukey’s Honestly lesion. The potential caries-related bacteria were Significant Difference (HSD) at the 0.05 level. identified by LEfSe analysis. The positive interactions Results: The two 265 nm LED prototypes significantly among predominant genera were revealed by network killed C. albicans, E. faecalis, S. aureus, and S. sanguinis analysis. The functional prediction indicated vigorous at 30, 60, and 90 second exposure times. The 280 nm microbial metabolism. LED prototype significantly killed S. sanguinis and E. 2. The fungal community: Fungi were detected in faecalis at 30, 60, and 90 second exposure times, but some of the samples, most of which were collected did not kill C. albicans and S. aureus until 60, and 90 from root caries patients. Candida albicans was the seconds exposure time. predominant fungus. Beta diversity showed clear Conclusion: The 265 nm and 280 nm LED prototype distinction between coronal and root caries. The Venn units effectively killed microorganisms and our results diagram demonstrated many unique fungal species in suggest a brief exposure of UVC LED may serve as an root carious lesion. The network analysis revealed even adjunct to current root canal procedures. more complex relationships among fungi, and negative interaction could be found between Candida and Supported by: Office of Research and Economic Plectosphaerellaceae. Development Conclusion: The oral microbiome in the elderly with caries in different sites or status showed different microbial community structures and diversity.

28 15. Development of a Cognitive Screening 16. Saudi Physicians’ Knowledge About Assessment for Dental Practitioners Diet in Relation to Dental Caries and Their Behaviors Toward Oral Health Alexandria C. Cashmore1, X. Chen1, J. Madiloggovit1, N.L. Denburg1 Amal Aljeshi1, J.L. Kolker1, 8 1 1University of Iowa, Iowa City, IA M.R. McQuistan , T.A. Marshall , S. Guzman-Armstrong1, E. Zeng1, Objective: 5.5 million American adults C.L. Comnick1, Y.M. Alyousef144 over the age of 64 suffer a cognitive 1 impairment (CI). These individuals University of Iowa, Iowa City, IA; 8 present dental clinicians with unique East Carolina University, Greenville, 144 challenges in regard to recognizing the presence of a CI NC; Immam Abdulrahman Bin Faisal and then administering quality, patient-centered care. University , Dammam, Saudi Arabia Cognitive assessment tools utilized in other areas of Objective: The aim of this study was to evaluate healthcare are not typically utilized by dentists due to physicians’ knowledge and practices regarding diet in their perceived lack of applicability to the profession. relation to dental caries in children 0-5 years of age. To address these issues our study aimed to develop a cognitive screening tool for use in dental offices. Methods: The study was a cross-sectional convenience sample study that targeted physicians who practiced in A cognitive screening tool with 16 candidate Methods: Saudi Arabia and who treated 0-5-year-old children. The items was first developed and then presented to 4 survey consisted of three parts. The first part queried dentists for a usability test and 5 geriatric experts demographic data and physicians’ practice patterns. (two geriatricians, one occupational therapist and two The second part investigated physicians’ sources of neuropsychologists) for a content validity test. The information about oral health and evaluated physicians’ tool was revised based on the results of the content knowledge about diet in relation to dental caries. The validity study and the usability test and subsequently third part evaluated physicians’ behaviors regarding oral pilot tested in seven English speaking participants aged health (including educating the patients’ parents about 65 and older together with the Montreal Cognitive oral health and referring their patients to a dentist). The Assessment (MoCA), Mini-Cognition Test (Mini-Cog), survey was distributed to the targeted physicians using the Dental Activities Test (DAT) and a survey for social media, specifically the WhatsApp application. demographics. Descriptive and correlative analysis were completed to describe the correlation between the new Results: The total number of respondents was 97. The instrument and the existing cognitive assessments. majority were female (74%) vs males (26%), Saudi (95%) vs non-Saudi (5%), and early medical graduates (median All of the participants of the usability and Results: 7 years practicing) with most graduating between content validity study felt that the instructions were 2011 and 2019. Most of the respondents were general clearly written and easy to be understood by geriatric practitioners (36%), followed by pediatricians (25%), patients. The proposed cognitive assessment had family medicine physicians (23%), and other specialties good content validity and is likely to identify persons (15%). The majority of the respondents practiced in the with cognitive impairment. While all dentists felt eastern province (67%) and in urban settings (88%). the proposed assessment is somewhat relevant to 72% practiced in the Ministry of Health and 90% their practice, half of them reported that they are worked in a setting in which there was a dental clinic unlikely to use it in their practice. The pilot test with in the practice. Some of the most commonly cited 7 elderly participants with a mean age of 76.5 years sources of information about dental health included old showed that the proposed cognitive assessment medical school, practice experience, communication was significantly correlated with the existing cognitive with dentists and physicians, and social media (> 50% screening tools (MoCA and Mini-Cog). While Item responded “Yes” to each of these sources). With respect 7a is least sensitive, item 3 was the most sensitive in to physicians’ knowledge, they tended to believe most identifying persons with cognitive impairment. strongly that processed foods high in sugar and sugar in Conclusion: Candidate items had good content validity, general, as well as taking formula milk to bed increased yet the usability needs to be improved. The candidate the risk of cavities. However, they were most unsure items correlated well with the existing cognitive about the relationship of cheese and xylitol to dental assessment tools. Candidate item 3 was the most caries. Fourty-eight percent of physicians believe that sensitive, and candidate item 7a was the least sensitive children should start going to the dentist at 1 year of in identifying persons with cognitive impairment. age. The majority of physicians(63%) would refer a Supported by: The University of Iowa College of child to a dentist based on dental emergencies, and Dentistry Dental Student Research Program 59% would refer if the child had cavities. When asked why they may not refer a child to the dentists, about 1/3 of the physicians agreed that children not having cavities (34%), not being sure if a referral is necessary (32%), or not knowing the appropriate dentist to refer to (28%), all impacted their decision to not refer. In term of counseling the patients’ parents, 37% did not counsel

29 about diet in relation to dental caries. No reasons were 18. Enhancing Student Learning in Dental strongly cited for not counseling about diet and the Anatomy by Using Virtual Three-Dimensional association with caries. Models

Amira Elgreatly1, A. Mahrous1 17. Implementing Effective Iowa Bioreposi- 1University of Iowa, Iowa City, IA tory Recruitment Strategies to Facilitate Personalized Medicine Objective: In order to provide restorations and dental prostheses that Sara E. Miller1, T. Busch1, K. Shin1, are esthetic, functional and in harmony L.M. Moreno Uribe1, X. Xie1, with a patient’s occlusion, practitioners K.A. Brogden1, B.A. Amendt1, A. Butali1 must have a thorough knowledge of dental anatomy. For this reason, the responsibility for 1University of Iowa, Iowa City, IA teaching dental anatomy usually falls upon restorative faculty. It has been shown that virtual three-dimensional Objective: To support the Precision Medicine Initiative (PMI), the University of models greatly enhance student learning and spatial Iowa College of Dentistry created a Dental Biorepository visualization. The aim of this presentation will be to 1) to collect medical and dental information from patients demonstrate how virtual three-dimensional models can in addition to biospecimens (e.g., saliva for DNA, RNA, be used to enhance the learning of dental anatomy; and microbiome, and teeth, bone, tissue). Like in most 2) demonstrate using videos and web-based portals research studies, one of the challenges is research how the virtual three-dimensional models were created subject recruitment, especially among moderate-to- from natural tooth scans and then used for educational severe dental cases from highly diverse dental clinics. purposes. Therefore, this work’s aim is to share our effective Conclusion: Creating virtual three-dimensional recruitment strategies for the facilitation of PMI at Iowa models of natural teeth provides a cost-effective, and beyond. low maintenance and accessible approach to dental anatomy education. This technique also preserves a Methods: We implemented a variety of clinic-specific recruitment strategies in June 2019. These include: (i) record of natural tooth anatomy that might provide an educating patients, families, and dental professionals avenue for future research. Having virtual files that can that all College of Dentistry patients/ blood-related be easily shared between collaborators might prove family members are eligible to participate, (ii) designing useful in the study of dental anomalies and morphology. visually-appealing recruitment materials written at 9th This technique can also used to generate virtual three- grade reading level, (iii) focusing on consenting and dimensional models in other fields to enhance student collecting samples during clinic sessions and delaying education and visualization. data entry until after clinic, (iv) using the clinic database system to efficiently identify cases who have an upcoming appointment and mail them a personalized 19. Bond Strength and Leakage Patterns of invitation letter weeks in advance of the upcoming Intraorifice Barrier Materials appointment, and (v) discussing the informed consent document over the phone to reduce the in-person visit Jacob N. Lensing1, E.C. Teixeira1 time to 10 minutes. 1University of Iowa, Iowa City, IA Results: From June 2019 through October 2019, there has been a 233% increase in the number of Objective: To evaluate (1) the bond biospecimens collected, most of which are from strength of a calcium silicate-based moderate-to-severe cases. From June 2016 through substitute (Biodentine), a glass ionomer mid-December of 2019, 1,956 individual subjects have cement (Fuji Triage Pink), and a flowable consented and donated 2,184 biological specimens. We resin composite (Permaflo Purple) via have extracted DNA from 90% of these samples, and push-out test; (2) the effect of different dentin slice they are available for future genetics and genomics thickness and (3) leakage at the material/tooth interface work. using micro-CT. Conclusion: By considering the specific dental clinic Methods: Single rooted teeth were selected and soaked when designing and implementing effective and in 5.25% NaOCl for 10min. Two slices (1mm +/- .1mm efficient recruitment strategies, it will expeditiously and 2mm +/-.1mm) were sectioned from the cervical progress the field of personalized medicine where third of each tooth. Three vertical holes were drilled data on medical, dental and genetics/genomics will be parallel to the canal into each slice using a .8 mm considered to improve diagnosis, prognosis, treatment carbide bur. Slices were placed in 2.5% NaOCl solution and ultimately prevention. (15min) and soaked (1min) in distilled water (DIW) to neutralize the NaOCl solution. Slices were immersed in Supported by: Roy J. Carver Charitable Trust, #16-4806 17% EDTA (3min), DIW, 2.5% NaOCl, followed by a final flush with DIW for 1min each. After drying, intraorifice materials were applied in each artificial canal, according

30 to manufacturer’s instructions. Specimens were stored analyzed using the machine learning algorithm known in 100% humidity at 37°C in artificial saliva. Push-out as the K-means for Longitudinal Data (KmL) which is test (n=12) was performed using a universal testing a k-means based R package specifically designed for machine and a .7mm diameter plunger at a cross-head analyzing longitudinal data. The algorithm determined speed of 0.5mm/min. Leakage was evaluated after the trajectory group membership by assessing the specimens (n=5) were immersed in silver nitrate/water distances of the individual trajectories from the solution (50% w/w) for 24 hours and then scanned centroid. The algorithm runs through these sets of using a micro-CT (Xradia 520 Versa). Each specimen criteria (Calinsky & Harabatz, Ray & Turi and Davies & was rotated 360 degrees and the highest percentage of Bouldin) to determine the “best” partitions that explain infiltration at the interface was accounted for using the the dataset. The base code and assumptions used ruler function. One-way ANOVA statistical analysis was were — Kml (Ebtraj, nbClusters = 3:6, nbRedrawing =5, performed followed by Tukey’s test. Two sample T-tests toPlot=”both”). were performed to evaluate the difference between slice Results: Based on the algorithm, four trajectory groups thickness (a=0.05). were identified as the optimal number of trajectories Results: Flowable composite (Permaflo Purple) showed using the Calinsky & Harabatz partition criterion. The the highest bond strength in both the 1mm and the trajectory group A (low caries) contained 53.8% of 2mm slice thickness groups, 20.31 MPa and 32.86 MPa, all individual trajectories with the mean DFS of 0.16, respectively. Both values were significantly higher than 0.34, 1.04, 1.53 at ages 9, 13, 17 and 23 respectively. The the calcium silica-based substitute (Biodentine) bond trajectory group B (medium caries) had 26.7% with the strengths, 13.96 MPa and 17.19 MPa. Glass ionomer mean DFS of 0.98, 1.96, 5.94, 9.34 at ages 9, 13, 17 and cement (Fuji Triage) was not significantly different from 23 respectively. The trajectory group C (high caries) Biodentine or Permaflo Purple in the 1mm group, but contained 14.1% with the mean DFS of 1.46, 4.26, 11.97, was significantly higher than Biodentine in the 2mm 21.95 at ages 9, 13, 17 and 23 respectively. The trajectory group with 15.09 MPa and 27.77 MPa, respectively. Fuji group D (very high caries) contained 5.3% of all Triage and Permaflo Purple also showed significantly individual trajectories with the mean DFS of 1.33, 14.50, higher 2mm bond strengths than 1mm. Permaflo Purple 30.00, 54.00 at ages 9, 13, 17 and 23 respectively. showed significantly less leakage than calcium silica- Conclusion: The machine learning technique provided based substitute and Fuji Triage. a robust and flexible mechanism for trajectory analysis. Conclusion: At baseline flowable composite with the There was an increase in the trajectory slopes after age adhesive system showed better properties than other 13 which might be due to changes in risk factors. The tested materials. Flowable composite and glass-ionomer next step in this study will be to identify those factors had the highest bond strength, regardless of the slice that predict trajectory group membership by modeling thickness. However, slice thickness is an important their relationship using supervised machine learning factor when designing push-out bond strength studies. techniques. Supported by: The University of Iowa College of Supported by: NIH NIDCR, Delta Dental of Iowa Dentistry Dental Student Research Program Foundation; Roy J. Carver Charitable Trust

20. Modeling Dental Caries Trajectories 21. Comparison of MMPs Extraction Assays Over a Life-Course Using Machine Learning and Their Roles in Studying Caries Lesion Technique Progression

Chukwuebuka E. Ogwo1, S.M. Levy1, Katelyn Stine1, C.L. Comnick1, X. Xie1, J.J. Warren1, A.M. Curtis1 M. Carrilho116, C. Vidal1 1University of Iowa, Iowa City, IA 1University of Iowa, Iowa City, IA; 116Midwestern University, College of Dental Objective: Unsupervised learning is a Medicine, Downers Grove, Illinois machine learning technique that uses algorithms to define hidden patterns Objective: The primary aim of this or structures and draw inferences from study was to analyze and compare three unspecified or unlabeled data. It is a novel analytical published and one newly developed in vitro protocols tool for longitudinal population-based studies in for MMPs extraction from dentin. The secondary aim dentistry. Our objective is to describe the changes in was to investigate their proteolytic profiles in the dental caries trajectories from childhood to adulthood progression of carious lesions. using machine learning algorithms. Methods: Dentin powder obtained from human healthy Methods: This is a longitudinal study of caries (non-cavitated) (H), initial caries (contained within trajectories over a life course using data from the Iowa enamel) (I) and deep carious (cavitated, in dentin) Fluoride Study. A total of 1,382 newborns were recruited (C) molars underwent protein extraction using three at birth and dental exams were conducted at ages 5, 9, different published protocols [G-EDTA, EDTA and PA] 13, 17 and 23. These analyses focused on the permanent and a newly develop protocol [Hybrid]. These protocols dentition at ages 9, 13, 17 and 23. The data were included demineralization and extraction via the

31 primary extraction agent of either EDTA, guanidine-HCl, intact human molars kept frozen for less than 3 months phosphoric acid, or a combination of those materials. were used to test resin-dentin shear bond strength Experiments were run in triplicate. The amount of total (SBS). Each tooth was sectioned into two halves under protein was evaluated via a bicinchoninic acid (BCA) copious water irrigation. After mounting teeth sections assay. The MMP gelatinolytic activity was analyzed via in acrylic resin, teeth surfaces were polished with zymography and densitometry (ImageJ). A multiplex 600-grit silicon carbide paper for 30s. Dentin surfaces assay was utilized to determine the presence of specific were acid-etched for 15s, washed for 15s then dried MMPs (1, 2, 3, 7, 8, 9, 10, 12, and 13). Statistically, the lightly with an absorbent paper to keep the dentin assays were compared using a coefficient of variation wet. Specimens were randomly divided according (CV), which provides a standardized measure of the to the experimental primer formulations used: Exp variability of each protocol to compare results among (experimental primer, neat formulation), Exp+MSN healthy, initial and deep carious samples. Qualitative (experimental primer containing unloaded MSN), analysis was performed to compare the amounts of Exp+MSN-APTES (experimental primer containing different MMPs among extracts and dentin tissue unloaded MSN functionalized with 3 Amino Propyl Tri condition. Ethoxy Silane), Exp+MSN-APTES-PACs (experimental primer containing MSN-APTES loaded with PACs Results: Three of the four protocols (G-EDTA, PA and Hybrid) showed to be effective for extraction of active after functionalization) and Exp+MSN-PACs-APTES gelatinases. The gelatinolytic activity of health dentin (experimental primer containing MSN-APTES loaded was shown to be different from carious dentin, with with PACs before functionalization). A control group higher activity for some of the extracts in those carious was bonded with a commercial primer (Scotchbond samples. Multiplex assay results exhibited a shift in MMP Multi Purpose, 3M). All groups received the bonding resin from SBMP, applied following manufacturer’s profile between H and C samples, with the greatest recommendations, and light cured for 10s (Paradigm changes specifically seen in MMP-2 and MMP-8 for some DeepCure, 3M). Teeth were restored with resin of the protein extracts. composite (Filtek Supreme Ultra) applied incrementally Conclusion: Profile of extracted MMPs is linked to tissue and light cured. SBS testing was performed until failure demineralization and varies according to the method of and results were expressed in megapascal (MPa). protein removal. As dentin progresses from healthy to Statistical analysis consisted of one-way ANOVA and carious, there is a shift in enzymatic profile and activity. Tukey pairwise t-tests (a=0.05). This finding supports the role of specific MMPs in caries ANOVA test showed a significant difference dentin degradation. Results: among groups (p < 0.001). The control group had Supported by: The University of Iowa College of the strongest bond strength (42.02 MPa), with no Dentistry Dental Student Research Program; American statistically significant difference than Exp+MSN-APTES Dental Education Association (32.01 MPa, p=0.094). No significant difference was observed among groups Exp (30.87 MPa), Exp+MSN (21.10 MPa), Exp+MSN-APTES, and Exp+MSN-PACs- 22. Dentin Bond Strength of a Dental Adhe- APTES (20.88 MPa) (p>0.05). The lowest bond strength sive System Containing Proanthocyanidin- was observed for Exp+MSN-APTES-PACs (17.52 MPa) with no statistically significant difference when Loaded Mesoporous Silica Nanoparticles compared to Exp+MSN-PACs-APTES. Sundes A. Elfagih1, L.R. Jaidev1, Conclusion: The addition of functionalized MSN C.L. Comnick1, E.C. Teixeira1, to the experimental primer formulations did not S.R. Armstrong1, A. Guymon1, X. Xie1, compromise the bond strength to dentin and showed A. Salem1, C. Vidal1 similar performance when compared to a commercial adhesive formulation. Although similar bond strength 1University of Iowa, Iowa City, IA numbers were observed regardless of when drug loading was performed, loading MSN with PACs Objective: A promising strategy to before functionalization resulted in similar bonding improve the longevity of adhesive restorations is dentin performance when compared to neat primer and primer biomodification, which uses natural compounds such as containing MSN and MSN-APTES. proanthocyanidins (PACs) to increase the biostability of collagen at the hybrid layer and improve dentin Supported by: Colgate Care Award mechanical properties. PACs-loaded mesoporous silica nanoparticles (MSN) is used to simplify dentin biomodification in the bonding protocol and promote sustainable delivery of PACs at the hybrid layer. This study assessed the immediate bonding performance of an experimental adhesive system containing PACs- loaded MSN. Methods: An experimental primer containing 15% of PACs-loaded MSN was prepared and used for bonding in a 3-step etch-and-rinse adhesive strategy. Extracted

32 23. Effect of PAMAM Dendrimer on the Den- 24. Hydroxyacids for Etching: Long-term tin Matrix Metalloproteinases Activities Bonding Performance and Dentin Biodegra- dation Liang Chen101 1 1 1 101Chongqing Medical University, Caroline LaRoy , B. Voy , F. Qian , Chongqing, China A. Bedran-Russo44, C. Vidal1 1University of Iowa, Iowa City, IA; Objective: The purpose of this 44University of Illinois, Chicago, study was to investigate the effect Chicago, IL of PAMAM dendrimer on the matrix metalloproteinases in dentin. Objective: To test the long-term bonding Methods: MMP Activity Assay Kit was used to performance and dentin biostability of detect the activity of purified recombinant human hydroxyacids used for enamel and dentin etching as MMP-2 (rhMMP-2) and dentin endogenous matrix alternatives to the aggressive phosphoric acid etchant. metalloproteinases treated with 10mg/ml PAMAMA Methods: Flattened surfaces of intact human extracted dendrimer, 100mg/ml PAMAM dendrimer and 2% CHX, molars were etched with 35% phosphoric acid (PA), respectively. Sound human third molars were collected glycolic acid (GLY), tartaric acid (TA), gluconic acid and prepared to dentine beams, and then loss of (GLU), or gluconolactone (GLN) for 15-seconds in dentin dry mass after 30 days was measured. At last, in situ (n=8) or 30-seconds in enamel (n=10). A three-step zymography analysis was performed to detect the total-etch adhesive system was applied and teeth were activity of endogenous MMPs and gelatinase in dentin. restored with resin composite. Dentin bond strength One-way ANOVA was used to analyze the overall (TBS) was assessed using the microtensile test after difference within each group and Tukey’s test was used 24-hour or 1-year of storage. Resin-enamel shear for the comparison between every two groups. bond strength (SBS) was obtained after 24-hours. Results: The activity of purified rhMMP-2 treated Failure pattern was classified as adhesive, cohesive with 100mg/ml and 10mg/ml PAMAM dendrimer in composite or in dentin/enamel, or mixed. For the were increased. But the test of dentin endogenous evaluation of dentin biostability, beams (6x2x1 mm) MMPs exhibited the total MMPs activity were were completely demineralized with the etchants (n=10) decrease to approximately 50% treated with different and incubated with media at 37°C for 30 days. The loss concentrations of PAMAM dendrimer. Dentine beams of dry weight and the amount of collagen degradation, incubated in 10mg/ml PAMAM dendrimer showed assessed using a hydroxyproline (HYP) assay, were only(4.3 ± 0.98)% loss of dry mass, which was lower obtained. Statistical analyses consisted of a one- and than control group(P<0.05). The situ zymography two-way ANOVA with the post-hoc Tukey-Kramer or analysis showed same result that the gelatinase activity Bonferroni correction tests, and Fisher’s exact test in dentin were inhibited by 10mg/ml PAMAM dendrimer (α=0.05). compared with control group. Results: For both immediate and long-term dentin Conclusion: In this study, PAMAM dendrimer was TBS and enamel SBS, etching with GLN resulted in the proved to effectively inhibit endogenous MMPs and lowest bond strength, while GLY, GLU and TA showed gelatinase in demineralized dentin and shows great no statistically significant difference when compared to potential as novel material to enhance durability of PA. There was no significant difference in dentin TBS adhesion. between 24-hour and 1-year of storage for each acid. The association between failure mode and etchant was Supported by: National Nature Science Foundation of statistically significant after 24-hour only (p<0.001). China No. 81700958, and Nature Science Foundation of Dentin demineralization with hydroxyacids significantly Chongqing No. cstc2018jcyjAX0275 reduced collagen degradation when compared to PA (p<0.05 in each instance), while no difference was observed among TA, GLN, and GLU. Conclusion: GLY, GLU and TA are potential alternative etchants to improve long-term stability of adhesive restorations and result in adequate bonding performance and reduced dentin degradation. Supported by: The University of Iowa College of Dentistry Dental Student Research Program

33 25. Copy Number Variation Analysis of Cleft 26. Functional and Sequencing Studies Lip and Palate Cases Reveals Novel Craniofa- Identify ZNF750 as CPO Candidate Gene cial Patterning Genes K. Duncan1, W.L. Adeyemo128, Sydney E. Arlis1, L.A. Lansdon1, H. Liu1, W.O. Awotoye1, T. Busch1, S.E. Miller1, G. Bonde1, A. Polyak147, K. Mohlke56, C. Adeleke1, A. Alade1, M. Li1, S. Girirajan147, B.W. Darbro1, M. Hassan1, L.J.J. Gowans127, R.A. Cornell1, D.W. Houston1, M.A. Eshete129, J.C. Murray1, J.C. Murray1, J.R. Manak1 M.L. Marazita59, R. Cornell1, 1 1University of Iowa, Iowa City, IA; Azeez Butali 56University of North Carolina, Chapel Hill, 1University of Iowa, Iowa City, IA; 59University of NC; 147Penn State University, University Pittsburgh, Pittsburg, PA; 127Kwame Nkrumah Park, PA University of Science and Technology, Kumasi, Ghana; 128Department of Oral and Maxillofacial Surgery, Objective: Clefts of the lip and/or palate (CL/P) are University of Lagos, Akoka, Lagos, Nigeria; 129School of one of the most common birth defects in the world, Public Health, Addis Ababa University, Addis Ababa, occurring in 1 in ~700 live births. Individuals with non- Ethiopia syndromic clefting (NSCL/P) account for about 70% of all cleft cases, while the rest are syndromic occurrences Objective: Very few candidate genes have been (SCL/P). Although a large variety of genetic analyses reported for cleft palate only (CPO). These include have been used to study CL/P, the contribution of GRHL3 from a recent GWAS and FAF1 from a candidate structural genetic variation to clefting remains poorly gene study. Efforts to identify additional CPO genes understood. through functional studies, bioinformatics and human genetics studies are now yielding results. The current Methods: We employed array-based Comparative Genomic Hybridization (aCGH) to assess likely study was designed to identify new candidate genes in pathogenic CNVs in over 1,000 clefting cases. We have the IRF6 gene regulatory network (GRN). primarily focused on identifying likely higher effect Methods: To identify members of the GRN in which size, rare deletions enriched in the clefting cohort IRF6 participates in surface epithelium, we assessed compared to controls in order to uncover genes that available chromatin mark datasets from the keratinocyte might be driving the disorder and playing larger roles in cell lines to identify elements that shared chromatin craniofacial development, similar to our recent strategy marks with a known oral-epithelium enhancer 9.7 for identifying ISTHMIN 1 (ISM1) as a novel clefting and kb upstream of the IRF6 transcription start site. craniofacial patterning gene. Specifically, we searched for sites with strong H3K27Ac signal and ChIP-seq peaks for Irf6, Tp63, and Klf4. Results: We identified eight putative craniofacial patterning genes, none of which have previously been We tested identified elements for periderm enhancer implicated in craniofacial disorders. CRISPR/Cas9 activity using zebrafish-based reporter assays. We mutagenesis in F0 zebrafish resulted in craniofacial sequenced 500 orofacial cleft samples from Ghana, dysmorphologies in six of these candidates, three Ethiopia, Iowa, Nigeria, Philippines and South Africa; of which (RIC1, COBLL1, ARHGEF38) were selected and the parent samples when available to identify de for additional functional validation in Xenopus novo variants. tropicalis. Once again using CRISPR/Cas9, we have Results: We identified 33 Irf6-Tp63-Klf4 binding sites confirmed that mutation of each of these genes in F0 with five of them showing high H3K27Ac enhancer animals results in variable but significant craniofacial signals. One of the enhancer signals was near ZNF750 anomalies, including abnormally shaped or absent gene, and published ChIA-PET evidence indicates this mouths and underdeveloped eyes and face. Geometric element interacts with the ZNF750 promoter. This morphometrics analysis also confirms the abnormal face element drove GFP expression strongly and exclusively shapes for each mutant. in the zebrafish periderm. Interestingly, three novel variants (not in any databases) of ZNF750 were Conclusion: Intriguingly, RIC1, COBLL1 and ARHGEF38 are all involved in either Rho- or Rab-GTPase signaling, found in three individuals with CPO: p. Ser160Pro, p. suggesting that these genes may be playing a role in Cys464Ser and p. Pro646Leu. Variants was absent cranial neural crest cell migration through modulation in mothers and no available sample from fathers to of actin filament dynamics and promotion of cell determine inheritance. The p. Ser160Pro and p. Pro646 membrane outgrowth. were predicted as probably damaging and deleterious by Polyphen and SIFT with a CADD score of 23.9 and Supported by: NIH grants to JRM (R01DE021071), 32, respectively. DWH (R01GM083999), JCM (R37DE-08559) and LAL (T32GM008629). Conclusion: Our study provides evidence that ZNF750 is a new candidate gene for CPO. Future studies to confirm the role of Znf750 in CPO etiology should be conducted. Supported by: NIH R00 DE022378 and the Robert Wood Johnson Foundation #72429.

34 27. Phenotypic Spectrum of Enamel Defects No case-control differences were found for hypoplasia in Nonsyndromic Orofacial Clefting and no gender differences were found for both defects. Conclusion: Preliminary results indicate that cleft Logan W. Sardzinski1, C. Pendleton1, defects or cleft surgery may not be causative for these T. Peter1, X. Xie1, J.T. Hecht114, enamel defects. However, the specific hypocalcification C. Padilla133, F.A. Poletta134, patterns identified correspond to 0.6-9.0 months in- I.M. Orioli135, C.J. Buxó-Martínez136, utero for teeth #53, 55, and 62 and birth-2.5 months F. Deleyiannis137, A. Butali1, post birth for #52. For subjects with OFC these time points coincide with the cleft formation and lip C. Valencia-Ramirez146, 146 1 repair surgery respectively. The presence of the same C.R. Mu—Eton , G.L. Wehby , hypocalcification patterns in controls may indicate 59 59 S. Weinberg , M.L. Marazita , different etiologies resulting in the same defect. Further L.M. Moreno Uribe1, B.J. Howe1 analyses controlling for additional covariates such as 1University of Iowa, Iowa City, IA; 59University of cleft-type and race/ethnicity will help clarify these Pittsburgh, Pittsburg, PA; 114University of Texas Health findings. Science Center at Houston School of Dentistry, Houston, Supported by: NIH K08 DE028012, R00DE024571, TX; 133Institute of Human Genetics, National Institutes S21MD001830, and U54MD007587. R00-DE022378, of Health, University of the Philippines Manila, Manila, R01-DE016148, Robert Wood Johnson Foundation Philippines; 134ECLAMC at Center for Medical Education #72429; The University of Iowa College of Dentistry and Clinical Research, CEMIC-CONICET, Buenos Aires, Dental Student Research Program Argentina; 135ECLAMC at Department of Genetics, Institute of Biology, Federal University of Rio de 136 Janeiro, Rio de Janeiro, Brazil; Dental and Craniofacial 28. Identification of the Transcription Genomics Core, School of Dental Medicine, University of Puerto Rico, San Juan, Puerto Rico; 137UCHealth Medical Factor AP-2 (TFAP2) as a Functionally Group, Colorado Springs, CO, USA; 146Clinica Noel, Relevant Keystone of Craniofacial Medellin, Colombia Ectodermal Enhancers

Objective: Children with oral clefts (OFC) often Eric Van Otterloo1, H. Li138, show enamel defects such as hypocalcification and T. Williams138 hypoplasia. The location of these defects within the clinical crown may correlate to the development of 1University of Iowa, Iowa City, IA; the cleft defect or to cleft-related surgical procedures. 138University of Colorado, Anschutz This study characterizes the location patterns of Medical Campus, Aurora, CO hypocalcification and hypoplasia in 715 subjects with nonsyndromic OFC and controls. Results will provide Objective: The craniofacial surface etiology insights, which in turn could improve treatment ectoderm—via communication with outcomes. underlying tissues—plays an essential role in shaping facial features and structures during development. Methods: This study included 367 case-probands Likewise, human genetics and animal models have affected with OFC and 348 controls recruited taught us that disruption to this ‘signaling program’ can internationally (United States, Hungary, Colombia, result in devastating structural birth defects. Despite Puerto Rico, The Philippines and Nigeria). this critical importance, how this ‘signaling program’ is Hypocalcification and hypoplasia were identified from established at the gene-regulatory-network (GRN) level intraoral photographs and defect location was classified within the ectoderm is unclear—in stark contrast to the as occurring in the incisal, middle, or gingival third of GRNs operating within the underlying tissues (i.e. the the clinical crowns in primary and permanent dentitions. cranial neural crest). Hypocalcification was further defined as diffuse or demarcated. Case-control differences were assessed Methods: To make a significant advance in our using Fisher’s Exact test and Holm-correction for understanding of the GRNs deployed during craniofacial multiple comparisons. ectoderm development we used ATAC-seq, along with craniofacial histone and gene expression datasets, to Results: Hypocalcification in the primary dentition identify enhancer elements unique to this tissue layer was present in 51.2% and 54.5% of cases and controls in mouse embryos. Subsequently, we used a variety respectively. For the permanent dentition, these of computationally-based approaches to identify percentages were 87.6% and 95% for cases and transcription factor occupancy at these enhancer controls respectively. Preliminary results indicated elements. Based on our observations, we took that controls had significantly (P<0.05) more diffuse- advantage of mouse conditional mutagenesis to test the hypocalcification on the buccal gingival-third of tooth functional relevance of one class of transcription factors FDI #52, buccal incisal-third of #53, #62 and on the identified, by removing them from the surface ectoderm lingual incisal-third of #55. Hypoplasia in the primary and anatomically, histologically, and molecularly dentition was present in 17.9% of the cases and 10.9% of characterizing the resulting defects. the controls. In the permanent dentition, hypoplasia was present in 36.3% of the cases and 12.5% of the controls. Results: We identified a subset of craniofacial surface ectoderm specific enhancers, whose associated genes

35 show a significant enrichment within this tissue, Beta values in regression analyses to identify the top relative to the underlying mesenchyme—consistent methylation variable positions (MVPs) highly associated with their ectoderm specificity. Within these enhancer with cleft-control status via MethLAB. To control for elements we found that the binding motif for the multiple testing we will use false discovery rate and AP-2 transcription factor family was significantly effect size criteria. Top MVPs will be annotated to over-represented. In agreement with a functional establish their relevance to lip/palate morphogenesis via role for AP-2 in the surface ectoderm, we found that gene ontology network analysis. tissue specific loss within this layer results in profound Results: We anticipate that the affected twins will craniofacial associated defects. In addition, we found present aberrant DNAm in loci that are crucial for that a subset of identified enhancer elements are lost craniofacial development when compared to their non- in AP-2 ectoderm mutants, and that the WNT-signaling affected twin. We also expect to observe differential pathway appears to be a key output of AP-2 function DNAm in the regulatory regions of cleft GWAS hits. within the surface ectoderm. Conclusion: Phenotypically discordant MZ twin studies Conclusion: We have established a comprehensive offer significant advantages to study epigenetic risk dataset of craniofacial surface ectoderm enhancers, factors as they control for many potential confounders providing a previously unrecognized network within compared to unrelated case-control studies. Our study this tissue. In addition, we have established AP-2 as an will identify epigenetic risk factors for OFCs, normally essential component of this network, in part, through invisible to GWAS and DNA sequencing methods, its regulation of WNT signaling. Together, these findings unraveling further biological mechanisms involved in the provide a rich resource for further exploring how the OFC etiology. surface ectoderm contributes to craniofacial anomalies. Supported by: NIH NIDCR 1K01DE027995-01A1 Supported by: EVO NIH NIDCR K99/R00 DE026823; COD Start-up funds TW NIH NIDCR R01 DE012728 and R01 DE019843 30. Non-Random Mutations in IRF6 Are As- sociated With Van Der Woude Syndrome 29. DNA Methylation Profiles of Monozygotic Azeez Alade1, C.J. Buxó-Martínez136, Twins Discordant for Orofacial Clefts W.L. Adeyemo128, T. Naicker145, 1 1 1 Aline L. Petrin1, X. Xie1, E. Zeng1, W.O. Awotoye , C. Adeleke , T. Busch , 1 1 1 R. Cornell1, R. Philibert1, A. Butali1, M.Y. Li , J. Olotu , M. Mohamed , 1 142 139 G.L. Wehby1, V. Willour1, R.T. Lie108, J. Pape , O. Adeniyan , O. Olatosi , 1 127 1 M.L. Marazita59, J.C. Murray1, S.E. Miller , L.J. Gowans , A. Butali L.M. Moreno Uribe1 1University of Iowa, Iowa City, IA; 127Kwame Nkrumah University of Science and Technology, Kumasi, Ghana; 1University of Iowa, Iowa City, IA; 128Department of Oral and Maxillofacial Surgery, 59University of Pittsburgh, Pittsburg, PA; University of Lagos, Akoka, Lagos, Nigeria; 136Dental 108University of Bergen, Bergen, Norway and Craniofacial Genomics Core, School of Dental Objective: Nonsyndromic orofacial clefts (OFCs) affect Medicine, University of Puerto Rico, San Juan, Puerto 139 142 approximately 1 in 700 individuals and cause significant Rico; University of Lagos, Idi-Araba, Lagos; Burton morbidity in those affected. Environmental and genetic Hospitals NHS Foundation Trust, Staffordshire, UK; 145 risk factors can affect disease status via epigenetic University of KwaZulu-Natal, Durban, South Africa processes, such as DNA methylation (DNAm), which Objective: Facial development occurs during the lead to changes in transcriptional activity of the early days of intrauterine life by the formation of target gene. We hypothesize that aberrant DNAm facial processes from the first Pharyngeal arch and and the resulting alterations in gene expression are subsequent fusion derangement results in Orofacial etiological for OFCs. Although monozygotic (MZ) clefts (OFC). Van der Woude syndrome (VWS), the twins share the majority of their genetic makeup, they most common cause of syndromic clefts accounting for can be phenotypically discordant on several traits and 2% of all cases. Mutations in the IRF6 gene accounts for diseases. DNAm is an epigenetic mechanism that can 70% of cases with majority of these mutations located be influenced by genetic, environmental and stochastic at the DNA binding domain (exon 3, 4) and protein events and may have an important impact on individual binding domain (exon 7-9). The aim of the current study variability. was to update the list of IRF6 variants reported for VWS Methods: Our target sample consist of 42 pairs of by compiling all the published mutations from 2013 to monozygotic twins discordant for OFCs. From these, date. 16 pairs have been bisulfite converted, amplified and Methods: . We used PubMed with the search terms; hybridized to the Methylation EPIC BeadChip to identify “van der Woude syndrome”, “IRF6”, and “Orofacial regions with differential DNAm that are associated with cleft” to identify eligible studies. We also compiled the OFCs. Our analytical pipeline uses the R packages Minfi CADD score for all the recorded mutations to determine and RnBeads to process methylation data into Beta the percentage of deleterious variants. Furthermore, we values at each specific CpG site and subsequently use sequenced VWS samples from Africa and Puerto Rico.

36 Results: Twenty one new mutations were identified Results: First, our analyses of Memo1 oral epithelial from nine papers. Majority of these mutations were in mouse mutants identifies that MEMO1 plays an exon 4. CADD score for mutations in exon 3 and 4 have essential role in the oral epithelial derived ameloblast CADD scores between 20-30 and mutations in exon lineage. Oral epithelial-specific loss of Memo1 results 7-9 have CADD scores between 30-40. The presence in compromised enamel formation—associated with of higher CADD scores in the protein binding domain a significant decrease in mineral density and eventual (exon 7-9) further confirm the crucial role played by tooth fracture. Molecular analyses identified loss of this domain in the function of IRF6. We identified five Memo1 in the oral epithelium results in a failure of IRF6 mutations, three novel missense mutations (p. ameloblast maturation, although the basis of this is still Phe36Tyr, p. Lys109Thr, and p. Gln438Leu) and two unknown. Second, in vitro analyses have identified that previously reported nonsense mutations (p. Ser424*and MEMO1 mRNA and protein is expressed robustly within p. Arg250*). oral epithelial cell lines and initial CRISPR/Cas9 loss-of- function studies suggest an essential role for MEMO1 Conclusion: Mutations in the protein and DNA binding domains of IRF6 ranked amongst the top 0.1% and in vitro, presenting a powerful and tractable model to 1% most deleterious genetic mutations, respectively. dissect MEMO1 function. Overall, these findings are important for diagnostic and Conclusion: Here, we present evidence that the protein counselling purpose in resource limited settings. MEMO1 has an essential role within the oral epithelium Supported by: NIH NIDCR R00 DE022378 and the and ameloblast development. Coupled with its role in Robert Wood Johnson Foundation (72429; A.B.) cranial bone mineralization, our findings suggest MEMO1 is a multifaceted protein in craniodental development. Further collaborations with the Liu Laboratory in the IIOHR will investigate the relative overlap of these 31. Finding MEMO—Identifying an Oral functions and how these processes might be exploited Epithelial Specific Requirement for MEMO1 in the context of tissue regeneration. During Ameloblast Development Supported by: EVO NIH NIDCR K99/R00 DE026823; COD Start-up funds; RNA Bioscience Initiative, 1 138 Michaela Schotanus , F. Smith , University of Colorado — Denver, School of Medicine C. Carey138, E. Van Otterloo1 1University of Iowa, Iowa City, IA; 138University of Colorado, Anschutz 32. A Novel IGSF3 Variant Is Associated With Medical Campus, Aurora, CO Hereditary Gingival Fibromatosis

Objective: Many genetic diseases Waheed O. Awotoye1, impact the development and function P. Ayanbadejo139, K. Umeizudike139, of mineralized tissues in the cranium (e.g. bones and 139 140 teeth). Despite this critical importance, our knowledge F. Ajayi , O. Olagundoye , 139 141 of this process is superficial, particularly compared to A. Akinshipo , O. Ayodele , mineralized structures of the trunk. Understanding the T. Busch1, M.Y. Li1, M.A. Musa125, unique gene regulatory networks (GRNs) and cellular M. Hassan1, C. Adeleke1, O. Olatosi139, and molecular mechanisms driving development of J. Pape1, A. Alade1, S.E. Miller1, craniodental tissues is an essential step in explaining, O. Adeniyan142, W.L. Adeyemo128, preventing, and treating associated genetic disorders. In A. Butali1 this regard, our lab has identified the protein MEMO1— 1 125 traditionally associated with breast cancer metastasis— University of Iowa, Iowa City, IA; Usmanu Danfodiyo 128 as a novel regulator of bone and enamel mineralization. University, Sokoto, Sokoto, Nigeria; Department of However, how MEMO1 functions within these structures Oral and Maxillofacial Surgery, University of Lagos, 139 is currently unknown. Akoka, Lagos, Nigeria; University of Lagos, Idi-Araba, Lagos; 140Lagos State University, Ikeja, Lagos; 141Lagos Methods: We are using in vivo animal models as well as University Teaching Hospital, Idi-Araba, Lagos; 142Burton in vitro cell culture loss-of-function models to determine Hospitals NHS Foundation Trust, Staffordshire, UK MEMO1’s cellular and molecular role within the oral epithelium—the precursor to the enamel forming Objective: Hereditary gingival fibromatosis (HGF) is ameloblasts. In vivo, we have utilized bulk and single a rare disease characterized by slow and progressive cell RNA-sequencing, immunohistochemistry, scanning enlargement of the attached gingiva covering the electron microscopy, µCT, and basic histological teeth and affecting speech, mastication and aesthetics. examination to define the defects associated with loss A few cases have been associated with mutations in of Memo1 within the mouse oral epithelium. In vitro, we SOS1. However, many cases have unexplained genetic are using oral epithelial cell lines (LS8, ALC) along with heritability. This study searched the human genome to real-time PCR, Western Blot analysis, CRISPR/Cas9 identify the genetic variants associated with HGF and genome editing, and eventually proximity labeling of explain the missing inheritance of the condition. MEMO1 associated proteins to further pinpoint MEMO1’s In this study, we did whole exome sequencing function in this cell type. Methods: of an affected Nigerian family: a 4-year-old child and

37 the father who presented of HGF, and an unaffected vertical migration. The age-related proliferation ability mother. VarSeqÆ software was used in the annotation decreased accompanied by proliferation layer cells and analyses of the variants. Out of the 255,692 shrink and superficial location. We killed the very variants called, 207,026 passed the quality control. superficial cells which expressing lubricin (Prg4), and The called variants were filtered for shared dominant observed increased proliferation of chondrocytes rather variants (present only in the father and son but absent than proliferation layer cells. However, killing Aggrecan in the mother). These variants were filtered based labeled cells in MCC leaded to acellular regions in on minor allele frequency by comparing with the anterior and middle part, and proliferated chondrocytes publicly available control database. Filtration based gathered in the cell defect area thereafter. When tracing on functionality was achieved using In-Silico tools: the Aggrecan positive cells after labeling at young Polyphen, SIFT, HOPE and CADD scores. age, mass aggregation of labeled cells was found in hypertrophic cartilage layer. Results: Out of the 207,026 variants that passed the quality check, 10 variants passed the filtration pipeline Conclusion: These results suggest part of the and were validated by Sanger sequencing. Among differentiated chondrocytes kept proliferation ability, the 10 variants, IGSF3 variant (c.931G>T p.Ala306Ser) and could be the stem cells reserved when partial cells has not been reported in any known publicly available deleted. control databases and is among the top 1% deleterious mutation (CADD score of 24) in the human genome. Sorting Intolerance From Tolerance (SIFT) and 34. Memo1, a Novel Therapeutic Target for Polymorphism Phenotyping (PolyPhen) predicted this variant to be benign and probably damaging Craniosynostosis respectively. This p.Ala306Ser variant is in a highly Yi Shu1, M. Zhu1, E. Van Otterloo1, conserved domain of the protein. The protein variant 1 has an increased size and reduced hydrophobicity thus L. Hong , disrupting the properties of the conserved domain 1University of Iowa, Iowa City, IA and functions such as protein-protein interaction. This domain is found in the extracellular matrix. Objective: Mediator of ErbB2-driven cell Motility 1 (Memo1) is a copper-dependent The novel variant in an immunoglobulin Conclusion: redox protein and plays an important gene is associated with HGF. Additional studies are role in endochondral ossification during required to confirm the role of the gene in HGF. mouse craniofacial development. It may serve as a Supported by: NIH NIDCR K99/R00 Grant DE022378 therapeutic target for craniosynostosis. (AB); Robert Wood Johnson Foundation Grant number The objectives of the study are to determine the Memo1 72429 (AB); NIH R90 training grant DE024296 (WA). variation in mouse osseous fused cranial sutures and human osteogenic differentiated bone marrow stromal cells (hBMSCs), and to demonstrate the inhibitory 33. Proliferation of Condylar Chondrocytes function of a Memo1 inhibitor on osteogenesis in vitro. in Physiology or After Partial Cells Death Methods: We quantified the Memo1 in the posterior- Induced frontal (PF) sutures of p16 mice and the hBMSCs under osteogenic differentiation. In addition, we quantitatively Yao He101 assessed the osteogenic differentiation of hBMCs after 101Chongqing Medical University, Memo1 was down-regulated using siRNA. Chongqing, China Results: Memo1 significantly increased in PF sutures in p16 mice, compared to the sagittal sutures. In Objective: The development of hBMSCs the Memo1 was upregulated 3 and 7 days after mandibular condylar cartilage (MCC) has osteogenic differentiation, and then decreased after long been characterized as chondrocytes 14 days. In addition, the transfection of Memo1 siRNA at the inferior portion apoptosis before effectively down-regulated the Memo1 in hBMSCs and replaced with differentiation of proliferation cells reduced the transcript of ALP, OCN and Runx2. in the superficial layers. While recent studies which demonstrated chondrocytes can directly transform Conclusion: Memo1 may involve in the osseous fusion into bone cells underneath, make reassessment the of cranial sutures and by targeting Memo1 using siRNA proliferation pattern of MCC necessary. we may potentially prevent premature suture fusion in craniosynostosis. Methods: We describe a method that uses confocal microscopy to rapidly and reliably assess indicators of Supported by: High Quality Talent Training Program of mandibular condyle cartilage in mice. And proliferation School of Stomatology, CQMU in physiological and several pathological conditions have been studied with this strategy applied on wild type and genetically modified mice. Results: We found stronger proliferation of MCC than humeral head with proliferative cells mainly

38 35. The Mechanism of Branched Incisors 36. Profiling Gene Expression in the Epithe- Formation in Dicer-Deficient Mice lial and Mesenchymal Compartments of Developing Rodent Incisor Fan Shao1, M.E. Sweat1, Y. Guo1, A. Phan1, B.A. Amendt1, H. Cao1 Yuwei Guo1, M.E. Sweat1, F. Shao1, 1 1 1 1University of Iowa, Iowa City, IA Y.Y. Swe at , S. Eliason , B.A. Amendt , H. Cao1 Objective: Mice models for the 1University of Iowa, Iowa City, IA research of tooth development have limitations, consequently, leave questions Objective: Teeth are developed from unanswered, such as the mechanisms the crosstalk of dental epithelial and of successional tooth formation and continuous tooth mesenchymal tissues. Tooth development occurs in growth. In our previously study, we found branched and stages, and the process begins under the control of f/f multiple incisors were developed in Pitx2-Cre/Dicer1 the oral epithelial tissue. The epithelial tissue of the (cKO) mice, which could be a model to uncover above dental placode instructs the development of the tooth mechanisms. by synthesizing signaling molecules including Shh, Methods: In this study, Single-cell RNA sequencing Wnt, Bmp and Fgf signals. These signaling pathways (scRNA-seq) was employed to understand the control the expression of specific transcription factors mechanism that govern branching process in DicercKO in the epithelium and mesenchyme. One of the mice. Stem cell niche, differentiated enamel epithelia earliest transcription factors to be expressed in the cells and mesenchymal cells of lower incisors in P0 dental epithelium is Pitx2 (paired-like homeodomain DicercKO and Dicerfl/+ mice; branched stem cells and transcription factor 2). We are interested in what mesenchymal cells in DicercKO mice were isolated by initiates the expression of the transcription factor Pitx2 laser capture microdissection (LMD). Libraries were and the formation of the primary tooth germ. made follow the Smart-seq2 protocol. Dental epithelium Methods: To determine what gene regulatory network and mesenchyme of e11.5 C57 mouse embryos were is required for tooth germ initiation, we profiled collected to test the protocol and library quality. gene expression in the developing oral epithelium Results: The cDNA size distributions were checked on and mesenchyme during early stages of tooth Agilent high-sensitivity DNA chip, which showed peaks development (E9.5, E10.5, E11.5 and E12.5). We used at 2 kb, indicated that the cDNAs were integrated. The Laser Microdissection (LMD) to isolate epithelial and library size distribution was further measured, showing mesenchymal tissues from early embryonic stages of the size ranged from 300 to 500bp. The concentration tooth development. After tissue isolation, we extracted of library was measured by qPCR and calculated RNA and performed RNA-seq using the SMARTSEQ-2 according to the size, which resulted in 7.29nM. qPCR protocol. results showed that Lef1 and Pitx2, markers of epithelia Results: We made libraries to profile the transcriptomes cells, were only expressed highly in dental epithelium of the first brachial arch of E9.5 and E10.5 murine sample, whereas, mesenchyme marker, Pax9 was only embryos and used LMD to isolate the epithelial and expressed highly in dental mesenchyme. mesenchymal tissues to make libraries from E11.5 and Conclusion: The library was qualified to proceed to E12.5 stages. sequencing. We expect to identify many known and Conclusion: Profiling the transcriptomes of cells from novel signaling molecules and transcription factors that the early stages of tooth development will help to involved in developing branched dental laminas. uncover the initiation program underpinning tooth formation, which may be applied to the clinic in the future.

39 37. Antimicrobial Efficacy of Platinum-doped 38. Entanglement-Driven Adhesion, Self- Silver Nanoparticles Against P. aeruginosa Healing, and High Stretchability of Double- Network PEG-Based Hydrogels Kan Wongkamhaeng1, J.A. Banas1, D.V. Dawson1, J.A. Holloway1, Yangyingfan Feng101, L. Chen101 1 1 A.J. Haes , I. Denry 101Chongqing Medical University, 1University of Iowa, Iowa City, IA Chongqing, China

Objective: There is a need for Objective: Hydrogels that are capable of alternate therapeutic agents to combat wet adhesion and self-healing can enable antibiotic-resistant bacteria. Silver nanoparticles major advances in a variety of biomedical (AgNPs) have been proposed due to their established applications such as tissue regeneration, antimicrobial action. However, concentrations needed wound dressings, wearable/implantable devices, and for antimicrobial activity may not be therapeutically drug delivery. We hereby aimed to develop a design viable. Platinum-doped silver nanoparticles (Pt-AgNPs) strategy to prepare hydrogels capable of self-healing are explored as bimetallic nanoparticles with potential and instant, repeatable adhesion to tissue matrices by for enhanced antimicrobial efficacy. The objective was introducing diffusive and giant polymer chains into a to measure the amount of ionic silver (Ag+) released covalently cross-linked hydrogel network. from Pt-AgNPs under bacterial growth conditions and Methods: PEG-based polymers were chosen as a model to determine the antimicrobial efficacy of Pt-AgNPs and the DN hydrogels can be achieved by combining a against P. aeruginosa. covalent PEGDA network with a noncovalent network Methods: Pt-AgNPs doped with 0.5, 1 and 2 mol.% containing diffusive, long PEG chains. Mc value of the

platinum (Pt0.5AgNP, Pt1AgNP and Pt2AgNP) were dynamic PEG chains by measuring the viscosity η of prepared by a chemical reduction method. Particle PEG solutions as a function of molecular weight Mw. DN morphology and concentration were investigated by hydrogels of various compositions were prepared by transmission electron microscopy (TEM) and atomic simply mixing 35 kDa PEGDA monomers with PEG of absorption spectroscopy (AAS). The oxidative release high Mw = 35 kDa or low Mw = 0.6 kDa in an aqueous of Ag+ up to 72h was measured by ion-selective solution, followed by radical polymerization of PEGDA electrode (ISE) on nanoparticle solutions with an in the presence of 0.5% w/v photoinitiator Irgacure initial silver concentration of 8µg.mL-1. The minimal 2959. The mechanical properties were measured by inhibitory concentration (MIC) was measured against conventional tensile tests. The adhesion and self- P. aeruginosa (105 CFU.mL-1) by a broth microdilution healing behavior of the DN Hydrogel were evaluated method. Undoped AgNPs and platinum nanoparticles by performing lap shear measurements and rheology. (PtNPs) served as controls. All experiments were Then this hydrogel were used as a three-dimensional conducted in triplicate. matrix for cell culture or as a tissue adhesive for wound healing, and the therapeutic effects of DN hydrogel Results: TEM revealed spherical AgNPs and PtNPs were evaluated by histological analysis. with mean diameters of 17.1±3.3nm and 7.0±2.2nm, respectively. Pt-AgNPs exhibited mixed morphologies Results: The adhesion to substrates including tissue with spherical, oval, or ribbon-like nanostructures matrices was instant and repeatable due to the diffusive of mean cross-sectional diameters ranging between PEG chains that can spontaneously penetrate and 7.0±2.2 to 12.0±2.5nm. At 72h, the highest amount of entangle with the substrate network. Combining the + -1 Ag was released from Pt2-AgNPs (276.0±2.6ng.mL ), intrinsic biocompatibility of PEG and rational design for -1 followed by Pt1-AgNPs (155.5±0.5ng.mL ), Pt0.5-AgNPs tuning the hydrogel network properties, we exemplarily (61.9±2.3ng.mL-1) and undoped AgNPs (16.9±6.1ng. demonstrated that this hydrogel can be used as a -1 mL ), respectively. Pt2-AgNPs exhibited the lowest MIC three-dimensional matrix for cell culture or as a tissue -1 (1.5±0.9µg.mL ), followed by Pt1AgNPs (5.0±0.0µg. adhesive for wound healing. The in vivo study showed -1 -1 mL ), and Pt0.5AgNPs (5.8±1.4µg.mL ). These were that the hydrogel is capable of effectively triggering all significantly lower than that of undoped AgNPs skin wound healing with a significantly lower immune (51.7±2.9µg.mL-1). No antimicrobial activity was found response in comparison to commercial tissue adhesives for PtNPs. currently used in clinics. Conclusion: Doping AgNPs with platinum significantly Conclusion: We reported a new strategy for preparing increased the amount of ionic silver released in solution, adhesive, self-healing, and highly stretchable hydrogels which increased linearly with platinum doping level based on the entanglement effects stemming from (R2=0.99, p<0.0001). The antimicrobial efficacy of Pt- diffusive giant PEG chains within a double-network AgNPs was significantly higher than that of undoped system. Our study provides new and critical insights nanoparticles (p<0.05) and increased with platinum into the design strategy to achieve adhesion and doping level. rehealability by taking advantages of the entanglement effect from double-network hydrogels and opens up a Supported by: NIH NIDCR R21 DE25700 new avenue for the application of entanglement-driven hydrogels in regenerative medicine.

40 39. PD-L1 Correlates With the Presence of 40. Biomarker Profiles in the Saliva of Chemokines and Cytokines in Gingival Cre- Children With Sjögren Syndrome Suggest vicular Fluid From Healthy and Diseased Inflammation Trending Towards a Strong Sites in Smoking and Non-Smoking Subjects Lymphocyte-Mediated Immune Response With Periodontitis Emily E. Starman1, M.P. Gomez Andrew Shelby1, G.K. Johnson1, Hernandez1, A.B. Davis1, E. Zeng1, X. Xie1, E.L. Thayer1, C. Pendleton1, S.M. Lieberman1, K.A. Brogden1, E.A. K.A. Brogden1 Lanzel1 1University of Iowa, Iowa City, IA 1University of Iowa, Iowa City, IA

Programmed Death-Ligand 1 (PD-L1) is Objective: Inflammation in the salivary a transmembrane protein expressed on and lacrimal glands likely begins years before diagnosis the surface of immune and non-immune cells. It binds of adult Sjögren syndrome. Since Sjögren syndrome to receptor Programmed Death-1 (PD-1) on T-cells and can also occur in children, assessing the chemokine, serves as an immune checkpoint to regulate immune cytokine, and biomarker (CCBM) profiles in these responses and inflammatory tissue damage. Cells of individuals may help to identify previously unknown periodontal tissues express PD-L1 when exposed to early events in the etiopathogenesis of both childhood periodontal pathogens or pro-inflammatory mediators. and adult Sjögren syndrome. Saliva proteomic and The presence of PD-L1 in gingival crevicular fluid (GCF) biomarker studies have reported increased levels of is not known nor is its relationship to periodontal CCBMs associated with Th1/Th2/Th17 responses. In this disease and smoking, an important risk factor for study, we hypothesized that unique profiles of CCBMs periodontitis. in saliva are associated with immune cell infiltrates and could identify immune events earlier in the disease Objective: The aims of this study were to a) assess the process. presence of PD-L1 in GCF and b) correlate PD-L1 values with the presence of chemokines and cytokines in GCF Methods: We collected saliva from eleven children from healthy and diseased sites in smoking and non- (11-20 years-of-age), formally diagnosed with Sjögren smoking subjects with periodontitis. syndrome and saliva from normal healthy children, matched for gender and age, who served as our study Methods: GCF samples were available from a previous controls. We determined the concentrations (pg/ml) of study assessing the influence of smoking on GCF 105 CCBMs, in triplicate, using multiplexed fluorescent cytokines in severe chronic periodontitis. PD-L1 values bead-based immunoassays. We used a one-way (pg/30s) were measured in these samples using a ANOVA, followed by the t test, to detect differences Milliplex immunoassay. The relationship between PD- among marker concentrations from the two groups at L1 with disease status and smoking was determined the 0.05 level of significance. using T-tests and the relationship between PD-L1 and other chemokines and cytokines was determined using Results: 41.0% (43/105) of CCBMs were elevated Pearson correlation. (p<0.05) in children diagnosed with Sjögren syndrome versus gender and age matched healthy children. We Results: PD-L1 was detected in GCF and values ranged used Over-Representation Analysis (ORA) in the WEB- from 0.0063-31.65 pg/30 sec. No differences were based gene set analysis toolkit, WebGestalt to assess found between the PD-L1 values at healthy sites and gene ontology and the nature of the underlying immune disease sites for all smoking subjects and non-smoking dysfunction in the etiopathogenesis of disease. ORA subjects (p = 0.9) and no differences were found identified CCBMs associated with autoimmune diseases: between the PD-L1 values at healthy and disease sites 19/43 CCBMs were in a gene set for autoimmune for smoking subjects (p = 0.11) or non-smoking subjects diseases, 18/43 CCBMs were in a gene set for chronic (p = 0.28). PD-L1 was positively correlated with GM-CSF diseases, and 23/43 CCMBs were in a gene set for joint values (p = 0.04) and negatively correlated with IL-5 diseases. ORA also identified CCBMs associated with (p = 0.03), IL-6 (p = 0.01), IL-8 (p = 0.0001), and MIP-1a lymphocyte-mediated immunity: 14/43 CCBMs were in (0.01) values. a gene set for regulation of immune effector processes, Conclusion: PD-L1 is present in GCF, and these values 16/43 CCMBs were in a gene set for regulation of appear to correlate with the presence of chemokines leukocyte activation, and 11/43 CCBMs were in a gene and cytokines. To what extent PD-L1 values contributes sets for lymphocyte-mediated immunity. These included to the periodontal status of the site, smoking, and B2M, C9, IFNB1, IL1B, IL6, IL10, IL12A, IL12B, IL21, inflammatory tissue damage will have to be determined TNFRSF1B, ULBP2 (p=2.25e-11). in future studies. Conclusion: Overall, 43 elevated CCBMs formed a profile that suggested early events in inflammation and autoimmunity trended towards a strong lymphocyte- mediated immune response. Supported by: A Pilot Research Award from the Sjögren syndrome Foundation; The University of Iowa College of Dentistry Dental Student Research Program

41 41. Acceptance and Factors Influencing Den- 42. Rubber Dam Usage in Clinical Dentistry tal Restoration Repairs Among US Dentists Garrett P. Schultz1, C. Cucco1, Wafaa Kattan1, E.C. Teixeira1, A.E. Williamson1, C.L. Comnick1, X. Xie1 132 1 O. Urquhart , S. Guzman-Armstrong , 1University of Iowa, Iowa City, IA J.L. Kolker1, M.R. McQuistan8, T. Peter1, C.L. Comnick1 Objective: Rubber dental dam (RD) usage has been the standard of care 1 8 University of Iowa, Iowa City, IA; East during root canal treatment (RCT). Carolina University, Greenville, NC; However, the use of this device for all 132 American Dental Association, procedures in which the root canal system is exposed Chicago, IL such as post placement or core build up procedures is controversial. The purpose of this survey was Objective: Although minimally invasive dental to determine current RD usage during RCT, post procedures such as restoration repairs increase the placement, and build-up procedures. longevity of tooth restorations, limited data exists pertaining to dentists’ beliefs and practices regarding Methods: A Qualtrics survey was emailed to specialists restoration repairs. The objectives of this observational and general practitioners with 1,334 surveys being cross-sectional survey of the the American Dental returned resulting in a 7.66% response rate. Questions Association Clinical Evaluators (ACE) panel were to: included age, primary role in dentistry, and usage of 1- assess the acceptance of dental restoration repair RD during various dental procedures such as: RCT, post 2-determine the main factors related to restoration placement, build-up, and lastly any influencing factors repair versus replacement; 3- identify the most common for not using a RD. materials and surface treatments used for dental Results: 1,334 (65.1% ≥41 years old) responses restoration repair. were included in the study. General practitioners Methods: A 15-item questionnaire was developed and corresponded to 15.59%, and specialists, specifically then distributed electronically to ACE Panel members Endodontists and Prosthodontists, corresponded to (n=785) using Qualtrics after IRB approval was received. 74.7% of the participants. The remaining 9.71% were The survey was distributed twice in a period of two involved with military, academics, or non-specified weeks in August 2019. Descriptive statistics were specialties. Approximately 2.62% of responders “rarely” conducted. use RD during RCT. In total, 17% rarely use RD during post placement procedures. Additionally, 17.7% “rarely” Results: There were 421 respondents who completed use RD during core buildup procedures. Among the the survey (Response rate=54%). Of the respondents, reasons for not using a RD, 41.7%, stated “use of other 83% stated that they repair defective restorations, while methods of isolation such dry-shield or IsoVac.” 17% always replace defective restorations. Respondents were likely to repair a defective restoration due to Conclusion: Currently the majority of root canal limited patient finances (66%) followed by whether a procedures are performed with RD usage. As patient has a compromised health status (40%). Nearly practitioners, providing the highest success rates half of the respondents (48%) reported they were possible for patients is imperative. The goal is to more likely to replace a defective restoration if it was continually increase RD usage not only for RCTs but all placed by another dentist, while the other half (49%) procedures that involve exposing the canal space. reported that this did not affect their decision. The most Supported by: American Association of Endodontics frequently (86%) cited reason for repairing a restoration Foundation was to repair a non-carious marginal restoration defect. Using resin composite to repair composite restoration was selected by 97% of the respondents, while 44% used composite to repair amalgam restorations. Prior 43. Survival Analysis of Crown Margin Repair, to repairing composite restorations approximately 34% A Retrospective Study of respondents use air abrasion as surface treatment versus 23% for amalgam restorations. Allison M. Schollmeyer1, T. Peter1, X. Xie1, S. Anamali 1, A. Jain1 Conclusion: The majority of respondents performed restoration repair as a treatment option for managing 1University of Iowa, Iowa City, IA defective restorations for both composite resin and amalgam dental restorations. Objective: Repairing restorations, including crowns, is a more minimally- Supported by: Graduate and Professional Student invasive and cost-effective treatment Government, University of Iowa option than replacement. The objective of this study was to determine the survival of crown margin repairs and the factors that were associated with the survival. Methods: For this retrospective survival analysis, electronic health records of patients since January 2008 were reviewed for 1012 crown margin repairs completed

42 at The University of Iowa College of Dentistry. Patients powder) were lyophilized and separated into aliquots of ages 25 and above were included in the study. Each (40 mg each) of each protocol and tissue condition subject had a crown margin repair done at the start (n = 15). Samples were incubated in 1 mL of incubation of the study and restorations were followed until end media (50 mM HEPES, 5 mM CaCl2, 0.001 mM ZnCl2, of the study in August 2019 or until they failed. Failure 150 mM NaCl, 0.3 mM PMSF, 3 mM NaN3) at 37 °C for 7 was defined as having an additional repair, crown days under agitation. Then, the incubation media were replacement, or extraction. In this survival analysis, used for the quantification of solubilized collagen by Cox Proportional Hazards Model was used to study measuring the amount of hydroxyproline (HYP) released the relationship between time until failure (in days) (expressed in µg HYP/mL/mg dentin). Two-way ANOVA and the variables; patient’s age, caries risk assessment, was performed with protocol, dentin condition, and tooth type and jaw, number of surfaces repaired, type the interaction between them. Subsequently, pairwise of repair material, crown type, root canal treatment, Tukey-adjusted t-tests were performed between provider type. conditions, protocols, and combinations of the two (a = Results: About 36.3% of the restorations failed during 0.05). the follow-up, with the median survival time being 1875 Results: Overall, there were significant differences days (5.1 years). In the final model, only repair material among protocols and dentin conditions (p < 0.001). remained as significant covariate. Hazard ratios for glass All pairwise comparisons between protocols were ionomer (GI), resin-based dental materials (RBC - dental significant, except for EDTA and G-EDTA. HYP release composite, flowable dental composite or sealant) and from healthy dentin was significantly higher than caries resin modified glass ionomer (RMGI) when compared to for G-EDTA and PA protocols (both p < 0.001). There amalgam were 2.0, 1.5 and 1.0 respectively. Of these, the was no difference in HYP among dentin conditions for values for GI and RBC were statistically significant. the EDTA and the hybrid protocols (all p = 1). Conclusion: The type of restorative material was the Conclusion: Substantial remaining endogenous only significant factor associated with survival of the proteolytic activity was observed after protein removal crown margin repairs. using the protocols G-EDTA and PA, which resulted in increased HYP release. In addition, more collagen degradation was observed in healthy than in caries 44. Comparison of Dentin Endogenous dentin for those two protocols, possibly due to a Proteolytic Activity After Protein Extraction high amount of remaining non-extracted endogenous enzymes. With Different Assays Supported by: The University of Iowa College of Bradyn Ellis1, K. Stine1, Dentistry Dental Student Research Program; American C.L. Comnick1, X. Xie1, C. Vidal1 Dental Education Association 1University of Iowa, Iowa City, IA

Objective: Caries progression in dentin 45. Effect of Dental Composite Marginal has been attributed to the activity of Repair Techniques on Enamel Bonding endogenous matrix metalloproteinases (MMPs). A better understanding of Alshimaa Alghamdi1, S.R. Armstrong1, the individual roles of MMPs in caries relies on the C. Vidal1, E.C. Teixeira1, F. Qian1, establishment of a validated standardized extraction R.R. Maia1 assay that can effectively monitor the levels and activity 1University of Iowa, Iowa City, IA of MMPs in dentin. This study assessed the effectiveness of four different assays for protein extraction from Objective: Evaluate the effect of the sound and caries dentin by measuring the level mechanical and chemomechanical surface of collagen degradation driven by the remaining treatments used when repairing dental-composite (DC) proteolytic activity from non-extracted enzymes. on the bond to enamel. Methods: Dentin powder was acquired from healthy Methods: A sample of 120 enamel specimens was (H), incipient (I), and carious (C) extracted human prepared using caries-free human molars. All specimens molars. One-gram aliquots of powder from the were flattened using a computer numerical control different tissue conditions were used for protein machine with a medium grit flat-end-cylinder diamond extraction using four protocols (n=3): G-EDTA (4M bur. Samples (n=30/per group) were equally divided guanidine-hydrochloride (G-HCl) followed by 0.5M into groups according to surface treatments and ehylenediaminetetraacetic acid (EDTA) and a second etching modes. Control group (SBU) was bonded using incubation with G-HCl, pH 7.4); PA (1% phosphoric acid Scotchbond Universal adhesive in selective-etch mode. demineralization followed by incubation with buffer Groups (A+SBU) and (CS+SBU); were bonded similarly containing 50 mM Tris-HCl, 5 mM CaCl2, 100 mM NaCl, after receiving surface treatment with 50µm-aluminum- 0.1% Triton X-100, 0.1% nonionic detergent P-40, 0.1 mM oxide-air-abrasion and 30µm-CoJet-abrasive-silane- ZnCl2 and 0.02% NaN3 pH 6.0); EDTA (50 mM Tris- application, respectively, for 10-second at 2-bar. Group HCl containing 4M G-HCl and 0.5 M EDTA pH 7.4); and (CS+Self-SBU) was treated as group (CS+SBU); but hybrid (a combination of G-EDTA and PA protocols). adhesive was used in self-etch mode. Filtek-Supreme- After protein removal, precipitates (remaining dentin Ultra-Universal-Restorative was packed in the cylindrical 43 mold of the Ultradent SBS jig. All specimens received defects (OR=2.92; p=0.022) and poor oral hygiene 5000 cycles of 10(±6)-55°C thermocycling with a (OR=9.32; p<0.001), consumed cariogenic beverages dwell of 28-2-28-2 seconds. Specimens were subjected more than 2 times per day (OR=2.19; p=0.005), and have to shear bond strength (SBS) testing and failure a parent or sibling with decay (OR=1.92; p=0.048). mode (FM) was evaluated under stereomicroscope Conclusion: Results of the study suggest several of magnification. the caries risk factors significantly associated with Results: One-way ANOVA with a post-hoc Tukey- ECC experience. Efforts for practitioners to promote Kramer test (Table) and parametric Weibull regression education regarding proper oral hygiene, limit model with Wald chi-square test (Figure) revealed cariogenic snacks/beverages, manage enamel defects, that there was a significant effect for the different DC and encourage regular dental care should be continued. repair techniques on SBS of enamel-DC bond (both Supported by: The University of Iowa College of p<0.0001). Group CS+Self-SBU had a significantly lower Dentistry Dental Student Research Program SBS compared to other groups, while no significant difference was noted among groups SBU, A+SBU and CS+SBU. Most failures were adhesive but no significant association was found between FM and the repair 47. Inhibitory Properties of Non-Mutans technique. Low pH Streptococci in the Caries Disease Conclusion: Within the limitation of this in-vitro Process

study, the inadvertent contact of enamel with the 1 1 CoJet particles and silane during the repair of DC may Ryan. M. Hemsley , M. Zhu , 1 impair the resultant SBS. While this cannot be avoided J.A. Banas clinically, the results also suggest that the use of a 1University of Iowa, Iowa City, IA universal adhesive in selective-etch mode may recover the bond strength of the silicatized enamel. Objective: Previous research in our laboratory identified seven strains of low pH non-mutans streptococci from three 46. Caries Risk Factors Associated With child donors in various disease states. These low pH non-mutans streptococci, referred to Early Childhood Caries as low-pH strep, may play a role in the initiation of dysbiosis of the oral microflora leading to the initiation Andrew J Carlson1, M.C. Skotowski1, 1 of carious lesions. The purpose of this study was F. Qian to: 1) identify inhibitory properties of these low pH 1University of Iowa, Iowa City, IA streptococci strains against common streptococcal plaque colonizing species, and 2) identify inhibitory Objective: The objective of this study properties of these low pH streptococci strains against was to investigate the relationships S. mutans for comparative purposes. between the caries risk factors and early childhood caries (ECC) experience among Methods: Banked stocks of low-pH streptococci were children visiting the University of Iowa Pediatric Dental revived and grown on BHI agar plates. Laboratory Clinic (UIPDC). strains of S. sanguinis, S. oralis, S. mitis, S. gordonii, and S. mutans were revived on BHI agar. Suspensions of Methods: Data were collected during a retrospective each strain were standardized to an optical density of chart review of patients, ages one through five years, 0.10±0.005 at wavelength 600nm. 10 microliter samples presenting for initial dental examinations in the UIPDC were placed 7mm apart on BHI plates to observe by third year dental students from 01/01/2017 to inhibition of growth. Sequence of plating was varied to 05/01/2019. Caries risk assessment (CRA) information determine which sample was the source of inhibition. was collected using a CRA form completed at the initial Samples were allowed to incubate for 24 hours, and dental examination. ECC experience was defined in this inhibition was measured in terms of percent inhibition. population by anyone who had frank caries, white spot lesions, and/or previous restorations. The statistical Results: In this study, low pH streptococci did not analyses consisted of descriptive statistics, bivariate inhibit, and were not inhibited by, S. oralis or S. mitis. analyses, and logistic regression (alpha=0.05). Low pH strep from one patient showed strong inhibition of S. mutans, and in turn was moderately inhibited by Results: A total of 398 subjects (30.4% had ECC S. mutans, depending on the order of inoculation. The experience, 50% females) who fulfilled all the inclusion same strains inhibited S. sobrinus when plated first, and criteria were included in the study. Of the 121 subjects also displayed inhibition of common plaque species S. who had ECC, the mean age was 4.0±1.4 years vs. gordonii and S. sanguinis. 2.5±1.3 years for those with no ECC. Bivariate analysis revealed that increased age of the child, irregular dental Conclusion: It is plausible that low-pH streptococci may care, low SES, caregiver with low dental health literacy, promote caries development by having an inhibitory child’s consumption of between-meal cariogenic snacks, effect on common colonizers of the oral cavity. In some and teeth not brushed everyday were significantly instances the low pH streptococci may elevate caries associated with presence of ECC. The logistic regression risk alongside the mutans streptococci whereas in other analysis showed that children in the ECC group were instances antagonism of the mutans streptococci is also more likely to be older (OR=1.84; p<0.001), have enamel possible.

44 Supported by: The University of Iowa College of 49. Changes in Mean Fluorosis Scores from Dentistry Dental Student Research Program Age 9 to 23

Steven M. Levy1, A.M. Curtis1, 48. Incorporation of Fluorophore Molecule J.J. Warren1, J.E. Cavanaugh1, for Enhanced Visualization of Dental J.L. Kolker1, K. Weber-Gasparoni1 Adhesive Resin 1University of Iowa, Iowa City, IA

Daniel H. Soh1, C.L. Comnick1, Objective: The few previous studies C. Vidal1, R.R. Maia1, K. Shin1, suggest that mild dental fluorosis declines C.A. Barwacz1 in severity from late childhood to adolescence. This study examined changes in mean person- and tooth- 1University of Iowa, Iowa City, IA level fluorosis from ages 9 to 23 in a birth cohort. Objective: Dentists currently lack a Methods: Fluorosis exams were conducted at 9, 13, 17, convenient and reliable methodology to and 23 years in the longitudinal Iowa Fluoride Study. predictably visualize thin increments of excess resin Fluorosis Risk Index (FRI) scores were determined for cement or remaining resin composite during its removal. each zone and then averaged separately for early- These challenges may result in routine clinical errors erupting, late-erupting, and maxillary incisor teeth, such as failure to achieve full removal of excess cement both at the tooth- and person-levels. Goodman and at prosthetic margins during crown cementation, Kruskall’s gamma statistic quantified the trends in complete removal of ageing composite during repair or mean fluorosis severity using the standard asymptotic replacement, or over-reduction of sound dental tissues standard error to test for a significant decline in mean during debonding of orthodontic fixed appliances such FRI with age. Wilcoxon signed-rank tests assessed as brackets. The goal of this study is to investigate whether the probability of having a lower follow-up the resin-dentin bond strength of a dental adhesive mean FRI score was significantly greater than having a system incorporated with different concentrations of higher score. Mean scores were categorized (0, 0.01 — a candidate fluorophore molecule (fluorescein) for 0.50, 0.51 — 1.00, 1.01 — 3) and compared over time. improved visualization of the adhesive under incident Results: Comparing mean person-level scores over time excitation wavelengths. for the 282 completing all 4 examinations showed that Methods: Extracted intact human molars were used to the percentages with scores of 0.51 or greater declined test resin-dentin shear bond strength (n=12). Teeth were with increasing age. Specifically, the percentages were sectioned in half, mounted in acrylic resin and dentin 18% (age 9), 10% (age 13), 5% (age 17), and 3% (age 23) surfaces were polished with 600-grit silicon carbide for early-erupting teeth, 16%(at 13), 6%(17), and 4%(23) paper prior to adhesive application. Samples were for late-erupting teeth, and 33%(at 9), 19%(13), 14%(17), randomly distributed according to the adhesive used for and 10%(23) for maxillary incisors. Mean tooth-level the bonding procedure: Control (Scotchbond Universal scores also declined. Percentages 0.51 or greater were Adhesive (SBU), 3M, with no fluorophore), SBU+1000 18% (age 9), 11% (age 13), 7% (age 17), and 6% (age 23) (SBU containing 1000 µM fluorescein), SBU+100 (SBU for early-erupting teeth (n=3,269), 14%(at 13), 7%(17), containing 100 µM fluorescein) and SBU+10 (SBU and 5%(23) for late-erupting teeth (n=4,251), and containing 10 µM fluorescein). After acid etching, primer 29%(at 9), 17%(13), 12%(17), and 9%(23) for maxillary and adhesive were applied following the manufacturer’s incisors (n=1,068). Gamma statistics for all tooth recommendation. Resin composite (Filtek Supreme groups at the person- and tooth-levels were significant Ultra, shade A2 Body, 3M) was applied on dentin surface (P<0.0001). and light-cured. Specimens were tested in shear until Conclusion: Fluorosis severity, defined by both the failure. Shear bond strength outcomes were measured person- and tooth-level mean FRI scores, tended to in megapascal (MPa) and compared among the groups decline throughout adolescence and early adulthood. using an ANOVA and Turkey pairwise t-tests (a=0.05). Supported by: NIH R03-DE023784, R01-DE12101, The averages of shear bond strength ranged Results: R01-DE09551, R56-DE012101, UL1-RR024979, UL1- from 32.9 to 36.5 MPa. There was no statistically TR000442, UL1-TR001013, M01-RR00059, the Roy significant difference in shear bond strength among the J. Carver Charitable Trust, and Delta Dental of Iowa four different groups (p=0.456) or between any pair of Foundation. the groups Conclusion: The incorporation of the fluorescein up to the concentration of 1000 µM does not affect the shear bond strength of a universal adhesive system. Future studies will investigate the minimal concentration of fluorophore in dental adhesive to be detected by human eye using IVIS spectrophotometer imaging system. Supported by: The University of Iowa College of Dentistry Dental Student Research Program

45 50. Examining Dental Plaque Isolates of 51. Predictors for the Counts of Selected Streptococcus for Potential Probiotic Activity Oral Pathogens in an Institutionalized Elderly Population Abigail M. Wieland1, J.A. Banas1 1 1 1University of Iowa, Iowa City, IA Kelsey R. Wenger , C. Pendleton , X. Xie1, D.J. Caplan1, D.R. Drake1, Objective: To investigate the in vitro L. Marchini1 inhibitory activity of mildly acidogenic 1 strains of Streptococcus, isolated from University of Iowa, Iowa City, IA pediatric dental plaque samples, against Objective: Fifteen percent of the United the highly acidogenic and cariogenic States population (48 million people) is species Streptococcus mutans, and Streptococcus 65 years of age or older, and about 5% (2.4 million) of sobrinus, and the health-related species Streptococcus them lives in a nursing home. There is strong evidence sanguinis. If a strain is inhibitory towards S. mutans and of an association between the increased frequencies of S. sobrinus, but S. sanguinis is unaffected by the strain, oral health infectious conditions and multiple systemic then this strain could be a potential probiotic for caries diseases, especially in older and immunocompromised reduction. persons. The aim of this paper was analyzing the Methods: Prospective probiotic strains (n=21) and predictors for the counts of selected oral pathogens in control strains were inoculated next to one another on an institutionalized elderly population. agar plates. Multiple trials were conducted in which Methods: This is a secondary analysis using data either the probiotic test strains or the control strains previously collected during a published research project were inoculated first and incubated for 24 hours prior entitled “Iowa nursing facility oral hygiene (INFOH) to the inoculation of the others. Growth inhibition was intervention: A clinical and microbiological pilot measured in millimeters as a percentage of the total randomized trial”. The INFOH’s baseline data included diameter of the inoculation. information regarding the nursing facility, patient Results: Four strains (11.12, 14.5, 14.27, and 14.28) were demographics, participants’ systemic health, cognitive identified as having probiotic potential based on strong abilities, patients’ oral health, and microbiology samples. inhibition of S. mutans and S. sobrinus, weak inhibition For non-denture wearers, a single microbiological of S. sanguinis, and resistance to inhibition by any of the sample was collected from each participant by “whole- control strains. Strain 11.12 showed 100% inhibition of S. mouth” swab, including teeth surfaces, oral mucosa, mutans and S. sobrinus, 29% inhibition of S. sanguinis, and tongue. For denture wearers, a sample was taken and was inhibited 30% by S. mutans and 18% by S. from the denture bearing hard and soft tissues, as well sanguinis. Strain 14.5 inhibited S. mutans and S. sobrinus as a sample from the denture surfaces. For the current by 59% and 51% respectively and was 28% inhibited analysis, the sample was divided in 3 groups: Group by S. sanguinis. Strain 14.27 inhibited S. mutans and 1 included people with teeth but no denture, group 2 S. sobrinus by 60% and 51% respectively and was 15% included people with teeth and denture, and group inhibited by S. sanguinis. Strain 14.28 inhibited S. mutans 3 included people with no teeth and with a denture. and S. sobrinus by 75% and 59% respectively and was Group 4, persons with no teeth and no denture, was 31% inhibited by S. sanguinis. dropped from analysis due to only one participant fitting into this comparison group. The secondary data Conclusion: The research identified 4 strains with potential probiotic activity for the prevention of analysis compared the numbers of viable cells assessed dental caries. All four were from pediatric subjects by spiral plating from the abovementioned groups without caries experience. Of the four, strain 14.5 was for total aerobic species, Porphyromonas gingivalis, most proficient at forming a sucrose-based biofilm, Fusobacterium nucleatum, Actinomyces viscosus, a property that could aid its retention at caries Aggregatibacter actinomycetemcomitans, and Candida susceptible sites. The results suggest that health-related albicans. A multivariate analysis was also performed to strains may be common in caries-free subjects and control for other available covariates. additional screening may identify several promising Results: Bivariate analysis showed significant probiotic candidates. differences in numbers of aerobic bacteria, F. nucleatum, Supported by: The University of Iowa College of and A. viscosus in the tissue samples among Groups Dentistry Dental Student Research Program 2 and 3 and Groups 1 and 3. Comparing the denture samples of Group 2 and 3 , it was observed that there is a difference in the counts of P. gingivalis and C. albicans. The comparison of tissue and denture samples from Group 3 showed differences for all microorganisms, except A. viscosus. Multivariate analysis showed that lower BMI, higher number of comorbidities and elevated plaque index were associated with higher A. viscosus counts for participants who had teeth. For participants with dentures, A. actinomycetemcomitans counts in the mouth were associated with higher denture plaque levels.

46 Conclusion: Predictors for elevated counts varied appropriateness, willingness to use SDF, and patients’ for different oral pathogens in this sample of willingness to use SDF were 3 (SD= 1.25) from a range institutionalized older adults. of —4-4, 2 (SD= 2.48) from a range of —6-6, 1 (SD= Supported by: Delta Dental of Iowa Foundation; The 0.74) from a range of —2-2, 1 (SD= 0.86) from a range University of Iowa College of Dentistry Dental Student of —2-2, respectively. In the multivariate analysis, a Research Program linear model found that the covariates “SDF Usefulness”, “SDF Appropriateness” and “SDF Patient Willingness to Use” were significantly associated with higher student willingness to use SDF (R2=0.395). 52. Willingness to Use Silver Diamine Conclusion: The results indicated that the graduating Fluoride Among US Dental Students students have a positive perception of SDF regarding its usefulness and appropriateness. Higher willingness Connor A. Dang1, C.L. Comnick1, 64 3 43 to use SDF is seen in students that believe patients are M. Tabrizi , L. Kaufman , A. Soto , accepting of SDF and that have a better knowledge 52 43 40 B. Smith , A. Ribeiro , T. Tobey , about SDF usefulness and appropriateness when used 12 27 1 O.R. Capin , D. Prince , X. Xie , in older adults. Graduating students appear inclined to L. Marchini1 utilize SDF upon entering private practice. 1University of Iowa, Iowa City, IA; Supported by: The University of Iowa College of 3Boston University, Boston, MA; 12Indiana Dentistry Dental Student Research Program University, Indianapolis, IN; 27Roseman University, South Jordan, UT; 40University 43 of Colorado, Denver, CO; University of 53. Speciation and Properties of Potential Florida, Gainesville, FL; 52University of Missouri, Kansas City, Kansas City, MO; Probiotic Strains of Oral Streptococci 64University of Texas, Houston, Houston, 1, M. Zhu1, J.A. Banas1 TX Erika Takanami 1University of Iowa, Iowa City, IA Objective: Silver diamine fluoride (SDF) appears as a promising therapy for arresting and preventing Objective: In our previous study carious lesions in difficult to treat, high risk populations, examining oral streptococci from children including frail and institutionalized older adults. with or without a history of caries, we Although data regarding the effectiveness of SDF identified several strains capable of has been presented, little is known on how the next growth on low pH agar plates but of generation of dentists perceive this newer, non-surgical modest acidogenicity based on terminal pH in broth treatment. This study aims to investigate the knowledge culture. We designated these strains as HAT-LA for and perceptions about SDF of graduating dental High Acid Tolerance and Low Acidogenicity. This study students in multiple American dental schools, as well as investigated the presumptive identities of the HAT-LA their willingness to use SDF in their practices. strains, determined if they could inhibit the growth of the cariogenic species Streptococcus mutans, and Methods: A survey was designed consisting of 21 total compared them to S. mutans for their ability to survive questions: 6 questions regarding students’ demographic an extreme acid challenge. information and their SDF content exposure contextualization, 8 questions tailored to investigate Methods: Multi-locus sequence analysis (MLSA) was 2 domains regarding students’ knowledge about SDF used to presumptively identify HAT-LA species. The (properties and indication), and 7 questions aiming to antagonisms between HAT-LA strains and S. mutans investigate 3 domains regarding students’ perceptions were tested by inoculating strains in proximity to each about SDF (SDF usefulness, appropriateness of using other on agar plates. The percent survival of each strain SDF and willingness to use SDF when in private after a pH 3 acid challenge was tested by comparing practice). Content validity was assessed by a panel viable counts with a neutral pH challenge. of five experienced faculty members and deemed Results: Of five HAT-LA strains, two were identified as appropriate by using the content validity index. The S. parasanguinis and one as S. anginosus. Two others survey was then distributed to graduating dental appeared to be non-streptococcal Gram-positive cocci. students at eight American dental schools. Descriptive One strain of S. parasanguinis fully inhibited growth of statistics were calculated as well as summary indices. A S. mutans when inoculated 24 hours in advance of S. multivariate analysis was performed for modeling the mutans and its survivability after acid challenge was students’ willingness to use SDF in their future practices. about two times higher than S. mutans. The other strain Results: A total of 386 surveys were collected from of S. parasanguinis inhibited S. mutans growth by about 8 schools. The score resulting from the SDF content 34% and had comparable survivability as S. mutans exposure questions was 3 (SD= 1.43) from a range of following acid challenge. The S. anginosus strain did 0-5. The score from knowledge about SDF properties not inhibit growth of S. mutans but was inhibited by S. was 4 (SD= 1.18) from a range of 0-6. The score from mutans. knowledge about SDF indications was 1 (SD= 0.52) Conclusion: The results show that S. parasanguinis from a range of 0-2. The scores from the questions might be protective for the host due to antagonism regarding students’ perception of SDF usefulness, SDF

47 against S. mutans and an ability to withstand low pH. S. 55. Impact of a Poverty Simulation on Den- parasanguinis strains may make excellent probiotics for tal Students’ Attitudes Towards Low-Income caries prevention. Populations Supported by: The University of Iowa College of Dentistry Dental Student Research Program Sheng H. Lu1, K. Leary1, M.R. McQuistan8, F. Qian1 1University of Iowa, Iowa City, IA; 8East 54. Antibiotic Usage in Endodontics: Carolina University, Greenville, NC A Survey of Fourth-Year Dental Students Objective: To understand how dental Kyle Barry1, C. Cucco1, students’ attitudes about poverty change A.E. Williamson1, X. Xie1, C.L. Comnick1 after participating in a poverty simulation. 1University of Iowa, Iowa City, IA Methods: Eighty-nine third year dental students participated in the University of Iowa College of Objective: Occasionally, endodontic Dentistry’s poverty simulation in August 2018. A 20-item infections necessitate antibiotics. Specific survey assessing students’ beliefs about poverty was circumstances where antibiotics are distributed immediately before and after the simulation. necessary is controversial. Differing Fifty-six students who answered both surveys were rationales exist regarding medications and dosing included in the analyses. Responses from the two regimens. Thus, confusion arises and antibiotics may be surveys were matched so that changes in beliefs could prescribed unnecessarily. The aim of this study was to be assessed. One point was assigned for each positive evaluate current fourth year dental students’ knowledge belief response (Maximum positive score=20), while a of appropriate antibiotic prescription. zero was assigned for each negative belief response. Methods: A survey was distributed via email to fourth- Results: Sum scores for responses on the pre- year dental students at 11 dental schools throughout simulation survey ranged from 3-19, while post- the United States. The survey was anonymous with no simulation responses ranged from 3 to 20. Seven identifying information. Participants were directed to a respondents did not undergo a change in beliefs. Eleven Qualtrics survey answering three questions concerning respondents exhibited a negative change in beliefs, antibiotic choice, duration, and alternative medication in while 40 respondents exhibited positive changes allergic patients; a fourth question presented six clinical after the simulation. The two questions with the most scenarios in which students determined if antibiotics are improvement between the pre and post surveys were indicated. “unemployed poor people could find jobs if they tried Results: Of approximately 1460 students, 137 harder” and “people who are poor should not be responded (9.4%). Amoxicillin was selected by 97.1% blamed for their misfortune” with an improvement of as the drug of choice for treatment in a non-allergic 20.3% and 24.6% respectively. The question with the patient, with 2.9% selecting Augmentin. Clindamycin highest percentage of positive responses in both the was selected by 89.1% in penicillin allergic patients. pre and post surveys, 84.5% and 90.9% respectively, was 93.4% selected a duration of 7, 10, or 14 days. 98.5% “there are additional emotional costs associated with determined antibiotics were not indicated for being poor in America.” symptomatic irreversible pulpitis (SIP)/ normal periapex. Conclusion: Participating in a poverty simulation can 95.6% determined antibiotics were not indicated in SIP/ help educate dental students about the challenges symptomatic apical periodontitis (SAP). Pulpal necrosis faced by patients living poverty and develop empathy (PN) /asymptomatic apical periodontitis (AAP) or SAP for their patients. were determined to not require antibiotics by 97.1% and Supported by: The University of Iowa College of 92.7%, respectively. PN/chronic apical abscess (CAA) Dentistry Dental Student Research Program did not require antibiotics according to 68.6%. All determined antibiotics were indicated for PN with acute apical abscess (AAA). 56. Investigating Critical Access Hospital’s Conclusion: Overall, the study population demonstrated adequate knowledge of indications and Role in Rural Iowa Dental Care appropriate prescription of antibiotics in the presence 1, P.C. Damiano1 or absence of endodontic infections. Charlie A. Rupp 1University of Iowa, Iowa City, IA

Objective: Rural communities often face unique challenges for accessing and utilizing primary health and dental care services, such as provider shortages and insurance coverage. With continued decline in the number of dentists practicing in rural areas and an increase in the number nearing retirement,

48 it is imperative to investigate existing programs to Half of PHS hygienists were employed by local public determine their role in bridging this healthcare gap. health agencies, followed by community health centers The purpose of this research study is to investigate the (CHCs) (19%) and nonprofit clinics (9.5%). Among following research question: What role do critical access participants, 61% of their supervising dentists worked hospitals play in providing or referring patients to dental in private practice, followed by 22% in CHCs. Regarding care in rural Iowa communities? acceptance of patient referrals, 21% of participants reported that their supervising dentist accepted Methods: Researchers conducted structured interviews all referrals, 50% accepted some referrals, and 29% with members from critical access hospitals and county accepted none. However, 71% of participants reported departments of public health within the University of that it was somewhat or very difficult to find dentists to Iowa Hospitals and Clinics network. Of the recruited accept patient referrals. counties, seven interviews were completed with emergency room staff, hospital administrators, and Conclusion: PHS hygienists were most frequently public health directors. Audio data collected from employed by government agencies, whereas a majority the interviews were verbatim transcribed using Rev of supervising dentists worked in private settings. transcription service and analyzed in Nvivo. We found imbalanced results with regard to patient referrals; although most supervising dentists accept at Results: Among the issues, access to dental care least some patient referrals, PHS hygienists still had a for Medicaid patients was the most commonly high degree of difficulty referring patients for care. This identified. In addition, these communities reported may be driven by an imbalance between the quantity of provider shortages, transportation issues, large elderly patient referrals and the number that dentists are able population, etc. Emergency room providers reported to accept. seeing patients several times a week with dental abscesses or other dental needs. When probed about Supported by: The University of Iowa College of the potential role for hospitals, many providers saw Dentistry Dental Student Research Program opportunity for coordinating care with a local dentist. Conclusion: Our preliminary interviews have shown that many issues identified in Community Health Needs 58. Teaching Rapid Oral Health Deterioration Assessment and the Rural Health Information Hub are Risk Assessment: A 5-year Report persisting in our Iowa communities, and these dental needs are presenting at local critical access hospitals. Trevor W. Craig1, D. Johnsen1, The findings from these interviews can inform the H. Cowen1, J. Hartshorn1, A. Sato1, development and implementation of a statewide survey L. Thompson1, C. Pendleton1, X. Xie1, of critical access hospitals and county department of L. Marchini1 public health. 1University of Iowa, Iowa City, IA Supported by: The University of Iowa College of Dentistry Dental Student Research Program Objective: An ever-growing older adult population is keeping their teeth for life. However, as this population ages, older adults are exposed to 57. Iowa Dental Hygienists under Public multiple risk factors that can lead to rapid oral health Health Supervision: Employment and Dentist deterioration (ROHD). The aim of this paper is to present a 5-year report about the effectiveness of Referral Patterns a learning tool that helps teach dental students the

1 1 thought process of the expert about how to assess the McKenna J. Woodward , J. Reynolds , risk of ROHD and implement customized treatment 1 M. Kelly plans in a systematic manner. 1 University of Iowa, Iowa City, IA Methods: A learning tool was previously developed using risk factors identified in the literature and the Iowa is one of 42 states in Objective: steps that expert faculty members apply in their clinical which dental hygienists can provide decision making, summarized in a set of ten questions. services in community-based settings A cohort of 188 students during a 5-year period were without first requiring an exam by introduced to the ROHD concept and asked to use the a dentist, a workforce model called public health guide in a presentation during their 5-week Geriatric supervision (PHS). This study aimed to fill a gap in and Special Needs rotation Two faculty evaluators were knowledge about PHS hygienists’ employment and their asked to grade the students on each question. Each working relationship with supervising dentists, including student was graded either Grasped (G), Applied (A), referral patterns. or Missed (M). Question 1 (Q1) Do we have the data for Methods: A 40-question survey was distributed to all general health conditions? Question 2 (Q2) Do we have dental hygienists working under PHS in Iowa (n=126). the data for social support? Question 3 (Q3) Do we Univariate and bivariate analyses were completed. have the data for oral health conditions? Question 4 (Q4) Which data are important? Question 5 (Q5) What Results: The survey response rate was 52%, with 69% of participants currently utilizing their PHS status. will happen if I do nothing? Question 6 (Q6) What is the patient’s risk? Question 7 (Q7) What treatment

49 alternatives are available? Question 8 (Q8) Recommend Conversely, their counterparts were more likely to have specific interventions with rationale. Question 9 (Q9) mothers with previous ECC awareness (55.9% vs. 47.1%; Develop a communications plan for patient/caregivers? p=0.004), be bottle-fed throughout the night (55% Question 10 (Q10) Self-Assessment. Faculty evaluation vs. 45%; p=0.016), and have caries (58.8% vs. 49.7%; agreement was also tested. Additionally, the students p=0.016). No significant associations were found related were given an evaluation in which they graded the to oral hygiene practices (p>0.05). Using birth-order importance of and commented on the exercise. as a predictor variable and caries-risk as an outcome variable for logistic regression analysis revealed no Results: The overall results of student evaluations significant relationship. across all years show that 83.6% of students had an A or G for Q1; 82.3% for Q2; and 83.1% for Q3, 83.1% Conclusion: Increased birth order was related to for Q4, 82.7% for Q5, 81.8 for Q6, 83.1% for Q7, 81.8% dietary habits and presence of caries among young low- for Q8, 69.7% for Q9 and 74.0% for Q10. Agreement income children, but was not supported as a risk factor between the two evaluators was scored at 98.11% for for caries. Q1, 97.14% for Q2, 100% for Q3, 98.10% for Q4, 96.24% Supported by: The University of Iowa College of for Q5, 97.17% for Q6, 95.28% for Q7, 94.34% for Q8, Dentistry Dental Student Research Program 85.85% for Q9, and 96.23% for Q10 across all years. Comparing the first full set of data from 2015 to 2018 students increased on G or A +21.9% on Q1, +22% on Q6, and +44% on Q9. Additionally, 94.4% of the students 60. Motivations for Rural Practice: A Qualita- reported across all years that the learning tool was very tive Study of Iowa Dentists important or important for the general dentist. Zachary W. Prouty1, J.C. Reynolds1 Conclusion: Across a 5-year period, the vast majority of the students were graded an A or G, examiner 1University of Iowa, Iowa City, IA agreement is high, and the students rated the learning tool as important or very important for the general Objective: The problem of recruiting dentist. and retaining healthcare workers in rural areas of the country is well defined in Supported by: The University of Iowa College of the literature. As Iowa is primarily a rural Dentistry Dental Student Research Program state, this study focused on exploring both why dentists choose to enter rural practice and why they stay. 59. Do Modifiable Oral Hygiene and Dietary Methods: This study employed a semi-structured Habits Differ by Birth Order? interview guide adapted from a similar study of rural, California physicians. Sixteen qualitative interviews were 1 1 1 Erin D. Kallsen , F. Qian , T.A. Marshall , conducted by phone in July-August 2019. All dentists M.K. Geneser1, K. Leary1, K. Weber- practicing in the most rural counties of Iowa as defined Gasparoni1 by the 2013 USDA Rural-Urban codes were contacted. Interviews were transcribed and thematic coding was 1University of Iowa, Iowa City, IA completed. Objective: A child’s birth order has Results: A total of sixteen rural-practicing dentists been identified as a risk factor for early (16.5% of dentists contacted) completed the interview. childhood caries (ECC). The primary goal of this study The three most common broad themes included was to assess whether modifiable oral hygiene and familiarity, community, and issues related to clinical dietary habits differ by birth order among low-income care delivery. Dentists cited their upbringing as a large children aged 0-48 months enrolled in the University of influence to enter rural practice. Living close to family Iowa’s Infant Oral Health Program (IOHP). and raising a family in a similar way as they were raised Methods: Data was obtained from 1,146 children’s was an equally important influence. Interviewees also baseline IOHP health history, clinical, and caries- cited feeling fulfilled as clinicians, as rural practice risk assessment forms for a cross-sectional study. requires dentists to perform a wide variety of Univariate, bivariate and multiple logistic regression procedures. analyses (alpha=0.05) were conducted to explore Conclusion: Rural-practicing dentists highlighted their variables associated with birth order, which was upbringing, personal relationships, and ability to provide dichotomized as first-borns (including only one child) a broad scope of clinical services as important reasons vs. later-borns. for deciding to both enter and remain in practice in a Results: 1,146 children (48.7% first-borns, 44.4% female) rural location. Interviewees overall reported satisfaction met the inclusion criteria for this study. Bivariate in their careers and intended as a group to remain in analyses revealed first borns were more likely to be rural Iowa practice. These findings may be used to breastfed (50.8% vs. 44.5%; p=0.046), had inadequate inform programs to recruit and retain dentists in rural fluoride exposure (56.3% vs. 46.9%; p=0.011), as well as areas. drink milk (52.1% vs. 43.7%; p=0.008), water (51.1% vs. Supported by: The University of Iowa College of 41.7%; p=0.011), and juice (56.6% vs. 47.3%; p=0.043). Dentistry Dental Student Research Program

50 61. Patient Failure Rates and Characteristics Supported by: The University of Iowa College of of Patients at the University of Iowa Pediatric Dentistry Dental Student Research Program Dental Clinics in Muscatine, Iowa

Tanner T. Brolsma1, K. Leary1, K. Flick1, 62. Member Awareness of Iowa Medicaid F. Qian1 Healthy Behavior Requirements

1 University of Iowa, Iowa City, IA David J. Strabala1, J.C. Reynolds1, 1 1 Objective: To determine failure rates S.C. McKernan , P.C. Damiano and characteristics of patients who failed 1University of Iowa, Iowa City, IA appointments at the University of Iowa Pediatric Dental Clinic (UIPDC) satellite Objective: Personal health responsibility location in Muscatine, Iowa (MPDC). requirements have been a growing trend in state Medicaid programs. Previous Methods: Data were collected from 732 patients aged studies have found that low member 0-18 years old who failed/late cancelled appointments and provider awareness of complicated program and 1,387 who kept appointments from June 1, 2017 structures resulted in limited success of healthy to May 31, 2018 at the MPDC. Patient data obtained behavior incentives. Iowa’s Medicaid adult dental included: age and sex of patient, distance from the program, the Dental Wellness Plan (DWP), requires two MPDC, time of day (AM or PM), day of week (Tuesday healthy behaviors to be completed annually to maintain or Thursday), month of year for the appointment, full dental benefits: a dental exam and an oral health and insurance provider (private insurance, Medicaid/ self-assessment. The aim of this study was to explore HAWK-I, or self-pay). Statistical analysis consists of factors related to members’ awareness about these descriptive and bivariate analyses (alpha=0.05). requirements. Results: A total of 2,119 subjects aged 0-18 years Methods: We analyzed data from a survey administered old who fulfilled the inclusion criteria were included in March 2018 to a stratified random sample of DWP in the study, comprising 732 subjects who failed the members. Dependent variables were member awareness appointments (mean age=8.4±4.2 years, 53.8% males) of the dental exam and self-assessment requirements. and 1,387 subjects who kept the appointments (mean Independent variables included demographic factors, age=8.6±4.3, 52.6% males). Of the 732 subjects who previous program enrollment, self-reported oral health failed the appointments, 34% were Hispanic and status, and dental utilization. Statistical significance 70.5% had Title XIX insurance, while among the 1,387 was determined by univariate and bivariate chi-square subjects who kept the appointments, 39.5% of subjects analyses. were Hispanic and 72.8% had Title XIX insurance. Bivariate analysis revealed that subjects with unknown Results: Overall, 40.4% of members were aware of ethnicity were more likely to fail appointments than either of the healthy behavior requirements, with 37.0% those who were Hispanic and other ethnicity (57.3% aware of the exam requirement and 19.3% aware of the vs. 31.2% and 34.9%; p<0.001). Moreover, subjects self-assessment. Member awareness about each healthy who preferred English (35.5% vs. 22.8%; p=0.001) and behavior requirement was significantly associated traveled 30+ miles from home to the MPDC (49.6% vs. with level of education, employment status, previous 33% and 34.5%; p=0.005) were more likely to fail the enrollment in DWP 1.0, among other variables. Members appointments compared to those who preferred other with the lowest level of awareness included those who languages and traveled less than a mile or within 30 had not utilized dental care, reported fair-poor oral miles from home to the MPDC, while subjects who had health status, and were previously enrolled in Medicaid. private insurance or Title XIX were more likely than Conclusion: Most members were not aware of the those who were self-pay to keep the appointments healthy behavior requirements. Further research could (69.8% and 66.2% vs. 44.1%; p<0.001). Sex, age, and improve how states inform members of Medicaid time, day of the week, and month of the year for the programs, helping members become more aware of appointment were not significantly associated with their benefits. failed dental appointments. Supported by: The University of Iowa College of Conclusion: The findings of this study demonstrates Dentistry Dental Student Research Program; Iowa that patients are more likely to miss appointments Department of Human Services based on the distance from their home to MPDC, their insurance status, and their preferred language. When placed in context with failure data from the UIPDC at the College of Dentistry in Iowa City, missed appointments can better be predicted for both locations based on their preferred language. However, previous study using the data from the UIPDC showed that failing appointments were associated with the day of the week for the appointment scheduled, while the data from MPDC revealed that the day of the week to be insignificant.

51 63. Preliminary Validation of an Ageism 64. Transportation Dependency and Oral Scale for Dental Students in Romania Pain Among Community-Dwelling Older Iowans Luke T. Veenstra1, P. Barlow1, A.E. Kossioni98, S. Mihaela Popescu152, Bobby L. LeWarne1, D.J. Caplan1, V. Mercut152, M. Jana Tuculina152, L. Marchini1, S. Sasser126, C. Russell126 152 152 M. Scrieciu , A. Stanusi , 1University of Iowa, Iowa City, IA; 1 L. Marchini 126Iowa Department of Aging 1University of Iowa, Iowa City, IA; 98National and Kapodistrian University, Objective: This cross-sectional study Athens, Greece; 152UMF Craiova, Romania aimed to evaluate the relationship between older adults’ dependency on Objective: Ageism is the prejudice or discrimination transportation and mouth pain. Our hypothesis was on the grounds of a person’s age. It is very prevalent that greater dependence on transportation would be among health providers, but a specific tool for assessing associated with greater prevalence of tooth or mouth ageism among dental students was lacking. The first pain causing difficulty in eating. dental specific ageism scale was developed in the USA, Methods: The Iowa Department on Aging (IDA) surveys and was then translated in multiple languages. The aim older Iowans to determine their eligibility for IDA social of this paper was to perform a preliminary validation programs. This analysis examined all participants age of the Romanian version of an ageism scale for dental 65+ who were surveyed between March - December students. 2017 regarding several variables related to dental Methods: The initial 27-question ageism scale was utilization; demographics; activities of daily living translated to Romanian and administered to 8th, 10th, and (ADLs); and instrumental activities of daily living 12th semester dental students. The data was analyzed (IADLs). After univariate and bivariate frequencies using Principal Components Analysis (PCA) with an were generated and evaluated, multivariable logistic orthogonal, Varimax rotation. The Kaiser-Meyer-Olkin regression models were generated where “dependence (KMO) and Bartlett’s Test of Sphericity statistics were on others for transportation” was the main exposure used to check for the adequate factorability of the variable and “I have tooth or mouth problems that sample with a KMO greater than 0.60 and Bartlett’s make it hard for me to eat” was the outcome variable. significance p < 0.05 considered acceptable. The Forward selection was employed to create a final data was then compared across several demographic model that controlled for important confounders of the variables using a combination of independent samples relationship of interest. t-tests and one-way between subjects analysis of Results: In this sample of 2692 older adults, 40% were variance (ANOVA). age 65-74; 37% were age 75-84; and 23% were age 85+. Results: The 27-item questionnaire was administered With regard to transportation, 2500 participants (93%) to a total of 210 Romanian dental students. Adequate responded to the question, with 76% of those indicating factorability was confirmed with a Kaiser-Meyer-Olkin a need for substantial help with transportation. With (KMO) of 0.676 and a Bartlett’s Test of Sphericity regard to having a tooth or mouth problem, 2072 yielding p < 0.001. PCA revealed a 10-item scale participants (77%) responded to the question, with distributed into three components that accounted 24% of those indicating a problem that interfered with for 58% of the overall variance. The first component eating. The final multivariable model indicated that contained 4 items related to the cost-benefit of there was not a statistically significant relationship providing care to elderly patients (α=0.80). The second between those two variables (p>0.05), controlling for component contained 3 items that revolved around the available confounders. perceptions of the elderly and their value in society Conclusion: In this sample of older Iowans, dependence (α=0.59). The third component contained 3 items on transportation was not associated with tooth related to the geriatric dental training and experience or mouth problems that made it difficult to eat. that the dental students has been exposed to (α=0.46). Suggestions for future research include incorporation Discriminant validity only showed differences in first of dental status variables into the IDA survey to permit component demographics based on having an elderly stratification of participants by dentate status or family member number of teeth. Conclusion: The preliminary validation of the Romanian Supported by: The University of Iowa College of version of the ageism scale produced three components Dentistry Dental Student Research Program encompassing 10 questions. The data demonstrated acceptable validity and reliability and can be used for further testing with larger samples. Supported by: The Richard L. and Nancy M. Christiansen Professorship in International Oral Health Education and Research; The University of Iowa College of Dentistry Dental Student Research Program

52 65. Use of Social Media by Dental Students 66. A Social Media Intervention for Improv- and Recent Alumni ing Dental Health in Adolescents

Madison M. Kasparek1, T.A. Marshall1 Susana J. Calderon1, J.A. Banas1, D.R. 1 1 1 1University of Iowa, Iowa City, IA Drake , X. Xie , C.L. Comnick 1University of Iowa, Iowa City, IA Objective: Knowledge and perceptions of social media (SM) use for dietary Objective: Adolescents in the United information by dental students and recent States face potential systemic health alumni is important as students and issues as a result of poor oral health. Their alumni provide dietary counseling for oral high risk for caries is associated with health. Our objectives are to understand students’and poor oral hygiene and high consumption of soda. We alumni’s use of SM and perception of SM food and need a better understanding of oral health behaviors nutrition content reliability. and the factors influencing these behaviors to reduce Methods: First (D1) and fourth (D4) year students and dental caries in adolescents. Our study focuses on five-year alumni (n=213) from the College of Dentistry exploring the effects of a health text message system were invited to participate. We designed a survey to and smartphone-based intervention on adolescent queried demographics, professional and personal SM tooth brushing behavior and dietary choices. We are use, sites visited for dietary information, and perceived reporting here changes in tooth brushing behavior and reliability (i.e., trustworthiness) of information found on colonization with cariogenic bacteria. each site. The survey was administered using Qualtrix; Methods: In this pilot study, a convenience sample of students were given 3 weeks to complete. 94 subjects aged 12 to 14 years old met the inclusion Results: Participants (n=67) were 58% female, and criteria to receive a health text message and use a 61% D1s, 24% D4s, and 15% alumni. Students were tooth-brushing app or use the tooth-brushing app younger than alumni (mean±SD: 23.7±2.2 vs. 33.6±2.8 without the text messages for 7 weeks. Subjects years; p<0.001). Forty-six percent of D1s, 56% of D4s, completed an oral health questionnaire, a sugary and 80% of alumni use SM for professional use. One beverage questionnaire, and saliva specimens were hundred percent of D1s, 94% of D4s, and 80% of alumni collected at the study baseline and endpoint. A two- use SM for personal use; 74% of D1s, 63% of D2s, and sided paired t-test was used to assess whether there 50% of alumni spend 1-2 hours/day on SM for personal were significant changes in the salivary presence of use. Facebook is the most visited SM site by students cariogenic bacteria over the duration of the study. and alumni (93%); both students and alumni reported Results: 90 subjects were enrolled in the study. The dietary information found on all SM sites as 0% reliable. subjects were 52% male and 48% female from different Less than 40% of students and alumni use PubMedÆ, socioeconomic statuses. 52% were Caucasian, 33% the Food and Nutrition Information CenterÆ (FNIC), were African American, 5% Hispanic, and 8% other or ChooseMyPlateÆ for personal and/or professional ethnic categories. 174 saliva samples were collected. use. Information on PubMed was classified as 33% 54 subjects agreed to receive the intervention text reliable by both students and alumni, on FNIC as 43% messages and 36 did not. The frequency of daily tooth reliable by students and 100% reliable by alumni, and brushing increased from 77% to 86%. Brushing twice ChooseMyPlate as 39% reliable by students and 67% a day increased from 60% to 63%. Using toothpaste reliable by alumni. increased from 53% to 56%. The compliance rate Conclusion: Our results suggest that students and for responding to text messages was 45%. The alumni use SM for personal and professional use, improvements in oral hygiene led to significant (p and recognize the unreliability of SM sites for dietary < 0.001) reductions in total salivary bacteria and information. total streptococci, but no change in the presence of cariogenic mutans streptococci. Supported by: The University of Iowa College of Dentistry Dental Student Research Program Conclusion: Our preliminary results suggest focusing on oral health led to an improvement in tooth brushing frequency and a reduction in overall oral bacteria. Dietary data is currently being analyzed. Further analyses are warranted to understand the lack of a reduction of cariogenic bacterial species. Supported by: NIDCR NRSA T-90 5T90DE023520-07 and donation from Proctor & Gamble Global Team.

53 67. Structural and Cognitive Barriers to 68. TMD and General Health Symptoms in Completion of a Healthy Dental Behavior in Adolescent Orthodontic Patients Iowa’s Medicaid Program Kane M. Louscher1, H. Chen1, K. Shin1, Aparna Ingleshwar1, J.C. Reynolds1, K. Kluesner1, C. Pendleton1, X. Xie1 1 1 S.C. McKernan , P.C. Damiano 1University of Iowa, Iowa City, IA 1University of Iowa, Iowa City, IA Objective: Temporomandibular disorders Objective: In July 2017, Iowa’s Medicaid (TMD) are a group of musculoskeletal adult dental program implemented a conditions that the prevalence of TMD Healthy Behaviors (HBs) Program wherein increase dramatically during adolescence. members must complete two HBs Orthodontic treatment is commonly performed during annually- a preventive dental visit and an oral health adolescent years. Although in general, orthodontic self-assessment. Failure to complete both behaviors treatment has not been identified as either harmful annually results in the payment of $3/month premium or beneficial to TMD, it is unclear if certain subgroups for the succeeding year, and, if premiums are not paid, of pediatric orthodontic patients may have greater a reduction in benefits. The Health Care Access Barriers vulnerability to TMD. Growing evidence suggested that Model (HCAB) is a framework to guide the identification comorbid pain and negative somatic and psychological of modifiable structural, cognitive and financial barriers symptoms are predictors of onset of TMD in early to access to care in poor and underserved populations. adolescence. The objective of this study is to evaluate Our study examines specific ‘structural’ and ‘cognitive’ the association between general health symptoms barriers associated with Iowa Medicaid members and the presence of TMD in adolescent patients when completion of a preventive dental visit. undergoing orthodontic treatment. Methods: A stratified random sample of DWP members Methods: Survey questions regarding general health were surveyed in March 2018 (N=18000). Outcome and TMD symptoms were developed and presented to is member self-report of completing a required current pediatric orthodontic patients (11 to 17 years preventive dental visit since program implementation. of age) at the University of Iowa College of Dentistry Barriers include: Structural- transportation problems, Orthodontics Clinic. The survey was administered communication from dental plan; and Cognitive- health through paper form or an online survey system literacy level, knowledge about specific aspects of the (Qualtrics). Participants were categorized into 2 groups: HBs program, and attitude toward the HBs program. TMD-free group (i.e., never had TMD symptoms), and TMD group (i.e., reported any history of TMD Results: Adjusted response rate was 25.2%. Final symptoms). Descriptive statistics and exploratory sample for our analyses included 2799 respondents. analysis were performed on group differences in all Of these, 54% reported completing a preventive dental general health symptoms with Fisher’s exact test. R 3.5.1 visit. Blockwise multivariable regression analysis showed was used. that structural barriers: (i) unmet transportation need for a dental visit, (ii) lack of a phone call or other Results: Overall, the distribution of general health communication from their dental plan, and cognitive symptoms seems to be different between groups. barriers: (iii) lack of awareness about dental check-up Participants with a history of TMD reported more requirement to retain full benefits, (iv) adequate health frequent general health symptoms related with literacy level, were significantly associated with lower musculoskeletal and connective tissue health, odds of completing a preventive dental visit, even neurological and cognitive function, anxiety, and sleep after adjusting for other sociodemographic variables disturbance and fatigue (p-values: 0.03 — 0.09). No (p<0.05). adjustments were made for multiple comparisons. Conclusion: We identified structural and cognitive Conclusion: Our results suggest that adolescent barriers to member completion of a preventive dental orthodontics patients with a history of TMD may have visit in a state-mandated Healthy Behaviors program. different general health symptoms compare to those State-led outreach efforts aimed at increasing without a history of TMD. The significance of such awareness about the Medicaid HBs program among its differences to the development of future TMD and its members, and policies targeting transportation barriers impact on orthodontic treatment planning warrants may help improve access to routine dental care. further evaluation. Supported by: Iowa Medicaid Enterprise Supported by: The University of Iowa College of Dentistry Dental Student Research Program

54 69. Comparison Between TAD-Supported 70. A Pilot Study on Post-Surgical Change RME vs. Conventional RME for Palatal in Condylar Position Expansion Nicole E. Youd1, V. Allareddy1, Samantha Marti1, C. West1, F. Qian1, A. Figueroa1, K. Shin1 1 S. Rengasamy Venugopalan , 1University of Iowa, Iowa City, IA S. Marshall1, T.E. Southard1, K. Shin1 Objective: The objectives of this study 1University of Iowa, Iowa City, IA were to compare pre- and post-surgical Objective: The purpose of this study position of the condyles after combined was to evaluate the relationship between LeFort I and bilateral sagittal split age and maturation at which a successful separation of osteotomy (BSSO) procedures and to evaluate post- the maxillary midpalatal suture (MPS) separation could surgical changes in condylar position in relation to be achieved, and if MPS could be improved with the the temporal bone (TMJ) using cone-beam computed utilization of a TAD-supported RME appliance. tomography (CBCT). The null-hypothesis of this study is that there is no significant change in pre- and post- Methods: Ninety-six consecutively treated subjects surgical condylar position in the TMJ. (mean age=13.8±2.6 years, 43 males, 53 females) exhibiting maxillary skeletal constriction underwent Methods: In this retrospective study, we observed nine conventional RME treatment and thirteen (mean patients who underwent bimaxillary surgeries including age=17.1±2.1 years, 7 males, 6 females) underwent RME BSSO for either advancement or setback. Fixation was treatment utilizing TADs. Subjects were also classified achieved with three bi-cortical positioning screws in all into pre-pubertal or post-pubertal groups based on cases. Preoperative and postoperative CBCT images maturation status. MPS separation was confirmed by were obtained, de-identified and evaluated using development of a diastema between upper central Invivo software. Each condylar head was evaluated on incisors and using a maxillary occlusal radiograph. coronal and sagittal planes. On the coronal images, Statistical analysis consisted of chi-square test, Fisher’s the medial most, lateral most, and midpoint distances test, the Wilcoxon rank-sum test, and simple linear were measured and on the sagittal image, the anterior regression (alpha=0.05). most and posterior distances were measured. Two observations were obtained one week apart to assess Results: Of the 96 subjects treated with a conventional subject reliability. An intra-Class Coefficient (ICC) test RME, 71.9% had a successful MPS separation. The was used for inter-rater reliability. A Wilcoxon Matched mean/median age of subjects who had a separation Pairs Test was used in order to determine if there were was significantly lower than those who didn’t have any significant differences between pre- and post- a separation (13.0\13.2 vs. 15.7\14.8 years; p<0.001). surgery measurements of condylar position. In those who were pre-puberty, 96.4% had a MPS separation and in those who were post-puberty 62.1% Results: Strong inter-rater reliability was evaluated with had a MPS separation (p=0.001). Moreover, the mean/ all estimations between 0.855 and 0.968. There were median months past puberty in those who had a MPS no significant differences between the pre- and post- separation was significantly lower than in those who operative measurements both in coronal and sagittal had no MPS separation (17.1\13 vs. 28.8\30 months; planes (P<0.05) except for the measurements at the p=0.007). For every additional increase in age by a year, midpoint distance of the left condyle. successful MPS separation decreased by an average of Conclusion: There is no significant change in condylar 14.1%. Of the 13 subjects treated with TAD-supported position post-operatively following bimaxillary RME, all of them were post-puberty and 100% had a orthognathic surgery with positional screw fixation in MPS separation. the mandible. Surgical movements do not appear to Conclusion: TAD-supported RME is a viable option cause significant changes in the post-operative condylar when treating post-pubertal adolescent patients. position during this surgical procedure. This study only However, MPS separation is highly likely to occur in analyzed a small sample size, and we plan to recruit pre-pubertal patients treated with conventional RME. more subjects for further analysis. As a result, patient age and maturation status must be Supported by: The University of Iowa College of considered when deciding between conventional or Dentistry Dental Student Research Program TAD-supported RME treatment for MPS separation.

55 71. Performance of Machine Learning 72. Evaluating Reasons for Failed General Algorithms on Premolar Extraction Pattern Anesthesia and Procedural Sedation Visits

Benjamin Phan1, T. Ling1, T. Peter1, Jasmine A. Butler1, F. Qian1, A. Lesch1, P. Fan1, K. Shin1 M. O’Malley1, K. Leary1 1University of Iowa, Iowa City, IA 1University of Iowa, Iowa City, IA

Objective: The decision of premolar Objective: This study evaluated reasons extraction for correcting malocclusions that pediatric dental patients missed their has been solely made based upon the history and physical (H&P) or treatment practitioner’s best clinical knowledge appointments utilizing general anesthesia and experiences. To assist the clinician’s decision, (GA)/procedural sedation (PS), and compared them to machine learning algorithms can be trained to learn patients who kept their appointments. the relationship between a patient’s pre-treatment Methods: Data were collected from a retrospective conditions and a practitioner’s treatment decision. chart review of 518 patients who failed/late cancelled, The objective of the study is to evaluate the overall or kept their GA, PS, or H&P appointments at the performance of 10 different machine learning algorithms University of Iowa’s Pediatric Dental Clinic (UIPDC) and test whether the performance differences are between January 1, 2018-April 30, 2019. The information statistically significant. obtained included patients’ demographics and reasons Methods: De-identified clinical records of 101 non- why the patient failed their appointments. Statistical extraction cases and 61 extraction cases were extracted. analyses consisted of descriptive and bivariate analyses The following attributes of each record were used as using chi-square test, Fisher’s exact test, Cochran- input features of machine learning models: ANB, 1-FH, Mantel-Haenszel test, and Wilcoxon rank-sum test 1-MP, 1-SN, 1-1, overjet, overbite, NA-U1, NB-L1, upper- (alpha=0.05). lip to E line, lower-lip to E line, maxillary arch length Results: 518 subjects were included, 86 who failed discrepancy, mandibular arch length discrepancy, Angle appointments (mean age=7.6±5.8 years; 64% males) and classification, curve of Spee, and crowding index. The 432 who kept appointments (mean age= 8.4±7.0 years; output of machine learning models is the decision on 61.6% males). Of those who failed, 82.6% had Medicaid/ extraction. The distributions of input and output as well DWP and 47.7% had special health care needs (SHCN). as their correlations are showed in Figure 1 and Figure 2 Compared to those who kept appointments, 80.8% respectively. Ten machine learning models were trained had Medicaid/DWP and 55.8% had SHCN. The most and tested: Multi-layer Perceptron, NaÔve Bayes, common reasons for failing appointments were reported Logistic Regression (LASSO and Ridge), Support Vector as “child illness” and “unknown”. Bivariate analysis Machines (Linear and Kernel), K-Nearest-Neighbor, revealed that subjects who were seen for emergency Decision Tree, Random Forest, and XGBoost. Pairwise care between consultation and the surgery visit were t-test was used to conduct hypothesis test. more likely to fail appointments than those who were Results: The proposed 10 models achieve average AUC not seen for emergency care (33.3% vs. 12.7%; p=0.001). ranging from 0.7034 to 0.7750. The top three models Additionally, mean/median days between consultation are Logistic Regression (LASSO), Random Forest and and surgery for subjects who missed appointments Logistic Regression (Ridge). They have statistically were significantly higher than subjects who kept significant superior performance over other 7, 6, and appointments (107.5/91 vs. 75.6/58; p<0.001). 6 models respectively. However, the performance Conclusion: Important distinctions were found between difference among them are not statistically significant. patients who failed their appointments and who kept Conclusion: We evaluated performance of 10 different their appointments. machine learning algorithms on the tooth extraction Supported by: The University of Iowa College of task using patients’ clinical records. For future work, we Dentistry Dental Student Research Program may consider training algorithms to learn directly from images instead of using software to manually extract a limited number of features, as images contain much richer information. Supported by: The University of Iowa College of Dentistry Dental Student Research Program

56 73. Effect of Different Forces on Inclination 74. Arhgap29 in Oral Epithelial Cells Is When Torqueing Upper Incisors Required for Palate Shelf Elevation

Robert Staley1, F. Qian1 Bethany Doolittle1, L. Rhea1, 1 1University of Iowa, Iowa City, IA M. Dunnwald 1University of Iowa, Iowa City, IA Objective: The purposes of this study were to compare torque angles in wide Objective: ARHGAP29, or Rho GTPase twin upper central incisor (WD) brackets activating protein 29, negatively regulates with non-torqued slots using 18X25 mil cellular RhoA activity. Genetic variants arch-wires: stainless steel (SS), tungsten- in ARHGAP29 have been linked to molybdenum (TMA), and nickel titanium (NT). Two an increased risk for nonsyndromic cleft lip and/or hypotheses were tested: (1) that a higher force for palate (NSCL/P) in humans. In mice, complete loss-of- torque and two lower force levels created similar angles function (LoF) mutations in Arhgap29 lead to death or inclinations in wide upper twin edgewise brackets, prior to embryonic day 8.5 (e8.5). This highlights the and (2) there is no difference in torque angles among requirement for Arhgap29 for life, but prevents further three arch-wire alloys in WD brackets at three different understanding of its role in craniofacial development. force levels. Thus, the objective of this study was to conditionally Methods: A machine made to torque recorded torque remove Arhgap29 from the oral epithelium to angles in degrees for WD brackets (n= 5/group). ascertain its function in this tissue during craniofacial The forces at the machine-arch-wire were 21Nmm, development. 4.91Nmm, and 2.94Nmm. One-way ANOVA with the Methods: Using a novel Arhgap29 floxed allele (A29fl) post-hoc Tukey’s HSD test was conducted to test for the along with a Keratin 14 Cre recombinase driver (K14Cre) difference in torque angles among the three types of in mice, Arhgap29 was deleted from ectodermal cells, arch-wire alloys at each force level (alpha=0.05). including the oral epithelium and the epidermis. We Results: Lower torque angles occurred in the WD performed histological examination on coronal sections brackets subjected to the lower force levels of 4.91Nmm of nine e14.5 litters and phenotypic characterization of and 2.94Nmm when compared to the high force of critical proteins involved in craniofacial development. 21Nmm. For the high force of 21Nmm, SS had the Results: K14Cre;A29fl/fl embryos collected at significantly lower angles compared to TMA and NT, e14.5 exhibited genotypes with proper Mendelian while NT had the significantly larger angles than SS and distribution ratios and mice survived into adulthood. TMA for the two lower forces. The lowest angle for the Our results show a significant increase in the number SS arch-wires was 9-degree, higher than the 7-degree of embryos with failed palatal shelf elevation or fusion inclination measured by Andrews (1989) in a sample of in K14Cre;A29fl/fl compared with wild type embryos. ideal occlusions. Interestingly, we did not observe intraoral fusion. Conclusion: (1) This study found significant differences Conclusion: Contrary to our hypothesis that altered in the angles for all three forces in the alloys, (2) the palatogenesis in Arhgap29 conditional null mutants at arch-wire alloys differed significantly in their angular e14.5 would occur due to abnormal oral adhesions as responses to the highest and two lower forces, (3) a previously described in a heterozygous LoF Arhgap29 future study is needed to discover a lower torque force mouse model, K14Cre;A29fl/fl embryos exhibited a delay associated with 7-degree torque angle for upper central in elevation and migration of palate shelves without incisors, and (4) on the basis of this research, SS wires oral adhesions. These data show that Arhgap29 in performed best for torqueing upper incisors, compared oral epithelial cells plays a previously undescribed role to TMA and NT wires. in palate shelf elevation, which furthers the overall understanding of genetic contribution to craniofacial development. Supported by: NIH NIAMS AR067739; The University of Iowa College of Dentistry Dental Student Research Program

57 75. Identification and Characterization of Results: Whsc1 is upregulated upon miR-24 inhibition at Wolf-Hirschhorn Syndrome Candidate 1 both transcription and translation levels. miR-24 directly binds to Whsc1 3’UTR and inhibits its production. Based (Whsc1) in miR-23-Cluster-Mediated Tooth on the IF staining, Whsc1 is expressing from early stage Development and restricting to stem cell niches in homeostatic tooth germ. Dan Su1, F. Shao1, S. Eliason1, H. Cao1, B.A. Amendt1 Conclusion: Whsc1 is a direct target of miR-24, which also has a great potential role in regulating tooth 1University of Iowa, Iowa City, IA development and tooth homeostasis. Our next step is to assess the miR-23/27/24 expression profile in tooth Objective: Tooth development or development and assess the Whsc1 expression pattern odontogenesis is the complex process change in our newly made miR-23/27/24 knockdown by which teeth form from embryonic mice (Rosa26Tg/Tg-PMIS-miR23/27/24). cells, grow, and erupt into the mouth. For human teeth to have a healthy oral environment, Supported by: NIH R43DE027569, NIH R01DE026433, all parts of the tooth must develop during appropriate NIH R03EB025873, NIH R21DE025328 stages of fetal development. Abnormal development of any part of tooth leads to dental anomalies, which occurs commonly with a prevalence of 36.7% to 76. GRHL3 Variants are Associated with 40.3% of non-syndromic patients. The process of South African Cleft Palate Only odontogenesis requires multiple layers of regulation between the dental epithelium and mesenchyme in Chinyere Adeleke1, T. Naicker145, a stage-specific manner, including Shh, BMP, Wnt T. Busch1, W.O. Awotoye1, M.Y. Li1, and FGF signaling pathways. In addition, microRNAs J. Olotu1, M. Hassan1, J. Pape1, (miRs) have also been found orchestrating this process. A. Alade1, O. Adeniyan142, O. Olatosi139, Our lab previously identified miR-23/27/24 cluster 1 1 participating the Pitx2-Hmgn2 regulatory network in S.E. Miller , A. Butali ameloblast differentiation. Members in this cluster are 1University of Iowa, Iowa City, IA; highly expressed in the epithelium and mesenchyme 139University of Lagos, Idi-Araba, Lagos; of developing mouse lower incisor. These data indicate 142Burton Hospitals NHS Foundation the potential role of miR-23/27/24 cluster in regulating Trust, Staffordshire, UK;145 University of tooth development. However, the underlying mechanism KwaZulu-Natal, Durban, South Africa has yet to be determined. By performing miR target prediction and literature research, we found that Wolf- Objective: For years, scientists have been studying Hirschhorn Syndrome Candidate 1 (Whsc1), a causative the etiology of cleft lip with or without cleft palate. gene of Wolf-Hirschhorn Syndrome (WHS), as a target Unfortunately, the genetic etiology of cleft palate only of miR-23/27/24 cluster. In this study, we investigate (CPO) is much less understood. Recently, however, the miR-23/27/24-Whsc1 regulatory axis in tooth variants of Grainyhead like transcription factor 3 development. To this end, we profiled Whsc1 expression (GRHL3) have been found to be associated with risk patterns during mouse tooth development and found for CPO in European and African populations including Whsc1 was expressed from early stages and restricted Nigeria, Ghana, and Ethiopia. to the stem cell niches in homeostatic tooth germ. Methods: In order to identify genetic variants that Understanding the miR-23/27/24-Whsc1 regulatory may further explain the etiology of CPO, we sequenced network may not only advance our understanding in GRHL3 in a South African population to determine the gene regulatory networks in tooth development if rare variants in the gene were associated with the under normal and defective conditions, but also provide presence of syndromic or non-syndromic CPO. We insights in tissue bioengineering to repair or regenerate sequenced the exons of GRHL3 in 51 cases. When tooth. necessary, we also sequenced the parents of the Methods: To identify targets of miR-23/27/24 cluster, individuals to determine the segregation pattern and we used miR target prediction software and found presence of de novo variants. several genes of our interest. One of them is Wolf- Results: Two missense variants, one novel and one Hirschhorn Syndrome Candidate 1 (Whsc1), which is known (p.Asp169Gly and p.Arg298Cys), were identified also a causative gene of Wolf-Hirschhorn Syndrome in exons 4 and 7, respectively. Both variants were found (WHS) and identified as a target of both miR-24 and in individuals with CPO. The novel variant was absent miR-23. To further confirm the targeting, we performed from all public exome and genome databases including RT-qPCR and Western blot to assess the change of 5,200 individuals from Africa and found in the mothers Whsc1 expression upon miR-24 inhibition, as well as of the individuals. Both variants were predicted to be luciferase assay to examine the binding of miR-24 at probably damaging by Polyphen. The novel variant the Whsc1 3’UTR. To investigate the miR-23/27/24- (p.Asp169Gly) was predicted to be tolerated by SIFT, Whsc1 regulatory axis, we first profiled the Whsc1 while HOPE analyses suggest that the variant may expression pattern during mouse tooth development by disturb the rigidity and/or correct folding of the protein. immunofluorescence staining (IF). The known variant (p.Arg298Cys) was predicted to be

58 deleterious by SIFT. One known intronic variant (GRHL3 and inhibited only by VD compared to untreated cell ENST00000528064.5) with potential to alter splicing lines. This result was statistically significant. was identified in exon 2 in an individual with cleft lip and Conclusion: VEGF was stimulated by all peptides Alveolus. This variant was previously reported in West but inhibited by VD suggesting that this peptide and East African populations, but this is the first report presents a potent action being able not only to control in a South African population. proliferation but also block VEGF in OSCC. In vivo Conclusion: This study provides evidence that variants experiment will provide broader and deeper results in GRHL3 contribute to the risk of syndromic or non- but, based on the results of this study, VD emerges as a syndromic CPO in the South African population. potent target against OSCC acting through VEGF. This Supported by: NIDCR DE022378; NIDCR R13DE027291; can provide insight for future therapeutic use. Robert Wood Johnson Foundation Grant number 72429; Supported by: The University of Iowa College of The University of Iowa College of Dentistry Dental Dentistry Dental Student Research Program Student Research Program

78. IL-10 Protects Periodontal Bone Loss 77. Possible interaction between VEGF, through Reducing Neutrophil Recruitment fl-catenin and Cardiac Hormones on Oral Squamous Cell Carcinoma Flora Y. Yen1, L. Sun10, M. Girnary56, Y. Jiao56, S. Zhang1 1 1 Grant L. Gullion , M.S. Campos 1University of Iowa, Iowa City, IA; 1University of Iowa, Iowa City, IA 10Harvard University, Cambridge, MA; 56University of North Carolina, Atrial natriuretic peptide (ANP) Chapel Hill, NC derivatives are most commonly recognized for their key role in blood Objective: The objective for the study pressure and volume regulation. is to quantify neutrophil infiltrates in the gingival Previous in-vivo and in-vitro studies tissue of Il10-/- mice through immunohistochemistry have also demonstrated their anti-proliferative role and compare it to wild type control mice in a ligature- in cancers such as human breast cancer, pancreatic induced murine alveolar bone loss model. adenocarcinoma, and lung cancer to name a few. Methods: The alveolar bone loss was induced in Il10- However, their role in head and neck cancers such as /- and age- and gender-matched wild type (WT) oral squamous cell carcinoma has not been thoroughly C57BL6 mice through a ligature model and quantified examined. Additionally, β-catenin and VEGF are through microCT analysis. The transcriptional level important molecules involved in oral squamous cell of several IL-17 mediated cytokine and chemokine carcinoma establishment and progression that have genes was assessed by quantitative real-time PCR and been suggested as therapeutic targets compared between Il10-/- and WT mice. Neutrophils, Objective: The objective of this project was to which can be are recruited through IL-17-mediated investigate if four cardiac hormones, namely vessel chemokine production, were stained through dilator (VD), long-acting natriuretic peptide (LANP), Immunohistochemistry and quantified by counting the kaliuretic peptide (KP), atrial natriuretic peptide (ANP), positive stained cells in the periodontal tissue above the would impact the levels of VEGF and β-catenin protein alveolar bone level between the first and second molars expression in oral squamous cell carcinoma (OSCC) cell where the ligature was placed. The examiner was blind lines. to the murine samples. Student’s t-test was applied to comparing the neutrophils infiltrated to the Il10-/- Methods: Proliferation assays were performed first in gingiva with WT control samples. order to confirm the inhibitory effect the four hormones had on cancer cell proliferation and to establish at which Results: Significantly more bone loss induced by concentration they had the maximal effect. Proliferation ligature was present in Il10-/- mice as compared to assays were performed twice using MTS kit and WT mice in the same bone loss model (p=0.0003). comparing the effect hormones had at concentrations The transcription of Il17 and several IL-17 associated of 100uM, 10uM, 1uM, 0.1uM and 0.01uM on OSCC19 cytokine genes such as Ccr2 and Rank in the Il10-/- cell lines. Second, cells seeded in a 96-well plate were gingival tissue was significantly higher than WT mice. treated with each hormone at 100uM in triplicate. ELISA Significantly more neutrophils were present in the Il10-/- assays were then performed to evaluate expression of gingival tissues than WT samples (p=0.02) β-catenin and VEGF. Conclusion: IL-10 protects the periodontal bone loss Results: According to the results, all four peptides in mice through mitigating neutrophil recruitment, a were able to inhibit the proliferation of cancer cells process that can be promoted by IL-17. and the most effective concentration was 100uM. All Supported by: NIDCR 1K99DE02786 (to S.Z); The four peptides were able to inhibit β-catenin expression University of Iowa College of Dentistry Dental Student but data were not statistically significant. On the other Research Program hand, VEGF expression was stimulated by all peptides

59 79. Potential Prognostic Role of Combined CD3+ patients, but no impact on PFS. Similarly, high EGFR and T cell markers in Oral Squamous CD8+ patients had significantly better OS compared to low CD8+ patients, but no impact on PFS. When EGFR Cell Carcinoma and CD3 expression was combined, EGFR+/ high CD3+ patients demonstrated significantly more favorable Wattawan Wongpattaraworakul1, 1 1 OS compared to EGFR+/ low CD3+. CD3 expression R. Anand , K.N. Gibson-Corley , had no impact on OS or PFS in EGFR- patients. When 1 1 G. Ofori-Amanfo , A. Simons EGFR and CD8 expression was combined, there 1University of Iowa, Iowa City, IA were no significant differences in OS among the expression groups. For PFS, EGFR+/ low CD8+ patients Objective: Oral squamous cell carcinoma demonstrated worse PFS compared to other groups. (OSCC) is the most common malignancy Conclusion: Altogether, it appears that CD3 and CD8 of the head and neck region. The patients who present expression impact survival outcomes in EGFR+ but not with advanced locoregional disease at diagnosis EGFR- OSCC patients. These results also suggest that have a high risk of developing secondary tumors EGFR+ OSCC patients may benefit more favorably from even after local control with radiotherapy is achieved. immunotherapy compared to EGFR- patients. Further Therefore, there is a great need to identify biomarkers investigations based on combinations of EGFR and T for recurrence and disease progression in OSCC cell marker expression are warranted to identify novel patients in order to facilitate patient management and and reliable prognostic/predictive biomarkers for OSCC allow for treatment modification. Epidermal growth patients. factor receptor (EGFR) is well known to be a general prognostic biomarker for head and neck squamous cell carcinoma (HNSCC), however the specific prognostic value of EGFR in OSCC is controversial. Recently, the 80. A Novel Endoplasmic Reticula Micrope- presence of CD3+ and CD8+ tumor-infiltrating T cells ptide BGRM1 Promotes Insulin Secretion in has been found to be associated with a significant Pancreas survival advantage in a variety of disease sites. In this study, we aim to determine if CD3 or CD8 expression F. Shao1, M. Li1, M.E. Sweat1, Q. Qian1, would enhance the prognostic value of EGFR in OSCCs. Y. Guo1, An-Vi D. Phan1, B.A. Amendt1, Methods: These studies utilized tumor samples of L. Yang1, H. Cao1 OSCC patients obtained from the archives of the 1University of Iowa, Iowa City, IA Department of Pathology at the University of Iowa Hospitals and Clinics. Tissue microarrays (TMAs) were Objective: In the past few years, many constructed using 3-6 morphologically representative small open reading frames (ORFs) were tumor regions (1 mm) chosen from 146 carcinomas found encoded functional proteins. These small proteins, from the oral cavity. None of the patients included in or micropeptides, play essential roles in diverse the TMA underwent prior radiation or chemotherapy. biological processes, including development, DNA Immunohistochemistry (IHC) for expression of repair, calcium homeostasis, myoblast, and metabolism. EGFR, CD3 and CD8 were performed. Quantitative Here, we want to know if BGRM1 can be encoded as a evaluation of EGFR staining was performed using a functional small protein in the pancreas. semiquantitative score (0-3+) where 0 represents To determine if the BGRM1 ORF is translated staining in <10% neoplastic cells and 1, 2, and 3 Methods: to a stable micropeptide, in vitro transcription and representing weak, moderate and strong in >10% translation were performed in HEK293T cells using neoplastic cells. Immunostaining scores of 3 and 2 were GFP or FLAG tagged full BGRM1 CDS. To identify the designated as EGFR-positive (EGFR+) and scores of 1 translation starting site, we deleted each potential and 0 were designated as EGFR-negative (EGFR-). For start codon and translated them in HEK293T cells. CD3 and CD8, the expression was scored on a scale Immunofluorescence (IF) staining was performed using from 0 to 3 which indicates the number of the tumor- organelle markers in ER, mitochondria, peroxisome infiltrating T cells. For CD3, immunostaining scores of and lysosome to assess BGRM1 localization. To identify 3 and 2 were designated as high CD3+, while a score protein interaction partner of BGRM1, HEK293T cells of 1 and 0 were designated as low CD3+. For CD8 were transfected with V5-SERCA3 and FLAG-GFP- immunostaining scores of 3, 2, and 1 were designated BGRM1 fusion proteins. Co-IP was carried out and as high CD8+, while a score of 0 was designated as followed by mass spectrometry and western blot low CD8+. Survival rates (i.e. overall survival [OS] analysis. and progression-free survival [PFS]) associated with expression of EGFR and combinations of EGFR/CD3 Results: GFP and a single ~10 kDa micropeptide were and EGFR/CD8 were determined by generating Kaplan produced only from clones that GFP or FLAG insert Meier curves and analysis using log-rank (Mantel-Cox) inframe right after predicted BGRM1 coding sequence. tests. qPCR result showed that BGRM1 RNA was highly abundant in transfected cells, and western blot revealed Results: We found that EGFR expression had no 2nd ATG was the start codon, which indicated that impact on OS, but EGFR+ OSCC patients demonstrated the length of BGRM1 CDS was 144 bp. We also found significantly worse PFS compared to EGFR-. High CD3+ BGRM1 was enriched in ER and promoted ER releasing patients had significantly better OS compared to low

60 calcium and raised intracellular calcium concentration Supported by: Dr. Shin’s start-up fund (Department of by interaction with SERCA3, further increase insulin Orthodontics, College of Dentistry & Dental Clinics) content under glucose stimulation in INS-1 cells. and Dr. Martin’s department fund (Orthopaedics and Rehabilitation). Conclusion: BGRM1 is a micropeptide coding gene that can be translated into a 48-amino acid protein, which has function in regulating intracellular calcium concentration and insulin secretion. 82. Variant Analyses of Catenin Alpha-2, Sonic Hedgehog, Activin A Receptor Type I, and Growth Differentiation Factor 11 genes in 81. Anti-Fibrotic Effects of Sulfasalazine and Orofacial Clefts in African and Puerto Rican Blebbistatin on Synovial Myofibroblasts Populations

1 1 1 Dongrim Seol , I. Song , J. Marks , Mary Y. Li1, J. Olotu149, T. Busch1, A. Tiwari1, S. Chinnathambi1, T. Naicker145, C. Adeleke1, V. Bravo136, E. Sander1, J. Martin1, K. Shin1 M. Musa125, M. Hassan1, S. Huang150, 1University of Iowa, Iowa City, IA W.O. Awotoye1, J. Pape151, A. Alade1, S.E. Miller1, A. Butali1 Temporomandibular joint Objective: 1 (TMJ) ankylosis is a seriously disabling University of Iowa, Iowa City, IA; 125 disease that impairs normal mandibular functions such Usmanu Danfodiyo University, Sokoto, 136 as speech and mastication. Alpha-smooth muscle actin Sokoto, Nigeria; Dental and Craniofacial (α-SMA) is a myofibroblast marker, and it is known Genomics Core, School of Dental to be highly expressed in pathological TMJ tissues. Medicine, University of Puerto Rico, 145 Myofibroblasts form fibrous scar tissue at sites of San Juan, Puerto Rico; University of tissue damage by rapidly secreting and contracting KwaZulu-Natal, Durban, South Africa; 149 a type I collagen-rich extracellular matrix, which University of Port Harcourt, Port 150 may result in fibrous tissues with high stiffness. Anti- Harcourt, Nigeria; Homestead High 151 fibrotic drugs targeting myofibroblasts (sulfasalazine: School, Cupertino, CA; University of SSZ) and collagen formation (blebbistatin, beta- Notre Dame, Notre Dame, IN aminopropionitrile: BAPN, and cis-hydroxyproline: CHP) Objective: Cleft lip with or without palate (CL/P) and can be an alternative therapeutic treatment modality cleft palate only (CPO) are congenital birth defects for TMJ fibrous ankylosis. The objective is to evaluate where the upper lip and/or palate fail to fuse properly inhibitory effects of anti-fibrosis drugs on myofibroblast during embryonic facial development. CL/P and CPO differentiation and contractile activity. fall under the larger category of orofacial clefts (OFCs), Methods: Bovine synoviocytes isolated from the TMJ which affect 1/700 live births world-wide and imposes synovium were pre- or post-treated with 80 or 160 µg/ significant social and financial burdens on affected ml SSZ to evaluate α-SMA expression. Myofibroblast individuals and their families. The etiology of orofacial differentiation was induced by 1 ng/ml transforming clefts is complex and likely results from a combination growth factor β1 (TGF-β1). For collagen gel compaction of genetic mutations with environmental covariates. assay, collagen gels containing 1x106 synoviocytes/ Recent genome wide association studies (GWAS) ml and supplied with 1 ng/ml TGF-β1 were treated with for orofacial clefting identified significant genetic 160 µg/ml SSZ, 14.6 µg/ml blebbistatin, 2 mg/ml BAPN, associations between several genes and OFCs. Of these or 80 µg/ml CHP for 56 hours. Areas of the α-SMA genes, we investigated the role of common and rare expression and the collagen gels were respectively variants in the CTNNA2, SHH, ACVR1, and GDF11 genes. quantified and normalized by no-drug control using Methods: We conducted Sanger sequencing of four Image J. genes in African and Puerto Rican CLP and CPO Results: Inhibitory effect of SSZ on α-SMA expression samples in order to find mutations that may provide was notable in representative images of pre- and post- potential explanations for OFCs missing heritability. treatment (Fig. 1A and 1B respectively). Myofibroblast Through using bioinformatic software like SIFT, induction was significantly prohibited in groups of pre- Polyphen, Provean Score, CADD, and HOPE, we treated with 160 µg/ml SSZ (p=0.012) (Fig. 1C). Similarly, analyzed probability of damage for each of the variants post-treatment attenuated myofibroblast differentiation found. with statistically significant decrease in α-SMA Results: From the variants found, after filtering for expression (Fig. 1D). Blebbistatin significantly inhibited damaging Polyphen scores, deleterious SIFT scores, the ability of synovial myofibroblasts to compact CADD scores above 20, and HOPE predicted amino collagen gels (p<0.001, Fig. 2). acid change effects, we ended up with 18 variants of Conclusion: SSZ and blebbistatin showed remarkable interest. Six missense mutations were found in SHH, one anti-fibrotic effects on α-SMA expression and collagen missense mutation in CTNNA2, six missense mutations gel compaction, respectively. The combinatory use of in ACVR1, and two missense mutations in GDF11. these anti-fibrosis reagents can be a therapeutic option Additionally, we found three silent mutations in SHH and to treat TMJ fibrous ankylosis. six in ACVR1 that may potentially alter splicing.

61 Conclusion: The findings of this study suggest that myofibroblastic differentiation. mutations in CTNNA2, ACVR1, SHH, and GDF11 may Supported by: Dr. Shin’s start-up fund (Department of contribute to risk of OFCs in African and Puerto Rican Orthodontics, College of Dentistry & Dental Clinics) populations. and Dr. Martin’s department fund (Orthopaedics and Supported by: NIH R00 DE022378; A.B and the Robert Rehabilitation). Wood Johnson Foundation (72429; A.B.)

84. Non-Viral Gene Delivery Using Biomimet- 83. Therapeutic Effects of MSC-Exosomes on ically-Mineralized Matrices for Bone Tissue Fibroblasts and Synoviocytes in TMJ Engineering

1 1 148 1 Ino Song , D. Seol , E. Kim , T. Lim , Timothy M. Acri1, N.Z. Laird1, J. Martin1, K. Shin1 L.R. Jaidev1, A.K. Salem1, K. Shin1 1University of Iowa, Iowa City, IA; 148Korea 1University of Iowa, Iowa City, IA Institute of Toxicology, Daejeon, Republic of Korea Objective: The development of synthetic materials for bone tissue engineering will Objective: The exosomes are the cell- alleviate the issue of rapidly increasing derived extracellular vesicles, which demand for bone grafts. Our hypothesis play a crucial role in delivering intracellular signaling is that combining calcium phosphate coatings and cargo including proteins, miRNAs, enzymes, etc. non-viral gene delivery in a single scaffold will further Especially, mesenchymal stem cell-derived exosome enhance bone regeneration. (MSC-Exo) is known for their therapeutic potentials in temporomandibular joint (TMJ) disorders. Meanwhile, Methods: 3D collagen scaffolds were cut from oxidative stress caused by accumulated reactive Collagen Plugs, and the mineralization process was oxygen species (ROS) in mandibular condylar carried out for 30 days. During the mineralization fibroblast is closely related to pathological problems process, Polyethyleneimine (PEI)-DNA complexes such as inflammation or arthritic degeneration of the were incubated with simulated body fluid (SBF) to joint. Likewise, fibrosis caused by myofibroblastic co-precipitate complexes into the mineral layer (CaP- differentiation of synoviocytes at the sites of damaged GAM). Scanning electron microscopy (SEM) and tissue, may result in TMJ fibrous ankylosis. The purpose energy dispersive spectroscopy (EDS) were used to of this study is to identify antioxidant and antifibrotic characterize the calcium phosphate coating. PEI-DNA effects of MSC-Exo on oxidative stress-induced complexes were fluorescently labeled, and their location fibroblasts and myofibroblastic differentiation-induced in the calcium phosphate layer was determined using synoviocytes in bovine TMJ, respectively. confocal microscopy. Bone marrow stromal cell viability was determined using an MTS assay at 24 hrs post- Methods: MSCs were collected from male bovine seeding. Osteogenic markers were quantified using subchondral bone and cultured in the medium with 10% ELISA for protein production and qPCR for osteocalcin exosome-depleted fetal bovine serum. The medium was and alkaline phosphatase on days two and seven of cell collected after 48 hours, and MSC-Exo were isolated by culture, respectively. Five-millimeter diameter defects the precipitation and size-exclusion chromatography. were created in the cranial bone of Fisher 344 rats. MSC-Exo characterization was conducted by using After implantation, scaffolds were imaged using micro- immunobinding assay, and the size and the quantity of CT and visualized through H&E staining. MSC-Exo were measured. Fibroblasts and synoviocytes were obtained from superficial layer of mandibular Results: SEM showed plate-like calcium phosphate condyle and synovium of TMJ, respectively. Fibroblasts crystal growths on the collagen, and EDS analysis were pre-treated with MSC-Exo, then treated with H2O2 revealed a calcium phosphate ratio of 1.5 which is to induce the oxidative stress. Synoviocytes were pre- similar to bone mineral. The apparent formation of two or post-treated with MSC-Exo, and myofibroblastic distinct growth factor layers suggests a biphasic release differentiation was induced by TGF-fl1. The levels of ROS of growth factors may be achieved based upon the and myofibroblastic differentiation were measured by confocal images. Rat calvarial defects treated with the immunofluorescence. CaP-GAM contained significantly more bone compared to collagen scaffolds based on micro-CT analysis. Results: MSC-Exo was sized between 60-130 nm and Additionally, histology revealed new bone formation was positive with 8 known exosome markers (Figure 1). was present throughout the core of the mineralized The level of ROS in the MSC-Exo pre-treated group was GAM. 69% lower than that in non-treated group (Figure 2A and 2B). Myofibroblastic differentiation was significantly Conclusion: This work suggests mineralization and (up to 74%) inhibited by either pre- or post-treatment of incorporation of gene therapeutic agents in a collagen MSC-Exo (Figure 2C-2F). scaffold enhanced new bone formation over the collagen scaffold alone. This work provides the basis Conclusion: MSC-derived exosomes may protect the for future investigations of CaP-GAM in bone tissue fibroblasts in condylar cartilage from oxidative stress engineering. and attenuate fibrous ankylosis by the inhibition of

62 Supported by: The Martin “Bud” Schulman Postdoctoral 86. ACT1-Mediated IL-17 Signaling in a Liga- Fellowship Award from the American Association of the ture-induced Alveolar Bone Loss Model Orthodontists (AAOF). Kyle J. Mercer1, S. Zhang1 1University of Iowa, Iowa City, IA 85. Nanoclay-Mediated Osteoinductive Factors Sustained Release for Bone Tissue Objective: Interleukin-17 (IL-17) cytokine Engineering family members play diverse roles in inflammatory diseases. While some IL-17 Jue Hu1, J. Miszuk1, H. Sun1 family members are pro-inflammatory and excessive signaling of those 1University of Iowa, Iowa City, IA cytokines cause tissue damage, others are important in maintaining the mucosal barrier and promoting Objective: It has been a significant technical challenge to sustain release repair. ACT1 is a gate-keeping adaptor protein for IL-17 bioactive molecules using a facile receptors that can bind to all IL-17 receptors. The aim method in a physiological/mild condition. of this study is to assess the role of the ACT1-mediated Nanoclay (Nanosilicates, NS) shows great IL-17 pathway in periodontitis. promise for drug delivery in vitro, while its potential Methods: We used a ligature model to experimentally mechanism for in vivo bone regeneration has barely induce periodontitis in Act1 knockout (KO) and wild- been defined. In this study, we explored the binding/ type (WT) mice. Alveolar bone loss in Act1 KO mice was drug release capacity of NS for osteoinductive factors measured by µCT scanning and was compared to the (e.g., BMP2 and phenamil) and followed their effects on level of WT mice. In addition, gene expression of several both osteoblastic differentiation and bone formation. cytokines important for immune cell chemotaxis and inflammatory response were quantified by RT-qPCR and Methods: In vitro and in vivo studies were carried out on NS binding to small molecules (phenamil) compared between Act1 KO and WT mice. and macromolecule (BMP2), respectively. 3D gelatin Results: While there was significant bone loss in KO nanofibrous scaffolds (GF) were prepared through a and wild type mice between the ligatured quadrant and thermally induced phase separation method together non-ligatured quadrant, bone level induced by ligature with particle leaching technique (TIPS&P). Either BMP2 in Act1 KO mice was not significantly different from the alone, NS alone or NS binding BMP2 composite (NS/ bone level of WT mice. BMP2) were incorporated into GF scaffolds. Conclusion: Complex IL17 signaling might play both Results: Our data revealed that NS had a strong pro-inflammatory and protective roles in periodontitis. binding ability to both molecules, which contributed The balance between pro-inflammatory IL-17 members to the controlled/sustained release of these drugs in and ones associated with tissue repair is critical in vitro and in vivo. In vitro release of phenamil from NS/ maintaining periodontal health. phenamil collagen gel showed markedly lower burst release and a prolonged release period up to 35 days compared to the phenamil alone sample, which was nearly completely released in 3 days. In vivo study shows that the GF-NS/BMP2 scaffolds demonstrated significantly stronger ability to promote new bone formation in a critical-sized cranial bone defect mice model at low-dose BMP2, while BMP2 alone at same dose can barely repair the defects. In vivo experiments for phenamil/NS will be completed soon. Conclusion: Our studies suggest nanoclay-mediated sustained drug release is an innovative and effective approach for bone tissue engineering. Supported by: NIH 5R03DE027491

63 87. Press-Fit 3D Electrospun Porous Nanofi- 88. Effects of Human Urine-Derived Stem brous Scaffolds for Bone Tissue Engineering Cells on the Cementogenic Differentiation of

1 1 1 Indirectly-Cocultured Periodontal Ligament Jacob Miszuk , J. Hu , H. Sun Stem Cells 1University of Iowa, Iowa City, IA Hongwei Dai101 Repair of critical-sized and Objective: 101 complex-shaped bone defects has Chongqing Medical University, presented many clinical challenges to Chongqing, China biomaterials development including but Objective: Human periodontal ligament not limited to: chemical composition, stem cells (PDLSC) have been widely mechanical properties, and capability for sustained applied as seed cells and cell sheets in drug release. Biomaterials-based drug delivery systems periodontal tissue regeneration. Despite commonly utilized for repairing irregular-shaped defects significant progresses in the PDLSC application, it is a are made of materials such as hydrogels, which however big challenge to promote cell proliferation and multiple possess poor mechanical strength and lack macro- differentiation of PDLSC because cell numbers at the porous structures required for support of cell/tissue initial obtaining are limited. The goal of study is to growth, leading to a desire for mechanically strong determine the paracrine effects of human urine-derived and highly porous materials capable of drug release stem cells (USC) on cell proliferation and osteogenic for bone repair. Our previous studies indicated that the differentiation of PDLSC when USC were indirectly-co- thermally induced self-assembled (TISA) 3D electrospun cultured with PDLSC. nanofibrous (NF) scaffolds are efficient for critical- sized defect repair, with high elasticity and mechanical Methods: After indirectly-co-cultured with USC at properties well suited for bone tissue engineering. different ratios (PDLSC/USC, 1/0.5, 1/1 and 1/2), number The elasticity of TISA scaffolds could be retained after of PDLSC among the three co-cultured groups visibly coating with hydroxyapatite (HA), suggesting this increased from day 5 to a similar extent, and the technique could possess press-fit characteristics, fitting expression of osteogenic and cementogenic genes and complex-shaped defects while providing sustained proteins in osteogenic medium significantly increased release from HA-incorporated drug. with an increasing proportion of USC, compared to USC-free control group. Methods: TISA-generated PCL scaffolds were coated via simulated body fluid, where the small molecule Results: Osteogenic matrix PDLSC sheets at a PDLSC/ phenamil, a BMP2 activator, was used to compare USC ratio of 1/2 contained denser collagen layers sustained release profile versus physically adsorbed and exhibited the increased expression of osteogenic drug. Scaffolds were characterized by SEM for and cementogenic proteins. In vivo transplantation morphological structures, and AFM for local mechanical showed that PDLSC sheets noncontact cocultured at a properties. Sustained release profiles of encapsulated PDLSC/USC ratio of 1/2 formed more new and dense phenamil were compared to physically adsorbed structures and expressed higher levels of osteogenic phenamil and measured by absorbance. In addition and cementogenic proteins. to phenamil, we also demonstrated that protein (e.g., Conclusion: The present results demonstrate that Bovine Serum Albumin) could be sustained release USC promote the proliferation and osteogenic and using the same strategy. cementogenic differentiation of PDLSC in a ratio- Results: Ubiquitous coating of HA on electrospun dependent manner through noncontact coculture and nanofibers was examined by SEM, indicating the ability further accelerate the regeneration of new structures of encapsulated drug to penetrate completely within by osteogenic matrix PDLSC sheets in vivo, suggesting scaffolds, and the resulting release curves demonstrated their use as a new strategy for application in clinical sustained release up to 21 days, compared to quick periodontal tissue repair. burst release of physically adsorbed drug. Conclusion: Osteogenic differentiation of C2C12 cells showed a significant increase in alkaline phosphatase activity and early marker Runx2 gene expression, indicating this composite scaffold may represent an excellent approach to promote critical-sized defect bone repair. Supported by: NIH NIDCR R03 DE027491 to HS; NSF/ EPSCoR IIA-1335423; NIH 5T90DE023520-07

64 . . . Pediatric Dentistry, continued from page 2 that infants see a dentist before the age of one, only a small percentage of infants see a dentist by this time. On the other hand, most infants visit their pediatrician several times during their first year of life. As a result, training pediatricians to provide basic infant oral screenings and education, and to identify risks for childhood caries is a promising avenue for improving preventive oral health care in early childhood.

Survey results from pediatricians who had an oral health rotation at the Infant Oral Health Program showed that they demonstrated more knowledge about early childhood caries prevention, including how to brush and the proper amount of fluoride toothpaste to use, and were more likely to examine the teeth of young children during pediatric exams than were pediatricians who graduated before this rotation was added.

“Medical professionals need to be trained in early childhood oral health, and it really makes a difference when they are,” said Weber-Gasparoni.

. . . Acces to Care, continued from page 3 In addition to these structural barriers, McKer- nan and her colleagues are exploring how clini- McKernan’s current project is a preliminary cal treatment patterns and the use of preventive study with the long-term goal of improving care care vary widely among dentists. For example, and access to preventive care for underserved some dentists rarely follow American Dental populations. Association (ADA) recommendations regarding the use of sealants and fluoride, which are McKernan and her colleagues at the Public known to significantly reduce tooth decay, and Policy Center, including Pete Damiano, Ray this can be especially problematic for low-in- Kuthy, and Julie Reynolds, among others, have come children and patients with special health collaborated to develop a holistic picture of oral care needs. health care preventive service needs in Iowa. They have found a number of structural and “There could be a number of factors that ac- public-policy barriers that limit access to routine count for these differences in care between preventive care, particularly for children. Cost is affluent and low-income populations—for exam- the number one barrier to dental care and this ple, insurance payment structures do not incen- is particularly challenging in Iowa with recent tivize preventive care and it may be common in changes to Iowa’s state-provided dental insur- certain regions for the community of dentists to ance plans that have made it unclear who and ignore or reject ADA recommendations,” McKer- what is covered. nan said.

Lack of transportation and not being able to These barriers, however, are not insurmountable. find a dentist, particularly one that will accept state-provided dental insurance, are also barri- “We need to know which levers make it more ers for underserved populations. likely that a dentist will follow preventive recommendations on the use of fluoride and sealants, “Transportation is obviously challenging in some and successfully implement those recommenda- rural areas where certain towns don’t have a tions with buy-in from the entire clinic—from the dentist or public transportation for getting to a dentist to the front-desk clerk,” McKernan said. town with a dentist,” McKernan explained. For McKernan, whether it’s helping dentists suc- But transportation is also a barrier for low-in- cessfully implement the best preventive prac- come families in urban areas with public trans- tices or reducing barriers in access to care, the portation. Work and bus schedules may turn an fruit that she hopes to see is a lasting, wide- hour long appointment into a task that takes spread improvement in preventive dental care the whole day. among underserved populations.

65 Author/Abstract-Number Index Presenters are underlined. Mentors are italicized.

Acri, T...... 84 Dawson, D.V...... 11, 37 Leary, K...... 55, 59, 61, 72 Adeleke, C...... 26, 30, 32, 76, 82 Deleyiannis, F...... 27 Lensing, J.N...... 19 Adeyemo, W.L...... 26, 30, 32 Denburg, N.L...... 15 Lesch, A...... 72 Ahmad, U...... 9, 12 Denry, I.L...... 37 Levy, S.M...... 20, 49 Ajayi, F...... 32 Doolittle, B...... 74 LeWarne, B.L...... 64 Akinshipo, A...... 32 Drake, D.R...... 51, 66 Li, H...... 28 Alade, A...... 26, 30, 32, 76, 82 Duncan, K...... 26 Li, M.Y...... 26, 30, 32, 82 Alghamdi, A...... 45 Dunnwald, M...... 74 Lie, R.T...... 29 Aljeshi, Amal...... 16 El Kerdani, T...... 11 Lieberman, S.M...... 40 Allareddy, V...... 70 Elfagih, S.A...... 22 Lim, T...... 83 Alyousef, Y.M...... 16 Elgendy, H...... 9 Lindquist, T...... 11 Amendt, B.A...... 1, 2, 3, 5, 6, 8, 17, Elgreatly, A...... 18 Ling, T...... 71 ...... 35, 36, 75, 80 Eliason, S.L...... 2, 3, 5, 6, 36, 75 Liu, H...... 25 Anamali, S...... 43 Ellis, B...... 44 Liu, Q...... 6 Anand, R...... 79 Eshete, M.A...... 26 Louscher, K.M...... 67 Arlis, S.E...... 25 Fan, P...... 71 Lu, S.H...... 55 Armstrong, S.R...... 22, 45 Feng, Y...... 38 Madiloggovit, J...... 15 Avila Ortiz, G...... 9, 12 Figueroa, A...... 70 Mahrous, A...... 18 Awotoye, W.O...... 26, 30, 32, 76, 82 Flick, K...... 61 Maia, R.R...... 45, 48 Ayanbadejo, P...... 32 Geneser, M.K...... 59 Manak, J.R...... 25 Banas, J.A...... 37, 47, 50, 53, 66 Gibson-Corley, K.N...... 79 Marazita, M.L...... 26, 27, 29 Barlow, P...... 63 Girirajan, S...... 25 Marchini, L...... 51, 52, 58, 63, 64 Barry, K...... 54 Girnary, M...... 78 Marks, J...... 81 Barwacz, C.A...... 48 Glenn, E...... 10 Marshall, S...... 69 Bedran-Russo, A...... 24 Gomez Hernandez, M.P.... 40 Marshall, T.A...... 16, 59, 65 Bonde, G...... 25 Gowans, L.J.J...... 26, 30 Marti, S...... 69 Bravo, V...... 82 Guangyue, L...... 7 Martin, J...... 81, 83 Brogden, K.A...... 14, 17, 39, 40 Gullion, G.L...... 77 McKernan, S.C...... 62, 67 Brolsma, T...... 61 Guo, Y...... 35, 36, 80 McQuistan, M.R...... 16, 41, 55 Busch, T...... 17, 26, 30, 32, 76, Guymon, A...... 22 Mercer, K.J...... 86 ...... 82 Guzman-Armstrong, S..... 16, 41 Mercut, V...... 63 Butali, A...... 17, 26, 27, 29, 30, Haes, A.J...... 37 Mihaela Popescu, S...... 63 ...... 32, 76, 82 Harless, J...... 14 Miller, S.E...... 17, 26, 30, 32, 76, Butler, J.A...... 72 Hartshorn, J...... 58 ...... 82 Buxo-Martinez, C.J...... 27, 30 Hassan, M...... 26, 32 Miszuk, J...... 85, 87 Calderon, S.J...... 66 He, Y...... 33 Mohamed, M...... 30 Campos, M.S...... 77 Hecht, J.T...... 27 Mohlke, K...... 25 Cao, H...... 1, 3, 6, 35, 36, 75, Hemsley, R.M...... 47 Moreno Uribe, L.M...... 17, 27, 29 ...... 80 Holloway, J.A...... 37 Morio, K.A...... 14 Capin, O.R...... 52 Hong, L...... 1, 5, 6, 8, 34 Mu-Eton, C.R...... 27 Caplan, D.J...... 51, 64 Houston, D.W...... 25 Murray, J.C...... 25, 26, 29 Carey, C...... 31 Howe, B.J...... 27 Nagumo, Y...... 5, 8 Carlson, A.J...... 46 Hu, J...... 85 Naicker, T...... 30, 76, 82 Carrilho, M...... 21 Huang, S...... 82 Ofori-Amanfo, G...... 79 Cashmore, A.C...... 15 Hyunok, J...... 11 Ogwo, C.E...... 20 Cavalcanti, B...... 1 Ingleshwar, A...... 67 Olagundoye, O...... 32 Cavanaugh, J.E...... 49 Jaidev, L.R...... 22, 84 Olatosi, O...... 30, 32, 76 Chakka, L.R.J...... 13, 88 Jain, A...... 43 Olotu, J...... 30, 76, 82 Chalkley, C...... 6 Jana Tuculina, M...... 63 O'Malley, M...... 72 Chen, D...... 4 Jiang, Q...... 13 Orioli, I.M...... 27 Chen, H...... 68 Jiao, Y...... 78 Padilla, C...... 27 Chen, L...... 23, 38 Johnsen, D...... 58 Pape, J...... 30, 32, 76, 82 Chen, X...... 15 Johnson, G.K...... 39 Pendleton, C...... 27, 39, 51, 58, 68 Chinnathambi, S...... 81 Kallsen, E.D...... 59 Peters, T...... 27, 41, 43, 71 Comnick, C.L...... 16, 21, 22, 41, 42, Kasparek, M.M...... 65 Petrin, A.L...... 29 ...... 44, 48, 52, 54, 66 Kattan, W...... 41 Phan, A.D...... 35, 80 Cornell, R.A...... 25, 26, 29 Kaufman, L...... 52 Phan, B...... 71 Couso-Queiruga, E...... 9, 12 Kelly, M...... 57 Philibert, R...... 29 Cowen, H...... 58 Kim, E...... 83 Poletta, F.A...... 27 Craig, T.W...... 58 Kluesner, K...... 68 Polyak, A...... 25 Cucco, C...... 42, 54 Kolker, J.L...... 16, 41, 47 Prince, D...... 52 Curtis, A.M...... 20, 49 Kossioni, A.E...... 63 Prouty, Z.W...... 60 Dai, H...... 88 Krongbaramee, T...... 1 Qi, H...... 6 Damiano, P.C...... 56, 62, 67 Laird, N.Z...... 84 Qian, F...... 24, 45, 46, 55, Dang, C.A...... 52 Lansdon, L.A...... 25 ...... 59, 61, 69, 72, 73 Darbro, B.W...... 25 Lanzel, E.A...... 40 Qian, Q...... 88 Davis, A.B...... 40 LaRoy, C...... 24 Remy, M.T...... 5, 8

66 Rengasamy Southard, T.E...... 69 Voy, B...... 24 Venugopalan, S...... 69 Staley, R...... 73 Warren, J.J...... 20, 49 Reynolds, J.C...... 57, 60, 62, 67 Stanusi, A...... 63 Weber-Gasparoni, K...... 49, 59 Rhea, L...... 74 Starman, E.E...... 48 Wehby, G.L...... 27, 29 Ribeiro, A...... 52 Stine, K...... 21, 44 Weinberg, S...... 27 Rupp, C.A...... 56 Strabala, D.J...... 62 Wenger, K.R...... 51 Russell, C...... 64 Su, D...... 75 West, C...... 69 Salem, A...... 22 Sun, H...... 85, 87 Wieland, A.M...... 50 Sander, E...... 81 Sun, L...... 78 Williams, T...... 28 Sardzinski, L...... 27 Sun, Z...... 2 Williamson, A.E...... 10, 42, 54 Sasser, S...... 64 Sweat, M.E...... 1, 2, 3, 5, 35, 36, Willour, W...... 29 Sato, A...... 58 ...... 80 Wire, C...... 102 Schollmeyer, A.M...... 43 Swe at , Y.Y...... 2, 3, 6, Wongkamhaeng, K...... 37 Schotanus, M...... 31 Tabrizi, M...... 52 Wongpattaraworkakul, W. 79 Schultz, G.P...... 42 Takanami, E...... 53 Woodward, M.J...... 57 Scrieciu, M...... 63 Tattan, M...... 12 Xie, X...... 10, 17, 21, 22, 27, Seol, D...... 81, 83 Teixeira, E.C...... 19, 22, 41, 45 ...... 29, 39, 42, 43, Shao, F...... 35, 36, 75, 80 Teixeira, F.B...... 1, 10 ...... 44, 51, 52, 54, 58, Shelby, A...... 39 Thayer, E.L...... 14, 39 ...... 66, 68 Shin, K...... 17, 48, 68, 69, 70, Thompson, L...... 58 Xu, H...... 6 ...... 71, 81, 83, 84 Tiwari, A...... 81 Yen, F.Y...... 78 Shu, Y...... 34 Tobey, T...... 52 Youd, N.E...... 70 Simons, A...... 79 Umeizudike, K...... 32 Yu, W...... 2, 3 Skotowski, M.C...... 46 Urguhart, O...... 41 Zeng, E...... 16, 19, 29, 40 Smith, B...... 52 Valencia-Ramirez, C...... 27 Zhan, F...... 6 Smith, F...... 31 Van Otterloo, E...... 28, 31, 34 Zhang, S...... 78, 86 Soh, D.H...... 48 Veenstra, L.T...... 63 Zhu, M...... 1, 34, 47, 53 Song, I...... 81 Vidal, C...... 21, 22, 24, 44, 45, Soto, A...... 52 ...... 48

Iowa Section of AADR – Presidents

1967-68 James Searls 1993-94 Lisa Wilcox 1968-69 C. Robert Kremenak 1994-95 Ana Diaz-Arnold 1969-70 N.N. Soni 1995-96 William Rubright 1970-71 Leslie Higa 1996-97 Karen Baker 1971-72 Clayton Shalla 1997-98 David Drake 1972-73 Mohamed Khowassah 1998-99 Clark Stanford 1973-74 Carl Svare 1999-2000 Janet Guthmiller 1974-75 Charles Sabiston 2000-01 Kaaren Vargas 1975-76 Steven Wei 2001-02 Rebecca Slayton 1976-77 William Grigsby 2002-03 John Warren 1977-78 Jimmy Pinkham 2003-04 Teresa Marshall 1978-79 Christopher Squier 2004-05 Galen Schneider 1979-80 Dorothy Rowe 2005-06 Kim Brogden 1980-81 Brian Clarkson 2006-07 Zoya Kurago 1981-82 James Wefel 2007-08 Karin Weber-Gasparoni 1982-83 Murray Hill 2008-09 Jeffrey Banas 1983-84 James Beck 2009-10 Marcela Hernandez 1984-85 Daniel Boyer 2010-12 Justine Kolker 1985-86 Mark Jensen 2012-13 Sherry Timmons 1986-87 Rick Walton 2013-14 Gustavo Avila Ortiz 1987-88 John Reinhardt 2014-15 Christopher Barwacz 1988-89 Richard Walton 2015-17 Veerasathpurush Allareddy 1989-90 Steven Vincent 2017-18 Kyungsup Shin 1990-91 John Keller 2018-19 Kecia Leary 1991-92 Ronald Ettinger 2019-20 Cristina Vidal 1992-93 Jed Hand

67 Acknowledgments We extend our grateful acknowledgment to the following members of our College of Dentistry family:

College of Dentistry Administration David Johnsen Scott Arneson Barb Colbert Susan Hackert Brian Howe Michael Kanellis Michelle Krupp Amanda Shoemaker Galen Schneider Sherry Timmons Jan Swartzendruber

College of Dentistry DEOs Gustavo Avila Ortiz (Dept. of Periodontics) Daniel Caplan (Dept. of Preventive & Community Dentistry) Kirk Fridrich (Dept. of Oral & Maxillofacial Surgery) John Hellstein (Dept. of Oral Pathology, Radiology & Medicine) Julie Holloway (Dept. of Prosthodontics) David Holmes (Dept. of Family Dentistry) Erica Teixeira (Dept. of Operative Dentistry) Fabricio Teixeira (Dept. of Endodontics) Thomas Southard (Dept. of Orthodontics) Karin Weber-Gasparoni (Dept. of Pediatric Dentistry)

Iowa Section of AADR Cristina Vidal Brian Howe Sara Miller

Judges Local AADR 2020 Daniah Alhazmi Steven Armstrong Jeffrey Banas Christopher Barwacz Kim Brogden Marcia Campos Huojun Cao Daniel Caplan Xi Chen Carolina Cucco Isabelle Denry David Drake Satheesh Elangovan Amira Elgreatly Tarek El Kerdani Matthew Geneser Manuel Gomez Nidhi Handoo Aditi Jain Maram Jaradat Justine Kolker Kecia Leary Amy Lesch Tad Mabry Fang Qian Julie Reynolds Sally Roushdy Kyungsup Shin M. Catherine Skotowski Kyle Stein Hongli Sun Kevin Tseng Eric Van Otterloo John Warren Karin Weber-Gasparoni Megumi Williamson Erliang Zeng

Moderators 2020 Sheila Britton Marue White Pamella Hughes

Councilor Iowa Section of AADR 2020 Kyungsup Shin

Iowa Institute for Oral Health Research Galen Schneider Jeff Banas Kim Brogden Sharon Seydel J. Michael Tilley Emma Thayer

Student Research Teresa Marshall Satheesh Elangovan Justine Kolker Sheila Britton

68 Technology & Media Services Chuck McBrearty Pat Conrad Hao Geng Sean Kelley Corey Lund Rhiannon Montelius Viki Mueller Rich Tack

Dental Facilities Services Justin Bringman Jim Christison Bob Day Deb Donovan Richard Madden Sherri O’Rourke Bob Watson

Division of Biostatistics & Research Design Xian Jin Xie Huojun Cao Joseph Cavanaugh Carissa Comnick Deborah Dawson Chandler Pendleton Tabitha Peters Fang Qian Erliang Zeng

Special thanks to: We would like to thank Sharon Seydel for many years of service to the Iowa Section of AADR as a treasurer/secretary. Her expertise and leadership were invaluable in making our previous annual meetings a success.

We would like to thank Angela Kim. Over the past 2 years, her effort and support substantially improved the judging and the awards selection process.

69 We extend our grateful acknowledgment to the following sponsors: Procter and Gamble Oral Care, Crest & Oral-B Desi Nuckolls

Glaxo SmithKline Colgate Oral Pharmaceuticals Monica Bronowicki

American Dental Association (ADA) Delta Dental of Iowa Foundation

Omicron Kappa Upsilon (OKU) National Dental Honor Society

Iowa Association of Endodontists Iowa Society of Periodontology Sponsoring the Michel Fuller Postdoctoral Award Sponsoring pre-doctoral and post-doctoral awards