Dentistry Commons^™

Filifactor Alocis Disrupts Efferocytosis To Sustain Inflammation In Periodontitis, Ella Dye, Silvia Uriarte, Ruth Idowu

The Cardinal Edge

Background: Filifactor alocis is a Gram-positive, obligate anaerobe that has emerged as a diagnostic marker of periodontitis. Neutrophils and macrophages are key players in oral immune homeostasis. Neutrophils are short-lived cells and constitutively undergo apoptosis. This apoptotic program can be accelerated or delayed by bacterial interactions. Macrophages clear apoptotic neutrophils via “efferocytosis,” a crucial mechanism for resolving inflammation and preventing tissue damage. The efferocytic process downregulates the expression and release of proinflammatory cytokines such as interleukin (IL)-6 and IL-23 while promoting anti-inflammatory responses. Our previous findings demonstrated that F. alocis delays neutrophil apoptosis, with fewer apoptotic cells observed after 18 …

New Bayesian Methods For Longitudinal Data Analysis With Complex Dependence Structures., Anish Mukherjee

Electronic Theses and Dissertations

Longitudinal data in real-world settings are frequently found to be heterogeneous and exhibit intricate spatio-temporal dependence structures. Analyzing such complex data to obtain reliable estimation while quantifying uncertainty necessitates using sophisticated Bayesian methodology. In this work, we present novel Bayesian methods developed to address these challenges. We often observe heterogeneity in longitudinal data, where the mean and variance for certain profiles meaningfully differs from the rest. Some profiles may also exhibit outliers at a limited number of measurements. Using a standard mixed effects model, which assumes homogeneity, can lead to overestimating the residual variance and inefficient estimation. In this work, …

Comparison Of Specific Jaw Position Measurements On A Static And Dynamic Virtual Patient., Payton Lofton

Electronic Theses and Dissertations

This study aimed to compared the differences in jaw position measurements in protrusive and open/close positions on a static virtual patient created using 3dMD System to those from a dynamic articulation of a virtual patient (MODJAW) as well as measurements between the Cadiax and MODJAW. Six fiducial surface markers were placed on a volunteer subject’s face and dynamic facial scans of protrusive and open/close jaw movement acquired and exported. A CBCT scan was also acquired. The mandible and maxilla were segmented and loaded into Vultus and aligned to the facial scan using the fiducial markers. Results were compared using a …

Genetically Engineering Gingipains For High Yield Large Scale Purification., Andrew E. Fuchs

Electronic Theses and Dissertations

Porphyromonas gingivalis is a keystone oral pathogen in the progression of periodontal disease and has been implicated in the etiology of many other systemic human diseases. P. gingivalis produces primary virulence factors termed the gingipains, a group of cysteine proteases. There is a high demand for high purity gingipains for downstream in vitro studies where P.g. is implicated, both oral and systemic. Gingipain production candidate mutant P.g. strains were generated to isolate each gingipain for large scale purification and the purified gingipains characterized. Two mutants were determined not to be viable for large scale purification of gingipains, each for different …

Enhancing Adherence To Best Practice Guidelines Related To Pressure Injury Prevention In The Operating Room At A Children's Hospital During Comprehensive Dental Procedures., Alyce Bailey Seaver

Doctor of Nursing Practice Papers

Background: 1,600,000 patients develop a hospital-acquired pressure injury every year, and 23% of these originate during surgery. Research has demonstrated that the incidence of hospital-acquired pressure injuries developing during surgery has risen over the past 5 years. This rise has been attributed to nurse circulators exhibiting poor knowledge regarding best practices for intraoperative patient positioning and intraoperative documentation that does not follow standards of care.

Purpose: This quality improvement project aimed to enhance circulator knowledge on best practices for intraoperative patient positioning and improve documentation of intraoperative patient positioning in the electronic medical record to comply with standards of …

The Emerging Oral Pathogen, Filifactor Alocis, Modulates Antimicrobial Responses In Primed Human Neutrophils., Ian J. Snider

College of Arts & Sciences Senior Theses

Periodontitis is an irreversible, chronic inflammatory, infectious disease of the oral cavity that affects approximately half of all adults 30 years or older in the USA. The oral cavity is under high immune surveillance because of its constant exposure to microbes in the environment. The primary immune cell responsible for this surveillance is the neutrophil. Pathogens associated with periodontitis possess virulence factors and have evolved strategies to evade neutrophil antimicrobial responses to survive. One such pathogen is Filifactor alocis, whose presence is associated with the progression of periodontitis. F. alocis manipulates several neutrophil antimicrobial functional responses to avoid killing, an …

Dental Morphology In A Juvenile Mammal From The Late Cretaceous Of South America: Tooth Eruption And Development., Kayla E Newton

Electronic Theses and Dissertations

Meridiolestids are a diverse and distinct clade of Cretaceous–Miocene South American dryolestoid mammals ranging in size from small shrew-sized insectivores to large dog- sized omnivores. Cronopio dentiacutus from the Cenomanian La Buitrera locality, Rio Negro Province, Argentina (Candeleros Fm.) is the oldest and best known of them, represented by skull material and associated jaws. A juvenile skull as attributed to Cronopio dentiacutus, based on tooth size and morphology, was collected from the type locality. The specimen includes the skull and both articulated lower jaws. The fossil is poorly ossified and partially flattened; CT scanning reveals most of the dentition …

Aggregatibacter Actinomycetemcomitans Exploits And Modulates The Immune Response By Human Neutrophils For Survival In The Anaerobic Environment., Hazel Ozuna

Electronic Theses and Dissertations

Aggregatibacter actinomycetemcomitans (Aa) is a Gram-negative facultative anaerobe and an opportunistic oral pathogen, strongly associated with localized periodontitis and other inflammatory diseases. Periodontitis is a chronic inflammation of the periodontium resulting from the inflammatory response of the host towards the dysbiotic microbial community present at the gingival crevice. The host immune response creates a hostile environment for microorganisms; therefore, it is important for Aa to be able to regulate the necessary genes to survive and thrive in such an environment. Aaexpresses several virulence factors such as a cytolethal distending toxin (Cdt), lipopolysaccharide (LPS) and leukotoxin A (LtxA), …

Development Of 3d-Bioprinted Scaffolds For Oral Probiotic Application., Jhanvi Patel

Electronic Theses and Dissertations

Background: Porphyromonas gingivalis adheres to and invades gingival epithelial cells, resulting in decreased cell viability. Previous studies have indicated that probiotics are effective against dental pathogens; however, few approaches provide sustained-delivery of active agents in the oral cavity. Hypothesis: Probiotics will limit P. gingivalis effects on Telomerase Immortalized Gingival Keratinocyte (TIGK) cells and 3D-printed scaffolds will prolong probiotic release. Methods: Lactobacillus acidophilus, Lactobacillus reuteri, and Bifidobacterium bifidum were assessed with adhesion and antibiotic protection assays to limit P. gingivalis effects on TIGKs. Scaffolds were printed with a select probiotic and evaluated for release kinetics. Results: Free L.a., …

Predicting Dental Student's Performance On National Board Dental Examination (Nbde) Part I: Exploring Demographic Factors, Dental Admission Test (Dat) Factors, Pre-Program Academic Factors, And Dental Program Academic Performance., Wei-Shao Lin

Electronic Theses and Dissertations

Dental students need to successfully challenge a national licensure examination to be able to practice dentistry. Dental educators currently have difficulty in identifying candidates who are at risk of failing this examination. This non-experimental quantitative study examined existing dental student data from the 2017, 2018, and 2019 graduating classes, using a retrospective and correlational approach to identify possible markers for at risk students. Demographic factors, dental admission test (DAT) factors, pre-program academic factors, dental program academic performance, and National Board Dental Examination (NBDE) Part I performance. A series of independent t-tests and One-Way analysis of variances (ANOVAs) were used to …

Epithelial Responses To Porphyromonas Gingivalis In The Community Context., Zackary Ray Fitzsimonds

Electronic Theses and Dissertations

Porphyromonas gingivalis, a keystone pathogen for periodontal disease, initiates a complex molecular dialogue with gingival epithelial cells, leading ultimately to disruption of host signaling pathways. Dysbiotic host responses are also thought to contribute to the initiation and progression of oral squamous cell carcinomas. Recently, the homeostatic commensal Streptococcus gordonii has been shown to antagonize P. gingivalis-induced epithelial cell signaling events in host cells, such as proliferation and migration. The aim of this study was to characterize pathways that P. gingivalis targets to disturb host signaling, with a specific focus on pathways that S. gordonii can restore to homeostatic …

Application Of Machine Learning Technologies For Detection Of Proximal Lesions In Intraoral Digital Images: In Vitro Study., Rohit Vadlamani

Electronic Theses and Dissertations

Background: Interpretation of bitewing radiographs is influenced by factors such as acquisition parameters (e.g. exposure, type of sensor), clinical technique, visualization (e.g. monitor type and calibration) and the observer (e.g. experience and fatigue bias). We hypothesized that the use of artificial intelligence (AI) will reduce visualization and observer factor in bitewing interpretation and improve diagnostic accuracy. Objective: The purpose of the present study was to evaluate the use of AI in the form of a machine-learning algorithm to detect and quantify proximal lesions compared with human trained observers. Methods: 16,000 anonymized, digital bitewings of patients were hand searched and non-bitewing, …

Functionalizing Nanoparticles With Cafa Protein To Target Bar Peptide For Oral Delivery Applications., Hetal Desai

Electronic Theses and Dissertations

Background: Porphyromonas gingivalis adherence to Streptococcus gordonii may be important for P. gingivalis colonization in the oral cavity. Nanoparticles encapsulating synthetic peptide BAR (BAR-NPs) inhibit P. gingivalis adherence more potently than free BAR. However, BAR-NPs would exhibit low retention in an open flow environment. Hypothesis: Targeting BAR-NPs to the streptococcal surface using CafA protein will enhance their efficacy. Methods: CafA-modified NPs encapsulating BAR were synthesized using double emulsion approach. Surface binding and retention, and release kinetics of BAR from CafA-modified NPs was assessed. Functional inhibition assays were performed using dual a species biofilm. Results: CafA-modified NPs demonstrated specificity of adhesion, …

Tobacco Enhances Bacterial-Induced Periodontal Bone Loss In Mice., Mina Iskander

Electronic Theses and Dissertations

Background: Tobacco smoking is the leading environmental risk factor for periodontal diseases. Delineation of the mechanisms underlying tobacco-induced or exacerbated periodontitis is hampered by the lack of an appropriate and reliable animal model. Hypothesis: We hypothesized that Porphyromonas-gingivalis-infected, cigarette smoke-exposed mice would represent reproducible models of acute (ligature model) and chronic (oral gavage model) tobacco-enhanced periodontitis that reflect multiple aspects of the disease noted in human smokers. Methods: In a chronic oral gavage disease model, Balb/c mice (6-8 weeks, 4 groups of n = 6 per group) were exposed to smoke produced by a Teague-10 smoking machine from 1R6F research …

Oral Health-Related Quality Of Life In Us Adults With Type 2 Diabetes., Giang Truong Vu

Electronic Theses and Dissertations

This dissertation focused on the relationship between type 2 diabetes (T2DM) and oral health-related quality of life (OHRQoL) and the factors associated with this relationship in the US. The objectives of the dissertation research were a three-part process: (1) to understand the relationships of T2DM with poor OHRQoL, clarify risk and preventive factors that affect this association, and identify research gaps in the literature, (2) to analyze risk factors associated with poor OHRQoL in US adults with T2DM using a nationally representative random probability cluster sample, and (3) to apply structural equation modeling (SEM) to a simplified Andersen’s Behavioral Model …

Using Active Learning Techniques To Improve Oral Health Literacy Among Children In Vulnerable Populations., Sarah Maria Downes

Electronic Theses and Dissertations

This thesis examines the effectiveness of an active learning approach in improving oral health literacy and attitude about science among at-risk students in the age range of third to sixth grades. This is done by designing and implementing a novel Oral Health Outreach module and video. Active learning components include engaging PowerPoint, oral hygiene discussion and demonstration, and finally a biofilm simulation, which utilizes glow-in-the-dark paint, dentoform models, and black lights that allow students to visualize the importance of plaque removal. Student comprehension of oral health concepts increased by an average of 52.4% on post-tests (n=61, p

The Emerging Oral Pathogen, Filifactor Alocis, Disrupts Neutrophil Functions To Enhance Survival And Dysregulate Inflammation., Irina Miralda Molina

Electronic Theses and Dissertations

Periodontitis is an irreversible, chronic inflammatory disease where pathogenic microbial communities accumulate in the gingival crevice. Advances in culture-independent techniques have facilitated the identification of new bacterial species in periodontal lesions, such as the Gram-positive anaerobe, Filifactor alocis. Neutrophils are a major component of the innate host response, and the outcome of their interaction with F. alocis may be a determinant of oral health status. While neutrophil functions typically protect the host against periodontal disease, oral pathogens have adapted to evade or disarm neutrophil microbicidal functions while promoting mechanisms that drive inflammation, which also provides a source of nutrients …

Transcriptional Influence Of Retinoic Acid And Its Effects On Angiogenesis Of Murine Salivary Glands., Isaac Feinn

College of Arts & Sciences Senior Theses

Salivary gland hypofunction is a major disorder of salivary glands, and can arise either from diseases such as xerostomia, or from defective epithelial morphogenesis during embryogenesis. Hundreds of thousands of individuals suffer from dry mouth, and there is currently no restorative therapy for these patients. Investigation of salivary gland developmental biology will inform regenerative therapies. Currently it is known that retinoic acid (RA), the biologically active form of Vitamin A, is required for proper development of the salivary gland, but little is known about its cellular mechanism regulating organogenesis. This study sought to analyze salivary gland development in Rdh10 knock …

The Q Rule In Bacteriodetes And The Identification And Characterization Of Porphyromonas Gingivalis Glutaminyl Cyclase., John Andrew Houston

Electronic Theses and Dissertations

Background: Porphyromonas gingivalis, a major pathogen associated with chronic periodontitis, secretes variety of proteins, majority of which begins with glutamine. Several of these proteins were found with pyroglutamate (pGlu) at N-terminus suggesting the presence of this posttranslational modification pathway in P.gingivalis. The observation that N-terminal glutamine is over-represented as the first amino acid after signal peptide cleavage, and subsequent confirmation of pGlu formation on the nascent protein via mass spectrometry, led us to conclude that an enzyme must be present as the executor of this reaction. Hypothesis: PG2157 is a glutaminyl cyclase and is responsible for the cyclization of …

Marginal Staining Between Pressed Lithium Disilicate Ceramic Crowns And Direct Restorative Materials By Various Fluids : A Microleakage Study., Sarah Ann Jestel

Electronic Theses and Dissertations

When treating patients with existing restorations in which indirect restoration placement is indicated and crown lengthening surgery is contraindicated, dentists may choose to finish the crown margin on an existing restoration. The interface between the two dental restorations (resin composite and ceramic crown) may be more susceptible to microleakage and fluid staining, reducing restoration longevity. In this study, 80 extracted molars received indirect restoration margins finished on different direct restorative materials (resin-modified glass ionomer and conventional, flowable, and bulk fill nano-hybrid resin composite) and subjected to common staining fluids of coffee, tea, red wine, or Coca-Cola. If the clinician must …

Development Of Bar-Peptide Nanoparticles And Electrospun Fibers For The Prevention And Treatment Of Oral Biofilms., Mohamed Yehia Mahmoud

Electronic Theses and Dissertations

Background: Periodontal diseases are globally prevalent inflammatory disorders that affect ~47% of U.S adults. Porphyromonas gingivalis (Pg) has been identified as a “keystone” pathogen that disrupts host-microbe homeostasis and contributes to the initiation and progression of periodontitis. Pg associates with oral streptococci in supragingival plaque and this interaction represents a potential target for therapeutic intervention. Previously our group developed a peptide (designated BAR), that potently inhibits Pg/Streptococcus gordonii (Sg) adherence in vitro and Pg virulence in a murine model of periodontitis. While efficacious, BAR (SspB Adherence Region) provided transient inhibition and required higher concentrations of BAR to disrupt established …

Effect Of Grape Components On Periodontal Disease., Juili Subodh Shivde

Electronic Theses and Dissertations

Background: Half of the adult American population (47 %) are victims of periodontitis, a chronic inflammatory disease which leads to destruction of the tissues supporting the tooth. Periodontitis is initiated by periodontal pathogens and caused by excessive or prolonged host mediated inflammation. Porphyromonas gingivalisis one important agent implicated in the etiopathogenesis of chronic periodontitis. Pro-inflammatory cytokines induced by periodontal pathogens can cause alveolar bone loss and periodontitis. Bone loss is caused by the imbalance of bone formation and bone resorption. Osteoclasts are major cells that cause bone resorption. Moreover, periodontal inflammation also leads to bone resorption. Grapes are rich …

Synthesis And Characterization Of Targeted Bar Encapsulated Polylactic-Co-Glycolic Acid Nanoparticles To Inhibit Porphyromonas Gingivalis Biofilm Formation., Ranjith Radha Krishnan

Electronic Theses and Dissertations

Periodontal disease is one of the most prevalent infectious diseases worldwide. Between 30-50% of the global adult population suffers from periodontal disease. Some form of periodontitis is present in 46% of American adults, corresponding to annual expenditures in excess of 14 billion dollars for treatment and prevention. Current treatments for periodontal diseases involve mechanical removal of plaque, correction of risk factors, gingival surgery and/or antibiotic therapy. To our knowledge there is no effective therapeutic approach that aims to limit pathogen colonization of the oral biofilm or re-colonization after treatment. Interaction of the pathogen Porphyromonas gingivalis with oral streptococci is critical …

Influences Of Porphyromonas Gingivalis On The Viability Of Esophageal Cancer Cells., Muddasir Mohammed

Electronic Theses and Dissertations

A recent study demonstrated an association between the Porphyromonas gingivalis (Pg)infection and the progression of ESCC (Gao et al., 2016). However, how Pg infection affects the nature of ESCC remains unknown. We examined the effects of Pg on the proliferation and chemotherapy drug-induced apoptosis of ESCC cells and elucidated the signaling molecules involved in these processes. Method: Apoptosis and cell proliferation were tested using Flow cytometry and Tetrazolium salt based proliferation assays respectively. Western Blot was utilized to detect the protein expression. CDK2 and Cyclin E were knocked down in the ESCC cells through transfection. Unpaired T-test and …

Cannabidiol Alters The Immune Response To Porphyromonas Gingivalis In Mice., Shilpa Singh

Electronic Theses and Dissertations

Background: Porphyromonas gingivalis is an important etiologic agent of chronic periodontitis, an infectious disease defined by destruction of supporting tissues of the teeth. Marijuana is a risk factor for chronic periodontitis, although underlying mechanisms are poorly understood. As phytocannabinoids have been ascribed antiinflammatory properties, we hypothesized that cannabidiol exposure would lead to altered immune response to P. gingivalis infection facilitating bacterial persistence and, subsequently, increased alveolar bone loss in cannabidiol (CBD)-exposed mice. Methods: P. gingivalis-infected cannabinoid receptor 2 (CB2) knockout and wild type C57/Bl6 mice were exposed, or not exposed, to cannabidiol. Oral swabs from mice were used to monitor …

Effect Of Porcelain Thickness And Translucency On The Final Shade Of Ips E.Max Cad Overlaying A Dark Substrate., Peter F. Alena

Electronic Theses and Dissertations

IPS e.max is a very esthetic lithium disilicate used in dental ceramics. Unfortunately, it can unintentionally change color after cementation with resin cements. The purpose of this study is to better understand how combining thickness and translucency affects the post-cementation shade of IPS e.max CAD overlaying a dark substrate, thereby enabling clinicians to choose more appropriate techniques and materials. IPS e.max CADs (A1 shade) had either a low translucency (LT) or high translucency (HT), and cut with 0.3mm, 0.5mm, and 1.0mm thicknesses. Each sample overlaid a resin cement and dark substrate, a spectrophotometer helped derive the color difference (ΔE*ab), and …

Long-Term Dental Outcomes Of The Professional Education Preparation Program., Samuel D. Petersen

Electronic Theses and Dissertations

Introduction: The Professional Education Preparation Program (PEPP) is a health careers pipeline program for Kentucky pre-health students from Health Professional Shortage Area counties and/or racial/ethnic groups underrepresented in the health professions. The purpose of this study was to determine the demographics of the dental PEPP participants and if, post dental school graduation, they were providing care for underserved patient populations Methods: PEPP dental graduates (n=114) had been previously identified. Participants were contacted by phone, asked to participate and then mailed a survey. Survey questions covered personal, practice and patient characteristics, procedures performed, insurance accepted and community outreach. Logistic regression analysis …

Intraoral Imaging At Insertion Of Implant Supported Restorations At An Academic Institution : Conformity To Established Guidelines., J. Alec Power

Electronic Theses and Dissertations

The objective of this study was to establish the frequency of intraoral imaging at the time of insertion of implant supported restorations at University of Louisville School of Dentistry (ULSD). After IRB approval (14.1215), patients on whom an implant-supported single unit fixed restoration was placed were identified from the electronic health record over a 4-year period. Type of prosthesis retention (cement vs. screw) and discipline responsible for crown placement was recorded. Bitewing (BWx) or periapical (pa) images taken at the time of prosthesis placement were accessed and reviewed. Overall radiographic frequency according to modality was tallied and compared using Chi-square …

Development Of Blended Polymeric Fibers To Alter The Release Of Peptide Targeting Porphyromonas Gingivalis., Sonali Suresh Sapare

Electronic Theses and Dissertations

Periodontitis is a chronic inflammatory disease that infects the tissues of the periodontium. It is estimated that 47.2% or 67.2 million American adults suffer from mild, moderate and severe periodontitis. Globally, 30-50% of the adult population is afflicted with periodontal disease, making it one of the most prevalent infectious diseases in the world. Therapeutics targeting P. gingivalis may be effective to alter periodontitis progression. However, the current treatment modalities that target critical pathogens to maintain host-biofilm homeostasis are limited, urging the development of specifically targeted therapeutics to limit P. gingivalis recolonization of the oral cavity after periodontal treatment and healing. …

The Role Of Kinases And Phosphatases In The Pathobiology Of Porphyromonas Gingivalis., Sarah Whitmore

Electronic Theses and Dissertations

Periodontal diseases result from the interplay between the dysregulation of the host inflammatory response and the actions of a dysbiotic bacterial community. These chronic inflammatory conditions affect persons on a worldwide scale. P. gingivalis is strongly implicated as a key periodontal pathogen in the more severe manifestations of periodontal diseases such as periodontitis. A core element of P. gingivalis pathogenicity is its dysregulation of innate immunity, including suppression of IL-8 production by gingival epithelial cells. The NF-κB family of related transcription factors plays a central role in regulating many important aspects of innate immune responses. NF-κB RelA/p65 homodimers regulate transcription …