Digital Commons Network^™

A Comparison Of Three-Dimensional Printing Technologies On The Precision, Trueness, And Accuracy Of Printed Retainers, Owais A. Naeem

Theses and Dissertations

Purpose: The aim of this study was to evaluate the differences in the precision, trueness, and accuracy of 3D printed orthodontic clear retainers produced using printer systems with various printing technologies.

Methods: Retainers (n=15) were printed using four different 3D printers: a stereolithography (SLA) printer, two different digital light processing (DLP and cDLP) printers, and a polyjet photopolymer (PPP) printer. The 3D printed retainers were transformed into a digital file through a cone-beam computed tomography scan that was compared to the original image using a 3D superimposition analysis software. At previously chosen landmarks (R6, L6, R3, L3, R1, L1) retainers …

A Comparison In Pediatric Dental Website Design From A Guardian And Pediatric Dentists’ Perspective., David M. Voth

Theses and Dissertations

Purpose: This project aims to determine which aspects of pediatric dental practice websites are preferable to the guardians of pediatric dental patients and which of these aspects are currently available to guardians on the websites of pediatric dental practices across the United States. The comparison will reveal if practice websites are meeting the needs of the guardians of pediatric dental patients. Our hope is to provide meaningful guidance to pediatric dentists designing new practice websites and to provide the guardians of pediatric dental patients with an appealing online experience during their use of the aforementioned websites. Methods: A survey with …

Comparison Of Endodontic Treatment Planning Decisions Using Cone Beam Computed Tomography Versus Periapical Radiography In Previously Endodontically Treated Molars, Sarah Alkanderi

Theses and Dissertations

Objectives: The aim of this study was to determine if treatment plans differ when evaluating previously endodontically treated molars using periapical images (PA’s) alone versus PA’s and CBCT.

Methods: A retrospective cohort chart review was conducted including 67 previously treated molars that had a CBCT taken. Two calibrated board-certified endodontists evaluated standard PA’s. A data sheet questionnaire regarding radiographic findings and treatment plan decisions was completed. Two weeks later, the same steps were repeated but the examiners evaluated both PA’s and CBCT images and again arrived at a recommended treatment plan.

Results: Agreement between raters was assessed with Cohen’s Kappa …

Recovery From Visual Dysfunction Following Mild Traumatic Brain Injury Is Associated With Adaptive Reorganization Of Retinal Inputs To Lateral Geniculate Nucleus In The Mouse Model Utilizing Central Fluid Percussion Injury., Vishal C. Patel

Theses and Dissertations

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality nationwide. Prevalence of mild TBI (mTBI) vastly outnumbers more severe forms however the associated morbidity has only recently gained public attention. Visual dysfunction is a significant component of mTBI associated morbidity with recovery of function linked with improvement in global outcomes. Examination of sensory and motor pathways in other brain injury paradigms support that recovery is largely dependent on adaptive plasticity of remaining connections. Current examinations of visual function recovery following mTBI is limited to identifying evidence for recovery and objective evidence for adaptive plasticity is limited. Therefore, …

Selenomonas Sputigena: Growth Conditions And Projected Virulence Factors Of An Emerging Oral Pathogen, Kayla A. Keller

Theses and Dissertations

Periodontal diseases are ubiquitous diseases. They can affect people through a chronic infection that happens over a lifetime, but also as an aggressive infection that afflicts the younger population. It not only results in tooth loss and a lower quality of life, but it can also lead to fatal secondary infections like cervical cancer, heart disease, and Alzheimer’s disease. This study looks at Selenomonas sputigena, an emerging oral pathogen, that has been hypothesized to contribute to periodontal disease. It has been linked to fatal septicemia and has been found in increased abundance within the oral biofilm during peak infection. …

Achieving Dentin Conservation Using Dynamic Navigation Technology For Locating Calcified Canals, Madison W. Saunders

Theses and Dissertations

Purpose: Pulp canal obliteration (PCO) is a common sequela of dental trauma, caries, restorations and vital pulp therapy procedures. Despite the application of high magnification and CBCT imaging, access cavity preparation for such cases is prone to procedural errors that may lead to substantial loss of dentin structure thereby reducing the long-term prognosis. This study aimed to achieve dentin conservation using a novel computer assisted dynamic navigation system (Navident) in comparison to freehand access preparation for locating calcified canals.

Methods: Forty maxillary and mandibular central incisors (tooth #9 and tooth #25) were 3-D printed to simulate PCO. They were randomly …

“It’S Supposed To Be Super Easy And It’S Not”: Black And Latinx Student Experiences In The Doctor Of Physical Therapy Admissions Process, Melissa Yeung

Theses and Dissertations

Data provided by the Physical Therapy Central Application System (PTCAS) suggests that despite the large numbers of applicants to Doctor of Physical Therapy (DPT) programs on an annual basis, a gap remains between the number of White and Black and Latinx applicants who are offered admission to DPT programs. Efforts made by DPT programs to increase the diversity of their incoming cohorts include the use of holistic review processes and enrichment programs to recruit more diverse classes. However, research suggests that the undergraduate experiences of students of color have an impact on their aspirations to graduate and professional schools, and …

Non-Invasive Retrieval Of Prefabricated Zirconia Crowns With Er,Cr:Ysgg Laser From Primary And Permanent Teeth, Connor W. Mccall Dds

Theses and Dissertations

Purpose: Compromised tooth structure on permanent and deciduous teeth in the pediatric population is increasingly being restored with tooth-colored prefabricated zirconia crowns. These restorations may need to be removed or replaced with permanent crowns. The purpose of this in vitro study was to explore the use of an Er,Cr:YSGG laser for removal of prefabricated zirconia crowns cemented with RMGI as a non-invasive alternative to rotary instruments.

Methods: Thirteen permanent and 12 primary molars were prepared to dentin and prefabricated zirconia crowns were passively fitted and cemented with two resin modified glass ionomer cements. The irradiation parameters for ErCR:YSGG were 4.5 …

Characteristics Of Alveolar Bone Marrow Cells From Patients Undergoing Dental Extractions Or Dental Implant Therapy, Meng H. Lee

Theses and Dissertations

Alveolar bone marrow stromal cells (aBMSCs) play important roles in craniofacial wound healing. To establish an easy, efficient and reliable method to harvest aBMSCs, we compared three different methods: extraction socket aspiration, osteotomy aspiration and bone core digestion. Samples of aBMSC were collected from two groups of subjects. Group 1 (dental extraction): after dental extraction, 22.5-gauge needles were used to collect 0.5-1cc marrow aspirate. Group 2 (dental implant): during implant surgeries, bone core and 0.5-1cc marrow aspirate were obtained from the osteotomy. Samples were cultured in petri dishes and attached cells were expanded. The population doubling time (PDT), surface markers, …

The Effect Of Print Angulation On The Accuracy And Precision Of 3d-Printed Orthodontic Retainers, Allison Williams

Theses and Dissertations

Purpose: The aims of this study were: 1) to compare the accuracy and precision of 3-

dimensional (3D) printed retainers at various angulations, 2) to evaluate the effect of angulation

on printing time and the amount of resin consumed.

Methods: Using a stereolithography (SLA) 3D printer, a total of 60 clear retainers were printed at five angulations (n=12, each): 15, 30, 45, 60, and 90 degrees. Six retainers were printed each cycle at a random order for all print angulations as print 1 and print 2. Digital images of the original and printed retainers were superimposed. Discrepancies on eight landmarks …

Amixicile As A Novel Antimicrobial Treatment For Periodontitis: A Pilot Study In The Non-Human Primate, Macaca Mulatta, Denver J. Lyons

Theses and Dissertations

Periodontitis is an inflammatory disease with a bacterial etiology in a susceptible host. Given the bacterial etiology, a selective antimicrobial agent with minimal side effects could be a useful adjunct to traditional therapy. Amixicile is a novel antimicrobial that targets the pyruvate: ferredoxin oxidoreductase (PFOR) which is an enzyme that is critical for anaerobic bacterial metabolism. It has been found to have no effect on commensal, aerobic microbes and has little to no side-effects thus far in animal models. In this study, two nonhuman primates of the Macaca mulatta species with naturally occurring mild chronic periodontitis were studied before and …

Exploring The Use Of Pulsed Erbium Lasers To Retrieve A Zirconia Crown From A Zirconia Implant Abutment, Ahmed Elkharashi

Theses and Dissertations

Removal of zirconia crowns, commonly used as cement-retained implant fixed restorations, can be challenging. Conventional methods of crown removal are time consuming and often leave irreparable damage to the crown, which can be costly to patients and practitioners. This research explored the use of two different types of pulsed erbium lasers, erbium-doped yttrium aluminum garnet laser (Er:YAG) and erbium, chromium-doped yttrium, scandium, gallium and garnet (Er,Cr:YSGG), as non-invasive tools to retrieve cemented zirconia crowns from zirconia implant abutments. Times needed to remove the crowns were recorded and analyzed using ANOVA (��=0.05). No statistical differences between the debond times of each …

Current Trends In The Management Of Invasive Cervical Resorption, Erik J. Foisy

Theses and Dissertations

Purpose: To determine how endodontic practitioners are currently managing cases of invasive cervical resorption. Also, to analyze how invasive cervical resorption (ICR) has been managed at Virginia Commonwealth University (VCU) over the past ten years.

Methods: Both domestic and international endodontists were invited to participate in a 14-question survey developed and administered via REDCap. Survey invitations were sent via email to currently practicing endodontists. Electronic dental records were queried for patients diagnosed with ICR at VCU in the preceding ten years. Results of both were summarized using descriptive statistics (counts and percentages). Fisher’s exact test was used to compare survey …

Repeat Full Mouth Dental Rehabilitation Under General Anesthesia For Medicaid Eligible Healthy Children Who Are High Caries Risk, Lajoi E. Wiggins

Theses and Dissertations

Purpose: To evaluate the treatment of healthy children who are high caries risk and of low socioeconomic status and who require repeat full mouth dental rehabilitation (FMDR) under general anesthesia (GA).

Methods: A retrospective chart review was performed on healthy Medicaid eligible patients who were initially between 18 months - 6 years of age who underwent FMDR under GA in the OR more than once at the Virginia Commonwealth University (VCU) School of Dentistry, Department of Pediatric Dentistry from January 2008 to December 2018. Biographical information for each patient was gathered into a REDCap™ Survey. Statistical analysis, chi-squared test with …