Dentistry Electronic Theses and Dissertations (UMKC)
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The items in this collection are the theses and dissertations written by students of the School of Dentistry. Some items may be viewed only by members of the University of Missouri System and/or University of Missouri-Kansas City. Click on one of the browse buttons above for a complete listing of the works.
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Item From interfacial nanostructures to advanced constructs: harnessing surfactant self-assembly at liquid interfaces(University of Missouri--Kansas City, 2025) Amirfattahi, Saba; Niroobakhsh, ZahraLiquid-in-liquid 3D (LL3DP) printing offers a promising platform for fabricating soft material structures by depositing an ink phase within an immiscible support bath. While this technique enables the creation of complex architectures for applications in biomedical engineering, drug delivery, and tissue scaffolding, its broader potential is currently limited by the stability and tunability of the liquid-liquid interface. The primary focus of this work is to develop and stabilize structured liquid interfaces that can support and facilitate LL3DP, enabling more reliable and versatile printing of soft materials. By designing material systems with enhanced interfacial stability and responsiveness, this approach aims to expand the library of printable inks and unlock new possibilities for controlled soft matter fabrication. In the first studied system, we investigate the stabilization of the liquid–liquid interface to fabricate a bicontinuous interfacially jammed emulsion gel (bijel) using the LL3DP approach. The bijel consists of two interpenetrating, continuous phases of immiscible liquids, stabilized by the self-assembly of colloidal particles—primarily nanoparticles— at the liquid interface. The structural features of the printed bijel constructs are characterized using confocal and scanning electron microscopy (SEM), while their mechanical properties are evaluated through shear rheometry. Compared to other soft materials explored for LL3DP, bijel-based prints offer unique advantages, including interconnected hydrophobic and hydrophilic domains confined within defined geometries, along with tunable structural and rheological characteristics. In the second system, a novel material system based on lipid self-assembly is presented to stabilize water-oil interfaces as the underlying mechanism in the LL3DP. The stabilization process, governed by the formation of nanostructures at the interface, is comprehensively analyzed using small-angle X-ray scattering (SAXS), rheometry, and microscopy techniques. This material system, once incorporated successfully in LL3DP, enables the fabrication of intricate 3D constructs, including fibers, substrates, and microneedle patches, which demonstrate exceptional mechanical properties and biocompatibility, as validated by tensile testing and cell viability assays. Finally, the incorporation of silica nanoparticles into a material system previously established for soft matter 3D printing is presented, which was shown to result in the formation of aerogels with significantly enhanced mechanical strength and stability. Such silica aerogels, known for their ultralight weight and high porosity, tend to reinforce the liquid-phase structures while preserving flexibility. Upon further characterization, SAXS measurements confirm improved nanostructural organization in these aerogels, while rheological properties are comprehensively characterized. The development of these aerogels with hierarchical ordering across multiple length scales opens new possibilities for designing high-performance, multifunctional materials for medical implants, tissue engineering scaffolds, and filtration systems. This thesis, by bridging 3D printing and interfacial stabilization through selfassembly of various colloidal components such as inorganic (silica) nanoparticles and small amphiphilic molecules, lays the foundation for future advancements in soft material fabrication. The precise control over liquid-phase architectures and their tailored mechanical properties, as well as structural ordering at various scales, offers new possibilities for designing new class of materials for medicine, biotechnology, and advanced manufacturing.Item Job satisfaction in orthodontics: private practice versus corporate practice(2024) Simister, Brandon; Scott, JoAnna M.; Walker, Mary P.This study investigated the current job satisfaction in orthodontics, specifically the reported job satisfaction among private and corporate practice orthodontists. The study also examined the demographics and practice characteristics of orthodontists whether they were in private or corporate orthodontics. Lastly, the study investigated what orthodontic work preferences were associated with private or corporate practicing orthodontists. A survey was sent to members of the American Association of Orthodontists (AAO) to collect this data. Based on the results of this survey, orthodontists who graduated from orthodontic residency in 2020 or later or had 3 or more office locations were significantly associated with that orthodontist being in private or corporate practice. All other demographic and practice environment findings did not yield significant associations. Additionally, the study found a significant difference in overall job satisfaction between private and corporate practice orthodontists, with private practice orthodontists reporting a higher level of satisfaction. Lastly, there was a significant association between what the orthodontist selected as their most important work preference and whether that orthodontist was in private or corporate practice. Those orthodontists who selected the ownership opportunity as their most important work preference were more likely to be in private practice.Item Digital indirect bracket bonding in orthodontic practice(2024) Boehm, Richard Charles; Scott, JoAnna M.; Walker, Mary P.This study investigated the use of indirect bonding in orthodontic practices, specifically whether the orthodontist demographics and practice characteristics influenced the use of indirect bonding within an office. This study also examined factors that influenced or deterred orthodontists from the use of indirect bonding in practice. A survey was sent to members of the American Association of Orthodontists (AAO) to collect this data. Based on the results of this survey, graduation year was the only significant association between orthodontist demographics and indirect bonding use. There were no significant associations between practice characteristics and indirect bonding use. This study did find, however, that individuals who were trained on indirect bonding use by sales staff or manufacturers and practice colleagues regarding indirect bonding were significantly more likely to utilize indirect bonding in practice. Similarly, orthodontists with no training on indirect bonding use were significantly less likely to use indirect bonding in their practice. The results of this study also suggested that while many orthodontists believe that there are benefits to using indirect bonding in orthodontic settings, many still have not incorporated this technique into their own offices.Item Effect of build angle and print layer thickness on clinical accuracy of 3D-Printed orthodontic models(2024) Knapp, Brandon T. S.; Lohfeld, StefanThis study investigated how variations in print layer thickness and build angle impact the accuracy of orthodontic models produced using a digital light processing (DLP) 3D printer. Orthodontic models were generated from a digital master model derived from an ideal maxillary typodont scan. The study tested six different configurations: 100 µm-0°, 100 µm-70°, 100 µm-90°, 170 µm-0°, 170 µm-70°, and 170 µm-90°. Following printing, the experimental models underwent scanning, and the scan data were analyzed against the digital master model using 3D superimposition software. A ±0.25 mm range was established as clinically acceptable deviation between the digital master and experimental models. The findings indicate that both build angle and print layer thickness influence the final accuracy of the printed models. In this study, models printed with a 170 µm layer thickness demonstrated slightly greater accuracy across all build angles compared to those printed with 100 µm thickness. These results suggest that choosing the appropriate print layer thickness can offer flexibility in achieving accurate clinical outcomes.Item Dental Students' Knowledge Related to Peri-Implantitis Diagnosis and Willingness to Treat or Refer: A Pilot Study(2024) Baum, Therin; Scott, JoAnna M.; Walker, Mary P.This pilot study examined whether demographic factors affect student knowledge, ability to diagnose, and willingness to refer biological implant complications, specifically peri-implant mucositis and peri-implantitis. This study examined the association between student knowledge and ability to diagnose and the association between student knowledge or ability to diagnose and student willingness to treat or refer cases. A 24-question survey, approved by the UMKC IRB, was distributed to 214 third- and fourth-year dental students at UMKC. The survey was divided into three domains including student demographics, student ability to diagnose biological implant complications and their willingness to treat or refer, and student knowledge of biological implant complications. Associations were evaluated using 2 sample t-tests, Chi-square or Fisher’s exact tests, and one-way variance (ANOVA) with Tukey pairwise post hoc tests. Data showed a statistically significant association between dental school class and knowledge of complications, ability to diagnose complications, and willingness to refer complications. There was not a statistically significant association between student knowledge and ability to diagnose implant complications or between student knowledge or ability to diagnose complications and the willingness to treat or refer. Overall, the results of this study suggest that dental school year is significantly associated with knowledge of, ability to diagnose, and willingness to refer biological implant complications.