Dental Materials Commons^™

Catechol-Containing Copolymers As An Active Ingredient For Denture Adhesives, Vincent Ying Wun Kong

Electronic Thesis and Dissertation Repository

Moisture inside the mouth adds challenge to making denture adhesives formulations. Some formulations have zinc to enhance adhesion on wet skin despite knowing the health hazards. Inspired by mussel foot proteins’ catechol unit’s strong underwater adhesion, nine catechol-containing copolymers (P1A-P3C) were synthesized by free radical polymerization of 3,4-dimethoxystyrene (3,4- DMS) with different styrene derivatives followed by deprotection. P1A-P3C were used to make Fn(P)-C-PBS denture adhesive formulations which had suitable shear stresses around ≥ 5 kPa satisfying ISO 10873. In-situ NMR studies of free radical polymerization of 3,4 - DMS and styrene derivatives allowed computation of their reactivity ratios showing all …

A Critical Review And Finite Element Study Of Structural Relaxation In Veneered 3y-Tzp Dental Structures, Prashant S. Shelar

Electronic Thesis and Dissertation Repository

Yttria stabilized Tetragonal Zirconia Polycrystal (3Y-TZP) materials veneered with porcelain are preferred for clinical practice due to their bio-functionality, biocompatibility, and affordability. However, these materials are often subjected to premature clinical failures due to combination of subsurface flaws and tensile stresses within porcelains. This work focuses on performing a critical literature review and evaluating veneer characteristics, i.e. structural relaxation, to form a suitable explanation for the development of subsurface stresses. User material subroutines, UEXPAN and UTRS are developed, validated and integrated in ABAQUS finite element solver. With the use of validated models, it is shown that faster cooling rates and …

The Effect Of Pigmentation On Latex And Non-Latex Orthodontic Elastics, Dustin Wilson

Electronic Thesis and Dissertation Repository

Background: Intraoral Elastics have been widely used in Orthodontics for well over 100 years. Changes in material composition, manufacturing and addition of color to elastics has shown to effect force levels over time.

Aim: The purpose of the study was to determine the effect of pigmentation on force levels and their degradation over time in both Latex and Non-Latex orthodontic intraoral elastics.

Materials & Methods: Groups consisted of elastics in Latex from American Orthodontics in both natural and four different colors, American Orthodontics Non-Latex in natural, Ormco Latex in both natural and four different colors, Auradonics Latex in both natural …

Metal Additive Manufacturing For Fixed Dental Prostheses, Mai El Najjar

Electronic Thesis and Dissertation Repository

The use of additive manufacturing (AM) in dentistry has gained momentum in recent years. However, high initial costs and uncertainty surrounding the quality of AM products are considered barriers to their use. This research compared dental substructures fabricated by AM versus conventional casting and milling.

Cobalt-chromium alloy rectangular bars and three-unit bridge substructures were fabricated by AM, casting or milling. Bars manufactured by AM exhibited superior flexural strength, shear bond strength of porcelain coating, and Vickers hardness. Bridge substructures fabricated by AM showed similar flexural stiffness to cast, similar flexural loads at failure to milled and cast, and overall accuracy …

Mass Spectrometry-Based Proteomics Analysis Of Bioactive Proteins In Emd That Modulate Adhesion Of Gingival Fibroblast To Improve Bio-Integration Of Dental Implants, David Zuanazzi Machado Jr

Electronic Thesis and Dissertation Repository

Titanium implants are used in dental practice to replace damaged or lost teeth. The implant needs to integrate with the surrounding gingiva to protect it against bacterial invasion that leads to implant loss. The biointegration is dependent on the implant surface that interacts with proteins from biological fluids to modulate tissues response. Tailoring the surface with specific proteins from the enamel matrix derivative (EMD) would be beneficial to improve the implant-gingiva interface since EMD can affect various cells including gingival fibroblasts. A surface-affinity approach using three different titanium surfaces and saliva was utilized as a model in combination with tandem …

Effect Of Clear Aligner Therapy On Masticatory Muscle Tenderness And Orthodontic Pain, Johnny Tran

Electronic Thesis and Dissertation Repository

Introduction: Patients undergoing orthodontic clear aligner therapy (CAT) may experience discomfort in their teeth and jaws, and often present with visible wear on their aligners. This multi-site prospective clinical study aimed to analyze tooth pain and masticatory muscle tenderness in patients subjected to CAT with Invisalign©.

Methods: Twenty-seven healthy adults undergoing treatment with Invisalign© were recruited from three university-based orthodontic clinics. Tooth pain and muscle tenderness were reported on visual analog scales in pain diaries prior to, and after starting CAT. Pressure pain thresholds (PPT) measured using pressure algometers were used to assess somatosensory changes in trigeminal and extra-trigeminal locations. …

Binding Of Salivary Proteins To Orthodontic Brackets, Maria Pia Canales

Electronic Thesis and Dissertation Repository

Objectives: The aim of this study was to investigate the effect of different orthodontic materials on the formation of the protein pellicle on the bracket surface.

Materials and Methods: We used X-ray Photoelectron Spectroscopy (XPS) to analyze the atomic composition of orthodontic metallic and ceramic brackets. Following XPS, the brackets were immersed in human whole saliva supernatant for 2-hour incubation at 37°C. Hydroxyapatite (HA) discs were used as control. Acquired pellicle was harvested with sonication for each group, and liquid chromatography electrospray ionisation mass spectrometry was used for protein identification.

Results: Differences reported by XPS and mass spectrometry were noted …

Underlying Mechanisms Regulating Gingival Healing And Fibrosis, Shawna Soheun Kim

Electronic Thesis and Dissertation Repository

Successful wound healing involves tightly controlled regulation of extracellular matrix (ECM) deposition and remodeling, and myofibroblast-mediated wound contraction, to restore normal tissue function. However, these events involved in healing are also associated with development of tissue fibrosis, which is characterized by excessive deposition of ECM and the presence of myofibroblasts. Increasing evidence suggests that periostin is a critical player in regulating skin healing and fibrosis. In contrast to most adult tissues, gingival connective tissue is known to heal more rapidly and with less scarring, yet is still associated with fibrosis, such as drug-induced gingival enlargement. The aim of this study …

Reinforcement Of Flowable Dental Composites With Titanium Dioxide Nanotubes, Manal Dafar

Electronic Thesis and Dissertation Repository

Flowable composites are widely used in dentistry. However, they suffer from poor mechanical properties. The aim of this study was to reinforce a flowable composite with TiO₂ nanotubes (n-TiO₂), which were synthesized using an alkaline hydrothermal technique then functionalized with silane or methacrylic acid (MA). The synthesized n-TiO₂ was characterized using X-ray diffraction, energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. Electron microscopy revealed a tubular morphology of n-TiO₂. Commercially available flowable composite was reinforced with varying amounts of nanotubes (0-5%). Dynamic Young’s moduli (E) and fracture toughness (K_IC) of composites reinforced …

Glass-Ceramics For Non-Metallic Dental Implant Applications, Selma Saadaldin

Electronic Thesis and Dissertation Repository

Metallic dental implants are an important treatment for the replacement of missing teeth. However, for esthetic and environmental issues, there is a need to develop non-metallic dental implant materials. In this thesis, two novel glass-ceramics (GCs), miserite and wollastonite, were synthesized for one-piece dental implant applications. Glasses were synthesized by wet chemical methods, followed by calcination, melting and quenching. The crystallization kinetics of these glasses were determined by differential thermal analysis (DTA). GC specimens were produced by cold pressing of the glass powder and sintering using schedules determined by DTA. The crystalline phases and microstructure of the GC samples were …