Dental Materials Commons^™

Biodegradable Nano-Hybrid Polymer Composite Networks For Regulating Cellular Behavior, Charles Henley Sprague

Masters Theses

Photo-crosslinkable polymeric biomaterials have emerged in the field of biomedical research to promote tissue regeneration. For example, scaffolds that can be crosslinked and hardened in situ have been known to make suitable implant alternatives. Since injectable and photo-crosslinkable biomaterials offer the advantage of being minimally invasive, they have emerged to compete with autografts, a current highly invasive method to repair diseased tissue. A series of novel photo-crosslinkable, injectable, and biodegradable nano-hybrid polymers consisting of poly(ε-caprolactone fumarate) (PCLF) and polyhedral oligomeric silsesquioxane (POSS) has been synthesized in our laboratory via polycondensation. To engineer the material properties of the nano-hybrid networks, varied …

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 …

Thermomechanical Characterization Of Variable Force Niti Orthodontic Archwires, Anjali Sudershan Krishan Mehta

Master's Theses (2009 -)

ABSTRACT THERMOMECHANICAL CHARACTERIZATION OF VARIABLE FORCE NITI ORTHODONTIC ARCHWIRES Anjali Mehta, BDS MDS Marquette University, 2015 Introduction: Nickel-Titanium (NiTi) archwires, due to their properties of superelasticity and shape memory, have been extensively used in orthodontic mechanotherapy. However, one of the shortcomings of these wires is that they deliver constant forces across the entire arch. The amount of force needed to move a tooth is a function of the surface area of the tooth and its supporting bone; and is lesser for single rooted anterior teeth compared to larger molars. The introduction of heat treatment of NiTi wires and the influence …

Influence Of Fluoride And Stress On The Mechanical Properties Of Nickel-Titanium Coils, Jennifer Ann Fehrman Roloff

Master's Theses (2009 -)

Objective: The objective of this study was to determine the influence of fluoride and stress on the mechanical properties of nickel-titanium open coil springs. Materials and Methods: Sentalloy nickel-titanium open coil springs (15 mm length) were divided into five groups. A control group was tested mechanically in as-received condition. The other four experimental groups were exposed to artificial saliva (Fusayama-Meyer solution) at 37oC for 12 weeks in a 2x2 factorial design with fluoride exposure and stress (compression) as the two factors. Those springs which were under compression were held at 5 mm in length for the entirety of the testing …

Changes In Composite Toxicity Following Exposure To Pulp Capping Materials, Audra Long

Master's Theses (2009 -)

Introduction: Direct pulp capping involves placing a material over the exposed pulp in order to maintain its vitality. For decades, calcium hydroxide (CH) has served as the gold standard for this purpose, but its toxicity to the pulp may negatively impact treatment outcomes. Mineral Trioxide Aggregate (MTA) has become a popular alternative based partly on its excellent biocompatibility. Pulp-capped teeth are often restored with highly toxic composite materials, but the pulp capping material’s ability to alter these toxic effects has never been investigated. The purpose of this in vitro study is to determine the effects of Dycal, a CH-based cement, …

Influence Of Fluoride And Stress On The Electrochemical Properties Of Nickel-Titanium Coils, Ashley Barnes

Master's Theses (2009 -)

The aim of this study was to examine the effects of fluoride and stress on the electrochemical properties of nickel-titanium coils. Forty Dentsply GAC NiTi coils were divided into four groups of ten and individually tested. Twenty coils were placed in a solution of artificial saliva, where ten of the twenty were compressed and the other ten were not stressed. The other twenty coils were placed in a 1500 ppm NaF solution, where ten were compressed and ten were not. The coils were connected to a computer driven potentiostat and three tests were conducted: open circuit potential monitoring for 2 …

Mechanical Properties And Patient Perceptions Of Commonly Used Clear Aligner Systems As-Received And After Clinical Use, Lauren Evan Montoure Teske

Master's Theses (2009 -)

Background/Objectives: This study aimed to investigate the viscoelastic properties of two clear aligner systems, Invisalign (Align Technology, Inc, Santa Clara, CA, USA) and Simpli5 (Allesee Orthodontic Appliances, Sturtevant, WI, USA), and determine if there was a difference after use. A survey assessed patients’ perceptions of the aligner material and post-treatment satisfaction. Materials/Methods: Mandibular aligners were collected from two patients after 2-3 weeks of use (n=6). Duplicate, unused aligners were obtained for each patient (n=6). Dynamic mechanical analysis (DMA) characterized the viscoelastic properties of the materials. Three tests were done on separate specimens: frequency scan (0.1-10 Hz under 25 μm displacement …

Oral Wellness: Using Occupational Therapy To Enhance Oral Hygiene Delivery In Long-Term Care, Lauryn J. Banovitz, Liberty Bellah, Rosemarie Lion

Dissertations, Masters Theses, Capstones, and Culminating Projects

Based on current literature, oral health in long-term care (LTC) facilities is frequently of low priority and does not follow evidence-based best practices. Poor oral health reduces the quality of life of older adult residents and patients and can lead to systemic diseases, such as cardiovascular disease, stroke, and pneumonia, the leading cause of death in LTC. Occupational therapists can play an instrumental role as oral care consultants, and educators, and can act as resource guides to raise the standards of oral care in LTC facilities.

This capstone project explored ways in which occupational therapy, a profession traditionally designated for …

Effect Of Autoclaving On Flexibility Of Four Different Nickel Titanium Files, Anushree Mehrotra

Master's Theses (2009 -)

Introduction: Nickel-titanium (NiTi) files, introduced over 2 decades ago, have the unique property of superelasticity, are more resistant to fracture and are more flexible than stainless steel files. Recent developments in NiTi include M wire and Controlled/Thermal Memory Technology resulting in files with claimed superior properties to conventional NiTi files. Manufacturers recommend sterilization of files prior to usage. These files may be subjected to further autoclaving if reused. The purpose of this study was to test the effect of multiple cycles of autoclaving on the flexibility of four brands of NiTi files and to evaluate differences between brands. Materials and …

Effect Of Toothbrushing On Surface Roughness And Shade Of Extrinsically Stained Pressable Ceramic Restorations, Lessly Arlette Garza

Master's Theses (2009 -)

The purpose of this study was to investigate the effects of toothbrushing on surface roughness and shade change of extrinsically stained pressable ceramic restorations. Materials and Methods: Two materials, IPS Empress Esthetic and IPS e.max Press, were studied. For each material, 24 disc-shaped specimens, 10mm (diameter) x 3mm (height) were fabricated. Three different methods (n=8) of applying extrinsic stain was performed on each material: Glazed (G): glazed only (control); Stain then Glaze (SG): stained and fired, then glazed and fired. Stained and Glazed (T): glazed and stained together. Samples where brushed using a multi-station brushing machine. Each specimen was brushed …

Differential Scanning Calorimetric (Dsc) Study Of New And Sterilized Nickel-Titanium Rotary Endodontic Instruments, Michael Dyriw

Master's Theses (2009 -)

Introduction: Nickel-Titanium (NiTi) files have become popular in endodontic procedures compared to traditional stainless steel hand files owing to their increased flexibility which is especially advantageous in curved canals. Due to the associated costs, endodontic instruments are frequently re-used, which requires sterilization between uses. With the application of temperature NiTi has the ability to undergo phase transformations, altering the properties of the instruments. The purpose of this study was to investigate phase transformations of four brands of NiTi rotary endodontic instruments in the as-received condition and after multiple sterilization cycles under steam sterilization, using differential scanning calorimetry. Materials and Methods: …

Comparison Of Three Different Nickel-Titanium Endodontic Rotary Systems In Shaping Simulated S-Shaped Canals, Elineida Perez

Master's Theses (2009 -)

Introduction: Preparation error may result during mechanical instrumentation because of the complex anatomy of the root canal. Thus, flexibility and resistance to fracture are ideal properties that endodontic instruments should have. The aim of the study was to compare the shaping ability of three different nickel-titanium rotary instruments in simulated S-shape root canals by measuring transportation and canal volume change CVC. Materials and Methods: A total of 60 S-shaped canals in resin blocks were randomly allocated into 3 groups (n=20): Vortex Blue (Dentsply-Tulsa Dental Specialties), HyFlex CM (Coltène/Whaledent) and EndoSequence (Brasseler USA). Canals were filled with dye and secured in …

Effect Of Surface Preparation On The Shear Bond Strength Of Orthodontic Brackets Bonded To Zirconia : An In-Vitro Study, Nathaniel Wieder

Student Theses, Dissertations and Capstones

Objectives: The purpose of this in-vitro study was to evaluate the effects of three different surface preparation methods on the shear bond strength of orthodontic brackets bonded to zirconia and determine the most appropriate method. Methods: 45 zirconia and 30 leucite-reinforced porcelain mandibular premolar crowns were divided into 5 groups and received the following surface preparations: 37% phosphoric acid and non-hydrolyzed silane, 4% hydrofluoric acid and hydrolyzed silane, microetch with 50μ Al ₂ O₃ particles. A universal adhesive primer containing MDP was applied and the brackets were bonded with a bis-GMA composite resin. Shear bond strength (SBS) at bond …

Exploration Of Materials Used In 3-Dimensional Printing For The Dental Industry, Holly Chang Hayden

Scripps Senior Theses

A limiting factor in the digitization of dental devices is the availability of materials suitable for use in both dentistry and the new digital technologies. As a rapidly growing industry, three-dimensional printing (3DP) has the potential to disrupt traditional manufacturing and prototyping methods. A review of both restorative materials and the current 3DP materials has lead to a focus on fiber- reinforced composites in the exploration for a new 3DP material. In addition, another area worth exploring and investing in would be 3D bioprinting as it opens up the possibility of regenerative dentistry.