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Effect Of Heat-Treatment Time On Bending Properties Of Cobolt-Chromium Orthodontic Wires, Melanie Hammerbeck Jul 2019

Effect Of Heat-Treatment Time On Bending Properties Of Cobolt-Chromium Orthodontic Wires, Melanie Hammerbeck

Master's Theses (2009 -)

Different protocols appear in the literature with respect to heat-treating cobalt-chromium orthodontic wires. The objective was to determine the effect of variable heat-treatment time and method on the bending properties of CoCr wires. Two tempers of CoCr ‘Elgiloy’ wires (Rocky Mountain Orthodontics), blue (B) and yellow (Y), were heat-treated for different durations. The groups (n=20/group/temper) included: 1) as-received (control); 2) brush-flame; 3) 480oC for 5sec; 4) 480oC for 10min; 5) 480oC for 2hr; and 6) 480oC for 5hr. Wire segments were tested by a three-point bend test. Stiffness/flexural modulus, percent recovery, and force values at select deflections were statistically compared …


Efficacy Of Invisalign Attachments: A Retrospective Study, Theresa Karras Jul 2019

Efficacy Of Invisalign Attachments: A Retrospective Study, Theresa Karras

Master's Theses (2009 -)

Objective: To compare the efficacy of Invisalign’s (Align Technology, Inc., Santa Clara, CA) optimized and conventional attachments on rotational and extrusive tooth movements.Materials and Methods: Initial, predicted, and achieved digital dental models from 100 orthodontic patients were exported from Invisalign’s ClinCheck software as stereolithography (STL) files and subsequently imported into the Slicer CMF program (open source, version 4.7.0) for superimpositions on posterior teeth with no planned movement. Rotational and extrusive measurements for both optimized and conventional attachment types were made on 382 teeth from the superimposition of the initial and predicted models (“predicted movement”) and from the superimposed initial and …


Injectable Gels With Potential Use In Endodontics, Maksim Montatskiy Apr 2019

Injectable Gels With Potential Use In Endodontics, Maksim Montatskiy

Master's Theses (2009 -)

Objective: To formulate a thermoreversible hydrogel using methyl-cellulose, carbon dots and inorganic salts to achieve physiologically compatible gelation temperature; to test cytotoxic effects of formulation against dental pulp stem cells.Materials/Methods: A 5% w/v methylcellulose (MC) solution was prepared and equal volumes of NaCl aqueous solution were added to make various sodium chloride salt concentrations and reach the final MC concentration of 2.5%. Samples were analyzed using a shear rheometer to monitor complex shear viscosity as a function of temperature to arrive at onset gelation temperature closest to targeted temperature. Carbon dots were synthesized by thermal method using ammonium citrate …


An In Vitro Study Of Surface Alterations To Peek And Titanium And Its Effect Upon Human Gingival Fibroblasts, Maryam Gheisarifar Apr 2019

An In Vitro Study Of Surface Alterations To Peek And Titanium And Its Effect Upon Human Gingival Fibroblasts, Maryam Gheisarifar

Master's Theses (2009 -)

Objective: Soft tissue attachment to different surfaces plays a pivotal role in long term success of dental implants. The aim of the current study was to evaluate viability and adhestion of human gingival fibroblasts (HGFs) upon specific surface modifications on different implant abutment materials. Material & Methods: A total of 150 specimens in 6 experimental groups were used: titanium alloy (Ti [smooth machined]), titanium laser-modified (TiL), PEEK (P [smooth machined]), PEEK laser-modified (PL), PEEK plasma treated (PP), PEEK laser and Plasma treated (PLP). The surface roughness (Sa), water contact angle (WCA), and X-ray photoelectron spectroscopy (XPS) were measured. Human gingival …


The Design And Physical Properties Of An Optimized Chitosan Hydrogel For Potential Use In Endodontics, Hunter Housley Apr 2019

The Design And Physical Properties Of An Optimized Chitosan Hydrogel For Potential Use In Endodontics, Hunter Housley

Master's Theses (2009 -)

Introduction: The aim of this study was to synthesize an optimized chitosan/carbon dot hydrogel and measure its effects on the proliferation of dental pulp stem cells. Methods: 1.5% w/v chitosan hydrogel samples were fabricated with 300 mg/ml aqueous β-glycerol phosphate (β-GP) to create an optimized chitosan with a gelation onset temperature below 37°C. Spermidine-functionalized carbon dots (CDs) were added to test groups in concentrations of 25 µg/ml and 50 µg/ml. Complex shear viscosity of the prepared hydrogel samples was evaluated with a Kinexus pro+ shear rheometer (Malvern Panalytical). Samples were evaluated for cellular proliferation with dental pulp stem cells at …


The Influence Of Full Coverage Restorations On Pulp Vitality: A Ten-Year Retrospective Study, Abby Yavorek Apr 2019

The Influence Of Full Coverage Restorations On Pulp Vitality: A Ten-Year Retrospective Study, Abby Yavorek

Master's Theses (2009 -)

INTRODUCTION: The incidence of pulpal disease after delivery of a full-coverage crown has been previously described as between 2-19%. The objective of this study was to identify and analyze the factors that contribute to the incidence of NS-RCT after the delivery of single-unit full-coverage restorations. MATERIALS AND METHODS: Insurance claims from 88,409 crown placements in the Delta Dental of Wisconsin Insurance database were analyzed from the years 2008 to 2017. The Cox Regression model was used to analyze the effect of the predictor variables on the survival of the tooth. Untoward events were defined as NS-RCT, tooth extraction, retreatment of …


Comparison Of Power Versus Manual Toothbrush In Reducing Gingivitis, Keerthi Kamreddy Apr 2019

Comparison Of Power Versus Manual Toothbrush In Reducing Gingivitis, Keerthi Kamreddy

Master's Theses (2009 -)

The purpose of the present 4-week, parallel-arm, single-blinded, clinical study is to investigate the efficacy and safety of a new power toothbrush in comparison with a standard flat trim ADA approved manual brush. The primary objective of this study is to evaluate the efficacy of powered toothbrush on gingivitis reduction compared to a manual toothbrush. Secondary objectives of this study are to evaluate the effectiveness of plaque removal.Materials & Methods: The study was a single-blinded parallel arm randomized controlled interventional trial. Forty-six male and female subjects with gingivitis (32 female and 16 males) with a mean age of 26 …


Effect Of Different Implant Abutment Materials On Optical Properties Of Translucent Monolithic Zirconia Crowns, Nisha Patel Apr 2019

Effect Of Different Implant Abutment Materials On Optical Properties Of Translucent Monolithic Zirconia Crowns, Nisha Patel

Master's Theses (2009 -)

Purpose: The purpose of this study was to evaluate the effect of implant abutment color on the final shade of monolithic translucent zirconia crowns. The null hypothesis was that abutment color or brand of zirconia would have no effect on color of monolithic translucent zirconia crowns.Material and methods: A maxillary right central incisor implant (Nobel Replace Trilobe RP) in a dentoform model was used to mill customized abutments of titanium, gold-anodized titanium, pink-anodized titanium, and zirconium dioxide. An A2 dentin shade polymethyl methacrylate abutment was used as a control. Four types of zirconia systems (BruxZir Anterior; Glidewell Laboratories, LAVA …


Evaluation Of Accuracy Of Static Computer-Guided Implant Placement Compared With Partially-Guided Or Free-Hand Placement, Laxmi Sukhtankar Apr 2019

Evaluation Of Accuracy Of Static Computer-Guided Implant Placement Compared With Partially-Guided Or Free-Hand Placement, Laxmi Sukhtankar

Master's Theses (2009 -)

Purpose: To evaluate precision and trueness of static computer-assisted implant surgery (sCAIS) in comparison with partially-guided and free-hand implant placement in vitro.Materials & Methods: The study was conducted on one hundred mandible replicas obtained from a cone beam computer tomography of a partially edentulous case for implant placement in mandibular right first molar site. First, the fully guided implant placement with different sleeve to bone distances (2mm = H2, 4mm = H4, 6mm= H6) was determined. Second, fully guided implant placement was compared with partially guided, and free implant placement. The achieved implant position was digitized and compared …