Dentistry Commons^™

Microstructure And Mechanical Properties Of Nickel-Free And Nickel-Containing Stainless Steel Orthodontic Wires, Amanda Olejniczak

Master's Theses (2009 -)

Introduction: In orthodontics, contact dermatitis caused by nickel allergy should be of concern with the number of nickel-containing appliances and wires used. Stainless steel archwires are commonly used throughout orthodontic treatment. With the release of nickel from these wires, some manufacturers have turned to nickel-free stainless steel alternatives. The goal of this research was to compare nickel-free stainless steel with traditional stainless steel archwires with regard to mechanical properties and microstructure. Materials and Methods: Nickel-free stainless steel and regular stainless steel archwires from four companies were included. Five random samples of each wire, vertically mounted in fast-set acrylic, were indented …

Dimensional Changes Of Facial Soft Tissue Associated With Rapid Palatal Expansion, Peter Charles Longo

Master's Theses (2009 -)

Introduction: Orthodontic treatment demands excellent outcomes in both function and esthetics. Despite the popularity of rapid palatal expansion in orthodontic treatment, few studies have examined its consequences on facial soft tissue using direct anthropometric measurements. The primary goal of this study was to determine facial soft tissue changes immediately following rapid palatal expansion. Materials and Methods: Twenty-eight patients (age range, 8-17 years) attending Marquette Dental School Orthodontic Post-Graduate Clinic were enrolled in the study. Facial soft tissue measurements were taken with digital calipers at two separate time points (T0: initial exam and T1: thirty days following expansion); measurements were recorded …

Composition, Phase Structure, And Corrosion Of Nickel-Free And Nickel-Containing Stainless Steel Orthodontic Wires, Amrita Rakalla

Master's Theses (2009 -)

Stainless steel wires have long been used in orthodontics. The austenitic stainless steel used in orthodontics contains approximately 18 wt% chromium and 8 wt% nickel. Nickel improves the corrosion resistance and helps maintain the austenite structure of stainless steel. Nickel is the most allergenic metal and is the most common metal associated with contact dermatitis in orthodontics. Nickel-free wires have been developed, and it was the goal of this study to compare nickel-free and nickel-containing stainless steel orthodontic wires to determine and compare their composition, phase structure, and corrosion properties. For each test, nickel-free and conventional stainless steel wires were …

Comparing The Vertical Misfit Of Casts Produced By Two Verification Jigs, Abdulaziz Saeed Alqahtani

Master's Theses (2009 -)

Purpose: To compare the dimensional accuracy between master casts fabricated with verification jigs made of acrylic resin and light cure Triad. Materials and Methods: 10 GC Pattern resin Pattern verifications jigs and 10 Triad gel verification jigs fabricated of a master cast of a mandibular model of 4 internal hex implants. A stone base was fabricated for each verification jig. One screw test was used to evaluate the vertical gap at the terminal abutment using a digital micrometer with an accuracy of 1μm to record the vertical gap for each sample. Results: Triad Gel group has the lowest average distortion …

An Investigation Into The Bonding Properties Of New Generation Ceramic Brackets As Compared To A Stainless Steel Bracket, Ami Inoue

Master's Theses (2009 -)

Introduction: More patients are seeking esthetic alternatives for their orthodontic treatment options, which has led to increased use of ceramic brackets in recent years. These brackets were marketed before independent scientific research was completed. Many of the early ceramic brackets used a silane coupling agent to allow for a chemical bond between the bracket and the adhesive resin. Early reports from clinicians of increased bond strengths and iatrogenic tooth damage after bracket removal were common. Manufacturers have made changes to their base designs, relying more on mechanical retention for bond strength. The goal of this study was to test the …

Effect Of Mechanical Vibration On Resistance To Sliding In The Fixed Orthodontic Appliance, David Robert Kennedy

Master's Theses (2009 -)

Objective: To determine the effects of mechanical vibrations produced from electric tooth brushes and a commercially available device called AcceleDent, on the resistance to sliding at the bracket-arch wire interface. Materials and Methods: All as-received wires and brackets were cleaned with 95% ethanol prior to testing. An individual metal bracket was mounted on a custom metal fixture. The custom metal fixture had a polyurethane material that resembled the mechanical feature of the human periodontal ligament. The test metal bracket was aligned and bonded passively with 4 other non-movable brackets using a straight piece of .0215" X .025" SS wire. Another …

Accuracy And Precision Of Die Spacer Thickness With Combined Computer-Aided Design And 3-D Printing Technology, Lisa Hoang

Master's Theses (2009 -)

Purpose: The purpose of this study was to evaluate the accuracy and precision of die-spacer thickness achieved by the combination of computer aided design and 3-dimension printing technology.

Materials and Methods: An ivorine maxillary central incisor was prepared for an all ceramic crown. The prepared tooth was duplicated by using poly (vinyl siloxane) duplicating silicone and 80 die-stone models were produced using type IV dental stone. Dies were randomly divided into 5 groups with assigned die spacer thickness of (25 μm, 45 μm, 65 μm, 85 μm, 105 μm) (n=16/group). The printed resin copings, obtained from 3D Systems ProJet DP …

Influence Of Taper On The Flexibility Of Nickel-Titanium Rotary Files, Christopher J. Kingma

Master's Theses (2009 -)

Introduction: Modern nickel-titanium instruments have various tapers and have been marketed to have superior flexibility from previous generations. Current ISO standards require force measurements at a static point along the file. Unfortunately, root canal anatomy varies and produces multiple forces along the length of the file. The purpose of this study was to determine the influence of taper on the flexibility of various nickel-titanium files.

Materials and Methods: The flexibility of stainless steel hand files and nickel-titanium rotary files of various tapers was measured. The sample size was 10 for each type, taper and size. The files were measured at …

A Comparison Of Two Methods To Articulate A Maxillary Cast With Lateral Cephalometry, Laura H. Lux

Master's Theses (2009 -)

The Kois Dento-Facial Analyzer, an arbitrary articulation system, is used by clinicians to articulate and evaluate clinical cases. There is, however, limited information for understanding how the Kois Dento-Facial Analyzer should be utilized. Dr. Kois and Dr. Lee originally patented the device in 2003 yet there is essentially no evidence-based research in the literature. The purpose of this study was to evaluate the outcomes of articulating the maxillary cast using the Kois Dento-Facial Analyzer in three-dimensions as compared to the position of the cast when using Panadent’s Pana-Mount Facebow. Fifteen dried human skulls were used as test subjects. Maxillary diagnostic …

Evaluation Of Effect Of 17% Edta And 5.25% Sodium Hypochloride Irrigating Solutions On Surface Hardness Of Brasseler Endosequence Root Repair Material, Himanshu Sharma

Master's Theses (2009 -)

Introduction: Root Perforation is an artificial communication between the root canal system and supporting tissue. Various endodontic researchers have published that sealing the perforation immediately has the best prognosis but this predisposes the repair material to come in contact with various root canal irrigants during the course of treatment. The aim of this study was to evaluate the effect of 17% EDTA and 5.25% sodium hypochlorite irrigating solutions on surface hardness of Endosequence Root Repair Material Putty (ERRM).

Method: ERRM, 5.25% Sodium Hypochlorite, 17% EDTA and Deionized water were used. 42 samples were prepared and divided into 2 groups. Each …

Flexibility Of Various Nickel-Titanium Rotary Endodontic Files, Chelsea Selin

Master's Theses (2009 -)

Introduction: Nickel-titanium rotary files were originally developed to allow for greater flexibility when instrumenting root canals. The increased flexibility of nickel-titanium instruments allowed operators to negotiate canal curvatures with greater ease. File design is continually changing. Manufacturers are trying to produce files that will work more efficiently and safely. Knowing the properties of files marketed is especially important in helping to choose an appropriate file system. Current ISO standards require force measurements at a static point along the file. The purpose of this study was to evaluate the flexibility of four different nickel-titanium files at three different points along the …

A Comparison Of Torsional Stress Properties Of Three Different Nickel-Titanium Files With Similar Cross-Sectional Design, Reid Wycoff

Master's Theses (2009 -)

The purpose of this study was to compare the in vitro torsional stress characteristics of Twisted Files (SybronEndo, Orange, CA) with two milled files of similar cross section, EndoSequence (Brasseler USA, Savannah, GA) and ProFile Vortex (DENTSPLY Tulsa Dental, Tulsa, OK).

Files of size 25/.06 and 30/.06 from the three file types were compared (n=20/group). Torsional stress resistance was evaluated by measuring the torque in gram-centimeters (g-cm) and angle of rotation (degrees) required for instrument separation with use of a torsiometer instrument. The fractured files were examined using SEM to look at deformation and fracture surface characteristics. The data was …

Comparison Of The Efficacy Of Various Ibuprofen And Acetaminophen Regimens On The Treatment Of Post-Endodontic Pain, Erik Deyoung

Master's Theses (2009 -)

The purpose of this study was to determine the efficacy of taking ibuprofen and acetaminophen at the same time versus alternating the same medications in patients with a diagnosis of symptomatic irreversible pulpitis.

Materials and Methods: Ten patients who presented for root canal therapy with a diagnosis of symptomatic irreversible pulpitis were included in this study. The patients were randomly assigned to 2 groups. Following root canal therapy, the patients in group A were instructed to take ibuprofen 600 mg and acetaminophen 1000 mg every six hours. Patients in group B were instructed to take ibuprofen 600 mg, wait three …

The Effect Of Water Storage On Bending Properties Of Esthetic, Fiber-Reinforced Composite Orthodontic Wires, Ju-Han Chang

Master's Theses (2009 -)

Introduction: The translucent optical property of fiber-reinforced composite wires meets the esthetic demand of orthodontic patients; however, studies need to be conducted to determine if they also have the desired mechanical properties for active orthodontic treatment. The goal of this research was to study the effect of water storage on the mechanical properties of fiber-reinforced composite archwires and compare it to conventional nickel-titanium (NiTi) and stainless steel (SS), and beta-titanium (TMA) archwires. Materials and Methods: Align A, B, C and TorQ A, B from BioMers Products, 0.014", 0.016", 0.018", 0.019" x 0.025" Nitinol Classic (3M Unitek), 0.016" SS, and 0.019 …

Postoperative Pain After The Use Of A Dexamethasone Rinse As An Irrigant Prior To Obturation, Sushant Mahajan

Master's Theses (2009 -)

Purpose: This randomized, single-blind pilot study was to determine the effect of dexamethasone on post-operative pain when used as an intracanal rinse prior to obturation.

Materials and Methods: Ten adult volunteers were enrolled. They presented to the Marquette University School of Dentistry for endodontic treatment and experienced pain from irreversible pulpitis. The patients were randomly assigned to either the control group that received standard of care treatment or the experimental group that received the rinse with 4 mg/mL dexamethasone solution prior to obturation. Before and after treatment, the patients recorded their pain level on the numeric rating scale (NRS). Recordings …

Intra- And Inter-Examiner Reliability And Inter-Method Comparison In Physical Anthropometry And Photogrammetry, Nikolay Mollov

Master's Theses (2009 -)

Objective: Orthodontic treatment can often effect changes in the facial complex. In order to assess what those changes are, precise and reliable methods for measuring facial structures need to be used. While the techniques used for measuring have become increasingly more sophisticated they have also become more expensive and cumbersome for daily use. This study investigated the reliability of two methods, physical anthropometry and photogrammetry, that were inexpensive and relatively easy to set up.

Materials and Methods: Ten examiners measured a sample comprised of 20 dental students (10 male, 10 female) twice over three weeks. Eighteen measurements were acquired directly …

The Effect Of Extracorporeal Shock Wave (Esw) On Cementoblasts In Vitro, Joshua Barta

Master's Theses (2009 -)

Root resorption is an adverse consequence of orthodontic treatment, and currently no effective treatment method exists. Extracorporeal shock wave (ESW) has been applied to enhance angiogenesis, growth and healing of bone, but the effects of ESW on root resorption have not been studied. Cementoblasts are the cells responsible for forming and repairing cementum covering the dental root, and ESW may enhance this reparative process. The purpose of this study was to investigate the effects of ESW on cementoblasts to determine if ESW could potentially be used to treat root resorption. OCCM.30 cementoblasts were prepared in suspension at a density of …

Effect Of Light-Cure Initiation Time On Polymerization And Orthodontic Bond Strength With A Resin-Modified Glass-Ionomer, Jess Thomas

Master's Theses (2009 -)

Introduction: The polymerization and acid<–>base reactions in resin<–>modified glass<–>ionomers (RMGI) are thought to compete with and inhibit one another. The objective of this study was to examine the effect of visible light<–>cure (VLC) delay on the polymerization efficiency and orthodontic bond strength of a dual<–>cured RMGI.

Methods: An RMGI light<–>cured immediately, 2.5, 5, or 10 minutes after mixing comprised the experimental groups. Isothermal and dynamic temperature scan differential scanning calorimetry (DSC) analysis of the RMGI was performed to determine extents of VLC polymerization and acid<–>base reaction exotherms. Human premolars (n = 18/group) were …

Agenesis Of Maxillary Lateral Incisors In Orthodontic Patients And The Relation To Overall Tooth Size, Jane Wright

Master's Theses (2009 -)

The maxillary lateral incisor is the second most frequently missing tooth in the dental arch with clinical management requiring a complex and multidisciplinary treatment approach. It has been suspected that teeth could be smaller in the maxillary or mandibular arches in patients experiencing agenesis of the maxillary lateral incisor, making ideal occlusal relationships and space creation for restoration of the lateral incisor difficult to obtain. The purpose of this study is to determine if a tooth size discrepancy exists in orthodontic patients with agenesis of the maxillary lateral incisor(s).

Forty sets of dental casts from Caucasian orthodontic patients (19 male …

The Effects Of Different Surface Treatments On The Shear Bond Strength Of Composite Resin To Machined Titanium, Mohammad Sadeq Aljadi

Master's Theses (2009 -)

Purpose: The purpose of this study was to evaluate the shear bond strength between machined titanium and composite resin using different surface treatments.

Materials and Methods: Titanium (Ti-6Al-4V) specimens were ground with 600 grit SiC paper and randomly divided into 6 groups (n=20/group). Group #1 (Control): samples were sandblasted with 110 µm Al₂O₃ for 10 sec. Group #2 (Rocatec): samples were treated with the Rocatec system following the manufacturer's directions but the silanization step was eliminated. Group #3 (Silano Pen): samples were treated with the Silano Pen system. Group #4 (H₂SO₄ etched): samples were …

Friction Testing Of A New Ligature, Alison Mantel

Master's Theses (2009 -)

Objective: To determine if American Orthodontics' (AO) new, experimental ligature demonstrates less friction in vitro when compared to four other ligatures on the market.

Methods: Four brackets were mounted on a custom metal fixture allowing an 0.018-in stainless steel wire attached to an opposite fixture with one bracket to be passively centered in the bracket slot. The wire was ligated to the bracket using one of five types of ligatures including the low friction test ligatures (AO), conventional ligatures (AO), Sili–TiesTM, Silicone Infused Ties (GAC), Synergy® Low-Friction Ligatures (RMO), and SuperSlick ligatures (TP Orthodontics). Resistance to sliding was measured over …

Metallurgical Characterization Of New Palladium-Containing Cocr And Nicr Alloys, Raghav Puri

Master's Theses (2009 -)

Recently introduced to the market has been an entirely new subclass of casting alloy composition whereby palladium (~25 wt%) is added to traditional base metal alloys such as CoCr and NiCr.

Objectives: The purpose of this study was to evaluate the microstructure and Vickers hardness of two new CoPdCr and one new NiPdCr alloy and compare them to traditional CoCr and NiCr alloys.

Methods: The casting alloys investigated were: CoPdCr-A (Noble Crown NF, The Argen Corporation), CoPdCr-I (Callisto CP+, Ivoclar Vivadent), NiPdCr (Noble Crown, Argen), CoCr (Argeloy N.P. Special, Argen), and NiCr (Argeloy N.P. Star, Argen). As- cast cylindrical alloy …

Effects Of Rapid Maxillary Expansion On Upper Airway; A 3 Dimensional Cephalometric Analysis, Yoon Hwan Chang

Master's Theses (2009 -)

The purpose of this study was to use cone-beam computed tomography (CBCT) to assess changes in the volume and cross sectional areas of the upper airway in children with maxillary constriction treated by rapid maxillary expansion (RME).

The study group consisted of 5 males and 9 females with mean age of 12.93 years with posterior cross bite and constricted maxilla who were treated with hyrax expander as part of their comprehensive orthodontic treatment. Pre and post RME CBCT scans were analyzed with 3D Dolphin 11.0 software to measure the retropalatal (RP) and retroglossal (RG) airway changes including volume and cross …

Marginal Ridge Thickness (Mrt) Of Maxillary Incisors, Mark Foster

Master's Theses (2009 -)

Aim: To determine the marginal ridge thickness (MRT) of maxillary incisors in orthodontic patients and the possible correlation between MRT and Bolton Index.

Methods: 120 pre<–>orthodontic treatment dental casts were collected, following the inclusion criteria: Quality pretreatment upper and lower casts, age 10<–>16, full permanent dentition (except 2nd and 3rd molars), no obvious wear/attrition/abrasion, no proximal restorations or crowns. For each cast, the mesio (M<–>D)distal (M<–>D) widths of the upper and lower teeth from left 1st molar to right 1st molar were measured to calculate Bolton Index. The MRTs of the maxillary incisors were measured in …

Cementoblastic Response To High Vs. Low Level Of Mechanical Force In Vitro, Natalie Nicole Mullally

Master's Theses (2009 -)

One of the possible complications of orthodontic treatment is apical root resorption. During orthodontic treatment, as the teeth are being moved, the alveolar bone is continually being modeled to accommodate the teeth. This process activates specific cells that are responsible for bone resorption and can have the unwanted effect of resorbing the apex of the tooth root adjacent to the bone. It is unclear exactly what aspects of orthodontic treatment may trigger the resorptive process. A positive correlation, however, between root resorption and mechanical loading applied during orthodontic tooth movement has been established implicating orthodontic treatment in this adverse effect. …

Bondable Lingual Spur Therapy To Treat Anterior Open Bite, Elissa Joy Mcrae

Master's Theses (2009 -)

The purpose of this study was to evaluate the effect of bondable lingual tongue spurs (BLTS; Tongue Tamers®, Ortho Technology, Tampa, FL) on measures of overbite and incisor position in a sample of anterior open bite subjects who had either a digit-sucking habit or an anterior tongue posture problem. Patient acceptance of the spurs was also evaluated. BLTS were placed on all maxillary and mandibular incisors of 12 subjects (mean age 13.9 years) with anterior open bite. Dental casts and lateral cephalometric radiographs were taken pre-treatment (T1) and after 6 months of lingual spur treatment alone (T2). Overbite and overjet …

An In Vitro Comparison Of The Setting Of Mta With And Without The Application Of A Moist Cotton Pellet, Craig Darrell Johnson

Master's Theses (2009 -)

Introduction: The purpose of this study was to compare the setting of MTA with and without the application of a moist cotton pellet. Methods: Fifty samples of MTA were mixed according to manufacturer’s instructions, placed with an amalgam carrier, and condensed with a plugger into a custom metal block with a well depth of 3.5 mm. Twenty-five of the MTA samples had a moist cotton pellet placed in contact with MTA mixture and twenty-five MTA samples had no moist cotton pellet in contact with the MTA mixture. The samples were placed in 100% humidity at 37°C and evaluated for penetration …

Bonding With Self-Etching Primers - Pumice Or Pre-Etch? An In Vitro Study, Ian J. Fitzgerald

Master's Theses (2009 -)

The objective of this study was to compare the shear bond strengths (SBS) of orthodontic brackets bonded with self-etching primer using different enamel surface preparations.

A 2-by-2 factorial study design was used. Sixty human premolars were harvested, cleaned and randomly assigned to four groups (n=15/group). Teeth were bathed in saliva for 48 hours to form a pellicle. Treatments were assigned as follows: Group 1 was pumiced for 10 seconds and pre-etched for five seconds with 37% phosphoric acid before bonding with self-etching primer (Transbond Plus). Group 2 was pumiced for ten seconds before bonding. Group 3 was pre-etched for five …

Bracket Bond Strength Effects Of Incorporation Of Novamin Into An Orthodontic Bonding Resin, Jeffrey Waterhouse

Master's Theses (2009 -)

Despite advances in caries research and the development of protective mechanisms and materials, orthodontic white spot decalcification remains a significant problem. Increased plaque buildup around orthodontic appliances, combined with inadequate hygiene and a susceptible patient, can lead to unesthetic demineralized lesions in enamel.

Relatively new to the arena of caries prevention, NovaMin, a bioactive glass, has shown some promise in areas of remineralization of early lesions, protection against acidic challenge, and has demonstrated antiplaque properties. This study explored a new application of the material, incorporation into an orthodontic bonding composite resin. Objectives of the study were: to determine if the …

Candida Albicans Adhesion And Biofilm Formation On Phosphated And Non-Phosphate Containing Poly(Methylmethacrylate) Polymers, Kathryn Elizabeth Ryan

Master's Theses (2009 -)

Denture-induced stomatitis is prevalent among prosthesis users, particularly the elderly and institutionalized where it has been estimated to be present in over 60-65% of denture wearers. Treatment of this clinical condition is problematic due to incomplete disinfection of the acrylic surface and rapid microbial re-colonization. Moreover, ingestion or aspiration of pathogens in denture plaque exposes the elderly and immunocompromised to unexpected infections.

Acrylic polymers have generally been used to replace missing teeth and periodontal tissues in edentulous or partially dentate patients. Currently, edentulous adults in the US population are common, with complete edentulism greater than 41% among Americans aged 65 …