Dentistry Commons^™

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 …

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 …

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 …

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 …

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 …

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 …

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 …