Dental Materials Commons^™

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 …

Comparing Velscope Vx And Traditional Oral Exams In Shisha (Hookah) Smokers: A Pilot Study, Amanda E. Kimball

Dental Hygiene Theses & Dissertations

The purpose of this study was to compare oral findings using two exam types, the VELscope Vx® screening device versus a modified oral examination in detecting oral potentially malignant lesions in shisha smokers.

Methods: Thirty-one participants who reported currently smoking shisha and tobacco were recruited. Participants were identified for smoking habits to include two groups, to include those who reported smoking shisha exclusively and those who reported smoking shisha and tobacco. Each group received both exam types; examiners used a standardized protocol. A health history questionnaire was also collected to assess participant's oral cancer risk factors such as age, race, …

Protaper Rotary Instrument Fracture During Root Canal Preparation: A Comparison Between Rotary And Hybrid Techniques, Huma Farid, Farhan Raza Khan, Munawar Rahman

Section of Dental-Oral Maxillofacial Surgery

AIMS:

This study aimed to compare the frequency of ProTaper rotary instrument fracture with rotary (conventional) and hybrid (rotary and hand files) canal preparation techniques. Secondary objectives were to determine whether there was an association of ProTaper file fracture with the canal curvature and to compare the mean time required for canal preparation in the two techniques.

METHODS:

An in vitro experiment was conducted on 216 buccal canals of extracted maxillary and mandibular first molars. After creating an access cavity and a glide path for each canal, a periapical radiograph was taken and the canal curvature was measured with Schneider's …

Advantage Of Combined Amalgam-Composite Restoration: In Vitro Leakage Study, Ahmed A. Madfa

Ahmed A. Madfa

Purpose: Evalute the leakage of Class II box composite restorations and compared with composite lined by flowable composite and combined amalgam-composite restoration. Method: Fifty-four Class II box shaped cavities were on the distal (1 mm below CEJ) surfaces, 18 cavities for each. Scotchbond Multi-Purpose adhesive system, Filtek Z250 composite, and a metal band system were used for all. After thermocycling test (1000 cycles, 5–55°C with 30 s) and dye immersion, the teeth were sectioned longitudinally in a mesio-distal direction and dye penetration was recorded. Results: Combine amalgam-composite restorations showed less gingival leakage than composite alone and composite lined by flowable …

Application Of Calcium Phosphate Materials In Dentistry, Ahmed A. Madfa

Ahmed A. Madfa

Calcium phosphate materials are similar to bone in composition and in having bioactive and osteoconductive properties. Calcium phosphate materials in different forms, as cements, composites, and coatings, are used in many medical and dental applications. This paper reviews the applications of these materials in dentistry. It presents a brief history, dental applications, and methods for improving their mechanical properties. Notable research is highlighted regarding (1) application of calcium phosphate into various fields in dentistry; (2) improving mechanical properties of calcium phosphate; (3) biomimetic process and functionally graded materials. This paper deals with most common types of the calcium phosphate materials …

Micromechanical Analysis Of Nanoparticle-Reinforced Dental Composites, Yi Hua, Linxia Gu, Hidehiko Watanabe

Department of Mechanical and Materials Engineering: Faculty Publications

The mechanical behavior of TiO₂ nanoparticle-reinforced resin-based dental composites was characterized in this work using a three-dimensional nanoscale representative volume element. The impacts of nanoparticle volume fraction, aspect ratio, stiffness, and interphase zone between the resin matrix and nanoparticle on the bulk properties of the composite were characterized. Results clearly demonstrated the mechanical advantage of nanocomposites in comparison to microfiber-reinforced composites. The bulk response of the nanocomposite could be further enhanced with the increased nanoparticle volume fraction, or aspect ratio, while the influence of nanoparticle stiffness was minimal. The effective Young’s modulus and yield strength of the composite was …

Characterising The Deformation Behaviour Of Human Tooth Enamel At The Microscale, Simona O'Brien

Theses: Doctorates and Masters

Enamel plays an important role in tooth function. Optimal combinations of composition and structure endow enamel with unique mechanical properties that remain largely unexplored. Specifically, more detailed understanding of the loadbearing ability of enamel is needed to mimic it synthetically and to design next generation biocomposite materials. This research investigates the variables that influence deformation behaviour of tooth enamel in relation to its hierarchical structure. Initially, a new method was developed for preparing flat, finely polished tooth samples that were maintained in their normal hydrated state for nanoindentation testing. In contrast to conventional methods, which commonly utilise either inappropriate or …

An Analysis Of Adhesion Promoters On Shear Bond Strength Of Orthodontic Brackets To Teeth, Loren Andrew Cadelinia

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose:The aim of this study was to evaluate the shear bond strength of two adhesion promoters, EnhancetmLC and AssureRUniversal Bonding Resin, and their effects with two different adhesion systems (Light Bondtmand TransbondtmXT). To better understand their behavior upon failure, the amount of adhesive remnant remaining on the tooth surface was also observed.

Methods:One-hundred forty human premolars, which were extracted for reasons other than this study, were utilized and divided into seven groups of 20 teeth each. Groups A1 and B1 were bonded without adhesion promoters and with two different adhesive systems - Light Bondtmand TransbondtmXT. Groups A2 and B2 were …

Frictional Forces Of A Fixed, Esthetic Orthodontic Appliance System, Brady Michael Nance

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose: The demands of an all esthetic fixed orthodontic appliance system are ever increasing in today's world. Frictional values of an esthetic, fixed orthodontic appliance system are needed to evaluate their clinical effectiveness for orthodontic treatment. The aim of this study is to evaluate the frictional values of various esthetic orthodontic archwires ligated to an esthetic orthodontic bracket.

Methods: Three types of stainless steel and nickel titanium alloy (niti) esthetic orthodontic archwires (epoxy, poly, plastic) in four sizes (.016, .018, .017 x .025, .019 x .025 inches) were ligated to both a stainless steel bracket system and a ceramic (esthetic) …

Effect Of Gingival Margin Design On Retention Of Thermoformed Orthodontic Aligners, Daniel P. Cowley

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose: The aim of this study was evaluate the effect of gingival margin design (scalloped vs. straight cut at gingival zenith vs. straight cut 2mm above gingival zenith) on the retention of thermoformed aligners. Retention of aligners is a critical requirement for efficient tooth movement.

Methods: Two thermoform aligner materials were used, Invisacryl A and Invisacryl C, in 0.040 mil (1mm) thickness. Six aligner designs were fabricated for each of the two aligner materials (12 total aligner designs). Aligner designs are scalloped, straight cut at gingival zenith (0mm), and straight cut 2mm above gingival zenith on a model with attachments. …

Virtual Three-Dimensional Analysis Of Dimensional Accuracy Of Dental Master Die Models Created By The Iterotm Electronic Impression Device And Those Made From A Polyvinyl Siloxane Impression Material, Polina P. Shcherbatov

Master's Theses

No abstract provided.

Shining A New Light On Selective Polishing, Caren M. Barnes

College of Dentistry: Faculty Publications

The era of selective polishing is over. Polishing is an integral procedure provided by dental hygienists. Patients look forward to the resultant smooth, clean feeling, and dental hygienists must ensure that all patients are polished according to their individual needs—ensuring the safety of their teeth and restorations.

Magnification Loupes In U.S. Entry-Level Dental Hygiene Programs - Occupational Health And Safety, Leslie Mchaney Congdon, Susan Lynn Tolle, Michele Darby

Dental Hygiene Faculty Publications

Purpose: The purpose of this study was to determine policies and practices regarding magnification loupes among faculty and students in accredited dental hygiene programs as measured by a 31 item, self-designed questionnaire. In addition, the study compared policies among dental hygiene programs in 2 year versus 4 year programs in terms of requirements for the use of magnification loupes.

Methods: After institutional review board approval, a 31 item self-designed questionnaire was emailed via Survey Monkey to 303 entry-level dental hygiene programs. An overall response rate of 75% was obtained. Data were analyzed using descriptive statistics and chi-square test of independence. …

Effect Of Toothbrush Abrasion On Frictional Resistance Of Aesthetic Orthodontic Archwires, Stephen Alexander Yamodis

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fixed orthodontic appliances (braces) are one of the most widely used appliances to correct malocclusion, however many patients prefer less metal display. To meet this demand more esthetically pleasing brackets and archwires have been developed. These esthetic components are often clear, white or tooth colored. Coatings of various types are commonly used to produce an esthetic archwire. However, these coating materials tend to wear and degrade, which may cause binding and increased resistance to friction, thereby potentially reducing the efficiency of tooth movement. Therefore, in vitro testing of tooth brush abrasion on frictional resistance of various aesthetic archwires was tested. …

Bacterial Adherence Of Streptococcus Mutans And Lactobacillus Acidophilus On Poly-Methyl Methacrylate And Thermoplastic Polypropene Used In Orthodontic Retention, Lindsay Ann Pfepper

UNLV Theses, Dissertations, Professional Papers, and Capstones

Retention is required in the majority of orthodontic patients throughout the remainder of their life. The two primary removable appliances are known as the traditional Hawley retainer or the vacuum formed retainer. These appliances were developed to maintain the position of the dentition without sacrificing oral health. The orthodontic population is at a higher risk for caries due to plaque accumulation from poor diet, suboptimal oral hygiene and often lack of motivation. These two retainers occupy different niches and are comprised of different materials; therefore the retainers' effect on oral health could be very different. An understanding of which bacteria …

Practicing Orthodontists' Use And Perceived Efficacy Of Self-Ligating Brackets, John-David Beuhler

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction.

The purpose of this study was to compare perceptions of efficacy and efficiency of Self-Ligating Brackets vs. conventional brackets between practicing Orthodontists and Orthodontic Residents.

Methods.

Cross-sectional survey research using a three-wave emailing of addresses from the current American Association of Orthodontists directory. The directors of all orthodontic residency programs in the US were asked to also distribute to all residents. The survey included five sections: (1) respondents' experience, (2) factors that influence, (3) positive or negative factors, (4) the perceived efficiency/efficacy, and (5) demographics. A 39% response rate (N=707) was obtained.

Results.

Over half (51.8%) …

Performance Of Melamine Modified Urea-Formaldehyde Microcapsules In A Dental Host Material, Noor Hayaty Abu Kasim Abu Kasim N.H.

Noor Hayaty Abu Kasim Abu Kasim N.H.

Urea-formaldehyde (UF) microcapsules filled with dicyclopentadiene (DCPD) show potential for making self-healing dental restorative materials. To enhance the physical properties of the capsules, the urea was partially replaced with 0-5% melamine. The microcapsules were analyzed by different microscopic techniques. DSC was used to examine the capsule shell, and the core content was confirmed by (1)H NMR spectroscopy. Capsules in the range of 50-300 mu m were then embedded in a dental composite matrix consisting of bisphenol-A-glycidyl dimethacrylate (Bis-GMA) and triethylene-glycol dimethacrylate (TEGDMA). Flexural strength, microhardness, and nanoindentation hardness measurements were performed on the light-cured specimens. Optical microscopy (OM) examination showed …

Human Platelet Lysate Permits Scale-Up Of Dental Pulp Stromal Cells For Clinical Applications, Noor Hayaty Abu Kasim Abu Kasim N.H.

Noor Hayaty Abu Kasim Abu Kasim N.H.

Background aims. Dental pulp stromal cells (DPSC) are considered to be a promising source of stem cells in the field of regenerative therapy. However, the usage of DPSC in transplantation requires large-scale expansion to cater for the need for clinical quantity without compromising current good manufacturing practice (cGMP). Existing protocols for cell culturing make use of fetal bovine serum (FBS) as a nutritional supplement. Unfortunately, FBS is an undesirable additive to cells because it carries the risk of transmitting viral and prion diseases. Therefore, the present study was undertaken to examine the efficacy of human platelet lysate (HPL) as a …

Development Of Craniofacial Implants Produced By Metal Injection Molding Of Titanium Alloy Using Novel Binder System Based On Palm Oil, Noor Hayaty Abu Kasim Abu Kasim N.H.

Noor Hayaty Abu Kasim Abu Kasim N.H.

Metal Injection Molding (MIM) is a cost-effective technique for producing small, complex, precision parts in high volumes. MIM consists of four main processing steps: mixing, injection molding, debinding and sintering. In the mixing step, the powder titanium alloy (Ti6Al4V) medical grade is mixed with a binder system based on palm stearin to form a homogeneous feedstock. The rheological studies of the feedstock have been determined properly in order to success during injection into injection molding machine. After molding, the binder holds the particles in place. The binder systems then have to be removed completely through debinding step. Any contamination of …

In Vivo Measurement Of Color Relationships Between The Maxillary Central Incisor And Canine As A Function Of Age, Marie E. Falcone

Master's Theses

Abstract

Introduction

It has long been taught that the basic shade (hue) of the patient can be taken from the canine (i.e. that tooth thought to have the highest chroma of a particular hue) and then that hue can be applied to other anterior teeth but at a lower chroma. However, this concept does not appear to derive from published measurements or observations. This study documented the color relationship between in vivo maxillary central incisors and canines to examine: (1) whether they share the same hue, but have different chromas (as commonly taught); and, (2) whether color differences (∆E values) …