Dental Materials Commons^™

Perspectives For Titanium-Derived Fillers Usage On Denture Base Composite Construction, Nidal Elshereksi

Nidal Elshereksi

Poly(methyl methacrylate) (PMMA) is an extensively used material in dentistry because of its aesthetics, processability, and reparability. However, PMMA is still far from being ideal in fulfilling the mechanical requirements of prosthesis. PMMA-based denture base polymers exhibit low fracture resistance and radiopacity behavior. Efforts to improve the mechanical and radiopacity properties of denture base materials through inclusion of silica-based fillers are ongoing. Although silane-treated siliceous fillers are commonly used, they are not sufficiently strong.They also exhibit cracks, which either cut through the glass fillers or propagate around the filler particles. This defect occurs when the dental composites are placed in …

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 …

Chemical Dental Plaque Control: Chlorhexidine Tooth Staining And Efficacy Of Common Whitening Procedures, Zoe Kiklis

Scripps Senior Theses

Chlorhexidine mouth rinses remove dental plaque from teeth, preventing dental caries, dental decay, and more serious systemic infections. Tooth discoloration due to extrinsic staining is the most prominent side effect of regular chlorhexidine use. Decreasing the concentration of chlorhexidine reduces staining area and severity. Staining can also be prevented and treated by tooth bleaching, a common cosmetic dental procedure that diminishes extrinsic staining by oxidizing chromagens adsorbed onto the tooth surface. In the proposed trial, common bleaching agents will be investigated for their efficacies in preventing chlorhexidine staining. Results of the trial could further the development of a chlorhexidine mouth …

Reinforcement Of Flowable Dental Composites With Titanium Dioxide Nanotubes, Manal Dafar

Electronic Thesis and Dissertation Repository

Flowable composites are widely used in dentistry. However, they suffer from poor mechanical properties. The aim of this study was to reinforce a flowable composite with TiO₂ nanotubes (n-TiO₂), which were synthesized using an alkaline hydrothermal technique then functionalized with silane or methacrylic acid (MA). The synthesized n-TiO₂ was characterized using X-ray diffraction, energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. Electron microscopy revealed a tubular morphology of n-TiO₂. Commercially available flowable composite was reinforced with varying amounts of nanotubes (0-5%). Dynamic Young’s moduli (E) and fracture toughness (K_IC) of composites reinforced …

Effect Of Post Materials On The Biomechanical Behaviour Of Endodontically Treated Tooth., Ahmed A. Madfa

Ahmed A. Madfa

Objectives: To study the stress distributions in maxillary central incisor restored with Ni-Cr custom-made, gold custom-made, prefabricated titanium and prefabricated glass fibre dental posts subjected to oblique occlusal load at 100 N. Materials and Methods: Four three dimensional finite element models of a maxillary central incisor restored with Ni-Cr (Model I), gold custom-made (Model II), prefabricated titanium (Model III) and prefabricated glass fibre (Model IV) dental posts were constructed and oblique loading of 100 N was applied. Stress analysing at the along the centre of the post and post-surrounding structure interfaces were computed. Results: The result of this study indicates …

Alumina Ceramic For Dental Applications: A Review Article., Ahmed A. Madfa

Ahmed A. Madfa

Alumina has received considerable attention and has been historically wellaccepted as biomaterials for dental and medical applications. This article reviews the applications of this material in dentistry. It presents a brief history, dental applications and methods for improving the mechanical properties of aluminabased materials. It also offers perspectives on recent research aimed at the further development of alumina for clinical uses, at their evaluation and selection, and very importantly, their clinical performance. This article also stated about the Functionally Graded Materials (FGMs) which has been conceived as a new material design approach to improve performance compared to traditional homogeneous and …

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 …

Endodontic Repair Filling Materials: A Review Article., Ahmed A. Madfa

Ahmed A. Madfa

The emergence of Mineral Trioxide Aggregate (MTA) as endodontic repair filling material has generated a lot of interest due to its superior sealing ability and biocompatibility. Although MTA possesses superior sealing ability to traditional endodontic repair filling materials, such as calcium hydroxide, but it has poor handling characteristics. A novel endodontic repair filling materials with similar chemical composition, but improved handling characteristics, was recently developed. Recently, BioAggregate repair filling materials is claimed as biocompatible material and promotes cementogenesis and forms a hermetic seal inside the root canal. More recently, Biodentine and EndoSequence endodontic repair materials introduced to the market. Both …

In Vitro Comparison Of Force Decay Between Three Orthodontic Sliding Retraction Methods, Pamela Steiger

Student Theses, Dissertations and Capstones

Objective: The purpose of this in vitro study was to determine if there is a difference in force decay between three sliding retraction methods under a standardized force delivery system (200 gm at 25 mm stretch) at 2, 4, 6, and 8 weeks. Background: In order to achieve proper esthetics, occlusion and stability, orthodontic treatment may require extractions. Elastomeric chains, Nickel Titanium (NiTi) coils, and active ligatures are commonly used to close these extraction spaces. Methods: Twenty samples of each retraction method (elastomeric chains, NiTi Coils and active ligatures) were evaluated under standardized conditions (200 gm at 25 mm). The …

Effect Of Cad/Cam Processing On Esthetic Characteristics Of Porcelain Veneers, Eduardo Cortes-Contreras

Student Theses, Dissertations and Capstones

Introduction: Dentistry has changed significantly during the last two decades. Patients are more aware and demanding of the latest technologies available in restorative dentistry. The purpose of this study was to determine any possible changes on the surface roughness, gloss and color change of CAD-CAM milled porcelain veneers following repeated milling times, before and after a glazing process. Methods: A Teflon disk-shaped mold was used as a cast to take a digital impression (BlueCam) in order to fabricate cylindrical-shaped specimens. A total of one hundred (N=100) specimens porcelain veneers using Empress CAD (I10) block, were milled using the CAD/CAM CEREC-SIRONA …

Influence Of Immediate Dentin Sealing On The Bond Strength Of Indirect Bonded Restorations, Alexander Duque

Student Theses, Dissertations and Capstones

Introduction: A critical issue and concern that has been documented in dentistry is the complexity of bonding to dentin, a fact that has been referred to as a less reliable technique due to the intrinsic characteristics of the dentin substrate. Effectiveness on dentin bonding is a clinical important approach for indirect bonded restorations in order to achieve a good adhesion that can surpass the test of time. Long-term clinical trials have shown that indirect bonded restorations have an increased risk of failure when using dentin as the major substrate. Consequently, an effort should be made to improve techniques and materials …

Thermal Characterisation Of Poly(Methyl Methacrylate) Filled With Barium Titanate As Denture Base Material, Nidal Elshereksi

Nidal Elshereksi

No abstract provided.

Bioerodible Calcium Sulfate Bone Grafting Substitutes With Tailored Drug Delivery Capabilities, Bryan R. Orellana

Theses and Dissertations--Biomedical Engineering

Bone regeneration or augmentation is often required prior to or concomitant with implant placement. With the limitations of many existing technologies, a biologically compatible synthetic bone grafting substitute that is osteogenic, bioerodible, and provides spacing-making functionality while acting as a drug delivery vehicle for bioactive molecules could provide an alternative to ‘gold standard’ techniques.

In the first part of this work, calcium sulfate (CS) space-making synthetic bone grafts with uniformly embedded poly(β-amino ester) (PBAE) biodegradable hydrogel particles was developed to allow controlled release of bioactive agents. The embedded gel particles’ influence on the physical and chemical characteristics of CS was …