Dental Materials Commons^™

Correlation Of Tooth Length Measurements Made On Cbct And 3t Mr Images, Andrew Scott Taylor

Loma Linda University Electronic Theses, Dissertations & Projects

Objective. This study compared tooth length measurements made on cone beam computed tomography (CBCT) scans and 3-Tesla (3T) magnetic resonance (MR) scans performed with and without an alginate bite registration surrounding the crowns of the teeth. Materials and Methods. One CBCT scan, one MR scan with alginate bite registration, and one MR scan without bite registration were performed on 12 subjects. The alginate bite registration was used to provide a proton-rich material to surround proton-poor teeth in an attempt to improve visualization of teeth. DICOM formatted images from each of the three scans for each subject were oriented in all …

Work Of Fracture In Ceramic Bracket Bonding Systems, Tye A. Roylance

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Work of fracture (WOE) is a method of analysis of the toughness or resilience of a bracket bonding system. It is an indication of a bracket bonding systems ability to withstand forces in the mouth below the force at which failure occurs. Work of fracture gives an indication of how much abuse the bracket/bonding system can withstand and still maintain an adequate adhesion to the tooth surface. This analysis incorporates shear bond strength and displacement and is determined in part by the elasticity and resilience of the specimen being studied.

Materials and Methods: One hundred and eighty bovine teeth …

Influence Of Stainless Steel Orthodontic Brackets On Magnetic Resonance Imaging, Christian James Hoybjerg

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Magnetic resonance imaging (MRI) machines provide 2D as well as 3D images that are excellent in contrasting soft-tissue in the maxillofacial region and are void of ionizing radiation. The drawbacks include the lack of depiction of cortical bony detail and image degradation caused by substances in the scanned area. Specifically, in the orthodontic field stainless steel brackets cause more distortion of MR images then any other bracket material. It is unknown what type of stainless steel alloy causes the most MRI distortion. The purpose of this study is to evaluate the degree of craniofacial MR distortion caused by various …

Immediate Provisionalization Of Single 3.0 Mm Diameter Implant In Maxillary And Mandibular Anterior Region, Kotaro Oyama

Loma Linda University Electronic Theses, Dissertations & Projects

Immediate provisionalization of single implants with standard (3.75 - 4.5 mm) and wide diameter (> 4.5 mm) has been well documented. When the space is limited, small diameter implants (3.0 mm) must be used. Although high success rates have been reported, they were limited to healed site and were placed as staged procedures. The purpose of this prospective study was to evaluate the success rate and peri-implant tissue response of small diameter (3.0 mm) implants undergoing immediate provisionalization in the esthetic area.

Eleven patients who had missing maxillary lateral incisor(s) and/or mandibular incisor(s) participated in this study. Thirteen 3.0 mm …

Influence Of Common Orthodontic Appliances On Magnetic Resonance Imaging, Joseph Matthew Elison

Loma Linda University Electronic Theses, Dissertations & Projects

Magnetic resonance imaging (MRI) is an essential diagnostic tool in modern medicine. Conditions such as cerebral vascular accidents, epilepsy and other seizure disorders, autism, cancer, migraine and cluster headaches benefit from its use. It has been discovered that 4-10% of all children and adolescents will experience a seizure at some point (Hauser, 1994) and MRI is one of the most common imaging modalities for seizure and epilepsy diagnosis. Unfortunately, some orthodontic materials cause distortion on MR images. Radiologists would probably require the removal of any distortion-causing orthodontic appliance prior to MR imaging. It is questionable whether radiologists would be comfortable …

De-Bonding 4 Brands Of Ceramic Brackets With The Waterlase Er,Cr;Ysgg Laser, Carter A. Lane

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine if the Biolase Waterlase Er,Cr:YSGG laser could be used as a safe and effective tool to de-bond four currently available orthodontic ceramic brackets. Changes in interpulpal temperature, enamel surface conditions and the amount of time the laser was activated to debond (sic) the ceramic brackets were evaluated. Forty human maxillary premolars were divided into four groups of ten. Prior to direct bonding, all extracted teeth were impressed and duplicated in Araldite epoxy resin as the control surface. Identical techniques were used to bond 10 ceramic brackets from each manufacturer. Three of the …

Comparison Of Bracket Bond Strength By Total, Self-Etch And Laser Treatment, Kyo Sung Shawn Kim

Loma Linda University Electronic Theses, Dissertations & Projects

Laser etching of enamel surfaces alters the physical and chemical characteristics of the enamel. These changes in characteristics enhance the bonding to enamel. The purpose of this study was to compare the shear and tensile bond strength of Er,Cr:YSGG hydrokinetic laser system (Biolase) with 37% phosphoric acid and self etching primer 30 minutes and 72 hours after bonding. Four different laser power output setting was observed: 1.5W, 2.0W, 2.5W, and 3.0W. Two hundred forty bovine teeth free of defect, caries, and dentin exposure were mounted in acrylic resin and divided into 24 groups of 10 teeth. Sixteen groups of 10 …

A Bond Strength Comparison Of Led And Halogen Light Curing Units, John Richard Kavanagh

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this research was to compare the tensile bond strength of orthodontic flat based buttons bonded to bovine teeth with four commercial light-emitting diode (LED) curing lights and one conventional quartz tungsten halogen (QTH) curing light.

The dental market has recently been introduced to a number of commercially available light-emitting diode (LED) curing lights. Tensile bond strength was evaluated for LED curing lights (Rembrandt® Allegro^TM, Den-Mat Corp, Santa Maria, CA), (LEDemetron, Kerr/Demetron Corp, Danbury, Conn), (Ortholux LED, 3M^TMESPE^TM, St. Paul, MN),and (FLASH-lite 1001, Discus Dental, Culver City, CA) are compared with one …

Bond Strengths Of Three Orthodontic Adhesives For Direct And Indirect Bonding, Aaron Rondon

Loma Linda University Electronic Theses, Dissertations & Projects

The technique of bonding orthodontic brackets utilizing a transfer tray, otherwise known as indirect bonding, is a dichotomous subject. It allows for more accurate bracket placement and reduced chair time for the patient and doctor, yet its technique sensitivity can yield bracket failures at the time of tray removal. With the recent development of 3M's Sondhi Rapid Set, an adhesive specifically designed for orthodontic bonding, the purpose of this study was to compare this fairly new indirect adhesive with 3M's Transbond XT and Reliance's Rely-A-Bond.

Two hundred and seventy freshly extracted bovine teeth were mounted in acrylic resin and divided …

Properties Of Experimentally Modified Orthodontic Adhesives: A Pilot Study, Adam Gary Lautt

Loma Linda University Electronic Theses, Dissertations & Projects

Bonded orthodontic brackets were introduced in the early 1960's and, since then, spontaneous debonding has been a constant nemesis. Consequently, many studies involving bond strength have been performed targeting brackets, adhesives, curing methods and types of teeth. The purpose of this study was to compare the properties of adhesive resins that have been experimentally modified in both the filler and the polymer.

Twenty different types of adhesives were prepared with variations in the ratios of the two different fillers (ground glass and Wollastinite fiber) and the polymer. System 1+ was used as a control since it was the original resin …

Patient Satisfaction And Effectiveness Of A New Resin Used To Bumper Orthodontic Brackets, Timothy B. Elison

Loma Linda University Electronic Theses, Dissertations & Projects

Fear of pain is a key factor in discouraging patients from seeking orthodontic treatment, with many patients discontinuing treatment due to pain experienced in the early stages of treatment. Patients often complain of traumatized lips and buccal mucosa, which is usually caused by the brackets. Orthodontists try to minimize this pain and discomfort by using bumpering materials. Although wax is the most commonly used product, there are many bracket bumpering materials available.

The purpose of this study was to evaluate the clinical effectiveness and patient comfort/satisfaction of a new flowable resin, Ortho Shield, designed to protect the lips and …

Failure Mode Of An Orthodontic Resin Alone And With Bonded Brackets, Marc Cody Dunn

Loma Linda University Electronic Theses, Dissertations & Projects

Since the introduction of bonded orthodontic brackets in the early 1960's spontaneous debonding has been a constant nemesis. Most attempts to avoid this problem by orthodontic manufactures have focused on "bond strength" issue. Whether they chose to address the materials, the bracket base or both, the common method used to evaluate improvements entailed the use of just one testing apparatus: a static universal testing machine such as the Instron.

Metal, ceramic and plastic bonded brackets were tested with the traditional shear/peel method as well as a new high strain rate impact test. The resin itself was also evaluated for physical …

Clinical Debonding Simulation Study Of One Metal And Two Ceramic Brackets, Hyunsup Shim

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study is to compare two mechanical debonding methods on ceramic brackets (TP MXi and 3M Clarity) and a metal bracket (GAC OmniArch) with four different bonding materials (light-cured, one-step chemical-cured, two-step chemical-cured, and Fuji GIC) in clinical simulation, where the diametral force was applied on the handle of the pliers. The effectiveness of mechanical debonding technique was determined by evaluating the following variables: the amount of force required to debond the bracket, the amount of residual adhesive remaining on the enamel surface, the frequency of unexpected bracket failure, and the prevalence of visible enamel damage. The …

Evaluation Of The Effects Of Heat Treatment Using Orthotherm On Thermally Activated Archwires, Brent J. Hurst

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate the effects of heat treatment on thermally activated nickel titanium archwires, and to determine the differences between wires from individual manufacturers. Thermally activated, nickel titanium wires were obtained from five different manufacturers in the 0.016 x 0.022 format. All wires were measured with a micrometer to determine their exact dimensions. Half of the wires were heat treated with the use of the Orthotherm Bending Art Programmer from Syrinx Medical Technologies (Berlin, Germany) while the other half served as a control. By passing an electrical current through the wires for a predetermined period …

A Comparison Of Bond Strength Between Three Glass Ionomer Cements Used For The Retention Of Orthodontic Bands, Bryan C. Johnson

Loma Linda University Electronic Theses, Dissertations & Projects

The study compared the retentive bond strength of Ketac-Cem with Ultra Bond-Lok and a 3M Experimental glass ionomer cement at 1 hour and 24 hours using laser and common light cure techniques. The sample consisted of one hundred twenty sound extracted human molars divided into 5 groups: Ketac-Cem (self-cure), Ultra Band-Lok (light-cure), Ultra Band-Lok (laser cure), 3M Experimental (light-cure) and 3M Experimental (laser cure). Stainless steel orthodontic bands with buccal and lingual cleats were cemented as per manufacturer's instructions for each of the test samples. The samples were placed in water until ready for testing. The shear bond strength of …

A Pilot Study Testing A Proprietary Sealant For Plaque Reduction, Jennifer Rowland

Loma Linda University Electronic Theses, Dissertations & Projects

Enamel demineralization due to increased plaque accumulation is a well-recognized problem associated with fixed orthodontic appliances. The purpose of this study was to evaluate the efficacy of a proprietary product to be marketed by 3M Unitek for the reduction of plaque accumulation and thereby reduce enamel demineralization.

Sixty four bovine teeth were divided equally into an untreated control group and a group treated with the proprietary sealant product. Both groups were subsequently immersed in a Streptococcus mutans culture. Plaque deposits from each group were removed, suspended in trypticase soy broth, serially diluted, and plated on trypticase soy agar at 1, …

An In Vitro Study Of Plaque Deposition And Its Comparative Effect On Bond Strength, Debra L. Finch Cook

Loma Linda University Electronic Theses, Dissertations & Projects

Treatment with fixed orthodontic appliances can change the environment in the oral cavity by creating stagnant areas that facilitate bacterial colonization and substance retention. The purpose of this study was to examine in vitro plaque formation associated with bonded orthodontic appliances and how this could affect bonding strengths.

Ortho Concise and Transbond XT were the composite resin materials used in this study. Mandibular incisor metal brackets were bonded to bovine mandibular anterior teeth. Each composite resin was studied in two groups: plaque growth and without plaque growth, and their bond strengths were compared at time intervals of 3,45, and 180 …

The Relationship Of Tooth Size And Arch Form To Arch Depth, Harold C. Avila

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine the relationship of arch form and tooth size to arch depth measurements of study models (Casts) and their respective lateral cephalometric radiographs (Radiographs) in a population of patients treated to an acceptable occlusion without extraction. One hundred and twenty casts were divided into three tooth size classes within each of four arch form categories. Results showed there was a statistically significant change in the arch depth measurement when tooth size was varied. There was no statistically significant change in the arch depth measurement when arch form was varied. The results showed greater …

A Comparative Study Of The Permanent Deformation Of Aesthetic Polymer Brackets, Samar Bou Assi

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to Investigate and compare the plastic or permanent deformation of different commercially available aesthetic polymer brackets (American, Ormco, GAC and RMO). It also examined the effect of tying the bracket wings with a wire ligature as well as the effect of thermocycling on the permanent deformation of these brackets.

Seven brackets of each type were tested In each of the three following conditions; group 1; tied with a wire ligature and loaded, group 2; thermocycled and loaded, and group 3: loaded only, with a total of 84 brackets tested. Each bracket was bonded to …

Change In Bracket Bond Strength And Enamel Calcium : Due To Repeated Bonding With Conventional And Resinomer Glass Ionomer Cements, David L. Wilkinson

Loma Linda University Electronic Theses, Dissertations & Projects

Glass ionomers chemically and mechanically bond to enamel. Repeated bonding may deplete calcium in enamel and reduce the bond strength. Seventy-five non-carious molars were randomly divided into three equal groups and metal brackets were bonded with either Ketac-Cem, Photac-Bond, or Fuji Ortho LC. The samples were stored in 100% humidity at 37° C for 7 days then shear/peel tested with an Instron machine. New brackets were repeatedly cemented with the same cement to the same tooth and shear/peel tested a total of five times. After each shear/peel test the tooth with the mean bond strength from each cement was set …

In Vitro Plaque Formation On Orthodontic Resin Sealants, Leland W. Pack

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to examine in vitro plaque formation on sealant coated enamel. The plaque growth on different types of sealants placed on enamel was compared to each other and to an unsealed enamel control. The antimicrobial properties of sealants were also studied.

Sealant coated bovine enamel disks were immersed in a S. mutans culture medium for four days. The amount of bacterial plaque formation was quantified by removing the deposit, suspending it in solution with subsequent serial dilution. Aliquots of the dilutions were then spread on blood agar plates and incubated for 48 hours. The number …

A Comparison Of Retentive Strengths Of Two Types Of Inner Surface Treatments Of Orthodontic Bands, Jean M. Rathbun

Loma Linda University Electronic Theses, Dissertations & Projects

Band failure during orthodontic treatment results in a potential for decalcification and/or caries and may cause a prolonged treatment time. An increase in the bond strength at the cement/band interface would likely decrease clinical band failure. Sand-blasting and photo-etching have been suggested to improve this bond.

This study investigated the retentive strengths of untreated orthodontic bands, sand-blasted bands and photo-etched bands when cemented with glass polyalkenoate cement on extracted human molars. The sand-blasted bands and photo-etched bands were both found to have significantly stronger bond strengths (p

The Effects Of Rapid Palatal Expansion Therapy On The Periodontal Tissues Of The Central Incisors, Richard Gutierrez

Loma Linda University Electronic Theses, Dissertations & Projects

The periodontal structures around the maxillary central incisors in thirty-nine post-orthodontically treated patients, twenty-five of these patients had experienced Rapid Palatal Expansion (RPE), were examined to determine the periodontal consequences associated with two ways of managing the resultant diastema. In fourteen patients the diastema closure was assisted by elastomeric chain and in eleven patients the diastema closure was not assisted. Fourteen non-RPE orthodontically treated patients served as controls. Height of attached gingiva, gingival sulcus depth, attachment level, and alveolar bone level were recorded. One examiner, using calibrated techniques, performed all the measurements. The RPE groups and the control group all …

Plastic Deformation Of A Polycarbonate Bracket : Utilizing A New Testing Apparatus, Terri L. Alfred

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to investigate the plastic (permanent) deformation of a polycarbonate bracket (Miura, RMO) under the following different conditions: (1) untreated, (2) immersed in 37°C-water for 120 days, and (3) immersed in 60°C-water for 24 hours. Ten brackets for each condition were tested, with a total of 30 brackets tested. Each bracket was bonded to a metal mesh pad which was tack welded to a solid stainless steel ring. The assembly was placed under a loading frame. This loading frame removes variables such as bond adhesive strengths, distortion of a wire used to deform the bracket …

A Pilot Study Comparing The Forces Applied : Using A Chin Cup And Three Types Of Protraction Headgear, Daniel Miles Beisiegel

Loma Linda University Electronic Theses, Dissertations & Projects

A pilot study comparing force distributions of a chin cup, the Great Lakes reverse pull headgear (RPHG), Ormco's adjustable dynamic RPHG, and Grummons RPHG was done. A skull from a 69 year old female which demonstrated a Class III malocclusion was used to perform the tests of force. Forces applied to and generated on the skull were measured using a water-filled balloon system. This method was tested and found to be reliable and accurate.

Repeated measurements of force were recorded for each of the areas of stress (forehead, cheeks, chin, and condyles, as well as the posterior and superior portions …

Load Deformation Test Of Mini Twin Metal Brackets : A Comparative Study, Karl D. Peach

Loma Linda University Electronic Theses, Dissertations & Projects

The trend toward more esthetic brackets has led to smaller brackets being used by orthodontists. The purpose of this study was to determine the force required to deform these smaller brackets and calculate the stress in the metal by using a torsional wire bending force. Ten types of brackets were tested and the results analyzed to determine how bracket geometry, manufacturing method, or material selection affected the strength of brackets. Results showed a significant difference between manufacturing methods, material used, and bracket geometry. Brackets made of 17-4 PH SS and 303 SS withstood higher stress than 316 SS, and all …

An In Vitro Quantitative Evaluation And Comparison Of A Custom And A Popular Stock Orthodontic Appliance, Richard Scott Anderw Schalo

Loma Linda University Electronic Theses, Dissertations & Projects

An in vitro performance evaluation and comparison of a patient individualized appliance (Elan, Ormco Corporation, Glendora, California) and a Roth prescription appliance ("A"- Company, San Diego, California) was made using the Ideal Tooth Relationship Index (ITRI).

The sample consisted of 19 duplicated sets of models for a total sample of 38. For each pair of models one set was bonded with an Elan appliance and a duplicated set was bonded with a Roth appliance. Bracket placement followed the manufacturers recommendations. The bracketed teeth from these models were sectioned out individually and the appliances allowed to fully express themselves on full …

An Evaluation Of Surface Enamel Damage Following The Debonding Of Ceramic Brackets : A Follow-Up Study, C. Steven Edney

Loma Linda University Electronic Theses, Dissertations & Projects

Surface enamel damage was evaluated after debonding ceramic brackets on forty-four bicuspid teeth. These teeth had been previously bonded with two different types of ceramic brackets. One of the brackets utilized a mechanical base for retention and the other bracket utilized a polycarbonate base for retention. The brackets were bonded to the respective teeth for a total of seven to ten days. After debonding, the teeth were extracted and evaluated with a scanning electron microscope. A metal bracket SEM scan was used for a control. The study concluded that: 1) all brackets alter the surface enamel, 2) metal brackets cause …

An Evaluation Of Surface Enamel Damage Following The Debonding Of Ceramic Brackets : A Follow-Up Study, B. Scott Hood

Loma Linda University Electronic Theses, Dissertations & Projects

To evaluate surface enamel damage after debonding ceramic brackets using their manufacturer's recommended methods, sixty four bicuspid teeth were bonded with three different types of ceramic brackets and one type of metal bracket. All the brackets tested utilized mechanical retention only. The brackets were debonded in the mouth seven to ten days after bonding, extracted and evaluated with a scanning electron microscope. The study concluded that: 1) all brackets alter the surface enamel, 2) there is a significant difference in surface enamel damage between the metal bracket and the ceramic brackets utilizing a tensile debonding method, 3) there is no …

The Fracture Strength Of Ceramic Brackets : An Update And Comparison, Christian P. Manley

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to compare the fracture strength of ceramic brackets which are currently on the market with ceramic brackets tested in a previous study at Loma Linda. Fracture strengths of standard edgewise ceramic brackets vs. pre-torqued ceramic brackets and bicuspid ceramic brackets vs. central incisor ceramic brackets were also compared.

A total of 160 Polycrystalline brackets, 8 categories in groups if 20, were tested for fracture strength. Each bracket was tested using the same testing model that was used in the previous study at Loma Linda. The brackets were tested by torquing a wire within the …