Dental Materials Commons^™

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 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 …

Retrofilling Materials : The Effects Of Two Setting Times On The Degree Of Dye Leakage Of Retrograde Filling Materials, Robert K. Higa

Loma Linda University Electronic Theses, Dissertations & Projects

Sealing of the root canal system is usually accomplished by the conservative endodontic approach. Cases where it is impossible to treat nonsurgically are usually treated surgically by an apicoectomy and retrofill. There is a lot of controversy in the literature over which retrofilling material is closest to ideal. Presently, the most popular materials seem to be Amalgam, Super EBA, and IRM. For this reason, these materials were chosen for this study to evaluate the leakage potential at two different time intervals to see if setting time of the material had any influence on the amount of leakage.

Seventy extracted single …

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 …

An In Vitro Evaluation Of Commercially Available Disposable Prophylaxis Angles, Caren M. Barnes, Lisa S. Fleming, Carl M. Russell

College of Dentistry: Faculty Publications

Although a number of manufacturers are marketing disposable prophylaxis angles, no literature exists regarding the mechanical efficacy and efficiency of these products. It was the purpose of this in vitro evaluation to compare and evaluate five brands of commercially available disposable prophylaxis angles for vibration, noise, heat rise, and torque. Random samples of each brand of disposable prophylaxis angle were utilized. Vibration was measured with a height gauge and running motor; noise was measured with a sound meter and heat rise was measured from 68°F on the head and body of the disposable prophylaxis angles, and torque required to destroy …

An In Vivo Comparison Of Commercially Available Disposable Prophylaxis Angles, Lisa S. Fleming, Caren M. Barnes, Carl M. Russell

College of Dentistry: Faculty Publications

A wide variety of disposable infection control products is being marketed including disposable prophylaxis angles. It was the purpose of this in vivo investigation to evaluate the clinical efficacy of five different brands of commercially available disposable prophylaxis angles. Utilizing a splitmouth design. 11 dental hygienists evaluated disposable prophylaxis angles while completing a routine oral prophylaxis. Fifty samples each of Brahler. Ash/Dentsply, Denticator. and Young Dental angles were compared to a control angle (Teledyne Getz). A questionnaire was completed by each operator following patient treatment (a total of 161 patients was treated). The questionnaire asked questions in which the four …

The Management Of Aerosols With Airpolishing Delivery Systems, Caren M. Barnes

College of Dentistry: Faculty Publications

In summary. aerosol production is inherent with airpolishers. as well as other dental equipment such as handpieces, ultrasonic scalers, and air/water syringes. By practicing prudent infection control techniques and utilizing proper operating techniques, the clinician can continue to enjoy the time-efficient and efficacious benefits of airpolishers, while ensuring a maximum protection from aerosols for the patient and the operator.

Short-Term Effects Of The PoliswabR On Supramarginal Bacterial Plaque Removal And Gingival Health In A Spinal Cord Unit Population, Beth Elaine Mckinney

Dental Hygiene Theses & Dissertations

The purpose of this investigation was to determine the short-term efficacy of a mechanical device (Poliswab^R) on supramarginal bacterial plaque removal and gingival health. The sample consisted of 15 residents in a spinal cord unit at the Hampton Veterans' Affairs Medical Center. A single blind, split-mouth, pretest-posttest design was used in the study with each subject serving as his own control. Over a two week period, each participant had his teeth cleaned once daily by a dental hygienist using a Poliswab^R containing sodium bicarbonate and dentifrice on one side of the mouth and a toothbrush without dentifrice …

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 …

The Impact Of Variations In Buccolingual Thickness Of Maxillary Anterior Dentition On First Order Arch Form Adjustments, Craig A. Andreiko

Loma Linda University Electronic Theses, Dissertations & Projects

Pre-adjusted bracket systems offer the clinician the convenience of working with both fewer in number and smaller magnitude adjustments in the archwire. The purpose of this study was to examine the normal variations in the thickness of the six maxillary anterior teeth and how this relates to anticipated first order bends in the archwire. A second purpose was to examine these same teeth for bilateral symmetry.

Thirty casts from the Loma Linda University completed treatment files were examined with respect to variations in the thicknesses of the crowns at the level of the archwire plane. From these, the mean difference …

Effects Of Ultrasonic Scaling And Hand Scaling On Root Typography, Kim Lee Herremans

Dental Hygiene Theses & Dissertations

The purpose of this study was to determine the effects of scaling and root planing with the modified P-10 Cavitron^R tip and curet instruments on root surface topography. Sample specimens included 20 periodontally involved extracted human teeth. Specimens were carved into a three split root design, each sample specimen acting as its own control. Control and experimental surfaces were randomly assigned to each specimen. Scaling techniques were applied on the assigned experimental surfaces for 2 minutes and 14 seconds. A scanning electron microscope was used to examine and micrograph root surface topography of experimental surfaces. Photomicrographs were evaluated using …

Amalgam Fillings: Do Dental Patients Have A Right To Informed Consent, Michael A. Royal

RISK: Health, Safety & Environment (1990-2002)

Recent animal studies have shown significant mercury absorption from dental fillings and resulted in unfavorable media attention. Yet, an FDA advisory committee has found no evidence of Risk to dental patients, and many dentists believe that patients are being unnecessarily alarmed. The paper reviews the history of amalgam fillings through the recent animal studies and concludes that the Risk, whatever it may prove to be, is sufficiently high to warrant permitting patients to choose between amalgam and alternative dental filling materials.

Treatment Of Periodontal Furcation Defects, Michael Martin, Bernard Gantes

Loma Linda University Electronic Theses, Dissertations & Projects

[Note: Three parts in one.]

I. Review of the Literature and Description of a Regeneration Surgical Technique

This report provides an abbreviated review of the literature on treatment and prognosis of periodontal furcation lesions. In addition, it describes a surgical technique designed to accomplish bone regeneration in class II furcation defects, together with the rationale for the development of this procedure. Results of treatment of 30 defects with this technique are presented in a subsequent report (Gantes et al. 1987).

II. Bone Regeneration in Mandibular Class II Defects

A total of 30 mandibular, buccal class II furcation defects were treated …

A Comparison Of Liquid And Gel Etchants Determining Shear And Tensile Bond Strengths Of Four Orthodontic Adhesives, Gary M. Edgmon

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to compare liquid and gel etchants (37% phosphoric acid) by measuring tensile and shear bond strengths of four orthodontic adhesive systems.

Four orthodontic adhesives were tested on 287 extracted human teeth, 144 of which were etched with liquid and 143 with gel. The four adhesives tested were Concise-3M, Challenge-Ormco (new product), Unite-Unitek (no mix), and Fuji Glass-ionomer filling material or cement.

To eliminate the use of wire for bracket engagement during testing, two devices were designed and machined for direct attachment to the Instron testing machine: a rigid push rod for shear force and …

Histologic Host Response To Polyoxymethylene Prosthesis As A Temporomandibular Joint Condylar Replacement, Frederick R. Mathews

Loma Linda University Electronic Theses, Dissertations & Projects

Polyoxyinethylene (Delrin) is a polyacetyl homopolymer which has been used successfully in many orthopedic joint replacements. To determine histologic host response to Delrin as a temporomandibular joint condylar replacement condyles were removed from ten fully mature macaca fasicularis monkeys. The condyles were replaced with a total prosthetic Delrin condyle attached to a titanium mesh. Specimens obtained at one, two, and six months indicated total acceptance of the Delrin, remodeling of the glenoid fossa and formation of bone between the middle cranial fossa and the roof of the glenoid fossa. These findings would indicate Delrin is a viable option for condylar …

Effectiveness Of A Hydrogen Peroxide, Sodium Chloride, Sodium Bicarbonate Dentifrice Upon Microbiota Associated With Periodontitis, Jill M. Modi

Dental Hygiene Theses & Dissertations

The purpose of this study was to investigate the effectiveness of a hydrogen peroxide, sodium chloride, sodium bicarbonate dentifrice upon quantitative changes in the sulcular microbial species Bacteroides melaninogenicus and in the gingival condition and plaque accumulation associated with periodontitis. Fifteen subjects from the Hampton Veteran's Administration Medical Center w e r e selected according to a standard criteria. Split mouth experimental design was used. One arch of each patient was assigned randomly to periodontal instrumentation. Half the mouth then was assigned randomly an experimental or a control dentifrice to be utilized once daily. culture analysis, the Gingival Index and …

Ua60/5/1 Scapbook, Junior American Dental Hygienist's Association

Student Organizations

Scrapbook documenting 1985-1986 of the Junior American Dental Hygienist's Association at WKU. People included in the scrapbook are: Liz Brooks, Cathy Buhl, Ann Burkeen, Chantal Byers, Sandi Carlson, Valerie Collett, Ann Cottrell, Shelly Durbin, Juanita Jones, Briann Legg, Virginia McCarty, Robin Shadd, ? Tabor, Aaron Tabor, Marcheta Watts, Patty Wheeler and Lacy Whittinghill.

Analysis Of The Time-Dependent Force Loss Of Orthodontic Wires, David Jaekwan Jo

Loma Linda University Electronic Theses, Dissertations & Projects

In testing the force loss of five brands of orthodontic wire under a variety of stress modes, it was found that; 1) heat treatment reduced force loss in all the wires; 2) the amount of time-dependent force loss increased when the magnitude of force was raised.

A further indication was that a sharp bend on the tested wire did not affect force loss. Force applied to unwind a loop produced force losses from 180 to 350% above the loss that occurred when force was applied to wind a loop.

The force loss data collected during a 72-hour period was analyzed …

Clinical Effectiveness Of Hydrogen Peroxide-Sodium Bicarbonate Paste On Human Periodontitis Treated With And Without Scaling And Root Planing, Sylvia M. Lyne

Dental Hygiene Theses & Dissertations

The purpose of this investigation was to determine the main and interaction effects of two oral hygiene regimens and periodontal instrumentation on the periodontal health status of subjects between the ages of 18 and 70 over a two-month period. The sample consisted of 16 subjects with moderate periodontitis. A split-mouth design was used; subjects brushed with fluoridated toothpaste on one side of the mouth and brushed with a hydrogen peroxide-sodium bicarbonate paste on the contralateral side. For each treatment, scaling and root planing were randomly assigned to one arch. At two-week intervals, the periodontal health status was measured using the …

A Comparison Of Enamel Detachments After Debonding Between Unitek's "Dynalok" Bracket And A Foil-Mesh Bracket: A Scanning Electron Microscope Study, Robert E. Meister

Loma Linda University Electronic Theses, Dissertations & Projects

The intent of this paper was to: 1. Evaluate the mode of adhesive failure when debonding both flexible and rigid base orthodontic brackets. 2. Evaluate the bracket bases for enamel detachments. 3. Measure the enamel detachments.

After preforming shear test on flexible and rigid base orthodontic brackets mounted to extracted human teeth it was determined that failure occurred at the enamel/adhesive interface 30% of the time, at the bracket/adhesive interface 10% of the time and a combination of these 60% of the time for both groups.

Five brackets from each group were evaluated for enamel detachments using energy dispersive x-ray …

An Evaluation Of 17-4 Precipitation-Hardenable Stainless Steel Alloy For Use As An Orthodontic Wire, Martin G. Martz

Loma Linda University Electronic Theses, Dissertations & Projects

17-4 precipitation-hardenable stainless steel, a high strength alloy developed for aircraft applications, has been examined for possible use in orthodontics. The effects of solution treatment, various refrigeration treatments, and various aging treatments on standard tensile properties were measured. Comparisons were made with the tensile properties of 18-8 stainless steel and a Co-Cr alloy presently used in orthodontics.

Solution treatment was found to decrease ultimate strength by 37.8%, 0.2% yield strength by 45.9%, and (YS)/E ratio by 36.7%, while having almost no effect on elastic modulus or percentage elongation. Refrigeration treatments had statistically significant but small effects on tensile properties. Aging …

A Comparison Of Two Rapid Palatal Expansion Appliances And Their Effect On Palatal Cross-Sectional Area, William D. Scott

Loma Linda University Electronic Theses, Dissertations & Projects

Two rapid palatal expansion appliances, acrylic-free and acrylic-reinforced, were compared for their effect on the cross-sectional area of the palate. Two groups, twenty-five patients in each, were selected so that they would match as closely as possible with regards to age and sex distribution. The pre-treatment and post-treatment maxillary models were duplicated, and this duplicate model was then trimmed in a specific manner to allow the cross-sectional area between the first permanent molars to be compared. The results indicate that there is no difference, at the five percent level of significance, between these two appliances. It is concluded that the …

Aseptic Techniques Currently Used In Dental Hygiene Clinics Within Accredited Dental Hygiene Programs, Jan Shaner Greenlee

Dental Hygiene Theses & Dissertations

The purpose of this survey was to assess the aseptic techniques currently used in 197 accredited dental hygiene programs in the United States. A self-designed, 51-item questionnaire examined the aseptic techniques used in: (1) preparation of the dental hygiene clinic and unit, (2) instrument preparation, (3) preparation of the student practitioner, (4) preparation of the patient, (5) preparation of radiographic equipment, and (6) treatment of the hepatitis patient.

The questionnaire and a letter of transmittal were mailed to the clinical supervisor of each accredited dental hygiene program. Data were obtained from 173 returned questionnaires and analyzed via modal and percentage …

Force Loss In Retraction Springs At 37°C As Affected By Time, Roger Edward Clawson

Loma Linda University Electronic Theses, Dissertations & Projects

Closed helix retraction springs fabricated from .016 X .016 inch Blue Elgiloy, Permachrome Standard stain less steel, and Multiphase orthodontic wire were tested at 37°C in their heat and nonheat treated condition to determine force relaxation properties. Electronic equipment consisting of load cells, regulated power supply, and an automatic recording device were used to measure force changes which occurred in the wire samples over a seven day period. A constant temperature was maintained by an ethylene glycol and water circulator. A temperature probe and an electronic thermometer monitored the 37°C water bath surrounding the wire samples. The data was graphed …

A Comparative Study Of Tensile Properties In Five Orthodontic Wires, Charles B. Mcdermott

Loma Linda University Electronic Theses, Dissertations & Projects

The tensile properties of .017 x .025" stainless steel. Multiphase, Blue Elgiloy, beta titanium, and Nitinol were tested and compared. All wires were tested in the "as received" condition. Fifteen samples of each type of wire were tested in order to determine the (1) modulus of elasticity, (2) .2% yield strength, (3) ultimate tensile strength, (4) percentage elongation and (5) maximum elastic deflection.

The modulus of elasticity and .2% yield strength are the most important properties to orthodontists because of their influence on the wire's stiffness, strength and range. The ratio of yield strength/modulus of elasticity, termed maximum elastic deflection, …

Your Child's Teeth (1981), American Dental Association, Bureau Of Health Education And Audiovisual Services, American Society Of Dentistry For Children

Patient Dental Health Education Materials 1929-1981

No abstract provided.

The Effects Of Testing Temperatures On Elastomeric Impression Materials, Charles J. Wagener

Master's Theses

No abstract provided.

Toxicity Of Root Canal Filling Materials On Hela Cells And Fibroblasts, Eldon P. Carman

Loma Linda University Electronic Theses, Dissertations & Projects

A study was undertaken to determine the concentration at which a sealer reaches a point of nontoxicity. An in vitro model utilizing HeLa cells and human fibroblasts was used to observe the effect of various concentrations of eight freshly mixed and eight set root canal sealers. Evaluation of toxicity was determined by cell survival which was measured by incorporation of ³H-thymidine into the nucleic acid components of each cell type used. Each dilution tested was allowed direct contact with the cells for 24 hours before toxicity evaluation. The results indicate that all sealers at concentrations presently used are cytotoxic …

An Ultra-Violet Light Microscopic Study Of The Hydroxylapatite Ceramic-Bone Interface Phenomena, Leonard W. Pierce

Loma Linda University Electronic Theses, Dissertations & Projects

Preparations used in this study were obtained from an investigation which had undertaken the following:

Durapatite, a hydroxylapatite ceramic was implanted in 24 mature Beagle dogs to study its maintenance effect on the alveolar bone of the mandible.

After dividing the dogs into two groups, a fresh socket and a healed socket group, the posterior teeth were removed and alveolectomies were performed. Eight ceramic implants were then placed in the right mandible of each animal in each group. The healed group received the implants five weeks after tooth removal and the fresh socket group received implants immediately after extraction.

The …

Methodology In Measurement Of Load Loss Or Gain In Orthodontic Wires : A Pilot Study, Merton S. Lacy

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this investigation was to develop methods and equipment to measure and record over any desired length of time the loss or gain in force of any material used in orthodontics that can produce a force upon an object. The material and the object being acted upon should not be disturbed while measuring that force.

Holding devices were designed and constructed in two basic forms. For intrusive and extrusive type forces, a load cell was fixed horizontally in such a position that an adjustable tube with a set screw to hold the wire could be rotated to cause …