Dental Materials Commons^™

The Effect Of Topical Fluorides On The Microleakage Of Sealants, N. Jared Nation

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The purpose of this study was to evaluate the possible microleakage found in two groups of sealants; a group bonded with a dentin bonding agent (DBA), and a group bonded without a DBA after exposure to a variety of topical fluorides.

Materials and Methods: Extracted, human molars were placed into 8 groups. Half of the groups contained sealants that were bonded with a DBA and the other remaining groups of sealants were bonded without a DBA. There were two control groups, one that had sealants bonded with a DBA and the other had sealants bonded without a DBA, but …

The Effect Of Naocl, Ca(Oh)2, Mta And Mtad On Root Dentin Fracture Resistance, Sunil Ilapogu

Loma Linda University Electronic Theses, Dissertations & Projects

Various materials are used for the treatment of immature teeth that have been subjected to trauma or decay. It is not well established what effect these materials may have on the immature root dentin. A concern would be the resistance to fracture of the remaining root dentin. The purpose of this study was to compare the resistance of fracture of bovine teeth treated with sodium hypochlorite, calcium hydroxide, gray MTA and gray MTA in conjunction with MTAD after certain periods of time. One hundred and ninety five freshly extracted, intact bovine incisors were prepared using a modified Haapasalo and Orstavik …

Bone Formation Using Platelet-Rich Plasma + Allograft: An Experimental Study In Sheep, Edgar Grageda

Loma Linda University Electronic Theses, Dissertations & Projects

Recently Platelet-Rich Plasma has been proven to be an effective regeneration adjunct when combined with autogenous bone in the reconstruction of mandibular defects. However, little is known about the effect of PRP when combined with a bone allograft in the maxillary sinus.

The purpose of this study was to quantitatively evaluate the ability of PRP to enhance bone regeneration in the maxillary sinus of sheep when combined with DFDBA + CCFDBA. Ten sheep were selected for bilateral sinus augmentation DFDBA + CCFDBA + PRP (test) and DFDBA + CCFDBA (control). Five were sacrificed at 3 months and the other five …

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 …

The Radiopacity Of 29 Resin Restorative Materials Compared To Enamel, Peter Lubisich Iv

Loma Linda University Electronic Theses, Dissertations & Projects

The radiodensity of a composite resin can greatly influence a clinician's ability to analyze a restoration for failure. The purpose of this study was to determine the relative radiopacities of 29 resin restorative materials compared to enamel, and to verify the comparable radiopacity between shades of 23 of the restorative composite resin materials. Composite resin discs measuring >5mm in diameter and 2 mm in thickness were made and polymerized. Radiographs were taken of the composite resin discs, which included an aluminum step wedge for calibration and a densitometer was used to measure the radiodensity of the composite resin samples. The …

Effects Of Mtad On Some Physical Properties Of Enamel And Dentin, Tanya Kristina Machnick

Loma Linda University Electronic Theses, Dissertations & Projects

Recently, a Mixture of Tetracycline, an Acid, and a Detergent (MTAD) has been advocated to remove smear layer and disinfect canals. The purpose of this study was to evaluate the effect of MTAD the flexural strength and modulus of elasticity of dentin as well as its effect on the bond strength to enamel and dentin. In Part I, dentin bars were randomly assigned to eight groups treated either with various concentrations of NaOCl (5.25%, 2.65%, 1.31%, 0.66%), 17% EDTA, MTAD, saline, or according to a clinical protocol with 1.3% NaOCl and then 5 min of MTAD. …

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 …

Evaluation Of Three Bonding Agents In The Repair Of Fractured Veneered Stainless Steel Crowns, Jennifer Liane Hoffer

Loma Linda University Electronic Theses, Dissertations & Projects

Dentists have long been challenged with finding an esthetic yet durable treatment option to restore badly carious anterior teeth. Veneered stainless steel crowns have become one of these options, but these restorations often return with the veneer fractured. To help restore esthetics, the crown may either be replaced or the veneer must be repaired. The purpose of this study was to evaluate the use of three bonding agents (PQ1, C&B Metabond, and Panavia) and one restorative material (Filtek Z250, 3M) in the repair of these fractured stainless steel crown veneers. The clinical significance is to determine the best methods of …

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 …

Identification Of Hard Tissue Using Dentin Sialoprotein (Dsp) As A Marker, Wallis E. Andeline

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to identify the early hard tissue formed in experimental pulp exposures capped with calcium hydroxide, mineral trioxide aggregate (MTA) or bone morphogenetic protein-7 (BMP-7) using dentin sialoprotein (DSP) as a marker. The pulps of eighty-five maxillary first, second and third molar teeth from twenty male rats were experimentally exposed. The exposed pulps were capped with calcium hydroxide followed by restoration with amalgam (n = 20), with MTA alone as a pulp capping agent and final restoration (n = 20) or with BMP-7 followed by restoration with MTA (n = 20). Ten teeth with Class …

Microleakage Of Various Restorative Materials Used For Preventive Resin Restorations, Jenny Chung Lee

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: This research was designed to compare the microleakage of various restorative materials used for preventive resin restorations and two methods of cavity preparation. The purpose of this study was: (1) to compare microleakage of four different restorative materials using two different type of preparation methods (bur and air particle abrasion) and (2) whether the use of a pit and fissure sealant over the restoration decreases microleakage.

Methods: One hundred and twenty eight, permanent human molars were randomly divided into four groups and restored with four restorative materials. Each group had been randomly divided into two subgroups. The teeth in …

Hard Tissue Healing Adjacent To Fresh Or Set Mta As Root-End Filling Material, Erol S. Apaydin

Loma Linda University Electronic Theses, Dissertations & Projects

Mineral trioxide aggregate (MTA) has been shown to promote regeneration of periradicular tissues when used as a root-end filling material. The purpose of this study was to compare the effect of fresh MTA with set MTA on hard tissue healing following periradicular surgery.

Under general anesthesia, the root canals of twenty-four mandibular premolars in four 2-year-old beagle dogs were filled with MTA. Two weeks later the root-ends of half of the samples were surgically exposed and resected to the level of set MTA within the canals. After exposing and resecting the other 12 root-ends, class I cavities were prepared in …

Hard Tissue Forming Potential Of Mta Compared To Common Root-End Filling Materials, Nooshin Noghreian

Loma Linda University Electronic Theses, Dissertations & Projects

An ideal characteristic of root-end filling materials used in endodontics is the ability to enhance hard tissue formation. Studies have shown that MTA has the potential to enhance hard tissue formation when placed in contact with periradicular tissues. The mechanisms involved in hard tissue formation of MTA and other root-end filling materials have not been completely elucidated. The purpose of this investigation was to study the mechanism of hard tissue formation of commonly used root-end filling materials and MTA by evaluating alkaline phosphatase (ALP) activity and cell layer protein. Extracts of materials tested in this experiment were added to the …

Fracture Properties Of Different Orthodontic Bonding Materials, Daryl Lynden Proctor

Loma Linda University Electronic Theses, Dissertations & Projects

Spontaneous debonding has proven a constant problem since the introduction of bonded orthodontic brackets in the early 1960's by Newman¹.

Components in classic bond strength testing are the bracket, the adhesive, the adhesive curing method, the type of teeth used, and the test method. These tests lead to extensive and compounding variables that make it difficult to evaluate the performance of any of the components individually.

The purpose of this study was to compare several contemporary orthodontic bonding adhesives by testing the physical and mechanical characteristics of the adhesives alone. Material properties compared were sonic and tensile measurements …

Evaluating Pit And Fissure Sealant Materials When Used As Bonding Agents In Preventive Resin Restorations, Paul Shields Gerber

Loma Linda University Electronic Theses, Dissertations & Projects

Preventive resin restorations (PRR) are an increasingly popular alternative to the traditional amalgam restoration for small occlusal caries in posterior teeth. The technique for placing the PRR was first suggested by Simonsen (1980) and involved a minimal removal of tooth structure. After preparation, the tooth is etched, followed by an application of a bonding agent, filled with composite, and then sealed with a pit and fissure sealant. In an attempt to simplify the protocol of the PRR this study was designed to determine if pit and fissure sealant material could serve a dual role and eliminate the need for a …

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 …

An Evaluation Of Root End Filling Materials Using Endotoxin, Hong-Ming Tang

Loma Linda University Electronic Theses, Dissertations & Projects

Mineral Trioxide Aggregates (MTA) was recently developed at Loma Linda University. It has been shown to possess good sealing ability when tested with dye, bacteria, and a fluid filtration technique.

Endotoxin is a component of the cell wall of Gram negative bacteria. It has been proposed that it may play a role in the pathogenesis of periradicular lesions. Previous studies have demonstrated that MTA can prevent the leakage of bacteria. However, the bacterial products were not tested during these studies.

This study used endotoxin to compare the sealing ability of SuperEBA, IRM, amalgam, and MTA.

The results showed that MTA …

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 Effect Of Root End Demineralization On Cementogenesis : A Long Term Investigation, Hamid R. Abedi

Loma Linda University Electronic Theses, Dissertations & Projects

Craig and Harrison¹² examined the effect of demineralization of resected root ends on wound healing following periradicular surgery. Based on its microscopic evaluations from 4-45 days, it was proposed that demineralization of resected root ends enhances cementogenesis. The purpose of this study was to investigate the longer term effects of demineralization on cementogenesis using Mineral Trioxide Aggregate (MTA) or amalgam as root end filling materials. After completion of root canal therapy and endodontic surgery on seventy-two roots of mandibular second, third and fourth premolars of six beagle dogs, 32/72 of the root ends at random were etched with 50% …

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 …

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 …

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 …

Mutagenecity Of Formocresol, Glutaraldehyde, Ferric Sulfate And Aluminum Chloride : Materials Used In Therapeutic Pulpotomies, Adolfo Barrera

Loma Linda University Electronic Theses, Dissertations & Projects

Ferric sulfate (Astringedent) and aluminum chloride (Hemodent) have been proposed as possible medicaments for use in primary teeth for therapeutic pulpotomies.

There is little information in the literature about the biologic properties of these medicaments.

The purpose of this study was to evaluate the mutagenic response of the ferric sulfate and aluminum chloride and compare them with glutaraldehyde (1.5%, 1% and 0.5% concentration) and formocresol (2%, 0.75%, 0.01% and 0.005% concentration). TA98 and TA1535 strain were used in the Ames test to assess mutagenecity. Neither ferric sulfate nor aluminum chloride exhibited mutagenic potential, in comparison with glutaraldehyde and formocresol, which …