Dentistry Commons^™

Anti-Inflammatory Agents And The Modulation Of Replacement Root Resorption, Geoffrey Toshio Okada

Loma Linda University Electronic Theses, Dissertations & Projects

Replacement resorption (RR) occurs following severe injury to the periodontal ligament (PDL). It has been suggested that inflammatory reactions precede RR. The purpose of this study was to examine and compare histologically the effect of topical application of two anti-inflammatory medications and stannous fluoride (SF) on the development of RR. Thirty-four roots of beagle dog mandibular 2nd, 3rd, and 4th premolars received root canal therapy. They were then extracted and left to bench dry for one hour. Following removal of their PDLs, they were soaked for five minutes in either 10 µg/ml ketorolac (n=10), 16 µg/ml of dexamethasone (n=10), or …

An In Vitro Study Of The Durability Of A Proprietary Decalcification Inhibiting Sealant, Michaela Camille Neagu

Loma Linda University Electronic Theses, Dissertations & Projects

Plaque accumulation, although undesirable, is prevalent in orthodontic patients with poor oral hygiene and is linked with enamel decalcification. A proposed product designed to seal the tooth around the orthodontic bracket was tested for its durability. It also was evaluated for its ability to seal the enamel.

We measured prepared areas of sixty bovine teeth that were divided equally into two groups: a control group, protected with light-cured Concise sealant, and a group treated with the test sealant, Odyssey, both by 3M Unitek. The teeth were thermocycled for 1000 cycles in alternating 5° C and 55° C waterbaths at 10-second …

A Comparison Of Four Curing Lights For Bonding Of Orthodontic Brackets, David Sy Nguyen

Loma Linda University Electronic Theses, Dissertations & Projects

Light cured adhesives have gained more popularity since their introduction more than three decades ago. Photo-polymerization allows more thorough curing on demand and thus facilitates better control of bracket placement. With new technologies, recently developed curing lights promise even more improvement. These systems are not only more sophisticated, but also more sensitive to the types of resins and clinical application. Specific comparison studies of the new systems in the orthodontic bonding are lacking because most of curing lights are originally designed for general dentistry.

This study evaluated the in-vitro ability of four curing lights to polymerize the Transbond XT bonding …

Orthognathic Surgery In The Juvenile Rheumatoid Arthritic Patient, David H. Gilbert

Loma Linda University Electronic Theses, Dissertations & Projects

This thesis attempts to use a retrospective evidenced base review of a series of five patients afflicted with juvenile rheumatoid arthritis and its inherent dento-facial deformity as a basis for establishing a proposal for a surgical protocol.

A review of pertinent and current literature is performed in describing the disease process as it relates to epidemiology, histopathophysiology, immunology, and clinical presentation. General treatment options are reviewed for the acutely and chronically afflicted patients as well as specific approaches to dento-facial reconstruction.

The studies reviews a series of five female patients who were evaluated and treated by the same surgeon at …

An Evaluation Of The Short And Long Term Effects Of Quad Helix Expansion, Sonja F. Finnie

Loma Linda University Electronic Theses, Dissertations & Projects

This study was conducted to examine, retrospectively, orthodontic and orthopedic changes resulting from quad helix expansion therapy in mixed and permanent dentition stages. Twenty-one subjects with an average age of 10.2 years who experienced an expansion of at least 3 mm with the quad helix appliance were selected for this study. The subjects were evaluated according to facial type and age for both short and long-term stability. Plaster dental casts and posteroanterior (frontal) radiographs were evaluated at the beginning of treatment (T1), at the completion of Phase 1 or full treatment (T2), and approximately two years following the completion of …

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 …

An Extension Of Euclidean Distance Matrix Analysis Applied To Craniofacial Growth Prediction, Mark K. Batesole

Loma Linda University Electronic Theses, Dissertations & Projects

This study is [sic] introduces a new extension of Euclidean Distance Matrix Analysis (EDMA) as applied to growth prediction analysis. Using EDMA eliminates the presupposition of a set growth pattern, which is introduced by traditional superimposition techniques. When EDMA is extended to analyze prediction methodologies, using a non-age-matched growth sample, some shortcomings become evident. These involve bootstrapping techniques, relative difference in growth, and absence of clinical, real world measure. To overcome these issues, a statistical approach using the Wilcoxen signed rank test, absolute difference in growth, and a new method to evaluate the error in a prediction methodology's landmark identification …

Post-Treatment Evaluation Of Isometric Function Of The Elevator Muscles, Margaret Barbara Kowalczyk

Loma Linda University Electronic Theses, Dissertations & Projects

This study mainly examined neuromuscular function, occlusal index, and centric relation-centric occlusion (CR-CO) discrepancy of 23 orthodontically treated patients. Phase I, craniofacial anomalous, and orthognathnic surgery cases were excluded from the study. Record taking was done in 2 sessions: (1) at the time of deband and (2) 3-4 months later. Records taken at each session included facial and intraoral photographs, impressions, CR wax bites, a facebow, and surface EMG (sEMG) recordings.

For the sEMG recordings, electrodes were placed on the upper hyoid, masseter, and anterior temporalis muscles. Subjects were asked to perform numerous tests; these included baseline, clenching to test …

Accuracy Of Zerobase™ Growth Prediction Of A Burlington Sample, Anitha Nair

Loma Linda University Electronic Theses, Dissertations & Projects

The accuracy of ZeroBase™ orthodontic software program was tested using a sample of 14 male and 14 female untreated subjects classified as skeletal Class II pattern by the Burlington growth center. Growth predictions were carried out by ZeroBaseTM from ages 6,9,12,14,16 in males and 6,9,12 and 14 in females. The mean computer predicted value was compared with the mean radiographic value to test the accuracy of the predictions. Predictions from age 14 were the most accurate (within one standard deviation), whereas the predictions from age 6 were the least accurate. In males, the accuracy of cranial base predictions was 73.3%, …

Periradicular Response Of Immunodeficient Rats To Mechanical Pulpal Exposure, James E. Stich

Loma Linda University Electronic Theses, Dissertations & Projects

Periradicular lesions develop as a result of the interaction between root canal irritants and the immune system. The purpose of this study was to investigate the periradicular response of immunodeficient rats to their oral flora. Twenty Sprague-Dawley rats received a total body irradiation dose of 750 cGy one week prior to the investigation. The pulps of the mandibular first molars of these animals and six nonirradiated rats were exposed mechanically with a ½ round bur and left open to the oral cavity. Additional irradiation (350 cGy) was administered bi-weekly to maintain immunosuppression. Periradicular specimens were obtained after two and four …

Various Presentation Styles For Informing Parents About Pediatric Dental Procedures, Tracy Dean Walker

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The treatment of pediatric dental patients can only be as effective as the degree to which the parent consents to treatment. This study was designed to A) determine the most effective method of communicating a dental procedure to the parent of a pediatric patient and B) determine the impact that various presentation methods would have on a parent's willingness to give informed consent.

Methods: A Pulpotomy procedure was explained to each parent by one of the following methods; 1) written, 2) written and model, 3) verbal or 4) verbal and model.

Results: A statistically significant relationship was shown between …

The Effect Of Mandibular First Molar Tip Back On Mandibular Incisor Long-Term Stability, Barton L. Soper

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study is to determine if mandibular first molar distal tip back during orthodontic treatment will result in improved long-term alignment of mandibular incisors. Our pre and posttreatment sample consisted of 57 Class I and Class II patients (40 female and 17 male). Incisor irregularity was recorded at T2 and T4 (average of 12.9 years postretention at T4). Molar tipback was evaluated T1 to T2 and T2 to T4. The sample was divided into 3 groups - molars tipped distally 1 degree or more during treatment, molars essentially not tipped, and molars tipped mesially 1 degree or …

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 …

Effect Of Obturation And / Or Coronal Seal On The Success Of Root Canal Therapy : An In Vivo Histologic Investigation, Douglas Snider

Loma Linda University Electronic Theses, Dissertations & Projects

Numerous studies have examined coronal leakage with in vitro protocols. A search of the literature showed the absence of a long term in vivo, histologic study, examining the effect of coronal and/or radicular leakage on periradicular health.

The purpose of this study was to evaluate the effect of obturation and / or coronal seal in preventing the formation of periradicular lesions in dogs over time. The study was conducted on six beagle dogs. Premolars were cleaned and shaped. Sixteen roots in each dog were randomly assigned to one of four treatment groups of equal size. Group one was obturated using …

Diagnosis And Treatment Of Swallowing Dysfunctions : Semg Cognitive Training As An Adjunct To Conventional Therapy, Vicky T. Nguyen

Loma Linda University Electronic Theses, Dissertations & Projects

This study compared surface electromyography (sEMG) cognitive training to conventional myofunctional therapy in controlling a swallowing dysfunction, commonly referred to as "tongue thrust". Nasal airway resistance (NAR) was assessed on every subject, to rule out mechanical obstruction that would prevent proper function. The scope of this investigation composed of evaluating baseline activity and dry swallowing patterns. Subjects were distributed to one of three treatment groups: sEMG cognitive training, conventional myofunctional therapy, and control, based on the degree of NAR (normal, mild, or moderate). Initial sEMG recordings were then taken on subjects that clinically demonstrated a tongue thrust habit to confirm …

The Validation Of An Existing Sleep Apnea Questionnaire And Its Application To Clinical Orthodontics, Jeffery C. Biggs

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to validate a sleep apnea questionnaire from the Loma Linda University Sleep Disorders Center, and then to utilize the questionnaire in order to identify potential sleep apnea patients from a pre-orthodontic patient sample. Study patients were selected from the Loma Linda University Sleep Disorders Center and the Loma Linda University Orthodontics Clinic, both in Loma Linda, California, USA.

Methods: The study sample represented all of the patients initially examined from 1996 through 1998 who were age 8-15 years old at the time of the initial exam. Validation of the questionnaire was based on responses …

Dna-Dna Checkerboard Hybridization To Identify Bacteria In Human Plaque Samples, Jasan Lee Zimmerman

Loma Linda University Electronic Theses, Dissertations & Projects

Previous research has shown that using DNA probes to identify the presence of specific bacteria in human plaque samples is superior to the commonly used anaerobic cultural procedures. Some periodontal pathogens are either uncultivable or very difficult to grow, such as Prevotella intermedia, P. nigrescens, and Eubacterium brachy. Digoxygenin probes were prepared for 15 oral bacteria. These probes were used with a checkerboard DNA-DNA hybridization scheme to analyze whether human plaque samples contained any of the 15 bacterial species. Our results have shown that this method is successful in identifying bacterial DNA present in the subgingival patient plaque …

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 …

Marginal Discrepancy Of Components Utilized For Implant Framework Construction, Mathew Thomas Kattadiyil

Loma Linda University Electronic Theses, Dissertations & Projects

This study evaluated marginal fit discrepancy of the abutment-implant body interface employing various components commonly utilized for implant framework fabrication. Four types of components ( castable plastic patterns, premachined gold abutments, premachined titanium abutments and CAD-CAM custom premachined titanium abutments) were evaluated. Five castable plastic patterns and five premachined gold abutme~ts from each of two manufacturers, five premachined titanium abutments and five CAD-CAM custom premachined titanium abutments were used. Components were affixed to a 3.75 x 10 mm dental implant and standardized measurements were obtained of the abutment-implant interface using a computerassisted microscope at various experimental time intervals. Measurements of …

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 …

Establishing Norms For A Mexican Group Using Ricketts, Steiner And Arnett Analyses, Mauricio Gonzalez Balut

Loma Linda University Electronic Theses, Dissertations & Projects

Most existing cephalometric analyses are based on norms for the Caucasian population. Therefore, they cannot be properly applied for Mexican or Hispanic patients. Ethnic variations in the normal positions of the maxilla and mandible influence and alter the diagnosis and treatment plan for each of the different type of malocclusions. Previous studies have addressed the difference between the Caucasian norms and the Hispanic norms, this indicates the variety of their skeletal, dental and facial features.

It is the purpose of this study to establish specific cephalometric standards for the native Mexican group, using the Steiner and Ricketts analyses along with …

The Relationship Of The Incisive Canal To Maxillary Median Diastema, Jeffery S. Corbett

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to assess the relationship between the incisive canal and maxillary median diastema, and to identify an imaging method capable of documenting the geometry and dimensions of the incisive canal. The sample consisted of 59 dry skulls, 26 of which had a maxillary median diastema ranging in size from 0.1 mm to 2.8 mm (mean 1.0 mm, SD = 0.7 mm). Each skull had all of the permanent maxillary teeth present from first molar to first molar and lacked any apparent non-orthodontic condition that could have caused the diastema. Diastema width and canal diameter were …

A Comparison In Processing Of Alginate Orthodontic Impressions By Commercial Labs, Robert Agnetta

Loma Linda University Electronic Theses, Dissertations & Projects

Many orthodontists use commercial orthodontic laboratories for the processing of their impressions including preparation of the impression for pouring, model retrieval, final trim, and labeling. It was studied, by way of random sample survey, what materials and methods were most commonly utilized in 100 offices of members of the American Association of Orthodontics. This survey data was analyzed and used to establish a protocol to study differences in dimensions of models made from impressions that were poured immediately, versus those that were stored and picked up at the office the same day they were taken, and those that were shipped …

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 …

Regeneration In Periodontal Defects With Rhbmp-2 : A Dosage Study, Paola Guglielmoni

Loma Linda University Electronic Theses, Dissertations & Projects

Bone morphogenetic proteins (BMPs) have been shown to induce bone formation in ectopic and orthotopic sites. This inductive capability has led to their evaluation as possible adjuncts in periodontal reconstructive therapy. Indeed, studies have reported periodontal regeneration following surgical implantation of recombinant human BMP-2. This study evaluated regeneration of alveolar bone and cementum following periodontal reconstructive surgery including implantation of a construct consisting of sterile lyophilized rhBMP-2 in buffer adsorbed onto an absorbable collagen sponge. Critical size mandibular supra-alveolar periodontal defects were surgically created, and an incomplete block design was used to evaluate the regenerative potential of rhBMP-2 at 0.05, …

Comparison Of Mandibular Surgical Techniques For Accessing Cranial Base Vascular Lesions, Michael A. Devlin

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: Treatment of vascular lesions of the high cervical internal carotid artery (zone III) resulting from penetrating trauma, blunt trauma, aneurysms, and atherosclerosis pose a challenge for vascular surgeons due to bony interference's of the mandibular ramus and mastoid process. Although many techniques have been described, two methods, have been identified as effective and associated with low morbidity. The purpose of this study is to compare these two methods, mandibular distraction and vertical ramus osteotomy, for their effectiveness at increasing access to the cranial base and distal internal carotid artery.

Materials and Methods: Five fresh frozen cadavers were utilized …

The Effect Of Systemic Doxycycline On Alveolar Bone Loss Following Periradicular Surgery, G. Reed Cummings

Loma Linda University Electronic Theses, Dissertations & Projects

Studies have shown an average of 0.5 mm to over 1.0 mm of bone loss following full thickness flap reflection. Recent investigations have revealed that the tetracycline family of antibiotics can prevent bone loss. The purpose of this study was to determine the effect of systemic Doxycycline on crestal alveolar bone loss following periradicular surgery in Beagle dogs.

The experiment was divided into two phases. The first phase served as the control (Non-Doxycycline), the second phase as the experiment (Doxycycline). Full thickness flaps were reflected in the mandibular left or right quadrant (control side) of five Beagle dogs. Using a …

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% …