Dentistry Commons^™

Detoxification Of Lipopolysaccharide By Endodontic Sealers, Dominic Côté

Loma Linda University Electronic Theses, Dissertations & Projects

Bacterial lipopolysaccharide (LPS) has been implicated in the pathogenesis of pulpal and periapical diseases. Several studies have evaluated the ability of various medicaments and irrigants used during root canal therapy to chemically detoxify LPS. The purpose of this study was to evaluate the ability of some endodontic sealers to detoxify LPS. This investigation compared the quantities of TNF-α released by human monocytes exposed to LPS or LPS pre-treated with sealers. The sealers tested were: Pulp Canal Sealer EWT (PCS), AH Plus (AH), and Sealapex (SA). Ca(OH)₂ and water (H2O) were respectively used as the positive and negative control materials. …

A Continued Investigation Of Craniofacial Growth In Infant Heart Transplant Recipients Receiving Cyclosporine, Gabriel Enriquez

Loma Linda University Electronic Theses, Dissertations & Projects

Since the mid 1980’s, Cyclosporine has proved to be an effective immunosuppressive drug and now has a widespread application in organ transplantation. Several studies, however, have implicated cyclosporine as adversely affecting craniofacial growth in the pediatric population. ^16,18 The purpose of this follow-up study was to continue to evaluate the possible untoward effects of long-term use of cyclosporine on craniofacial growth in a group of infant heart transplantation recipients by re-evaluating as many subjects as possible from the original study and evaluating new subjects. A pediatric group (N=13) was composed of six Caucasian subjects (4 male and 2 female, ages …

Resorbable Barrier Effect In Sinus Graft Using Anorganic Bone, Kyung-Soo Choi

Loma Linda University Electronic Theses, Dissertations & Projects

The effect of a resorbable membrane on new bone formation in human maxillary sinus augmentation using anorganic bovine material is unclear at the present time. As a pilot study, six patients who required bilateral maxillary sinus augmentations for endoessous dental implant treatment were grafted with anorganic bovine bone material. All six patients had a resorbable collagen membrane placed over the graft material on only one side for the sinus augmentation. At the time of implant placement, a minimum of 8 months following sinus graft healing, a biopsy was made of each side to permit histomorphometric analysis.

Similar amounts of new …

Variability In Selecting Lateral Cephalometric Landmarks In Two Cbct Image Modes, Dana Nguyen

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The purpose of this study was to determine the variability of lateral cephalometric landmark selection in two cone beam computed tomography (CBCT) lateral cephalometric simulations: 1) a mean projection image (MPI) and 2) a serial sagittal slice image (SSSI).

Methods: A MPI is a two-dimensional (2D) image obtained from the NewTom 3G^TM CBCT that resembles the conventional lateral cephalogram. A SSSI is a 2D image also obtained from CBCT data, but is created by superimposing a series of selected thin sagittal slices containing the required cephalometric landmarks. This study compared the Ricketts and Steiner analysis of the MPI …

Adolescent Craniofacial Morphology Associated With Degenerative Joint Disease, Byron Diehl

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this retrospective research was to evaluate the association of degenerative joint disease (DJD) on the skeletal and dental patterns of affected adolescent individuals. The T1 lateral cephalometric radiographs of 48 subjects were reviewed, consisting of 18 subjects with DJD and 25 subjects without DJD. The age of subjects ranged between 10 - 17 years with a mean age of 13 years. Linear and angular cephalometric measurements were taken to evaluate the skeletal, denture base and dental characteristics of the two groups. Overall, there were 24 variables chosen to represent the cranial base, maxillary jaw position, mandibular jaw …

Implant Success In Distracted Bone Versus Autogenous Bone-Grafted Sites, Jeffrey Allan Elo

Loma Linda University Electronic Theses, Dissertations & Projects

Endosseous implants are the treatment of choice for restoring function and reconstructing edentulous areas of the maxilla and mandible. Alveolar defects can be reconstructed by either distraction osteogenesis or autogenous bone grafting. After alveolar reconstruction, endosseous implants are used to support and retain the prosthesis for restoration of form and function. We retrospectively analyzed the success rates of endosseous implant placement in distracted versus autogenous bone graft reconstruction sites in our patient population at Loma Linda University Medical Center, Department of Oral and Maxillofacial Surgery. 82 consecutive patients requiring alveolar augmentation prior to implant placement were evaluated. All patients were …

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 …

In Vitro Antimicrobial Efficacy Of Calcium Hydroxides In Root Dentin, Josef W. Lubisich

Loma Linda University Electronic Theses, Dissertations & Projects

Enterococcus faecalis is the most commonly isolated bacteria in failed root canal treatment. Endodontic intracanal medicaments are commonly tested using standardized bovine cylinders infected with bacteria. The literature is not clear on whether calcium hydroxides are able to remove E. faecalis from the dentinal tubules. One reason for this is that there are several varying forms of calcium hydroxide commonly used. The purpose of the present experiment was to determine whether four commonly used calcium hydroxide products were able to reduce E. faecalis from four incremental samples of dentin and to determine if there was a statistically significant difference between …

A Comparison Of Cadiax Axiography & Newtom 3g Tomography Condylar Measurements, David Phillip Brock

Loma Linda University Electronic Theses, Dissertations & Projects

This study compared the curves for the mandibular movement obtained from computerized axiography (Cadiax) and NewTom 3G cone beam volumetric tomography.

Fifteen subjects (n=15) from the Loma Linda University School of Dentistry obtained a Cadiax mandibular jaw tracing and a NewTom 3G scan of their condyles and surrounding structures while in centric relation (CR). In addition, three condylar measurements obtained from the Cadiax and the NewTom 3G were compared: sagittal eminential angle (SEA), progressive mandibular lateral translation (PMLT), and early mandibular lateral translation (EMLT).

No differences were noted between the Cadiax and the NewTom 3G mandibular tracings when the gender …

Comparing The Use Of A Manual And A Power Toothbrush By 3-To-4 Year-Old Children, Lorena Delgado Salcedo

Loma Linda University Electronic Theses, Dissertations & Projects

PURPOSE: To compare the ability of three-to four-year-old children in performing toothbrushing with manual versus battery-powered toothbrushes with and without oral hygiene instructions.

METHODS: This study was a randomized, controlled, examiner-blind, 4-period crossover design performed on 50 healthy children, ages 3 to 4 years old. Children were assigned either a manual or power toothbrush at visit one and alternated between the two types of toothbrushes each week, for four weeks. Plaque was scored before and after brushing using the Greene and Vermillion -Simplified Oral Hygiene Index. ^18,19 At their last two visits of the study, the children received brushing instructions …

Effects Of Diabetes Mellitus On The Healing Of The Dental Pulp, Stuart Evan Garber

Loma Linda University Electronic Theses, Dissertations & Projects

Diabetes Mellitus (DM) has been implicated as a factor affecting healing. The purpose of this study was to use the healing of experimentally exposed pulps subsequent to pulp capping as a model to determine the effect of DM on healing.

Twenty-two Sprague-Dawley rats were divided into two groups of eleven animals each. In one group, DM was induced by injection of 70 mg/KG of streptozotocin. In the other group, the animals were injected with sterile saline. Under anesthesia with Ketamine and Xylazine, the pulps of the maxillary first molars of all rats were exposed using a 1/16 round bur under …

Shear Strengths Of Three "One-Step" Self-Etching Dental Bonding Agents, Jeff G. Alcaide

Loma Linda University Electronic Theses, Dissertations & Projects

Objective: To compare the dentin shear bond strength of three self-etching bonding agents with that of a conventional total-etch bonding system.

Materials & Method: Extracted third molars (120) were fixed in 10% formalin and randomly divided into eight groups of 15 specimens each. The specimens were mounted in acrylic resin and the surface ground to expose superficial dentin. A standardized smear layer was created by polishing the surfaces with wet 600-grit silicon carbide paper. Each adhesive system was placed on the specimen surface according to the manufacturers' instructions. The specimen then was mounted onto a standardized jig and light cured. …

Bone Morphogenic Protein Induced Repair Of The Premaxillary Cleft, Rick J. Rawson

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study is to evaluate the bony augmentation of premaxillary clefts in humans using recombinant bone morphogenic protein (rhBMP-2) in a collagen sponge carrier. 12 patients with unilateral cleft alveolar ridges were evaluated pre- and 4 months postoperatively. 10 patients were repaired with rhBMP-2 while two others were grafted with anterior iliac crest particulate marrow cancellous bone (PMCB). Computed tomographic studies were used to evaluate preoperative alveolar cleft volumes, postoperative bone bridge volumes, and pre/post operative volume ratios.

A pre/post operative volume ratio for patients repaired with rhBMP-2 ranged from 24.1% to 90.6% with a mean of …

The Effect Of Calcium Hydroxide Pastes On Root Dentin Fracture Resistance, Kurt W. Sturz

Loma Linda University Electronic Theses, Dissertations & Projects

Calcium hydroxide is a common intracanal medicament used in the treatment of immature teeth that have been subjected to trauma or decay prior to root canal therapy. The effect of calcium hydroxide on immature root dentin is important. One area of concern is the effect that calcium hydroxide has on the fracture resistance of an immature tooth. It is the aim of this study to compare the effect of four different commercially available calcium hydroxide pastes on the fracture resistance of bovine teeth. Seventy-five freshly extracted, intact bovine incisors were prepared according to a modified Haapasalo and Orstavik technique. Each …

Influence Of Keratinized Mucosa, Bone Dimensions On Mucosal Recession And Bone Loss, Jeanette Keng Ling Chua

Loma Linda University Electronic Theses, Dissertations & Projects

Background: To accomplish successful esthetic outcome, it would be an advantage if some pre-implant placement conditions could be identified which would predict soft and hard tissue outcomes post-implant placement. This study was designed to evaluate the influence of 1) height of mid-buccal keratinized mucosa at implant surgery and 2) thickness of mid-buccal bone after osteotomy on the amounts of mid-buccal mucosal recession and bone loss during the first year after implant treatment. This report presents the initial 3-month follow-up.

Materials and methods: Nine patients scheduled for surgical placement of a total of 11 single-staged implants, without adjacent teeth and planned …

Training Program To Improve Estimation Of Patients' Periodontal Pain Experience, Yoon Jeong Kim

Loma Linda University Electronic Theses, Dissertations & Projects

Background: The purpose of this study was to determine if periodontal residents could enhance their ability to appraise the pain levels experienced by their patients from probing, using Visual Analog Scale (VAS) to record pain. We hypothesized that with increasing experience by repeated comparisons of the patients' VAS pain ratings with independent ratings by the residents, they would improve their ability to appraise their patients' pain experiences.

Methods: For each of three periodontal residents, 40 consecutive periodontitis patients were asked to express the degree of pain they experienced during the probing. Independently, the residents rated the pain level they perceived …

Mineralized Bone Allograft In Maxillary Sinuses Histology And Histomorphometry, Sammy Stefan Noumbissi

Loma Linda University Electronic Theses, Dissertations & Projects

Background: Demineralized freeze-dried bone allografts (DFDBA) and deproteinized bovine bone xenografts (DMBBX) have been used for sinus augmentation for many years with varying results, but very little has been reported on the clinical efficacy or the histological analysis of mineralized solvent dehydrated bone allografts (MSDBA) as sinus graft materials. This study histologically and histomorphometrically evaluated an MSDBA material called PUROS to augment atrophic human maxillary sinuses.

Materials & Methods: Seven partially and completely edentulous patients requiring unilateral (n=4) or bilateral (n=3) sinus grafts prior to implant placement were selected for this study. Test grafts consisted of MSDBA, and control …

Dynamic Determinants Of Incisal Display, Shawn Paul Pesh

Loma Linda University Electronic Theses, Dissertations & Projects

The principal objective of this study was to use computer aided design (CAD) to better illustrate and quantify the relationship of mandibular arch depth, mandibular arch width, overbite, and overjet in the presence of mandibular dental crowding. To date, there has been no research examining how changes in the mandibular arch limit the orthodontist's ability to control overbite and overjet. Understanding how to effectively manage overbite and overjet are crucial to the clinician's ability to manipulate incisal display. Polyvinyl siloxane impressions of both maxillary and mandibular arches of a Caucasian patient were taken and used to pour dental stone models. …

Vital Pulp Therapy With Mineral Trioxide Aggregate: An Outcomes Study, Heather H. Lauer

Loma Linda University Electronic Theses, Dissertations & Projects

Mineral trioxide aggregate (MTA) is used in a variety of endodontic procedures. MTA is proven to provide good marginal adaption to dentin, to be biocompatible, and to stimulate dentin bridge formation through animal studies. These properties make MTA a potentially useful material to be used in vital pulp therapy. Clinical data on the use of MTA as a vital pulp medicament is sparse. The purpose of this study was to evaluate the clinical outcome of vital pulp therapy using MTA as the pulp medicament. Inclusion criteria for patient selection for recall was based on pulp treatment necessary from carious pulp …

Accuracy Of The Newtom 3g™ In Measuring The Angle Of The Articular Eminence, Rehana Khan

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine the accuracy of the Newtom 3G™ in determining the angulation of the articular eminence. The benefits of conducting this study were to provide additional uses for the standard records that are taken for the purposes of orthodontic treatment, as well as evaluate the Newtom 3G™ for accuracy in measuring the anatomy of the glenoid fossa. This study required 20 participants that volunteered to allow their records to be used. Records evaluated were the Newtom 3G™, impressions, and wax check bite registrations. The wax record was taken using the 'forced bite' technique to …

Ricketts And Steiner Analysis Using Newtom 3g™ Scout Images, James I. Gibson Iii

Loma Linda University Electronic Theses, Dissertations & Projects

NewTom 3G™ scout images have the general appearance of traditional lateral cephalometric radiographs. The purpose of this research was to determine if Ricketts and Steiner analyses could be accomplished on NewTom 3G™ scout images.

This was a retrospective study comparing the use of NewTom 3G™ scans in DICOM (Digital Imaging and Communications in Medicine) format to scout images from 25 consecutive patients of the Loma Linda University School of Dentistry Department of Orthodontics, three of these patients did not meet the inclusion criteria. The DICOM images were used to create controls. The controls and scout images were digitized using QuickCeph™. …

Stability Of The Miniscrew-Bone Interface: Reverse Torque Values In Rabbits, Daniel John Drye

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Miniscrews are used in orthodontics as practical temporary anchorage devices (TAD's). The purpose of this animal study was to measure reverse torque values for Absoanchor 1.2 mm and Micerium 1.5mm miniscrews at 0, 2, and 12 weeks under loaded and unloaded conditions.

Methods: Ninety-six miniscrews were placed in the femora of twelve rabbits and allowed to heal for either two or twelve weeks. Half of the fixtures were loaded immediately with NiTi open coil springs producing a force of 150-200g and the other half served as unloaded controls. For each of the healing times, two and twelve weeks, …

The Outcome Of Mta As A Root End Filling Material: A Long Term Evaluation, Christopher M. Sechrist

Loma Linda University Electronic Theses, Dissertations & Projects

Periradicular surgery is a viable option to save natural teeth when non-surgical treatment fails or when endodontic retreatment is not feasible or contraindicated. Laboratory and animal studies have demonstrated that MTA is biocompatible, provides an excellent seal against penetrating bacteria, and promotes hard tissue healing. The purpose of this study was to provide long term (>3 years) clinical evidence for its use as a root-end filling material in endodontics. The clinical records of 294 patients who had MTA used during endodontic treatment from 1996 to 2001 were reviewed. From these, 75 patients whose root end cavities had been filled …

Magnification In Images Produced By Five Popular Digital Lateral Cephalometric Machines, Gretchen Marie Schnepper

Loma Linda University Electronic Theses, Dissertations & Projects

Modern digital lateral cephalometric images are produced by machines that vary in a number of critical features such as: 1) machine geometry, 2) movement (or lack of movement) of the x-ray source, 3) movement (or lack of movement) or x-ray detectors, 4) cephalostat geometry and 5) digital data manipulations by proprietary software. The purpose of this study was to evaluate the magnification characteristics of images produced by five commercial digital lateral cephalometric machines. These digital image magnification characteristics were then compared with images produced by an analog cephalometric machine. The two goals of this study were to: 1) measure the …

Treatment Outcome Of Root Perforations Repaired With Mineral Trioxide Aggregate, Stephen H. Paik

Loma Linda University Electronic Theses, Dissertations & Projects

Root perforations during root canal therapy have a significant negative impact on long-term prognosis of teeth. Proper treatment is critical in managing these accidental procedures. Laboratory and animal studies have demonstrated that Mineral Trioxide Aggregate (MTA) is biocompatible, provides an excellent seal against penetrating bacteria, and promotes hard tissue healing. The purpose of this study was to determine the long term treatment outcome of root perforations repaired with MTA.

Ninety-nine records from the Graduate Endodontic Clinic at Loma Linda University School of Dentistry from 1996 to 2001 were reviewed. Clinical and radiographic evaluations were completed. Three independent examiners evaluated digitized …

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 …

Laser And Led Effects On The Proliferation Rate Of Periodontal Ligament Fibroblasts, Allen J. Job

Loma Linda University Electronic Theses, Dissertations & Projects

PURPOSE: To compare the effectiveness of a Gallium Aluminum Arsenide (GaAlAs) diode laser and a light emitting diode (LED) on periodontal ligament fibroblast cell proliferative rates.

METHODS and MATERIALS: PDLF obtained from freshly extracted permanent teeth were cultured under standard conditions until a subconfluent monolayer was present. The next section took 5 days to complete. On day 1, the initial cell concentration of 700 uL/cm² was plated on 96-well assay plates and placed in a CO₂ incubator at 37° C for 24 hours. On day 2, cell counts were first verified using hemocytometry then were irradiated using an …

The Effect Of Pre-Heating On Depth Of Cure And Surface Hardness Of Resins, Peter R. Bond

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction of a device to pre-heat composites prior to curing has prompted this study to evaluate the effect of pre-heating on the surface hardness and depth of cure of composite resins. Factors considered in this study included curing time (10, 20 and 40 seconds), curing temperature (70, 100 and 140 degrees F), curing light type (halogen and LED), and composite type (hybrid and microhybrid).

The surface hardness portion of the study included 180 samples (5 of each of 36 combinations of factors) prepared according to the ADA standard for surface hardness. Four Knoop hardness measurements were obtained from both the …

Resonance Frequency Analysis As A Determinant Of Implant Initial Stability, Negar Tabandeh

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The clinicians' decision regarding immediate loading is largely determined by the assessment of initial stability of the dental implant. Computed tomographic assessment of recipient site bone quality, insertion resistance torque and post-insertion resonance frequency are currently the only objective methods of measurement establishing initial stability.

Purpose: A study was designed to measure resonance frequency of root form dental implants placed in cadaver jaws. The resonance frequency values were compared to previous subjective and objective data reported in prior studies in the series.

Materials and Methods: Resonance frequency measurements were secured using the Osstell ™ mentor unit on 4.0 X …

Histological Comparison Of White And Gray Mta In Repair Of Furcation Perforations, Miguel Elias Mego

Loma Linda University Electronic Theses, Dissertations & Projects

Mineral trioxide aggregate (MTA) has been shown to promote regeneration of the periodontal apparatus when used as a repair material in furcation perforations. Two variations of MTA (Gray and White) have been introduced to the dental market. The purpose of this study was to histologically compare the in vivo response to immediate furcation perforation repair using gray or white MTA in beagle dogs.

Under general anesthesia, non-surgical root canal therapy and furcal perforations were performed on sixteen mandibular premolars of eight 2-year old beagle dogs. The perforations were immediately repaired with either white (n=8) or gray (n=8) MTA. The animals …