Dentistry Commons^™

A Comparative Study Of Conventional-Ligating And Self-Ligating Bracket Systems, Gabriela Garcia

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this research was to determine the frictional resistance of four self-ligating brackets and two conventional bracket systems using two different types of orthodontic arch wires in both wet and dry fields. Six different brands of upper right central incisor brackets with 0.018-in slots were evaluated. Group A : self-ligating bracket: Opal (Ultradent), Damon 2 (Ormco), Time (American Orthodontics), In-Ovation (GAC). Group B: conventional-ligating: Virage (American Orthodontics), and Mini-Twin (Unitek) served as the control brackets. Two different orthodontic wires of varying alloys and sections were tested: 0.016-in round stainless steel (Ormco) and 0.016x0.022 inch rectangular nickel-titanium (American Orthodontics). …

Comparison Of Different Methods Of Assessing Ridge Width Prior To Implant Placement, Lung-Cheng Chen

Loma Linda University Electronic Theses, Dissertations & Projects

The aim of this study was to compare the following 3 methods of assessing alveolar ridge dimensions prior to placement of dental implants: 1) ridge mapping measurement before surgical flap reflection using a caliper; 2) direct caliper measurement following surgical exposure of the bone, and 3) measurement using images from cone beam computerized tomography.

Sixteen subjects having 25 sites for planned implant placement or ridge augmentation were recruited. An acrylic stent was fabricated for each patient. The stent provided 3 buccal/lingual pairs of consistent measurement points for each implant site, located 4, 7 and 10 mm from the summit of …

The Effect Of Rapid Maxillary Expansion On Nasal Cavity Volume And Nasal Airway Resistance, Todd Ehrler

Loma Linda University Electronic Theses, Dissertations & Projects

This study examined the effects of Rapid Maxillary Expansion (RME). Using Cone Beam CT scanning technology and Rhinomanometry, the volume and nasal airway resistance (NAR) of the nasal cavity was measured immediately before and after RME.

27 subjects (16 female, and 11 male), ages 9-18 were enrolled in the study. After RME all subjects had a statistically significant increase in nasal cavity volume. The pre expansion group experienced a statistically significant reduction in NAR when compared to the post expansion group. Individuals with a high pre expansion NAR experienced the greatest reduction in NAR. The correlation between change in volume …

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 …

Cbct Panoramic Images Vs. Traditional Panoramic Radiographs, Sunny Young Hutchinson

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this research was to compare the accuracy of angular measurements of the panoramic image of the Newtom 9000™ Cone Beam Computed Tomography (CBCT) with the Sirona™ Orthophos panoramic unit. The study was separated into three parts: phantom study, patient study, and archform study. The phantom study used fabricated phantom typodonts to compare angular measurements between the Newtom 9000™ panoramic image and the Sirona™ panoramic radiograph. Accuracies of the measurements were then determined by comparing the values to the actual phantom typodont. No marked differences in angular measurements were recorded for the phantom typodont using either of the …

Prevalence Of Degenerative Joint Disease In A Pre-Orthodontic Adolescent Sample, Marie Mansour

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this research was to determine a prevalence of degenerative joint disease in our pre-orthodontic adolescent patients age ten through seventeen. The prevalence was assessed according to gender. Severity of DJD was established for each patient and a "red flag" for diagnosis was identified. The purpose was also to establish norms for joint space for patients with and without degenerative joint disease. Correlations to distal condyle position and angle classification were described. 123 consecutive patients, 77 female and 46 male T1 NewTom records were reviewed. Severity of DJD was classified according to none, mild, moderate, and severe. Sagittal …

Cone Beam Ct And Digital Radiography. A Comparative Study Of P/A Cephalometrics., Michael John Erickson

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine if Rickett's posterio-anterior (P/A) cephalogram measurements could be obtained from Cone Beam Computerized Tomographic (CBCT) images taken on the NewTom QR-DVT 9000™.

Fifteen frontal cephalometric radiographs were chosen for good image quality, with no regard for patient age or gender. Each cephalogram was traced three times by the same operator using ZeroBase™ software. Landmarks were located and measured according to the Rickett's frontal analysis technique. Methods were devised for obtaining analogous measurements using CBCT images on the same group of patients.

Measurements obtained using CBCT correlated well with those obtained using the …

Condylar Remodeling After Distraction Osteogenesis And Bilateral Sagittal Split Osteotomy, Robert Barker Hoffman

Loma Linda University Electronic Theses, Dissertations & Projects

The present pilot study is a histological evaluation of mandibular condyles taken from minipigs that underwent either traditional mandibular advancement (bilateral sagittal split osteotomy), or a distraction osteogenesis procedure to advance the mandible. One pig received a bilateral sagittal split osteotomy with an immediate mandibular advancement of 14 mm, while another pig underwent distraction osteogenesis consisting of a gradual advancement of 2 mm per day to advance the mandible the same distance. The control animal received no surgery.

In the present study, the mandibular condyles of the three pigs (2 control, 2 bilateral sagittal split osteotomy, and 2 distraction osteogenesis) …

Levels Of Intravenous Enterococcus Faecalis That Cause Heart Colonization, Louis Zane Stromberg

Loma Linda University Electronic Theses, Dissertations & Projects

While previous studies have shown that presence of bacteria in systemic circulation can cause infective endocarditis, there is no information on the specific amount of bacteria necessary to cause this condition. The purpose of this study was to establish the minimum level of circulating bacteria that will cause colonization of damaged heart valves in rats. Fifty-two Sprague-Dawley rats were anesthetized and their heart valves were damaged using an established protocol. A clinical isolate of Enterococcus faecalis was transformed with a plasmid bearing the luxF and Chloramphenicol cassettes to label the bacteria with the light-emitting protein. After four weeks, the rats …

Pain Experienced By Patients Using Thinner Vs. Thicker Probes During Probing, Mohamed A. Hassan

Loma Linda University Electronic Theses, Dissertations & Projects

The aim of the present study, performed during periodontal recall visits, was to compare the levels of pain experienced by patients during periodontal probing using probes with tip diameters of either 0.40 mm or 0.63 mm.

Prior to the maintenance procedures, three groups of 20 adult patients were examined by 3 different therapists. Diagonal maxillary/mandibular quadrants were probed with a 0.40 mm and a 0.63 mm probe, respectively. At the completion of probing of each quadrant, the patients were asked to describe their pain using a Visual Analog Scale (VAS).

The results were as follows: Most patients showed low VAS …

Pain Experienced By Patients During Periodontal Examination, Mohammed A. Al-Ajmi

Loma Linda University Electronic Theses, Dissertations & Projects

The aims of the present study were to determine the level of pain experienced by patients from probing during periodontal examination, and to find out to what extent the examining periodontist and the dental assistant could estimate the degree of pain experienced by the patients.

For each of three periodontists, 20 patients referred for periodontal diagnosis and treatment were selected. The periodontist carried out his examination, which included probing at six sites per tooth. Following probing, the patients rated the pain using a Visual Analog Scale (VAS). The periodontist and the dental assistant who helped out during the examination independently …

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 …

Effect Of Anti-Tgfß1 And Pycnogenol® On Scar Formation In Rats, Pilseong Kim

Loma Linda University Electronic Theses, Dissertations & Projects

Wound healing is a complex biologic process that involves chemotaxis and division of cells, neovascularization, synthesis of extracellular matrix proteins, and remodeling of the repaired tissues. Of equal importance is the restoration of normal tissue structure and function without scar formation. The aim of this study was to find out the clinical effects of anti-TGFß1 and Pycnogenol® on scarless wound healing on rat skin.

An acute incision wound model was used with 20 healthy rats. Four incisions were made on each rat's skin and 4 different variables were applied by local infiltration. The four variables were anti-TGFß1, Pycnogenol®, PBS, and …

Detection Of Bacteria To Dental Tissue By Low-Light Imaging, G-Hong Robert Hsu

Loma Linda University Electronic Theses, Dissertations & Projects

Bacteria have been shown to play an important role in the development of pulp and periradicular disease. The source of the infective bacteria is most often the oral cavity. Previous studies have detected bacteria in teeth that are structurally intact that seemingly have no communication intraorally. Anachoresis has been proposed as a mechanism for localizing circulating bacteria to such teeth. In several previous bacteriologic anachoresis studies, bacteria have been found to localize in inflamed dental tissues. The criticism most commonly associated with these investigations has been the potential contribution of contaminant bacteria resulting in false positive findings.

Low-light image analysis …

Clinical Effectiveness Of A Subperiosteal Anchorage Device, Monica Anne Witte

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this pilot study was to evaluate the clinical efficacy of a subperiosteal anchorage device, the palatal OnPlant™, during orthodontic retraction of protruding anterior teeth in cases requiring maxillary premolar extraction. Seven subjects (5 female, 2 male), ages 13 to 55, were selected for the study. The OnPlant was surgically placed in the mid-palatal region through a well-defined subperiosteal tunnel. Following the manufacturer recommended osseointegration period of four months, the OnPlant was uncovered and attached to the first molars by means of a transpalatal bar. Standard orthodontic treatment then commenced to retract the anterior teeth after the first …

Measured Effects Of Rapid Palatal Expansion On Nasal Cavity Volume Utilizing Cbct, Jon Neal Robinson

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate and predict the expected changes that occur in the nasal cavity volume following rapid palatal expansion. Eighteen subjects (11 female, 7 male), ages 9 to 18, requiring rapid palatal expansion in conjunction with comprehensive orthodontic treatment, were selected for the study. Rapid palatal expansion was accomplished using the standard, banded hyrax appliance. Three-dimensional cone beam computed tomograms using the NewTom 9000™ were acquired before and after expansion. Serial coronal slices of the nasal cavity were made using the QV9000™ software program. The resultant serial images were imported into 3-D Doctor™ for analysis …

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 Histological Effects Of Mandibular Distraction Osteogenesis On Rabbit Condyles, Eunice Jungmin Hong

Loma Linda University Electronic Theses, Dissertations & Projects

The present study is a histological evaluation of condyles taken from rabbits that underwent either a midline or paramedian distraction osteogenesis procedure on the mandibles. Fifteen rabbits were originally operated on and eight of these fifteen successfully made it through both the distraction osteogenesis procedure and the 1 month holding period that followed. There was one control animal.

In the present study, the condyles from these nine rabbits (1 control, 2 midline distraction osteogenesis, 6 paramedian distraction osteogenesis) were prepared for histological evaluation (18 total). Step serial sections were cut along the coronal plane and the sections from the anterior …

Healing Following Placement Of A Subperiosteal Orthodontic Anchoring Device, Oliver Hoffmann

Loma Linda University Electronic Theses, Dissertations & Projects

Background: A method to accomplish orthodontic anchorage using a hydroxyapatite-coated disk that is placed below the periosteum in the mid-palatal area has been developed (OnPlant, Nobel Biocare, Yorba Linda, CA, USA). This report describes the early to 8-month healing events of the first 8 consecutive cases of placement of the OnPlant device at the Advanced Periodontics Clinic at Loma Linda University School of Dentistry. In addition, it presents the results of a questionnaire on how the patients experienced the various procedures. A radiographic analysis of the side of placement of the device was performed.

Methods: At 2 weeks and at …

Dental Treatment Options For Snoring - A Pilot Study, Kainaz Khushrooh Byramjee

Loma Linda University Electronic Theses, Dissertations & Projects

This study compared the effectiveness of an anterior repositioning device, the Silent Nite®, to two new treatments in their ability to stop/reduce snoring. Comfort and side effects of each treatment were also evaluated.

Twenty-three subjects, in good medical condition along with their spouse/partner participated in the five-week study. A disposable sleep apnea screener, SleepStrip,™ was used to select only non-sleep apnea patients. The treatments tested were: (1) Silent Nite® (control - Treatment A), (2) Loma Linda Appliance (Treatment B), and (3) Snore Tape (Treatment C). Each participant received all three treatments separated by a one week "wash-out" period of no …

Effects Of Various Hemostatic Agents On Bone, David Daryl Roland

Loma Linda University Electronic Theses, Dissertations & Projects

Previous studies have evaluated the effects of various hemostatic agents on radicular tissues following apical surgery. The purpose of this study was to examine the early osseous responses to seven hemostatic agents under identical conditions in rabbits. Sixteen adult male New Zealand white rabbits were used for this study. Following anesthesia, utilizing a midline submandibular incision, standardized bony defects were prepared on the lateral-superior regions of the mandible. Test materials were placed using standardized volumes and exposure times. Bone wax, Surgicel, Capset, alginate, Cut-Trol, Hemogin-L, and silver nitrate were compared to control sites irrigated with saline. Test materials or controls …

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 …

Assessment Of Alveolar Bone Density Using Implant Insertion Resistance Torque, Scott Sangmoo Lee

Loma Linda University Electronic Theses, Dissertations & Projects

Background: Implant stability during healing is a pre-requisite for successful osseointegration. In the case of early or immediate implant loading, it is necessary to achieve high level of stabilization during surgical placement. Fixture stabilization can be measured by resonance frequency analysis or implant insertion resistance torque measurement. The aim of this study is to correlate pre-operative radiographic bone density to implant insertion resistance torque in human cadaver jaw bone.

Materials & Methods: Sixty-four implant osteotomy sites in human cadaver jaw bones were previously examined radiographically using quantitative computed tomography (QCT) and quantitative cone-beam computed tomography (QCBCT). Forty-two implant insertion sites …

Synovial Fluid Hydrostatic Pressure In The Tmj After Mandibular Advancement In Sus Scrofa, Samuel A. Demirdji

Loma Linda University Electronic Theses, Dissertations & Projects

Mandibular advancement is performed in patients routinely by traditional bilateral sagittal split osteotomy (BSSO) or less commonly by distraction osteogenesis (DO). The influence of mandibular advancement on the temporomandibular joint (TMJ) is well recognized but not fully explored. This study involved the direct measurement of synovial fluid hydrostatic pressure (SFHP) in the TMJ after mandibular advancement by either BSSO or DO in two male mature minipigs, Sus scrofa. Titanium pressure transducers were inserted into the right superior temporomandibular joint spaces of the minipigs and the measurements were displayed on an AC/DC amplifier. The first minipig underwent BSSO, which involved immediate …

Quantification Of Bone Deposition In Onlay Bone Grafting, Gregory Alan Kammeyer

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to quantitatively evaluate; 1) mandibular posterior mono-cortical block onlay bone graft success rates 2) the amount of grafted bone retained after initial resorption in radiographic projections. Seven consecutive patients with 14 mandibular posterior implant sites requiring bone augmentation for implants of a standard 3.8mm x 10mm dimension were sought. Mono-cortical block bone grafts from the ipsilateral ascending ramus were placed then observed with two standardized CT scans, dividing them into two groups: Group A had the first CT at 4 weeks after graft placement and a second taken before Prosthodontic reconstruction, 36.7 weeks later. …

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. …

Ultrasonic Removal Of Bacteria From Plated Cells, Cecilia Chi-Pei Kao

Loma Linda University Electronic Theses, Dissertations & Projects

Children often present with dental trauma to pediatric emergency departments and pediatric dental offices. There is a wide spectrum of types of dental trauma. Although research has been done concerning the treatment of avulsed teeth, the current recommendations in the published guidelines might still be improved for better long term prognoses. One may speculate that ultrasonification of an avulsed tooth prior to replantation may dislodge existing surface bacteria and improve the prognosis for the tooth. This was as an in vitro study to test this concept. Epithelial cells were grown in 6-well tissue culture plates. Standardized amounts of Staphylococcus aureus …

The Effect Of Ultrasonics On Fibroblast Cells, Sheila A. Harris

Loma Linda University Electronic Theses, Dissertations & Projects

The field of dentistry uses the debriding properties of ultrasonic vibration. It is unknown if this property is detrimental to the periodontal ligament (PDL) of an avulsed tooth. This information is important when a clinician is faced with a debris-covered avulsed tooth following a traumatic event. The purpose of this study was to determine the effect that ultrasonic vibration has on those PDL cells most numerous and most vital to a successful tooth replantation, namely, the fibroblasts.

Several fibroblast cell sources were exposed to varying ultrasonic times. These included a commercially available cell line of human foreskin fibroblast (HFF), a …