Dentistry Commons^™

Effect Of A Two Piece Scalloped Implant Design On Interproximal Bone Apposition/Retention - A Pilot Study In Rabbits, Aladdin Jamal Al-Ardah

Loma Linda University Electronic Theses, Dissertations & Projects

The aim of the study was to evaluate the effect of an experimental two piece scalloped implant design with a scalloped elliptical coronal part and an HA surface treatment on the bone to implant contact percentage in comparison to a commercially available HA treated implant. The possibility of bone apposition / retention along the exposed coronal scalloped part and the effect of the presence of a junction on the bone to implant contact percentage and bone apposition / retention were analyzed. 10 rabbits were included in the study with each rabbit receiving one control implant in one tibia and one …

Factors Influencing Contrast Resolution Of Cone Beam Ct Using The Cb Mercuray, Roger M. Anderson

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Cone Beam Computed Tomography (CBCT) has an application in all dental specialties. CBCT is an aid in implant dentistry to evaluate anatomical landmarks in both quality and quantity. Hounsfield Unit (HU) values represent a grayscale that is standardized on CT machines relative to the density of water and air. It has been reported that the HU value represents an actual value of the bone density. However, recent studies at Loma Linda University have suggested that HU values retrieved using CBCT machines may be altered by various factors.

Purpose: The aim of this study is to evaluate the specific dosage …

Short-Term Clinical Evaluation Of Nobelreplace® Tapered Groovy Implant, Manouchehr Pouresmail

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this clinical investigation was to make comparisons and to achieve estimates of the short-term implant success, marginal bone resorption, and soft tissue responses around the immediately loaded NobelReplace® Tapered groovy implant (with groove on a rough collar portion) as compared to an implant without a groove on the collar (Replace®Select Tapered). This was a randomized controlled and prospective investigation in which subjects were consecutively included according to strict inclusion/exclusion criteria. Single stage procedure was used with immediate function. Seventeen subjects were recruited, and were randomly divided in two groups. Each group was received the predetermined type of …

Comparison Of Mandibular Alveolar Bone With Facial Type Using Cbct, Jason M. Loop

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate the relationship between facial type and cortical bone thickness (mm), cortical bone density (rHU) and trabecular bone density (rHU) in the mandibular alveolar bone. Twenty-five consecutive dolichofacial, 25 consecutive mesiofacial, and 25 consecutive brachyfacial patients with T1 lateral cephalograms and CBCT scans were used in this study. A Ricketts analysis was used to compute the VERT index for each patient. All statistical analyses were performed at the significance level of α = 0.05. The one-way ANOVA and LSD post hoc tests indicated there was a statistically significant relationship between facial type and …

Buccal Bone Changes Following Rapid Maxillary Expansion (Rmf), Long-Term Results, Elena S. Iacob

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to use Cone Beam Computed Tomography (CBCT) images to quantitatively evaluate buccal bone changes of maxillary first premolar (P1), second premolar (P2) and first molar (M1) shortly after Rapid Maxillary Expansion (RME) and at the end of orthodontic treatment, as well as to evaluate the variables that may be associated with the short-term and long-term changes. Forty-seven consecutive patients (25 males and 22 females) with a mean age of 14.5years and who required RME as part of their orthodontic treatment and had pre-RME (T1) and post-RME (T2) CBCT images available were used for the …

Cephalometric Analysis Using Magnetic Resonance Imaging, Wade A. Williams

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The purpose of this study was to determine if T1-weighted 3D magnetic resonance images performed at 3.0 Tesla could be used to conduct routine orthodontic cephalometric analysis.

Methods: Three cranial imaging methods were compared using sixteen non-growing subjects (10 male and 6 female) who were not claustrophobic, did not have any metallic restorations on the distal of first molars, had no medical implants and the female subjects were not pregnant. Sagittal cranial images were produced by three methods: (1) a digital lateral cephalometric (LC) radiograph (Orthophos XG Plus, Sirona^TM, Bensheim, Germany), (2) a 12-inch FOV cone beam …

Characterization Of Rhbmp-2 Induced Heterotopic Bone Subjected To Distraction Osteogenesis, Anne J. Yoon

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to characterize and analyze the heterotopic bone regenerate which formed following implantation of recombinant human bone morphogenetic protein-2 (rhBMP-2) and to determine by epi-illumination, x-ray photometry and histology, if there is increased and sustained osteogenic potential present with distraction osteogenesis of this heterotopic bone. While many previous studies have documented the osteogenic potential of BMP-2, no study to date has shown the results of application of force on this ectopic bone. Our study included three control rats (non-expansion) and six experimental rats (expansion). Of the control rats, #76 (a pilot study rat) had already …

Orthodontic Mini-Implant Failure: Assessing The Relationship To Bone Quality Using Qcbct, Joshua Schneider

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate the cortical bone thickness (mm), cortical bone density (HU), and trabecular bone density (HU) of mini-implants sites in both the maxilla and mandible using QCBCT to determine if they had any effect on mini-implant failure rate. Patient characteristics (age, gender, facial type), mini-implant characteristics (date of placement, manufacturer, length, and diameter), and the mini-implant site (region) were also evaluated. One hundred and six mini-implants in 50 consecutive patients with complete patient records, CBCT information, and T1 radiographs were included in the study. Thirty-four of the 106 mini-implants were considered "failures" resulting in …

An In-Vitro Investigation Of The Physical Properties Of Alginate Alternatives, Rishi Dinesh Patel

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate the detail reproduction, gypsum compatibility and linear dimensional change of three recently introduced irreversible hydrocolloid (alginate) alternatives. The materials that were tested are Position Penta Quick® (3M ESPE™), Silgimix® (Sultan Dental) and Alginot® (Kerr™). These materials were tested in accordance with ANSI/ADA Specification No. 18 for Alginate Impression Materials and No. 19 for Dental Elastomeric Impression materials. The irreversible hydrocolloid impression material Jeltrate Plus antimicrobial® (Dentsply Caulk™) served as the control.

MATERIALS AND METHODS: The ADA specification die was used to undertake the testing of the new materials. The parameters of detail …

The Comparative Radiopacity Between Primary And Permanent Teeth, Robert C. Lee

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: This in vitro study compared the radiopacity between human primary and permanent enamel and dentin. It also compared the radiopacity between human anterior and posterior teeth.

Methods: Extracted primary and permanent teeth were used in this study. One mm enamel and one mm dentin slices were cut from each extracted tooth. Radiographs were taken of each enamel and dentin specimen 1 mm in thickness along with an aluminum step-wedge using procedures specified in International Standards Organization (ISO) 4049:2000. A densitometer was used to measure the Optical Density (OD) of the radiographs of the specimen and the accompanying aluminum step-wedge. …

Recognizing A Dysfunctional Swallowing Pattern Using Surface Electromyography (Semg), Michelle F. Couto

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The purpose of this study was to determine if a surface electromyography (sEMG) assessment of swallowing is better at identifying Oral Muscular Dysfunction (OMD) than a clinical evaluation (observation & digital palpation) of swallowing. The assessment was conducted on children ages 9 to 17, who were patients at the Orthodontic Department at Loma Linda University, School of Dentistry. Additionally, the prevalence of a “perceived” swallowing dysfunction was assessed.

Methods: This study included 39 randomly selected subjects from the orthodontic patients at Loma Linda University. Each subject’s “dry” swallow was evaluated using two separate methods: (a) sEMG and (b) digital …

Comparison Of Microleakage In Three Sealant Placement Protocols Vs. The Enamel Loc System, Audrey T. Sheu

Loma Linda University Electronic Theses, Dissertations & Projects

PURPOSE: To evaluate sealant microleakage using four different application techniques.

METHODS: The four application techniques evaluated were acid etch only, Adper L-Pop bonding, Optibond bonding, and Enamel Loc One-Step Sealant. Sixty-four extracted third molar teeth were assigned on one of four application techniques (n=16) and Clinpro sealants applied according to the manufacturer's instructions. The teeth were thermocycled for 500 cycles, dyed, and embedded in resin. The samples were then sectioned and evaluated for microleakage on the buccal and lingual surfaces. Statistical methods employed to analyze the data were the Kruskal-Willis rank test and the Mann-Whitney U test.

RESULTS: No significant …

Immediate Provionalization Of Single Threaded Oxidized Implants On Maxillary Premolars Healed Sites: One-Year Study, Kiyotaka Umezu

Loma Linda University Electronic Theses, Dissertations & Projects

Osseointegrated endosseous implants have been widely used and become a predictable treatment option for completely and partially edentulous patients. The viability and predictability of this treatment modality have been supported with the high success rates in numerous studies. Clinical guideline requires a healing period of 3 to 6 months without functional loading to achieve osseointegration with machine surface implants. Therefore, numerous studies on immediately loaded implants have been conducted in an attempt to minimize or eliminate this healing period. The purpose of this study was to evaluate the success rate of the immediately provisionalized oxidized-surface implants in healed sites supporting …

Immediate Provisionalization Of Single 3.0 Mm Diameter Implant In Maxillary And Mandibular Anterior Region, Kotaro Oyama

Loma Linda University Electronic Theses, Dissertations & Projects

Immediate provisionalization of single implants with standard (3.75 - 4.5 mm) and wide diameter (> 4.5 mm) has been well documented. When the space is limited, small diameter implants (3.0 mm) must be used. Although high success rates have been reported, they were limited to healed site and were placed as staged procedures. The purpose of this prospective study was to evaluate the success rate and peri-implant tissue response of small diameter (3.0 mm) implants undergoing immediate provisionalization in the esthetic area.

Eleven patients who had missing maxillary lateral incisor(s) and/or mandibular incisor(s) participated in this study. Thirteen 3.0 mm …

Effect Of Short Exposure Of Naoci/Edta On E. Faecalis In Extracted Human Teeth, Rylan N. Gustafson

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this project was to study the antibacterial effect of the short exposure of 5.25% NaOCl and 17% EDTA on eight strains of Enterococcus faecalis in extracted human teeth. The crowns of 240 single rooted teeth were removed and the canals were instrumented to ISO 0.36. The canals were irrigated with 5.25% NaOCl and 17% EDTA, autoclaved and separated into eight groups of 30 teeth consisting of 20 experimental teeth, 5 positive and 5 negative controls. Each group was inoculated with one of eight different strains of E. faecalis in BHl broth and incubated for four weeks. The …

Effect Of Gutta Percha On The Retention Of A Post Using Different Cements, Saeda H. Basta

Loma Linda University Electronic Theses, Dissertations & Projects

This study evaluated the effect of residual gutta percha on the retention strength of prefabricated post cemented with four different cements. Forty intact mandibular single canal canines or premolars were selected for standardized size and quality, endodontically treated, and decoronated to the cementoenamel junction. A post space was prepared to accommodate Para post XP size 4 (Coltene, Whaledent Inc., Cuy Falls, Ohio) to a depth of 8 mm. The Obtura heated gutta percha system was used to inject a very thin line of gutta percha along one lateral wall to the depth of the future post. Forty obturated teeth were …

Veneer Failure On Preveneered Primary Posterior Stainless Steel Crowns, Matthew H. Gustafsson

Loma Linda University Electronic Theses, Dissertations & Projects

PURPOSE: The purpose of this study was to determine the amount of force required to fracture or dislodge the veneered facings from three veneered lower primary molar stainless steel crowns (SSC) and to characterize the veneer failures.

METHODS: The following veneered crowns were used in this study: NuSmile crowns, Kinder Krowns, and EC crowns. Twenty lower right primary first molar crowns were used from each manufacturer, for a total of 60 crowns. All crowns were cemented with glass ionomer cement to a custom fabricated die. Twenty-four hours following cementation, each die with the cemented crown was placed into a custom …

Precision Of Temporary Anchorage Device Placement With 2d Vs. 3d Diagnostic Tools And Surgical Guides, Howard Lee

Loma Linda University Electronic Theses, Dissertations & Projects

Current methods of temporary anchorage device (TAD) planning and placement are performed by radiographic analysis in a two-dimensional plane that lends itself to inaccuracy secondary to variations in the angle from which the radiograph is taken, as well as the magnification of the radiographic image, resulting in an increased likelihood of placement errors. The purpose of this study was to compare a three-dimensional (3D) TAD planning and placement technique to a traditional two-dimensional (2D) technique. In the 2D group, periapical radiographs and pre-fabricated wire guides were used for planning and placement of TADs on five plastic models. For the 3D …

Influence Of Mandibular Fixed Retainers On Diagnostic Quality Of Cranial Mri, Norman E. Carter

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate the diagnostic quality of MR images taken on subjects with different types of orthodontic lingual retainers in place. The study provides guidelines and recommendations for use of lingual retainer materials in those patients who are or may potentially undergo routine magnetic resonance imaging. Ten subjects had impressions taken and models made for retainer tray fabrication. Removable trays with each lingual retainer material incorporated in them were fabricated from the models. Subjects underwent scans with each of the five test trays in place. T1 sagittal (T1), T2 axial (T2), gradient echo (GRE), and …

Immediate Implant Placement In Extraction Sites With Periapical Lesions: A Retrospective Study, Yuan-Lung Hung

Loma Linda University Electronic Theses, Dissertations & Projects

Immediate implant placement into fresh extraction sites has become a relatively routine clinical procedure with a favorable prognosis. However, immediate placement into extraction sockets with lesions has not been extensively documented in humans. Therefore, the purpose of this study was to retrospectively determine the survival rate of implants placed into extraction sockets with visible periapical lesions.

Patient charts of 544 immediately placed implants from Loma Linda University School of Dentistry, Center for Prosthodontics and Implant Dentistry were examined. Eighty-six of the 544 implants had been placed immediately into extraction sockets with periapical lesions and they were included in this study. …

Distraction Of Heterotopic Bone Formed With Bmp-2 In A Rat Model: The Technique, Stacie Dawn Fenderson

Loma Linda University Electronic Theses, Dissertations & Projects

Multiple studies have shown that ectopic bone forms when bone morphogenic proteins (for example BMP-2 and BMP-7) and a collagen matrix are surgically placed in a rat model either orthotopically or heterotopically. Bone begins to form by the 14 day, and is at it maximum calcified state by the 21st day. The purpose of this study is to observe and quantify the effect of distraction osteogenesis on the ectopic bone. First, a preliminary procedure was performed by surgically placing a titanium cage into the back of a rat just caudal to the thoracic vertebrae. The anterior corners were sutured to …

The Effects Of The Quadhelix Appliance On The Dentition And Adjacent Buccal Bone, Shannon Hilgers

Loma Linda University Electronic Theses, Dissertations & Projects

Maxillary palatal expansion has long been used in orthodontics as a means of correcting constricted and collapsed dental arches. The quadhelix appliance, developed by Drs. Robert Ricketts and Ruel Bench, expands buccal segments and causes distobuccal rotation in upper first molars. The objective of this study was to assess the direct effects that the quadhelix appliance on the surrounding dentition and buccal bone in the maxillary premolar and molar areas in a finite, measurable manner. This assessment was made using the NewTom 3G. The pre-quadhelix and post-quadhelix NewTom 3G images of twenty patients treated in the Graduate Orthodontic Clinic at …

The Skeletal Effects To The Maxilla After Rapid Maxillary Expansion Using Cbct, Brett J. Garrett

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to use cone beam computed tomography (CBCT) to quantitatively evaluate and compare skeletal expansion and alveolar tipping of the maxilla at the maxillary canine (Cl), first premolar (PI), second premolar (P2) and first molar (Ml) after rapid maxillary expansion (RME). Transverse effects to the maxillary suture, nasal width and maxillary sinus were also assessed. Included in the study were thirty consecutive patients (17 males and 13 females; mean age = 13.8 + 1.7 years) requiring RME using Hyrax appliances as part of their comprehensive orthodontic treatment. The pre-RME and post-RME measurements of palatal and …

Detection Of Simulated Apical Root Resorption Using Three Cone Beam Ct Machines, Marcus Paulson

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine orthodontists' ability to discriminate small differences of simulated apical root resorption (SARR) on extracted teeth, using the output from three cone beam computed tomography (CBCT) machines. Twenty-four unrestored maxillary anterior teeth exhibiting normal morphology, were collected. The teeth were scanned by three CBCT machines: 1) the NewTom 3G (AFP imaging, USA), 2) the iCAT (Imaging Sciences, USA) 3) and the MicroCAT II (Siemens Medical, USA). Using a sandblaster the apical portion of each tooth was reduced in 0.5 mm increments up to a total reduction of 1.5 mm. Each root modification was …

The Effect Of Mtad On Eight Strains Of E. Faecalis In Contaminated Root Canals, Bradley M. Newberry

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this investigation was to determine the antimicrobial effect of Biopure MTAD (a mixture of a tetracycline isomer, an acid, and a detergent) as a final irrigant on eight strains of Enterococcus faecalis (E. faecalis) in contaminated root canals of extracted human teeth. In addition, the Minimum Inhibitory Concentration (MIC) and Minimum Lethal Concentration (MLC) of MTAD were also measured on the same strains of bacteria. Two-hundred and forty extracted human teeth were instrumented using 1.3% NaOCl followed by 17% EDTA to remove the smear layer. The teeth were randomly contaminated with one of eight strains of E. …

Salivary Characteristics In 3 And 4 Year-Old Children With And Without Visible Caries, Gloria Yañez

Loma Linda University Electronic Theses, Dissertations & Projects

PURPOSE: To compare salivary characteristics in 3 and 4 year-old Head Start children with and without visible caries.

METHODS: This case-control study was performed on 84 healthy 3 and 4 year-old Head Start children. After consent and inclusion criteria were met, each child was screened and assigned to one of two test groups based on their caries status. Group 1 consisted of children with no visible evidence of caries, although non-visible caries may have been present. Group II consisted of children with visible evidence demonstrating three or more carious lesions. Each child's unstimulated and stimulated whole saliva samples were collected …

Comparison Of Laser And Phosphoric Acid Etching On Sealant Shear Bond Strength, Seth David Latimer

Loma Linda University Electronic Theses, Dissertations & Projects

PURPOSE: To compare the effect of traditional phosphoric acid etching with Er,Cr:YSGG laser enamel etching on the shear bond strength of sealant material.

METHODS: Extracted healthy third molars were mounted in acrylic exposing the flattest surface available. Three groups of twenty teeth were used to evaluate traditional acid etching with 37% phosphoric acid as a control group as well as two different laser settings. The sealant material was attached using specialized jigs and then subjected to shear bond strength testing utilizing the ultradent method (MTS machine). Statistical methods employed were the Kruskal-Wallis rank test and the Mann-Whitney U test.

RESULTS: …

A Microleakage Study Of Cements With Stainless Steel Crowns, Heidi Joy Apuy

Loma Linda University Electronic Theses, Dissertations & Projects

PURPOSE: To compare the ability of newer adhesive resin cements and traditional glass ionomer cements to prevent microleakage under stainless steel crowns on extracted permanent third molars.

METHODS: All teeth were hand prepared and stainless steel crowns were cemented according to manufacturers' instructions. The specimens were thermocycled for 500 cycles and immersed in 2% methylene blue dye solution for 8 hours. Each tooth was imbedded in resin and cut into I mm thick sections by a slow speed diamond saw. The amount of microleakage was measured in microns under a traveling microscope. The measurements of each section of a tooth …

Effect Of Polishing Brushes On Dental Composite Resins, Robert Shun-I Wang

Loma Linda University Electronic Theses, Dissertations & Projects

PURPOSE: The effectiveness of many commercially available composite finishing and polishing devices have been studied and compared. However, no studies have directly compared the effectiveness among the polishing brushes. This study set out to (1) investigate the surface roughness reduction and gloss value increase of two universal dental composites polished by three polishing brushes and two well-studied finishing and polishing systems, and (2) to evaluate resulting surface morphology using scanning electron microscopy (SEM).

METHODS: 10 specimens were fabricated for each of five polishing groups for both composite resins, one microhybrid (Herculite XRV) and one nanofilled composite (Filtek Supreme Plus). Each …

Reproducibility Of Two Non-Consecutive Scans Using A Newtom 3g; In Vitro Model, Hyoung Jin Park

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The aim of this study was to evaluate the reproducibility of mineral density measurement expressed in Hounsfield Units (HU) using a phantom device with known mineral densities and the NewTom 3G Cone Beam Computerized Tomography (CBCT).

Materials and Methods: A phantom device made of 21 HA cylindrical disks with known densities was fabricated. The phantom was scanned in 6, 9, and 12 inch fields of view using a NewTom 3G CBCT. The scans were repeated at non-consecutive sessions. Volumetric data in each of the scans were formatted to DICOM images. HU values of the regions of interest were retrieved …