Dentistry Commons^™

7th Annual Pacific Research Day Abstracts, University Of The Pacific

Excellence Day

No abstract provided.

Etiology Of Oral Disease In View Of Microbial Complexity, Anne C. R. Tanner, Jacques Izard

Department of Food Science and Technology: Faculty Publications

The number of different microorganisms recognized in the oral cavity using molecular methods has more than doubled compared with the number isolated using cultural techniques. This finding necessitates a reevaluation of which species may be pathogens in dental infections. Molecular methods used to determine microbial diversity include broad range target Polymerase Chain Reaction with ‘universal primers,’ and cloning amplicons or denaturing gradient gel electrophoresis to separate DNA fragments before sequencing. These molecular methods have clarified and expanded the taxonomy of oral microbial species. Discrepancies between comprehensive molecular and cultural methods suggest that neither method alone can adequately evaluate associations of …

Periplasm Organization In Treponema Denticola As Studied By Cryo-Electron Tomography, Jacques Izard, C.-E. Hsieh, C. A. Mannella, Ronald J. Limberger, M. Marko

Department of Food Science and Technology: Faculty Publications

As a spirochete, the genus Treponema is one of the few major bacterial groups whose natural phylogenic relationships are evident at the level of gross phenotypic characteristics such as their morphology. Treponema spp. are highly invasive due to their unique motility in dense media, and their ability to penetrate cell layers. This feature is associated with the helical cell body and the presence of flagellar filaments in the periplasm. Treponema denticola is an oral pathogen involved in endodontic infections and periodontal diseases. The presence and quantity of T. denticola in the subgingival biofilm is correlated with the severity of periodontal …

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 …

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 …

Inside Unlv, Cate Weeks, Carol C. Harter, Diane Russell, Holly Ivy De Vore

Inside UNLV

No abstract provided.

6th Annual Pacific Research Day Abstracts, University Of The Pacific

Excellence Day

No abstract provided.

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 …

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 …

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 …

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 …

5th Annual Pacific Research Day Abstracts, University Of The Pacific

Excellence Day

No abstract provided.

Distraction Osteogenesis In Edentulous Alveolar Bone With Rhbmp-2 Enhancement, Liviu F. Eftimie

Loma Linda University Electronic Theses, Dissertations & Projects

Distraction osteogenesis, a unique system of affecting rapid bone healing in fractures, realigning malformed bones, and lengthening congenitally short and traumatically shortened bones has become an increasingly utilized technique for the maxillofacial region. The use of distraction osteogenesis has been described for increasing the height of edentulous mandibular alveolar ridges while concurrently forming new bone within the ridge to allow for adequate reconstruction. A standard protocol for performing distraction osteogenesis in the maxillofacial region has been well documented in the literature. Standard distraction osteogenesis requires an initial surgery to place the distraction osteogenesis device and mobilize the segment to be …

Linder-Aronson S Analysis Using Rhinomanometry And Newtom, Noel Moser

Loma Linda University Electronic Theses, Dissertations & Projects

Investigations into the effects of airway patency on craniofacial development are essential to ensure that interceptive orthodontic treatment provides the maximum benefit to the patient. The aims of this study were to (1) compare the size of the nasopharyngeal airway space on lateral cephalometric and 3D volumetric radiographs to determine if volumetric scans can be of greater diagnostic value than a lateral cephalometric film in determining the degree of airway blockage or patency and (2) to examine the correlation between functional airway resistance, as evaluated by rhinomanometry, and radiographic constriction due to nasal turbinate and adenoid size.

Twenty-eight subjects from …

Il-10 And Alveolar Bone Loss, Abdulaziz Saud Al-Rasheed

Loma Linda University Electronic Theses, Dissertations & Projects

Interleukin-10 (IL-10) is a cytokine with anti-inflammatory activities. IL-10 knockout (KO) mice exhibit severe intestinal inflammation in the presence of normal gut flora. We hypothesized that IL-10 KO mice would also be susceptible to inflammatory periodontal disease resulting in alveolar bone loss (ABL). The purpose of this study was to compare naturally occurring ABL in IL-10 KO and wild type (WT) mice. Twelve IL-10 KO and 12 WT mice, age-(7 months) and sex-(male) matched, were used. Half of the mice were on 129/SvEv and half on C57BL/6J background. Animal heads were defleshed and treated to remove all organic material. ABL …

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

Loma Linda University Electronic Theses, Dissertations & Projects

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

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

Loma Linda University Electronic Theses, Dissertations & Projects

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

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

4th Annual Pacific Research Day Abstracts, University Of The Pacific

Excellence Day

No abstract provided.

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

Loma Linda University Electronic Theses, Dissertations & Projects

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

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

Development Of A Model For Infective Endocarditis Via Intravenous Injection And Tooth Infection Of Rats Using Pathogenic Bacteria, Shahrokh Shabahang

Loma Linda University Electronic Theses, Dissertations & Projects

Historically, focal areas of infection have been linked to a number of systemic ailments. During the early part of the 20th century, patients who were suffering from inexplicable diseases and who were suspected of having infected teeth were referred to the dentist for multiple extraction of their dentition. The discovery of antibiotics provided a false sense of security that the war against microorganisms is no longer a concern for mankind. However, more recently, it has become common belief that increasing numbers of systemic diseases are linked to chronic infections. Recovery of bacteria from representative tissues has led investigators to believe …

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

Loma Linda University Electronic Theses, Dissertations & Projects

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

Optimum Bonding Time Of Four Different Curing Lights, Nathan Don Cotten

Loma Linda University Electronic Theses, Dissertations & Projects

With the development of new high-intensity curing lights, the time required to bond orthodontic brackets is steadily decreasing. The objective of this study was to determine the optimum curing time for bonding orthodontic brackets using four different visible curing lights (Standard Optilux 501, High Intensity Optilux 501 with Turbo Tip, Virtuoso Plasma Arc, and ESPE LED light). This study also tested the new generation of light emitting diode (LED) lights to determine if they can be used for bonding orthodontic brackets. Three hundred freshly extracted bovine teeth were mounted in acrylic resin and divided into 20 groups of 15 teeth …

3rd Annual Pacific Research Day Abstracts, University Of The Pacific

Excellence Day

No abstract provided.

Looking Back At Fluoridation, Allan Mazur

RISK: Health, Safety & Environment (1990-2002)

The author reviews the 50-year history of the debate over fluoridating drinking water as a public health measure.