Dentistry Commons^™

Healing Following Periodontal Reconstructive Surgery : Surgical Implantation Of A Collagen Matrix Or Demineralized Freeze-Dried Bone Allograft, Seong Yong Choi

Loma Linda University Electronic Theses, Dissertations & Projects

Healing following periodontal reconstructive surgery including surgical implantation of a collagen matrix or demineralized freeze-dried bone allograft (DFDBA) was evaluated in a preclinical (collagen) and a clinical (DFDB A) study.

Contralateral periodontal fenestration defects in 7 beagle dogs were used to evaluate the effect of a collagen matrix on periodontal healing. The defects (6x4 mm) were created through the buccal cortical plates of the maxillary canine teeth following elevation of mucoperiosteal flaps. The collagen was fitted to the defects on one side, while contralateral defects served as controls. Raps were repositioned and sutured. Dogs were sacrificed 4 weeks after surgery …

Long-Term Posttreatment Upper Incisor Inclination : Relative To Facial Axis Angulation As A Measure For Incisor Placement, David Lawrence Sparks

Loma Linda University Electronic Theses, Dissertations & Projects

This study was designed to determine whether upper central incisor inclination approximated the facial axis, long-term, posttreatment, regardless of the initial malocclusion or immediate posttreatment incisor inclination. Lateral head films at pretreatment, immediate posttreatment and long-term posttreatment were traced and evaluated. The sample was divided into facial type. Angle classification and treatment type (extraction vs. non-extraction). Statistical analyses included means, standard deviations, confidence intervals, population t tests and chi-square tabulations.

The results revealed that the upper central incisor did not approximate the facial axis after a minimum of 7 years posttreatment. This failed to support the use of the facial …

Measurement Of Blood Flow In Reflected Muco-Gingival Tissue Flaps In Cats : Using The Radiolabeled Microsphere Method, Gary T. Wuchenrich

Loma Linda University Electronic Theses, Dissertations & Projects

Blood flow to the maxilla and mandible may vary due to differences in vascular supply and in physiologic, metabolic and pathologic conditions. In general it is accepted that oral tissues have an abundant blood supply; however, there is little information quantifying blood flow to these regions. In this study, the maxillary tissues were chosen to measure the blood flow in attached and reflected gingival tissue in adult cats using the radiolabeled microsphere method.

Sixteen cats with permanent dentition, clean mouths, and without inflamed gingiva upon visual inspection were used and divided into two groups. Group 1 consisted of six cats …

An In Vitro Quantitative Evaluation And Comparison Of A Custom And A Popular Stock Orthodontic Appliance, Richard Scott Anderw Schalo

Loma Linda University Electronic Theses, Dissertations & Projects

An in vitro performance evaluation and comparison of a patient individualized appliance (Elan, Ormco Corporation, Glendora, California) and a Roth prescription appliance ("A"- Company, San Diego, California) was made using the Ideal Tooth Relationship Index (ITRI).

The sample consisted of 19 duplicated sets of models for a total sample of 38. For each pair of models one set was bonded with an Elan appliance and a duplicated set was bonded with a Roth appliance. Bracket placement followed the manufacturers recommendations. The bracketed teeth from these models were sectioned out individually and the appliances allowed to fully express themselves on full …

Load Deformation Test Of Mini Twin Metal Brackets : A Comparative Study, Karl D. Peach

Loma Linda University Electronic Theses, Dissertations & Projects

The trend toward more esthetic brackets has led to smaller brackets being used by orthodontists. The purpose of this study was to determine the force required to deform these smaller brackets and calculate the stress in the metal by using a torsional wire bending force. Ten types of brackets were tested and the results analyzed to determine how bracket geometry, manufacturing method, or material selection affected the strength of brackets. Results showed a significant difference between manufacturing methods, material used, and bracket geometry. Brackets made of 17-4 PH SS and 303 SS withstood higher stress than 316 SS, and all …

Periodontal Repair In Dogs : Part I : Evaluation Of The Natural Disease Model ; Part Ii : Eptfe Barrier Membranes Support Wound Stabilization And Enhance Bone Regeneration, James Marc Haney

Loma Linda University Electronic Theses, Dissertations & Projects

Animal models are frequently consulted for histometric analysis of reconstructive periodontal therapy. Statistical analysis of induced lesion defects and surgically created defects from our laboratory suggest defect size homogeneity is critical for the model to discriminate treatment effects. This study characterizes natural disease defects in beagle dogs. Buccal-lingual histologic sections from the 2nd, 3rd, and 4th mandibular premolar teeth (P2, P3, P4) from 6 aged beagle dogs with natural disease defects were evaluated for variation in defect height between pair matched tooth types, and jaw quadrants, as well as estimated confidence intervals for treatment differences between left and right pair …

An Assessment Of Three Different Forms Of Sterlization And Clinical Usage On Various Orthodontic Pin And Ligature Cutters : A Pilot Study, Warren L. Creed

Loma Linda University Electronic Theses, Dissertations & Projects

With an awareness of cross infection in dentistry and of AIDS (acquired immune deficiency syndrome), sterilization in the dental office has been brought to the public's attention by the news media. Much work has been done on which sterilization methods are acceptable but little has been written about the effects of sterilization procedures on the instruments themselves. In this study, 36 pin and ligature cutters were sterilized 250 cycles using three different methods of sterilization following the guidelines given by the Center for Disease Control (CDC). The cutters were examined for changes in lateral hinge movement, visual appearance and ordinal …

Identification Of Risk Factors Associated With Pulpal Disease, Shelley R. Aronson

Loma Linda University Electronic Theses, Dissertations & Projects

A few studies have identified etiologic factors in pulpal disease, but little is known about the odds ratios of factors associated with pulpal disease. Odds ratios are well established measures of the effects of exposure to a particular outcome, and are comparisons of exposure to non-exposure in cases versus controls. The purpose of this study was to compare exposure of individual teeth to hypothesized risk factors in endodontic cases and in controls. This case-control study consisted of a chart review of 301 endodontic cases and 301 controls. Caries, types of restorations, and periodontal disease were the most significant factors. With …

Reproducibility Of Periodontal Probing, Su-Fang Wang

Loma Linda University Electronic Theses, Dissertations & Projects

This study evaluated reproducibility of periodontal probing by conventional manual and automated force-controlled electronic probes. A total of 1206 sites (6 sites per tooth including maxillary and mandibular incisor/canine, premolar, and molar sites) in 15 patients with history of moderate or advanced chronic periodontal disease were examined. Probings included probing pocket depths (PD), as well as probing attachment levels (PAL) from a reference stent. Measurements were recorded to the nearest 0.5 mm with both methods. Patients were examined twice, 7 to 10 days apart. At each visit, all sites were probed first with the conventional probe and then with the …

Interleukin 1-Beta In Symptomatic And Asymptomatic Human Periradicular Lesions, Gerald C. Lim

Loma Linda University Electronic Theses, Dissertations & Projects

Interleukin 1-Beta has been shown to be a potent mediator of bone resorption and has been implicated in resorption in periradicular lesions. In this study we compared the local concentrations of IL-1β in symptomatic and asymptomatic human periradicular lesions. Periradicular tissues from patients with symptomatic and asymptomatic lesions were obtained and stored at -70°C. Pulpal tissues from unerupted third molars and chronically inflamed gingival tissues were also obtained and used as negative and positive controls, respectively. Tissue samples were homogenized, and supernatants were assayed for IL-1β by ELISA. Significantly higher levels of IL-1β were found in symptomatic and asymptomatic lesions …

A Study Of Crown And Root Angulation On Maxillary First And Second Bicuspids, Craig A. Chamberlain

Loma Linda University Electronic Theses, Dissertations & Projects

Pre-adjusted bracket systems offer the clinician the convenience of working with both fewer in number and smaller in magnitude adjustments of an archwire. The purpose of this in vitro study was to examine the normal variations in crown angulation of individual maxillary bicuspids, in a simulated flat plane of occlusion, and how this relates to marginal ridge discrepancies. A second purpose of this study was to examine these same teeth for the angulations of the roots. Fifty maxillary first bicuspids and thirty eight second bicuspids from the Loma Linda University Dental School restorative dentistry department were, in a flat plane …

Soft Tissue Changes Of The Lower Lip Following Isolated Mandibular Advancement Osteotomies, Ronald Roy A. Simus

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate the soft tissue changes that occur following isolated mandibular advancement surgery. A sample of 70 non-growing patients were examined by tracing pre and post-operative radiographs. Then various landmarks were chosen and hand measured to determine hard and soft tissue changes. Significant correlations were found for many of the horizontal and vertical tissue landmarks and weaker correlations for all other landmarks. The decrease in the interlabial gap and the angular changes in the lower lip reflect the direction of surgical movement. The data from this study supports previous studies of smaller sample sizes …

An Evaluation Of Surface Enamel Damage Following The Debonding Of Ceramic Brackets : A Follow-Up Study, C. Steven Edney

Loma Linda University Electronic Theses, Dissertations & Projects

Surface enamel damage was evaluated after debonding ceramic brackets on forty-four bicuspid teeth. These teeth had been previously bonded with two different types of ceramic brackets. One of the brackets utilized a mechanical base for retention and the other bracket utilized a polycarbonate base for retention. The brackets were bonded to the respective teeth for a total of seven to ten days. After debonding, the teeth were extracted and evaluated with a scanning electron microscope. A metal bracket SEM scan was used for a control. The study concluded that: 1) all brackets alter the surface enamel, 2) metal brackets cause …

Assessment Of The Accuracy Of Three Methods Of Computerized Growth Prediction Of The Soft Tissue Profile, In Untreated Individuals, Pat Diciccio

Loma Linda University Electronic Theses, Dissertations & Projects

This study was performed to determine the accuracy and reliability of the long range growth predictions for profile structures by three computer software systems (QuickCeph™ for Apple Macintosh™ systems. Rocky Mountain Data Systems™ for IBM™ mainframe systems, and Facial Print™ for IBM™ personal computers), on untreated individuals. The total sample consisted of 90 Caucasian children from the Burlington Growth Centre. These were subdivided into groups of 15 children in each of mesiofacial, dolichofacial, and brachyfacial growth types for both males and females, with Angle class I occlusions, normal overbite, and normal overjet. Points measured consisted of 14 skeletal and soft …

Evaluation Of Trismus Associated With Mandibular Fractures As It Relates To The Need For Direct Laryngoscopy And Intubation : A Prospective Study, Stephen T. Goei

Loma Linda University Electronic Theses, Dissertations & Projects

Trismus associated with mandibular fractures is thought to increase the risks of general anesthesia. Nasotracheal intubation is necessary since the dental arches will be occluded at the end of the procedure. To establish an airway, an awake nasal intubation or fiberoptic endoscopy is required if direct laryngoscopy cannot be performed due to trismus. A prospective analysis of fifty-one patients with various types of mandibular fractures indicated that trismus was for the most part due to two factors, pain induced guarding and infection. In this series, direct laryngoscopy was easily performed after induction and paralyzation in cases without infection. Direct laryngoscopy …

A Non-Human Primate Model For Evaluating A Fenestration Corticotomy Technique, Philip G. M. Khng

Loma Linda University Electronic Theses, Dissertations & Projects

A study model has been designed to evaluate the effectiveness of a new fenestration corticotomy procedure in two non-human primates Macaca fasicularis.

The objective of this study was to evaluate the efficacy of a new conservative corticotomy procedure to facilitate dental translation using fenestrations. This pilot study compared treatment and control quadrants of each individual animal's maxilla and mandible with both having the same retraction appliance and force on the 2nd premolar following extraction of the 1st molars. The null hypothesis stated that there was no significant statistical difference between the new conservative corticotomy procedure (fenestrations) when compared with …

An In Vitro Study Comparing The Conventional Step-Back Instrumentation Technique To A Combination Step-Back/Ultrasonic Technique, James A. Eberhardt

Loma Linda University Electronic Theses, Dissertations & Projects

Cleaning and shaping the root canal system is an important phase of endodontic therapy, and must be performed thoroughly and completely if successful root canal therapy is to be expected. A number of investigators have compared different methods of cleaning and shaping of the root canal system. The purpose of this study was to compare the effectiveness of the conventional step-back technique with that of a combination step-back/ultrasonic technique. This combination technique is a modification of the conventional step-back technique using an ultrasonic instrument alternately with hand instrumentation. Utilizing 40 canals from extracted human mandibular molar teeth with a curvature …

A Shear Bondstrength Evaluation Of Five Orthodontic Light-Cured Adhesives, Perry M. Unruh

Loma Linda University Electronic Theses, Dissertations & Projects

In this study, the shear bondstrengths of five commercially available orthodontic light-cured adhesives were evaluated with respect to two types of curing lights and various cure-times. A total of 160 Transcend brackets (mechanical retention) were utilized. The brackets were individually bonded to knurled stainless steel testing rings via the respective adhesives. Each bracket was sheared from the testing ring using an Instron machine. For each adhesive a 2, 5, 10, and 20 second cure-time, and an immediate, 5 minute, 20 minute, and 24 hour shear test time was employed. The adhesives were cured using high intensity and low intensity visible …

Development Of Periapical Lesions In Immunosuppressed Rats, Phillip A. Waterman Jr.

Loma Linda University Electronic Theses, Dissertations & Projects

The pathogenesis of periapical lesions is the interaction of the oral flora with the existing host defenses. The role of bacteria has been established in endodontic disease but the contribution of the host defenses in periapical lesion formation is less clear. The purpose of this study was to compare periapical lesion development in immunosuppressed rats with that in normal rats. Thirty-five, eight-week old Sprague-Dawley rats were equally divided into seven groups. Groups 1, 2, and 3 were given weekly injections of Cytoxan, an immunosuppressive agent. Groups 4, 5, and 6 received no immunosuppressive therapy. Group 7 served as a control, …

Antibacterial Effects Of Various Endodontic Irrigants And Medicaments On Selected Anaerobic Bacteria, Patrick K. Ohara

Loma Linda University Electronic Theses, Dissertations & Projects

This study was undertaken to determine the antibacterial effects of various endodontic irrigants and medicaments against six selected anaerobic bacteria. In part 1, the organisms were mixed separately with dilutions of six irrigants in tubes containing fluid thioglycolate broth and allowed to remain in contact for specific time periods before being evaluated for growth. In part 2, the vapors of six medicaments were tested using agar plates streaked with the bacteria.

For part 1, the six irrigants were ranked as to their ability to inhibit bacterial growth. Statistical analysis showed that chlorhexidine and hydrogen peroxide were significantly more effective as …

Transforming Growth Factor-Beta 1 Expression In Developing Ovine Teeth As Visualized By In Situ Hybridization, Søren Jepsen

Loma Linda University Electronic Theses, Dissertations & Projects

Recently we demonstrated that human dentin contained relatively high amounts of transforming growth factor beta (TGF-ß) and proposed that dentin TGF-ß originated from odontoblasts. Because of the suggested role of TGF-ß in mediating cellular interactions in dental cell development by paracrine mechanisms, we studied the expression of TGF-ß message in developing teeth by in situ hybridization. 5 µm serial sections of neonatal sheep mandibular third molars that had been fixed in glutaraldehyde and paraffin-embedded were used for in situ analysis. An [³⁵S]-labeled cRNA probe, complementary to TGF-ß1 mRNA, was constructed from human TGF-ß1 cDNA. Northern analysis of total …

A Pilot Study On The Evaluation Of Short Term Effects Of Jasper Jumper Therapy, Eric D. Fraser

Loma Linda University Electronic Theses, Dissertations & Projects

Lateral cephalometric radiographs were obtained for ten patients treated with Jasper Jumper appliances from three locations. Pre and post-appliance measurements were compared to determine the cephalometric effects seen in this group of patients. All patients in this study exhibited mesofacial to brachyfacial growth patterns and were all of growing age. All patients were treated to Class I along the complete buccal segment. The results yielded the following conclusions: 1) the facial axis did not open and the lower face height did not increase significantly for this group of patients, 2) there is an intrusive effect delivered to the upper first …

Retrofilling Materials : The Effects Of Two Setting Times On The Degree Of Dye Leakage Of Retrograde Filling Materials, Robert K. Higa

Loma Linda University Electronic Theses, Dissertations & Projects

Sealing of the root canal system is usually accomplished by the conservative endodontic approach. Cases where it is impossible to treat nonsurgically are usually treated surgically by an apicoectomy and retrofill. There is a lot of controversy in the literature over which retrofilling material is closest to ideal. Presently, the most popular materials seem to be Amalgam, Super EBA, and IRM. For this reason, these materials were chosen for this study to evaluate the leakage potential at two different time intervals to see if setting time of the material had any influence on the amount of leakage.

Seventy extracted single …

Ability Of Cylindrical Root Form Implants To Withstand Controlled Lateral Forces, Silvio Emanuelli

Loma Linda University Electronic Theses, Dissertations & Projects

The ability of root form implants to withstand lateral forces has been investigated in animal model. Two new techniques for quantification of forces generated by a loading device have been developed and tested. The strain gages bonded to the loading device were calibrated either intraorally by a micro load cell, or in laboratory by Instrom Machine.

Preliminary results indicate that laterally applied continuous forces up to 6,000 grams do not elicit failure of root form implants.

New In Vivo And In Vitro Techniques For Quantification Of Lateral Force Levels That Cause Implants To Fail : A Progress Report On Monkey Research, V. Leroy Leggitt

Loma Linda University Electronic Theses, Dissertations & Projects

Two new techniques for quantification of forces generated by an expansion screw apparatus placed between pairs of cylindrical endosseous titanium implants are described, along with preliminary data gained from their use in Macaca rhesus monkeys. Strain gages were bonded to the expansion apparatus and were calibrated either directly by micro load cell, or indirectly by Instron Machine to reflect the applied force.

Immediate loads of up to 6 kilograms have been applied to the implants with no increase in mobility as verified by a Periotest device. No previous studies on the orthodontic uses of implants have evaluated in vivo forces …

An Evaluation Of Surface Enamel Damage Following The Debonding Of Ceramic Brackets : A Follow-Up Study, B. Scott Hood

Loma Linda University Electronic Theses, Dissertations & Projects

To evaluate surface enamel damage after debonding ceramic brackets using their manufacturer's recommended methods, sixty four bicuspid teeth were bonded with three different types of ceramic brackets and one type of metal bracket. All the brackets tested utilized mechanical retention only. The brackets were debonded in the mouth seven to ten days after bonding, extracted and evaluated with a scanning electron microscope. The study concluded that: 1) all brackets alter the surface enamel, 2) there is a significant difference in surface enamel damage between the metal bracket and the ceramic brackets utilizing a tensile debonding method, 3) there is no …

Soft Tissue Changes Of The Upper Lip Following Isolated Le Fort I Osteotomies, Kendall E. James

Loma Linda University Electronic Theses, Dissertations & Projects

Pre-operative (T-1) and post-operative (T-3) radiographs were obtained and traced for fifty-one non-growing patients who had undergone isolated Le Fort I osteotomies. These tracings were then digitized with the results arranged in a data file and subjected to statistical analysis. The purpose of this study was to establish ratios for certain hard to soft tissue movements that could be used to aid the clinician in post-surgical soft tissue profile prediction. The results showed that even though a large sample was used, individual patient variability remained high particularly in the horizontal directions. Most ratios found in this study were consistent with …

Condylar Angulations As Related To Submental-Vertex Radiographs, Jady L. Chiakowsky

Loma Linda University Electronic Theses, Dissertations & Projects

Pretreatment submental-vertex radiographs were obtained for 637 adolescent patients (307 males, 330 females) who had presented themselves for orthodontic treatment. The purpose of this study was to: (1) determine the relationship between condylar angulations and depth of cut with the variables: age, sex, and race, and (2) establish normative values for the categories studied. The results indicated that no significant differences existed between the condylar angulations for the variables measured. However, significant differences did exist between the depth of cut for the variables measured and there was significant interaction between age and race with respect to the depth of cut. …

Predicting Post-Treatment Maxillary Lip Position : A Comparison Of Two Techniques, Kevin J. Andrews

Loma Linda University Electronic Theses, Dissertations & Projects

The objective of this study was to compare the "drape" technique as proposed by Economides with the Holdaway technique in predicting post-treatment maxillary lip position and to determine which method was more accurate. Pre and post-treatment lateral cephalograms were traced for ninety (Caucasian) cases equally divided by sex into three treatment groups: a) non-extraction with at least 4mm of upper incisor retraction, b) extraction of upper first bicuspids only, and c) extraction of all first bicuspids. VTO's were constructed as outlined by Economides (drape) and Holdaway for prediction of post-treatment maxillary lip position. The predicted lip positions were compared to …

The Periodontal Intraosseous Defect Following Root Conditioning With Citric Acid And Wound Closure Including A Ptfe Membrane : An Experimental Study, Betty Glaser Kersten

Loma Linda University Electronic Theses, Dissertations & Projects

Treatment of the intrabony or intraosseous periodontal defect has rendered much attention over the last few decades. Numerous approaches have been advocated; however, overall comparisons between treatments do not exist. This review summarizes and discusses outcomes of therapeutic modalities in the intrabony periodontal lesion from controlled clinical studies. The modalities reviewed include scaling and root planning, gingival flap surgery, gingival flap surgery including wound closure with interdental denudation, root-biomodification, placement of autologous, allogenic, or xenogeneic bone grafts, placement of alloplastic grafts, and placement of tissue guiding barrier membranes. In addition histologic observations of healing in the intrabony periodontal lesion are …