Dentistry Commons^™

Impact Of Maximal And Minimal Mouth Opening On Mandibular Flexure Via Scanning, Kangyeong Lim

Loma Linda University Electronic Theses, Dissertations & Projects

Background: Mandibular flexure during mouth opening affects prosthodontic outcomes, but digital scanner research is limited.

Methods: Seventy dental students (35 males, 35 females) had two impressions taken: one with maximum and one with minimum mouth opening.

Results: First molars showed higher deviations than premolars. Females had larger deviations, though not statistically significant.

Conclusion: First molars exhibit greater flexure than premolars.

Keywords: Mandibular flexure, deformation, mouth opening, digital, intraoral scan, three dimensional(3D), prosthetic

Comparison Of Thickness Between Thermoformed And Printed Orthodontic Aligners, Omar Souman

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The fabrication of thermoformed orthodontic aligners involves processes that irreversibly alter material properties, resulting in aligners that exhibit high variation in thickness. The non-uniform thickness can lead to unpredictable forces that can adversely affect orthodontic tooth movement. With recent technological advancements enabling the printing of orthodontic aligners, it is of clinical interest to investigate their variation of thickness.

Purpose: This study utilized Micro-Computed Tomography (Micro-CT) and Geomagic Control X metrology software to compare the thickness of thermoformed and direct printed aligners.

Materials and Methods: Intraoral scans of 13 orthodontic patients were used to generate standard tessellation …

Maxillary Central Incisor Rr In Hispanic And Non-Hispanic White Patients With Rme, Madison Healy

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Apical root resorption is one of the most common adverse effects of orthodontic treatment. Forces used during orthodontic tooth movement can cause permanent loss of apical surfaces of teeth and although most reported cases of root resorption are asymptomatic, the process is irreversible and often unpredictable. Thus, it is of clinical interest to investigate which patients may be at greatest risk.

Purpose: This study utilized Cone Beam Computed Tomography (CBCT) to evaluate whether rapid maxillary expansion (RME) in Hispanic patients increased the severity of orthodontically induced apical root resorption.

Materials and Methods: Pre-treatment (T1) and post-treatment …

Force Comparison Of Rotational Tooth Movements For Loop-Design And Traditional Aligners, Robert Olsen

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction

This study aimed to evaluate the force (F) and torque (Tq) exerted on a rotated canine and molar tooth by two different aligner systems. An ArchForm loop clear aligner (AFL) was compared to a traditional clear aligner (T) with the force (F) and torque (Tq) compared. A reduction in F and Tq with AFL aligners could possibly decrease the incidence of Orthodontic Root Resorption (ORR), while also creating more effective forces for tooth movement.

Materials and Methods

Two types of T aligners varying by material thickness were compared to two types of AFL aligners varying by loop width. All …

Titanium Particles Within Mucosa During Non-Surgical Implant Debridement, Holvin Louie

Loma Linda University Electronic Theses, Dissertations & Projects

Titanium implants affected by peri-implantitis lesions are often treated non-surgically with various instruments, which may produce titanium particles that can become lodged within the peri-implant mucosa. Thus, a foreign body reaction may ensue. The aim is to assess the embedment of titanium particles into soft tissues from titanium implants via a stainless-steel ultrasonic scaler (SSU) versus a titanium hand scaler (TH). Sand-blasted, large grit, acid-etched surface-treated titanium implants were implanted into pig legs after creating peri-implantitis defects. Each implant was subjected to only one instrument type. Sequential strokes were conducted followed by thorough irrigation with sterile water. Soft tissue curettage …

Effect Of Splinting Implant Scan Bodies Intraorally On The Trueness Of Complete Arch Digital Impressions: A Clinical Study, Kawther Mahmoud Ali

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The purpose of this study was to investigate the effect of splinting scan bodies intraorally on the trueness and scan time of implant digital impressions of the edentulous arch.

Materials and Methods: Nineteen edentulous jaws undergoing fixed complete denture treatment with a minimum of 4 implants were selected for this study. Verified master casts of the patients’ edentulous jaws were scanned with a desktop laboratory scanner and scan bodies to obtain a reference (control) scan for each patient. Intraoral scan bodies were hand tightened on all the implants in the edentulous arch and an intraoral scan was …

A Study In Fresh Human Cadaver Heads Examining The Incidence Of Maxillary Sinus Membrane Perforation During Crestal Sinus Elevation Comparing Osteotomes To Osseodensification Drills., Thaer Alqadoumi

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Crestal sinus membrane elevation technique is a surgical procedure that helps gain vertical bone volume when there is a pneumatization of the maxillary sinus. Due to some visual limitations inherent to the procedure, the potential for maxillary sinus membrane perforations and subsequent complications exists. A crestal sinus lift using osseodensification drills has been used lately but there are not many studies to support the protocol. The primary aim of the study is to evaluate the incidence of sinus membrane perforation during Osseodensification compared to the incidence of bone added crestal sinus elevation using osteotomes (BAOSFE). The secondary aim …

Evaluating The Effect Of The Protector Cap Technique For Castable Implant Abutments On Reverse Torque Values, Mohammed Alfaifi

Loma Linda University Electronic Theses, Dissertations & Projects

Statement of problem: The most common mechanical complication reported regarding the implant abutment is screw loosening attributed to masticatory forces and insufficient preload torque.

Purpose: The purpose of this study is to evaluate the differences in reverse torque value between UCLA abutments with no casting performed, UCLA abutments cast using a conventional manner, and UCLA abutment cast using protection caps and pegs.

Material and methods: Thirty implants with a standard diameter (4.3 mm) conical connection (NobelReplace Tapered Groovy 4.3 × 13 mm; Nobel Biocare) and thirty premachined 4.3 mm gold UCLA abutments (Branemark System™ Nobel Biocare, Inc) were used in …

The Effect Of Omega-3 Polyunsaturated Fatty Acids On Periodontal Inflammation In Rats, Hardev M. Singh

Loma Linda University Electronic Theses, Dissertations & Projects

Aim: The aim of this study was to evaluate any possible beneficial effects of omega-3 polyunsaturated fatty acids (Ω-3 PUFAs) as a dietary supplement when incorporated into the diet of rats that had periodontitis induced via a ligature model.

Materials and Methods: 20 male rats (Sprague Dawley) were divided into 2 groups as following: 1) Control group with ligature-induced periodontitis and no Ω-3 PUFA in the diet; and 2) Test group with ligature-induced periodontitis and Ω-3 PUFA introduced in the diet. The ligature was placed around the mandibular first molars in the gingiva sulcus for a period of …

Evaluating The Treatment Effectiveness And Efficiency Of The Df2 Protocol Using Invisalign® For Treatment Of Class Ii Malocclusion: A Retrospective Comparison Study, Bryan J. Otis

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: This retrospective study evaluated the treatment effectiveness and efficiency of the DF2 protocol for correction of class II malocclusions in comparison to conventional protocol using Invisalign®.

Materials and Methods: Clinical and cephalometric data of patients that were treated for class II malocclusion between July 30, 2014 and July 22, 2021 were reviewed and selected. The selected patients were matched for age, sex, and treatment complexity and divided into two groups: Group 1 (G1) —DF2 protocol and Group 2 (G2)—conventional class II Invisalign®. Clinical variables to represent the skeletal and dentoalveolar changes during treatment were assessed using pre-treatment (T1) …

Comparison Of The Upper Airway Volume In Orthodontically Treated Cases With First Premolar Extractions, Krystal Park

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Comprehensive orthodontic treatment often entails extraction of teeth to accomplish treatment goals. A potential side effect of extraction therapy is arch length shortening resulting in decreased space for the tongue which may cause a low tongue posture and a possible reduction in airway space. The purpose of the study was to retrospectively determine if extractions of all first premolars during orthodontic treatment and the resulting movement of mandibular incisors are correlated with a reduction in airway volume.

Materials and Methods: The T1 and T2 CBCT’s of 80 patients were collected and reviewed. The cases were divided into treatment (extraction) …

Summary Description And Treatment Plan Elements Derived From Cbct And Mri Based Orthodontic Records, Mainer Cruz

Loma Linda University Electronic Theses, Dissertations & Projects

Objectives: This study examined the agreement of summary description and treatment plan elements derived from cone beam computed tomography (CBCT) and 3-Tesla (3T) magnetic resonance imaging (MRI) scans.

Methods: This retrospective study involved thirteen human subjects, all of whom had one CBCT scan (NewTom 5G, AFP Imaging, USA) and one MRI scan (Siemens Medical Solutions, DE) of the whole head performed within a two-week period. CBCT images were taken with a field of view of 18x16 inches and resolution of 0.3x0.3x0.3 mm, over an exposure time of 5.4 seconds. MR images were acquired using a 3.0T imaging system …

Effect Of Finishing And Polishing Techniques On The Fit Accuracy And Dimensions Of Conventional And Cad-Cam Removable Partial Denture Frameworks, Majed Altoman

Loma Linda University Electronic Theses, Dissertations & Projects

Rapid advancements in computer-aided design and computer-aided manufacturing (CAD-CAM) in removable dental prosthodontics have offered new modalities for fabrication of removable partial denture frameworks. The standard tessellation language (STL) files of the scans are used to digitally design the removable partial denture (RPD) framework, which are then printed in cobalt-chromium (Co-Cr) alloy and finished and polished according to manufacturers’ recommendations. There are few studies compare the fit accuracy of the cast DPD framework versus the CAD-CAM RPD frameworks which found that CAD-RP frameworks exhibited the highest discrepancies, using different methods of evaluation. Good fit between the denture base and the …

Accuracy Of Digital Indirect Bonding Technique Utilizing 3d-Printed Trays, Phillip Ha

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: This study investigated the bracket placement accuracy of a digital indirect bonding (dIDB) technique utilizing 3D-printed trays and the effects of dental crowding and tooth type on bracket placement accuracy.

Material and Methods: Thirty digital mandibular models of various amounts of arch length discrepancy (ALD) were categorized into 3 groups according to the amount of ALD. Digital bracket placement was performed from second molar to second molar using Indirect Bonding Studio (3ShapeTM, Copenhagen, Denmark) and this virtual model was used as the control. Indirect bonding trays were designed using Appliance Designer (3ShapeTM) and 3D-printed with the SprintRayTM …

Accuracy And Reproducibility Of Cone Beam Computed Tomographs For The Assessment Of Bony Tissues, An Ex-Vivo Study, Saad Hamad Almujel

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The purpose of this study was to evaluate the impact of implant blooming artifact on the assessment of the peri-implant buccal bone thickness, the accuracy of two CBCT devices, and the reproducibility of CBCT images obtained in different exposure timelines.

Materials and Methods: Four dental implants were placed in the mandible of a cadaver head. The distances between dental implants and the thickness of the peri-implant buccal bone were measured with a high precision caliper. The cadaver head was scanned using 2 different CBCT devices, 12 repeated scans were made while the cadaver head in its initial …

Rotational Forces Generated By Traditional And Loop-Design Clear Aligners, Grant Essink

Loma Linda University Electronic Theses, Dissertations & Projects

Objective: This study aims to evaluate force (F) and torque (Tq) generated by a novel “loop-design” clear aligner compared to the F and Tq generated by a traditional clear aligner design. The novel design may reduce the risk of orthodontic root resorption (ORR), by reducing forces during tooth rotation.

Materials and Methods: Traditional clear aligners (T) and ArchForm Loop clear aligners (AFL) were compared for differences in F and Tq exerted on selected canine and molar teeth. The test tooth was sectioned out of the test model, attached to a load cell and replaced in the test model …

A Comparison Of The Area Of The Internal Nasal Valve In Cbct And Mri, Chantelle Ghiam

Loma Linda University Electronic Theses, Dissertations & Projects

Objective: This study compared the agreement between whole head Cone-Beam Computed Tomography (CBCT) and 3T Magnetic Resonance Imaging (MRI) methods to assess the cross-sectional area of the internal nasal valve.

Methods: Thirteen human subjects (mean age 15y11m) were used in this study. All scans were preformed [sic] within two weeks of one another. CBCT images were made with an 18x16 inch field of view, exposure time of 5.4 s, and resolution of 0.3x0.3x0.3 mm. 3T MR images were captured as contiguous sagittal images of the whole head with a T1-weighted 3D imaging sequence (Magnetization Prepared Rapid Acquisition by …

Attitudes And Understanding Of Orthodontic Treatment Using Comic Vs. Text Format, Darron Miya

Loma Linda University Electronic Theses, Dissertations & Projects

Objectives: To examine adolescent patient attitudes and understanding of basic orthodontic treatment information presented in either comic book format or plain text.

Methods: This study involved subjects undergoing orthodontic treatment at the Loma Linda University Graduate Orthodontic Clinic. Subjects were randomly assigned to two groups: Group 1 subjects received an orthodontic comic book to read, while Group 2 subjects received a plain text information sheet containing the same pertinent information as Group 1. All subjects completed an identical survey regarding the material they read. Statistical analysis consisted of a chi-square test at α = 0.05 to determine potential …

Comparison Of Heat Generated During Twist Drilling Protocol By Guided And Non-Guided Implant Surgery, Joshua Lee

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Guided implant surgery is becoming more prevalent among clinicians and is crucial for cases in which there are concerns about the proximity of the implant to vital anatomical structures, esthetic concerns, and the amount/quality of bone available. Surgical guides help with the angulation and positioning of the implant through the use of a CBCT scan and digital intraoral impression. However, there are some drawbacks with guided surgery. Heat that is generated during the osteotomy is one of the issues that has been of concern. The guide acts as a shield against the water irrigation from reaching the osteotomy …

A Comparison Of Heat Generated Between Carbide And Diamond Bur During Implantoplasty, Bryce Chun

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: This study was conducted to evaluate heat generated during the implantoplasty procedure by comparing the heat generated using either a carbide or diamond round bur. Materials and Methods: Bovine ribs were selected as the osseous model for this study. Changes in temperature were measured using a digital thermometer (Extech SDL200 four channel thermometer, Extech instruments, Melrose MA). Ther k-thermocouples were positioned within the implant screw access, apex of the implant, and crestal bone adjacent to the implant and ambient air. 5 bovine rib bone blocks were prepared by place 5 cylindrical titanium grade 5 alloy large grit sand blasted …

Synthesis And Characterization Of Hemocompatible Antibiotic Nanoparticles, Elvin Muhindo Walemba

Loma Linda University Electronic Theses, Dissertations & Projects

Porphyromonas gingivalis is a causative agent of periodontal disease and a risk factor for cardiovascular disease. Novel treatment of periodontal disease using nanomaterials can supplement or replace the use of antibiotics and mechanical debridement. Nanomaterials can be optimized for effectiveness and specificity and minimum toxicity. Synthesized Ag nanoparticles stabilized in Pluronic F127 were used to produce bimetallic core/shell Ag/Au nanoparticles with optimized Ag+ release and reduced toxicity. We tested the F127-stabilized nanoparticles for their antimicrobial activity and hemocompatibility in planktonic bacteria and citrated whole blood, respectively. Both Ag and Ag/Au bimetallic nanoparticles inhibited P. gingivalis W83 growth. We then evaluated …

Measurements Of The Pharyngeal Airway Using Whole Head 3t Mri And Cbct, Victoria Geren

Loma Linda University Electronic Theses, Dissertations & Projects

Objective: This study compared pharyngeal airway measurements (volume, linear, area) made using whole head Cone-Beam Computed Tomography (CBCT) and 3T Magnetic Resonance Imaging (MRI) methods.

Methods: Eleven subjects (mean age 15y11m) received whole head CBCT (NewTom5G, AFP Imaging, USA) and 3T MRI (Siemens Medical Solutions, DE). Each subject received both scans within a one-month period of time. CBCT images were made with an 18x16 inch field of view, exposure time of 5.4s, and resolution of 0.3x0.3x0.3mm. 3T MR images were captured as contiguous sagittal images of the whole head with a T1- weighted 3D imaging sequence (Magnetization Prepared …

Clinical Effects Of Oral Hygiene Instruction Via Texting In Orthodontic Patients, Jessica Liu

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: This randomized controlled study quantitatively investigated whether providing oral hygiene instruction (OHI), through texting images and videos, affected oral hygiene status in orthodontic patients.

Materials and Methods: Sixty patients between 13-21 years of age, with visible plaque and used a smart phone, were recruited from the Graduate Orthodontic Clinic at Loma Linda University. Once recruited (T1), an initial survey was completed, MBI and OPI were recorded, and OHI was given. Subjects were randomly distributed into either a control or experimental group. The experimental group received OHI texts weekly, whereas the control group did not. After 3 months …

Comparison Of Maxillary Sinus Dimensions And Volumes On Cbct And 3t Mr Images, Cara Hodgson

Loma Linda University Electronic Theses, Dissertations & Projects

Objective: This study compared the height, width, length, and volume of the maxillary sinus in Magnetic Resonance Imaging (MRI) and Cone-Beam Computed Tomography (CBCT).

Methods: Eleven human subjects participated in the study (mean age of 14y7m). One CBCT scan and one MRI scan were performed on each patient. CBCT images were captured with an 18 x16 inch field of view that covered the whole head. Contiguous sagittal MR images of the whole head were produced using a 3.0T imaging system with a T1-weighted 3D imaging sequence and isotropic resolution of 1.0 x1.0 x1.0 mm. Images were imported as …

Accuracy Of Surface Area And Volume Measurements Of Teeth Determined From Cbct, Joseph Hourany

Loma Linda University Electronic Theses, Dissertations & Projects

Objective: This study compared surface area and volume measurements made from 3D scans of physical teeth and segmented teeth taken from Cone-Beam Computed Tomography (CBCT) scans of a cadaver. Methods: A cadaver specimen was imaged by CBCT and all the teeth were subsequently extracted and cleaned of any tissue. Of all the extracted teeth, sixteen single-rooted teeth were included in this study. The extracted teeth were scanned with a 3M True Definition 3rd Generation intraoral scanner (3M, ESPE) to generate a stereolithography (STL) file to serve as the control for this study and their surface area and volume measurements as …

Ratio Of Rme Appliance Expansion To Increase In Arch Perimeter Using Cbct Imaging, Evan Agnetta

Loma Linda University Electronic Theses, Dissertations & Projects

Objective: This study measured CBCT images to determine if a consistent ratio exists between the quantifiable number of millimeters a cemented rapid palatal expansion appliance is opened and the subsequent increase in the arch perimeter obtained due to lateral expansion of the arch.

Methods: The following measurements: arch perimeter, arch width at first molars, first bicuspids, appliance length, as well as arch depth; were taken from CBCT images of patients who had completed RME therapy. These were obtained both before and after maxillary palatal expansion therapy using a fixed rapid palatal expander. Correlations were calculated for each of …

In-Vitro Comparison Of Retention Among Contemporary And Conventional Post-And- Cores, Hatem Alqarni

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: Computer-aided design/computer-aided manufacturing (CAD/CAM) technology is gaining popularity in dentistry, and more recently, used to fabricate custom post-andcores (PC) for endodontically treated teeth. The purpose of this study was 1) to evaluate the overall retention of conventional cast gold post-and-cores compared to CAD/CAM fabricated printed, milled titanium post-and-core and milled zirconia post-and-cores based on load, time of dislodgement and 2) to evaluate the mode of failure of the post-and-cores.

Materials and Methods: A maxillary central incisor was selected. Root canal treatment was performed, and acrylic resin pattern was used to fabricate post-and-core. A total of 80 post-and-cores (20 …

Comparison Of Antimicrobial Agents Ozonated Olive Oil And Chlorhexidine Gluconate - An In Vitro Study, Amelia David

Loma Linda University Electronic Theses, Dissertations & Projects

Aim: This study was aimed to compare the antibacterial effect of a commercially available OzOO with CHX 0.12% oral rinse solution against periodontal pathogens F. alocis, Aa, S. mitis, and S. mutans using a disk diffusion method.

Materials and Methods:

The antimicrobial agents OzOO and 0.12% CHX were impregnated onto sterile discs and placed onto bacterial cultures of F.alocis, Aa, S.mutans, and S.mitis to evaluate their antimicrobial activity by the disk diffusion susceptibility method. The bacterial growth inhibition zone surrounding each disc was measured in millimeters of diameter with calipers to assess the antimicrobial activity of each agent. …

Complications Associated With Mandibular Fixed Complete Arch Prostheses Based On Implant Distribution, Shivani Karre

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The objective of this study is to compare incidence and type of complications associated with mandibular implant supported fixed complete arch prostheses based on implant distribution. Material and Methods: Patient Selection: The retrospective study included data collected from axiUm CE Version 6.05.01.2007 from year July 2007 to July 2018 for all patients treated with mandibular implant supported fixed complete arch prostheses (MISFCPs) at Loma Linda University School of Dentistry (LLUSD). One hundred and twenty seven patient’s charts were reviewed to document implant distribution and incidences of complications associated with each implant distribution groups on MISFCPs. Complications like screw …

Accuracy Of Intraoral Scanners With Different Total Occlusal Convergence Angles: An In-Vitro Study, Brittany M. Pang

Loma Linda University Electronic Theses, Dissertations & Projects

Digital intraoral imaging has become more utilized in contemporary dental practice. This is performed using an intraoral scanner and it can be used as an alternative to making conventional impressions when indicated. This technology has many advantages, such as decreasing the number of appointments by eliminating traditional techniques, along with a reduction of laboratory time and improved patient comfort. The accuracy of intraoral scanners is currently being assessed in various aspects. To our knowledge, no study has yet addressed the accuracy of intraoral scanners in regards to total occlusal convergence (TOC) of complete coverage of anterior and posterior preparations in …