Digital Commons Network^™

Accuracy Of Implants Placed With Surgical Guides: Thermoplastic Vs. 3-D Printed, Caitlyn K. Bell

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The purpose of this study was to evaluate the accuracy of placed implants using two different guided implant surgery materials: thermoplastic vs. 3-D printed surgical guides. Materials and Methods:Twenty duplicate mandibular models, ten thermoplastic and ten 3-D printed surgical guides were used. Twenty implants were placed following the guided surgery protocol. Cone beam computed tomography scans of placed implants and the control implant were superimposed to measure deviations. Results: The thermoplastic group showed average deviations of 3.4 degrees, 1.3mm at the head, and 1.6mm at the apex of the implant compared to 2.36 degrees, 0.51mm, and …

Ricketts Analysis Using Conventional And Dolphintm Generated Cbct Lateral Cephs, Yeganeh Parhizkar Jewell

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The aim of this study was to evaluate the difference between Ricketts analysis measurements made on Sirona Orthophos XG Plus (Sirona Dental Systems, Charlotte,NC) lateral cephalograms, and DolphinTM generated perspective and orthogonal lateral cephalograms from CBCT (NewTom 5G; QR srl, Verona, Italy). Materials and Methods: A Sirona digital lateral cephalogram and DophinTM synthesized CBCT lateral cephalograms of a radiographic phantom in orthogonal and perspective projections were created. Horizontal and vertical measurements were made in multiple planes on the radiographic phantom to compare each imaging modality. Twenty-five lateral cephalometric radiographs were selected retrospectively from the records of patients of …

Comparison Of Two Methods Of Transpalatal Arch And Lingual Arch Activation, Taoran Zhang

Loma Linda University Electronic Theses, Dissertations & Projects

The TPA and LA can be activated with two methods: the “shape-driven method” where the appliance is made to match the final tooth position and the “force-driven method” where the appliance is made to make sure the force system delivered by it at the beginning is consistent with the planned tooth movement. This study compared the two methods in vitro quantitatively with typodont teeth and multi-axis force torque transducers in all three dimensions. Results: In the TPA first order activation, with comparable Fy (force on Y axis) reading, the shape-driven activation group had a significantly higher Mx (moment on X …

An Evaluation Of Root Length Change Measurements Using Intraoral Scan And Panoramic Radiographs, Elijah C. Wang

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: This study was intended to evaluate the accuracy of using panoramic radiographs to measure root length change over the course of orthodontic treatment, using intraoral scans of crowns, and a mathematical model to account for distortions in the radiographs. The study additionally evaluated whether a best-fit equation could be created from the calculated data to minimize differences to the measurements of root resorption made on CBCT scans. Materials and Methods: Twenty-one patients were selected who had comprehensive orthodontic treatment, and all teeth in the upper right quadrant were evaluated in this study. T1 and T2 CBCT images were compared …

Correlation Of Tooth Length Measurements Made On Cbct And 3t Mr Images, Andrew Scott Taylor

Loma Linda University Electronic Theses, Dissertations & Projects

Objective. This study compared tooth length measurements made on cone beam computed tomography (CBCT) scans and 3-Tesla (3T) magnetic resonance (MR) scans performed with and without an alginate bite registration surrounding the crowns of the teeth. Materials and Methods. One CBCT scan, one MR scan with alginate bite registration, and one MR scan without bite registration were performed on 12 subjects. The alginate bite registration was used to provide a proton-rich material to surround proton-poor teeth in an attempt to improve visualization of teeth. DICOM formatted images from each of the three scans for each subject were oriented in all …

The Effect Of Orthodontic Treatment On Sagittal Root Position Of The Maxillary Central Incisor, Jeremy Haines

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Sagittal root position (SRP) of maxillary incisors is an important factor in implant treatment planning. Kan et al defined four classes of SRP in an effort to aid implant placement treatment planning and these SRP classifications represent a novel approach to describing bone changes around the maxillary incisors. The effect of orthodontic tooth movement, specifically changes in inclination, on SRP is of interest in potentially facilitating immediate implant placement. Purpose: The purpose of this study was to use Cone Beam Computed Tomography (CBCT) to evaluate the adaptation of alveolar bone around the maxillary incisors as a result of orthodontic …

A Cbct Study Of Pharyngeal Airway Changes Due To Fixed Functional Appliances, Scott T. Peterson

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The purpose of this retrospective study, using head and neck Cone-Beam Computed Tomography (CBCT) images, was to measure and compare volumetric, area, and linear changes of the pharyngeal airway space in patients treated with a MARA or Herbst Class II correction appliances. Materials and Methods: Twenty-six patients treated with a MARA (mean age 13.2), nine with a Herbst (mean age 12.12) , and a control group twenty-five orthodontically treated class I patients (mean age 13.11). T1 and T2 CBCT images were measured and compared between the three groups for area, length, and width measurements along the velo-, oro-, and …

Histomorphometric Analysis Of Maxillary Sinus Grafts: A Randomized Controlled Study, Mina Nishimoto

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this clinical investigation was to evaluate and compare the degree of new bone formation through histomorphometric analysis following maxillary sinus grafts (MSG) using three different bone graft materials. Thirty-one MSG were performed using a lateral window approach for patients who required implant placement in posterior maxilla. Each sinus was randomly selected to receive one of three bone graft materials; Group A: anorganic bovine bone mineral (ABBM) [Bio-Oss®], Group B: anorganic equine bone mineral (AEBM) [Equimatrix®], or Group C: mineralized cancellous bone allograft (MCBA) [OSSIF-i sem™]. A total of 28 bone cores were obtained at a mean time …

Influence Of Low Temperature Degradation On Microstructural Integrity Of Zirconia Dental Implants, Mona Monzavi Rahimi

Loma Linda University Electronic Theses, Dissertations & Projects

Zirconia dental implants have become more popular in the field of implant dentistry. However, concerns have been raised regarding low temperature degradation and its influence on phase stability and micro-structural integrity in terms of increased micro-crack formation. In the case of dental implants, this could possibly result in delamination and interference with bone to implant contact and eventually lead to loss of integration and failure. Nevertheless, no study has reported the effects on commercially available Zirconia dental implants. The primary aims of this study was to determine if there is a correlation between ageing duration and 1) depth of tetragonal-monoclinic …

Oral Health Education Intervention To Assess Oral Health Knowledge And Behavioral Change, Ryan Bakhshi Baker

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate an oral health education intervention on oral health behaviors, oral health knowledge, and diet/amount of sugar consumed by fifth and sixth graders attending charter schools in the city of San Bernardino. Caries status of this particular population was recorded via dmft/DMFT and ICDAS. 143 students (aged 9-13 years) completed a 19 question pre-intervention survey related to oral health behaviors, dental knowledge and diet/amount of sugar consumed. Subjects then participated in an oral health education intervention comprised of an oral health education video and an interactive oral health game. An oral exam recorded …

Accuracy Of Volumetric Analysis Software Packages In Assessment Of Tooth Volume Using Cbct, Saylee Nimbalkar

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate the accuracy of volumetric analysis software packages in assessment of tooth volume using cone beam computed tomography and compare them to the volume obtained using an optical digital scanner. Twenty-four single rooted teeth indicated for extraction were collected. Cone beam computed tomography scans of these teeth resting in a custom scan jig were taken. Three dimensional digital models were obtained from the DICOM image cone beam computed tomography files using segmentation software packages (Anatomage, Mimics, and Amira) and volumes were calculated for each of the segmented teeth. The teeth were then scanned …

Effects Of Microwave Irradiation On The Dimensional Stability Of Complete Denture Bases, Miguel Pappaterra

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Maintenance for complete dentures is a role that must be undertaken by the patient. It has been determined that two minutes of microwave irradiation at 650 Watts provides denture disinfection, and three minutes provide sterilization32,34. There is insufficient data on how this practice affects the long term dimensional stability of commonly used complete denture bases in the United States. Purpose: The purpose of this study was to perform an in-vitro investigation, testing and comparing the effects of microwave irradiation on the dimensional stability of three types of complete denture bases. Materials and Methods: An edentulous master cast with reference …

Comparison Of Retention Between Milled And Conventional Denture Bases: A Clinical Study, Abdulaziz Abdullah Alhelal

Loma Linda University Electronic Theses, Dissertations & Projects

The advancement in dental material technology led to the improvement in the fabrication method of PMMA denture bases. Denture base adaptation can be influenced by the amount of polymerization shrinkage that occurs during the processing method of fabrication. CAD/CAM dentures milled from prepolymerized PMMA acrylic resin blocks theoretically have reduced or no polymerization shrinkage. There have been no clinical studies, to date, that have compared retention values between milled and conventionally processed denture bases. Therefore, the purpose of this study clinical study was to compare the retention values between conventional heat polymerized and digital milled maxillary denture bases.

Twenty patients …