The Effect Of Crowding On The Accuracy Of 3d Printed Aligners, Tonya Spangler

Theses and Dissertations

Purpose: To evaluate the accuracy of three-dimensionally (3D) printed aligners compared to conventional vacuum-formed thermoplastic aligners with varying levels of dental crowding.

Methods: Digital intraoral scans of 10 different cases were assigned to their respective groups (n=10, each, 30 total) as follows: no crowding (control), moderate crowding, and severe crowding. Using 3Shape software, digital aligner samples were created in standard tessellation language (STL) file format and randomly 3D printed. The same STL files of each case were also sent to a dental laboratory for the fabrication of vacuum-formed samples, which is the current technology used for manufacturing aligners. The intaglio …

Exploring The Use Of Pulsed Erbium Lasers To Retrieve A Zirconia Crown From A Zirconia Implant Abutment, Ahmed Elkharashi

Theses and Dissertations

Removal of zirconia crowns, commonly used as cement-retained implant fixed restorations, can be challenging. Conventional methods of crown removal are time consuming and often leave irreparable damage to the crown, which can be costly to patients and practitioners. This research explored the use of two different types of pulsed erbium lasers, erbium-doped yttrium aluminum garnet laser (Er:YAG) and erbium, chromium-doped yttrium, scandium, gallium and garnet (Er,Cr:YSGG), as non-invasive tools to retrieve cemented zirconia crowns from zirconia implant abutments. Times needed to remove the crowns were recorded and analyzed using ANOVA (��=0.05). No statistical differences between the debond times of each …

Designing Biomimetic Implant Surfaces To Promote Osseointegration Under Osteoporotic Conditions By Revitalizing Mechanisms Coupling Bone Resorption To Formation, Ethan M. Lotz

Theses and Dissertations

In cases of compromised bone remodeling like osteoporosis, insufficient osseointegration occurs and results in implant failure. Implant retention relies on proper secondary fixation, which is developed during bone remodeling. This process is disrupted in metastatic bone diseases like osteoporosis. Osteoporosis is characterized low bone mass and bone strength resulting from either accelerated osteoclast-mediated bone resorption or impaired osteoblast-mediated bone formation. These two processes are not independent phenomena. In fact, osteoporosis can be viewed as a breakdown of the cellular communication connecting bone resorption to bone formation. Because bone remodeling occurs at temporally generated specific anatomical sites and at different times, …

The Efficacy Of A Fluoride-Containing Orthodontic Primer In Preventing Demineralization, Alyssa G. Ricci

Theses and Dissertations

Purpose: To evaluate the efficacy of a fluoride-containing orthodontic primer in preventing demineralization adjacent to brackets and compare the quality of enamel on tooth surfaces that received interproximal reduction (IPR).

Methods: Patients at the VCU Orthodontic clinic who consented to orthodontic treatment involving extraction of at least 2 premolars were recruited to this pilot clinical study. Brackets were bonded to premolars using one of two primers, fluoride-containing experimental or control. IPR was also performed, and the experimental primer was applied to randomly selected teeth. Extracted teeth were analyzed visually for the presence of white spot lesions (WSLs). Micro-CT analyses were …

Evaluation Of Fit For 3d Printed Retainers As Compared To Thermoform Retainers, David J. Cole

Theses and Dissertations

ABSTRACT

EVALUATION OF FIT FOR 3D PRINTED RETAINERS AS COMPARED TO THERMOFORM RETAINERS

By David Cole, D.M.D.

A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University

Thesis Directors: Eser Tüfekçi, D.D.S., M.S., Ph.D., M.S.H.A.

Professor, Department of Orthodontics

Sompop Bencharit, D.D.S., M.S., Ph.D.

Associate Professor and Director of Digital Dentistry, Department of General Practice

Introduction: Despite recent advances in three-dimensional (3D) printing, little information is available on 3D printed retainers

Methods: Three reference models were used to fabricate traditional vacuum formed, commercially-available vacuum formed, and 3D printed …

A Comparison Of The Antimicrobial Efficacy Of Silver Diamine Fluoride And Silver Nitrate: An In Vitro Study, Nicholas L. Luke

Theses and Dissertations

A COMPARISON OF THE ANTIMICROBIAL EFFICACY OF SILVER DIAMINE FLUORIDE AND SILVER NITRATE: AN IN VITRO STUDY

By: Nicholas L Luke, D.D.S.

A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University.

Virginia Commonwealth University, May 2018

Thesis Advisor: William O. Dahlke Jr., D.M.D.

Pediatric Dentistry, Department Chair

Purpose: To determine the antimicrobial efficacy of SDF and SN/NaF.

Methods: Three bacterial species were combined to create an in vitro biofilm. Treatment was completed with SN, SN/NaF, SDF, SDF½ or untreated (control).

Results: The untreated group demonstrated significantly higher …

An Investigation Of Surface Characteristics Of Enamel Treated With Infiltrative Resin: A Scanning Electron Microscopy Study, Danielle E. Easterly

Theses and Dissertations

AN INVESTIGATION OF SURFACE CHARACTERISTICS OF ENAMEL TREATED WITH INFILTRATIVE RESIN: A SCANNING ELECTRON MICROSCOPY STUDY

Danielle E. Easterly, Doctorate of Dental Surgery.

A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University.

Virginia Commonwealth University. 2017.

Director: Dr. Eser Tüfekçi

D.D.S., M.S., Ph.D., M.S.H.A.

Objective: To evaluate the microstructural changes of a resin infiltrant (ICON®, DMG America LLC, Englewood, NJ) after six months of simulated toothbrushing.

Materials and Methods: Ten extracted third molars (n=10) were collected. Artificial white spot lesions were created and resin applied. Environmental SEM …