Dentistry Commons^™

Validation Of The Flexcell®Fx-5000 Tension System To Evaluate The Expression Of Cementum Protein-1 In Human Periodontal Ligament Cells While Under Cyclical Orthodontic Tensile Force, Allison Nicholls

Electronic Thesis and Dissertation Repository

The pressure-tension theory of orthodontic tooth movement (OTM) states that there are differences in microenvironment between the tension and compressions side within the periodontal ligament, leading to differential gene expression within those zones. Cementum protein 1 (CEMP-1) is a human-specific protein localized to the root of a tooth and may play a role in OTM. The first objective was to develop a protocol to apply tensile force to human PDL cells similar to that within the tension zone during OTM. For this, the FlexCell®FX-5000 Tension system was used and fluorescent microscopy was used to confirm validity of the protocol. The …

Root Canals Shaped By Nickel-Titanium Instrumentation With Automated Computerized Numerical Control Systems, Liming Wang, Wenxiang Li, Yeon Jee Yoo, Shin Hye Chung, Soram Oh, Hiran Perinpanayagam, Kee Yeon Kum, Yu Gu

Dentistry Publications

Background: To investigate the efficacy of a nickel-titanium (NiTi) file with an automated computerized numerical control (CNC) system for root canal shaping. Methods: The movement of the automated device and the insertion angle were investigated. In Experiment 1, simulated resin root canals were randomly divided into four groups (n = 20): manual downward movement using a handpiece (Group 1), vertical downward movement by CNC (Group 2), reciprocating up and down movement by CNC (Group 3), and spiral up and down movement by CNC (Group 4). In Experiment 2, five different insertion angles of the NiTi file were evaluated (n = …

Evaluation Of Cyclic Fatigue And Bending Resistance Of Coronal Preflaring Niti File Manufactured With Different Heat Treatments, Soram Oh, Su Young Moon, Antonis Chaniotis, Eugenio Pedullá, Adel Saeed Al-Ghamdi, Fawzi Ali Al-Ghamdi, Ayman Omar Mandorah, Hiran Perinpanayagam, Kee Yeon Kum, Ove A. Peters, Seok Woo Chang

Dentistry Publications

Coronal preflaring NiTi files should possess proper hardness, resistance to fracture and flexibility. This study compared the bending resistance and cyclic fatigue resistance of three orifice preflaring NiTi files. HyFlex EDM Orifice opener (#25/12), HyFlex CM (#25/08) and One Flare (#25/09) were tested (n = 46/instrument). Bending resistance was assessed with the stress when perpendicular displacement was applied to a 3 mm point from the file tip, and was performed at either room temperature (RT, n = 10) or body temperature (BT, n = 10). Cyclic fatigue resistance was tested with an artificial ceramic root canal at RT (n = …

Neighborhood Contexts And Oral Health Outcomes In A Pediatric Population: An Exploratory Study, Vladyslav A. Podskalniy, Sharat Chandra Pani, Jinhyung Lee, Liliani Aires Candido Vieira, Hiran Perinpanayagam

Dentistry Publications

Aims: This study aimed to explore the impacts of neighborhood-level socioeconomic contexts on the therapeutic and preventative dental quality outcome of children under 16 years. Materials and Methods: Anonymized billing data of 842 patients reporting to a university children’s dental over three years (March 2017–2020) met the inclusion criteria. Their access to care (OEVCH-A), topical fluoride application (TFL-CH-A) and dental treatment burden (TRT-CH-A) were determined by dental quality alliance (DQA) criteria. The three oral health variables were aggregated at the neighborhood level and analyzed with Canadian census data. Their partial postal code (FSA) was chosen as a neighborhood spatial unit …

Non-Thermal Atmospheric Pressure Plasma-Conditioned Root Dentin Promotes Attraction And Attachment Of Primary Human Dental Pulp Stem Cells In Real-Time Ex Vivo, Yeon Jee Yoo, Min Ji Kang, Hiran Perinpanayagam, Joo Cheol Park, Seung Ho Baek, Kee Yeon Kum

Dentistry Publications

This study investigated if non-thermal atmospheric pressure plasma (NTAPP) treatment of root dentin surfaces promotes human dental pulp stem cell (hDPSCs) adhesion. Freshly extracted human single-rooted teeth (n = 36) were decoronated and cut (first vertically, then horizontally) into root dentin slices (3 mm thick). Primary hDPSCs cultures were seeded onto slices randomly assigned to pretreatment groups (n = 9/group): NaOCl (1.5%), EDTA (17%) then NTAPP (Group I); NaOCl then NTAPP (Group II); NaOCl then EDTA (Group III); and NaOCl alone (Group IV). Cell viability and proliferation were measured using MTT assay with log-linear statistical analysis. Cell attachment and spreading …

Catechol-Containing Copolymers As An Active Ingredient For Denture Adhesives, Vincent Ying Wun Kong

Electronic Thesis and Dissertation Repository

Moisture inside the mouth adds challenge to making denture adhesives formulations. Some formulations have zinc to enhance adhesion on wet skin despite knowing the health hazards. Inspired by mussel foot proteins’ catechol unit’s strong underwater adhesion, nine catechol-containing copolymers (P1A-P3C) were synthesized by free radical polymerization of 3,4-dimethoxystyrene (3,4- DMS) with different styrene derivatives followed by deprotection. P1A-P3C were used to make Fn(P)-C-PBS denture adhesive formulations which had suitable shear stresses around ≥ 5 kPa satisfying ISO 10873. In-situ NMR studies of free radical polymerization of 3,4 - DMS and styrene derivatives allowed computation of their reactivity ratios showing all …

A Critical Review And Finite Element Study Of Structural Relaxation In Veneered 3y-Tzp Dental Structures, Prashant S. Shelar

Electronic Thesis and Dissertation Repository

Yttria stabilized Tetragonal Zirconia Polycrystal (3Y-TZP) materials veneered with porcelain are preferred for clinical practice due to their bio-functionality, biocompatibility, and affordability. However, these materials are often subjected to premature clinical failures due to combination of subsurface flaws and tensile stresses within porcelains. This work focuses on performing a critical literature review and evaluating veneer characteristics, i.e. structural relaxation, to form a suitable explanation for the development of subsurface stresses. User material subroutines, UEXPAN and UTRS are developed, validated and integrated in ABAQUS finite element solver. With the use of validated models, it is shown that faster cooling rates and …

Debt And Stress Amongst Orthodontic Residents, Timothy Renison

Electronic Thesis and Dissertation Repository

Background: The cost of education to become an orthodontist has increased significantly over recent years which has led to an increase in debt of graduating orthodontists.

Aim: This paper aims to assess whether debt amongst orthodontic residents in North America is associated with their stress levels, attitudes towards debt, financial literacy and mathematics anxiety.

Materials and Methods: Web-based software was used to fabricate a questionnaire, based on previously validated scales, in which respondents were asked questions regarding their debt levels, stress levels, attitudes towards debt, financial literacy and math anxiety.

Results: A total of 101 orthodontic residents completed the online …

The Role Of Gsk3 Alpha And Beta In Embryonic Craniofacial Development, Harman Jassar

Electronic Thesis and Dissertation Repository

Background: The GSK-3 genes (Gsk3a and Gsk3b) have been known to affect many cellular processes and signaling pathways some of which are implicated in the growth and development of the craniofacial skeleton.

Aim: The purpose of this study was to assess the effect of chondrocyte-specific deletion of Gsk3a and Gsk3b on the size of the mandible and craniofacial skeleton in embryonic mice.

Materials & Methods: Mice were bred to generate cartilage-specific Gsk3a and Gsk3b KO mice. On embryonic day 18.5 (E18.5) the offspring were gathered by caesarian section. Whole mount skeletal staining was completed on the specimens using …

Guidance For Dental Treatment Of Patients With Disabilities During Covid-19 Pandemic, Eun Jung Kwak, Jieun Kim, Hiran Perinpanayagam, Kee Yeon Kum

Dentistry Publications

People with disabilities are challenged managing their oral hygiene and more often burdened with oral diseases. They often require immediate dental treatment for severe pain and greater precautions are needed to cope with COVID-19. The potential for COVID-19 infection can be relatively high in patients with disabilities due to concomitant systemic diseases, unique individual circumstances, relationship with caregivers and the living conditions of long-term care facilities, which make them vulnerable to the virus. For behavior management, dental treatment is often provided under general anesthesia with meticulous preoperative evaluation and the use of high-quality viral filters. In response to COVID-19, additional …