• The effects of altered salivary viscosity on the incidence and extent of dental caries in rats

      Biesbrock, Aaron Reed; Department of Oral Pathology (Augusta University, 1989-05-02)
      The research was intended to determine whether alterations in salivary viscosity brought about by altering dietary components affected the incidence and extent of dental caries in rats.
    • The stability of an increased vertical dimension of occlusion in growing and non-growing golden hamsters

      Berman, Scott C.; Department of Oral Biology (Augusta University, 1993-03)
    • Toxicity of visible light-cured denture resins

      Barron, Dara Jewell; Department of Oral Biology (1992-04)
      In this study three commercial formulations of visible light-cured (VLC) denture resins have been analyzed. The products used are those suggested for the reline, repair and fabrication of dentures to improve their fit. The biocompatibility of these resins was investigated by measuring RNA and DNA synthesis of oral epithelial cells in vitro. The extent to which oral cells recover from toxic resin exposure, the conversion of monomer into polymer, the presence of inorganic filler, and resin leacha~ility have also been studied. It was shown that VLC denture resins inhibit the synthesis of RNA and· DNA relative to a heat-cured resin control (p~0.05). Although epithelial cells appeared to recover from toxic resin exposure, this recovery was inconsistent among experiments. Infrared spectroscopy illustrated chemical group differences that occurred before and after photo-polymerization. Using these differences, the conversion of monomer into polymer ranged from 77% to 97%. This conversion was significantly affected (p< .003) by the type of curing unit, duration of photo-polymerization, and surface exposed to visible light. Soluble substances in cured and uncured resin products were analogous using HPLC. The range of inorganic filler present was 0-15%. These investigations suggest that visible light-cured denture resins may impair the replication of oral epithelial cells. This effect may be related to the leachability of unpolymerized resin constituents, the presence or absence of filler particles, or polymerization by-products.
    • Efficacy of Epigallocatechin-3-gallate-palmitate as a Virucidal Compound Against Norovirus

      Widjaja, Nicole; Department of Oral Biology and Diagnostic Sciences (Augusta University, 2020-05)
      Norovirus is a highly infectious, non-enveloped virus found to be the leading cause of global gastroenteritis outbreaks. Every year within the United States, this virus is responsible for an average of 19-21 million cases of acute gastroenteritis, approximately 570-800 deaths, and has been the cause of 1.7 to 1.9 million outpatient visits. On a global scale, healthcare costs and lost productivity are estimated to $60 billion due to illnesses and outbreaks caused by the burden of norovirus. Unfortunately, current measures to prevent the transmission of norovirus remain insufficient as the Center for Disease Control and Prevention (CDC) can only recommend hand washing with soap and water as the best preventative measure. The only other hand hygiene method available is alcohol-based hand sanitizers, but the CDC states that they are not effective in inactivating norovirus particles and warns that it should not be considered a substitute to hand washing. Recently, epigallocatecin-3-gallate (EGCG) a major component extracted from the leaves of Camellia sinensis, also commonly known as tea plant, has shown potential to be the next viable candidate as an antiviral solution. Lipid derivatives of EGCG, most notably EGCGpalmitate, has shown to express potent antiviral properties and has showed to play a crucial role in the fight against other non-enveloped viruses such as poliovirus and adenovirus. In this study, we determined the efficacy of EGCG-palmitate in novel formulations against human norovirus surrogates by utilizing the EU international standards for hand hygiene in vitro studies against norovirus. Evidence is provided determining the virucidal activity of alcohol-based ProtecTeaV formulations containing EGCG-palmitate as well as the potential for EGCG-palmitate as a persistent residual virucidal activity against norovirus surrogates, feline calicivirus (FCV) and murine norovirus-1 (MNV-1). By creating an effective, environmentally friendly, non-toxic and long lasting solution composed of EGCG-palmitate, the results of this innovative approach would expand the options available to reduce the transmission of norovirus essentially bridging the gap for a new preventative hand hygiene and ultimately impacting the spread of norovirus on a worldwide scale.
    • Influence of Porphyromonas gingivalis on Anti-Apoptotic/Autophagic Signaling Pathways in Human Dendritic Cells

      Meghil, Mohamed; Tawfik, Omnia; Elashirty, Mahmoud; Rajendran, Mythilypriya; Arce, Roger; Schoenlein, Patricia V.; Cutler, Christopher; Department of Oral Biology & Diagnostic Sciences, Department of Periodontics, Department of Cellular Biology and Anatomy (Augusta University, 2019)
      The purpose of this study was to investigate the molecular mechanisims of P. gingivalis-mediated disruption of homeostatic apoptosis and autophagy in DCs.
    • Innate Lymphoid Cells in Periodontitis: A Novel Therapeutic Modality

      Ghaly, Mira; Emami, Golnaz; Khodadadi, Hesam; Mozaffari, Mahmood; Baban, Babak; Department of Periodontics, Department of Oral Biology and Diagnostic Sciences (Augusta University, 2019)
      To determine the presence of ILCs in human periodontium which are emerging immune cells with the potential to be targeted, via novel therapies, in the treatment of peridontitis.
    • Proliferative Verrucous Leukoplakia (PVL) Expresses High Levels of Toll-Like Receptor 2 (TLR2)

      Koh, Joon; Kurago, Zoya; Georgia Cancer Center (Augusta University, 2019)
      In the current study, we analyzed samples of human oral mucosal PVL and other epithelial disorders to test the possibility that, if TLR2 is involved in early stages of carcinogenesis, then keratinocytes in early-intermediate stages of PVL may express more TLR2 than keratinocytes in non-dysplastic epithelium.
    • Phosphorylation of EPS8 Mediates Its Downstream Signaling and Biological Functions

      Shahoumi, Linah; Yeudall, W. Andrew; Department of Oral Biology & Diagnostic Sciences, Georgia Cancer Center (Augusta University, 2019)
      The purpose of this study was to investigate the role of EPS8 phosphorylation in modulating biochemical signaling, cell proliferation and motility in HNSCC.
    • Biocompatibility and mechanical/physical properties of 3D printed, milled, and conventionally processed denture base materials

      Ulmer, Mallory; Biomedical Sciences (Augusta University, 2019-12)
      According to the American College of Prosthodontists, over 36 million people in the USA are edentulous with a 2:1 predilection for geriatric patients1. Each year, an estimated 15% of edentulous Americans will seek denture treatment1. Conventional dentures require multiple visits and lab processing time. 3D printing technology offers the potential to reduce the number of appointments and speed up the time until patient rehabilitation. However, the newly FDA-certified 3D printer denture resins, featuring secretive and proprietary formulae, lack studies concerning their biocompatibility/safety and mechanical strength. This study aims to investigate the biocompatibility and physical properties of one such 3D printer resin, NextDent® Base (Vertex, Soesterberg, The Netherlands), and compare it to pre-existing conventional polymethyl methacrylate (PMMA) denture base (Lucitone 199, Dentsply Sirona, York, Pennsylvania) and milled PMMA denture base (IvoBase CAD®, Ivoclar Vivadent AG, Schaan, Liechtenstein). The cytotoxicity was examined using of 12 discs: conventional PMMA, milled PMMA, as-printed 3D printer resin, post-cured 3D printer resin, and Teflon controls. An MTT assay using human periodontal ligament (900L) cells was employed, and specimens were aged for 1, 3, 7, 10, and 14 days. After day 7, there were no statistically significant differences among the groups, excluding the Teflon control, which showed significantly less cell viability on day 14. Bars of conventional PMMA, milled PMMA, as-printed 3D printer resin, and post-cured 3D printer resin were subjected to a 3-point bend test to examine flexural strength and moduli differences. The mean flexural strength was 63.8 ± 3.06, 82.6 ± 1.9, 5.1 ± 0.4, and 22.1 ± 6.4 MPa, respectively, while the flexural moduli were 1757.3 ± 109.5, 2226.7 ± 76.3, 110.3 ± 20.3, and 537.0 ± 210.6 MPa, respectively. The flexural strength and modulus were significantly different among all groups. Weibull analyses for conventional PMMA, milled PMMA, as-printed 3D printer resin, and post-cured 3D printer resin revealed a Weibull modulus of 23.5, 42.8, 16.6, and 3.7, respectively, and a characteristic strength of 65.2, 83.5, 5.3, and 24.5 MPa, respectively. The characteristic strength was significantly different among all groups as well. The Weibull modulus was significantly different between all groups, except for conventional vs. as-printed, which were not significantly different. In summary, milled PMMA featured significantly greater mechanical properties. Both 3D printed groups proved to be very weak, with the as-printed group being the weakest of all. The differences between the as-printed and post-cured groups highlight the importance of properly post-curing the resin. While the biocompatibility results showed promise, the mechanical testing results were disappointing. Unfortunately, the findings suggest that 3D-printed denture base resin is not yet ready for clinical use.
    • The Effect of Nrf2 on Inflammatory Responses of Human Monocytic Cells After Blue Light Exposure

      Trotter, Leigh Ann; Trotter, Leigh Ann; Department of Oral Biology (12-Apr)
      Blue light treatment alters cellular signaling and affects intracellular biochemical processes in tissues. PURPOSE: This study determined the ability of blue light to modulate Nrf2 and decrease LPS-induced secretion of pro-inflammatory cytokines from cultured, human monocytic cells. METHODS: Cultured THP-1 human monocytic cells were exposed to LPS and blue light treatment. Western Blot analyses, EMSA, and ELISA were used to evaluate NF?B, Nrf2, HO-1, TNF-?, IL-6 and IL-8 production. RESULTS: Light treatment increased nuclear Nrf2 and increased HO-1. Cells pretreated with light had no detectable NF?B-DNA binding. LPS treatment increased nuclear NF?B, and had little effect on Nrf2. Light pre-treatment significantly decreased the amount of TNF-? by 63% and IL-8 by 55%. CONCLUSIONS: Blue light increases the production of Nrf2 and HO-1, decreases the ability of Nf?B to bind in the nucleus, and leads to a decrease in the secretion of pro-inflammatory proteins in human monocytic cells.
    • The role of Toll-like receptor (TLR) 2 in the systemic immune response profile of mice induced to develop squamous cell carcinoma of the upper aerodigestive tract

      El-Shafey, Sally; El-Shafey, Sally; Department of Oral Biology (4/1/2017)
      Background Head and necksquamous cell carcinomais associated with immunosuppression, a state in which the progression of cancer is associated with disturbances in the immune system functions. Emerging studies suggest a fundamental role for the innate immune system, particularly Toll-like receptor 2 (TLR2), in this process.QuestionsIn this study, we investigated the potential roles of TLR2 on systemic immune profile in a mouse model of headand necksquamous cell carcinoma.MethodsTwo different protocols of a mouse model of 4-nitroquinoline 1-oxide and ethanol-induced carcinogenesis to induce head and neck squamous cell carcinoma were used. To evaluate the systemic immune profiles, total RNA wasisolated from the spleens of four groups of animals, including carcinogen-treated and control untreated wild-type and toll-like receptor 2-deficient animals. Quantitative real-time PCR was performed forgenesrepresentative of house-keeping genes, type 1 and type 2 immune responses, regulatory T and B cells, and adenosine receptors.Results and ConclusionIn the standard protocol of 4-nitroquinoline 1-oxide and ethanol-induced carcinogenesis, there was asignificant upregulation of adenosine receptor A2a in the spleens of wild type iiimice treatedwith4-nitroquinoline 1-oxide and ethanolrelative to wild type untreatedanimals. In the standard protocol of carcinogenesis, there was a significant upregulation of CD39 in the spleens of TLR2-koanimalstreated with 4-nitroquinoline 1-oxide and ethanol relative to untreated TLR2-ko mice. These results suggest that carcinogenesis in the upper aerodigestive tract is associated with alterations in the systemic immune profile reflected in the spleen. However, the specific impact on the immune profiles appears to be affected by the presence or absence of TLR2.

      Elzinga, Jennifer Lynn; Department of Oral Biology (2/1/2013)

      Abraham, Pheba; Abraham, Pheba; Department of Oral Biology (5/1/2017)
      This study was to explore the effect of local, matrix-bound bisphosphonates to monocytedifferentiation and osteoclast function in vitro. Experiments were designed using osteoassay plates. Cell-viability, differentiation, resorption pits and gene expression were analyzed to see the effect of matrix-bound BPs on monocyte differentiation and osteoclast function. EDTA was used as a chelating agent to remove the bound BPs. There was a dose dependent response in the differentiation and resorption pits. With chelation, there was increase in differentiation, resorption pits and increase in the calcium and PYD in the supernatant. Thus, matrix-bound Bisphosphonatesare biologically active and they inhibit monocyte differentiation and osteoclast function. Thereby removal of this matrix-bound drug can rescue osteoclast differentiation and function.