• Dentin Sialophosphoprotein (DSPP) Gene-Silencing Inhibits Key Tumorigenic Activities in Human Oral Cancer Cell Line, OSC2

      Joshi, Rajeshree; Tawfik, Amany; Edeh, Nneka; McCloud, Veronica; Looney, Stephen W.; Lewis, Jill; Hsu, Stephen; Ogbureke, Kalu U.E.; Department of Oral Biology; Department of Pathology; et al. (2010-11-12)
      Background: We determined recently that dentin sialophosphoprotein (DSPP), a member of the SIBLING (Small integrin-binding ligand N-linked glycoproteins) family of phosphoglycoproteins, is highly upregulated in human oral squamous cell carcinomas (OSCCs) where upregulation is associated with tumor aggressiveness. To investigate the effects of DSPP-silencing on the tumorigenic profiles of the oral cancer cell line, OSC2, short-hairpin RNA (shRNA) interference was employed to silence DSPP in OSC2 cells.
    • Differential effects of taurine treatment and taurine deficiency on the outcome of renal ischemia reperfusion injury

      Mozaffari, Mahmood S.; Abdelsayed, Rafik; Patel, Champa; Wimborne, Hereward J. C.; Liu, Jun Yao; Schaffer, Stephen W; Department of Oral Biology; Department of Oral Health and Diagnostic Sciences (2010-08-24)
      Taurine possesses membrane stabilization, osmoregulatory and antioxidant properties, aspects of relevance to ischemic injury. We tested the hypothesis that body taurine status is a determinant of renal ischemic injury. Accordingly, renal function and structure were examined in control (C), taurine-treated (TT) and taurine deficient (TD) rats that were subjected to bilateral renal ischemia (60 min) followed by reperfusion (IR); sham operated rats served as controls. Baseline urine osmolality was greater in the TD group than in the control and the TT groups, an effect associated with increased renal aquaporin 2 level. The IR insult reduced urine osmolality (i.e., day-1 post insult); the TD/IR group displayed a more marked recovery in urine osmolality by day-6 post insult than the other two groups. Fluid and sodium excretions were lower in the TD/IR group, suggesting propensity to retention. Histopathological examination revealed the presence of tubular necrotic foci in the C/IR group than sham controls. While renal architecture of the TD/IR group showed features resembling sham controls, the TT/IR group showed dilated tubules, which lacked immunostaining for aquaporin 2, but not 1, suggestive of proximal tubule origin. Finally, assessment of cell proliferation and apoptosis revealed lower proliferation but higher apoptotic foci in the TT/IR group than other IR groups. Collectively, the results indicate that body taurine status is a major determinant of renal IR injury.
    • Direct Composite restorations Using a Clear PVS Matrix to restore Worn Anterior Dentition to Create an Ideal Occlusal Plane

      Fowlkes, Colton; Romero, M; Urbanawiz, D; Department of Restorative Sciences (Augusta University, 2019)
      This clicnical case documents the use of a clear PVS matrix technique to restore the incisal edges of worn mandibular anterior teeth using flowable composite to provide a 20 degree template for eventual complete maxillary denture and mandibular removable partial denture frabrication.
    • DNA Sequencing of Extensive Odontogenic Keratocysts with Possible Therapeutic Implications

      Abdelsayed, Macarius; Kolhe, Ravindra; Abdelsayed, Rafik; Department of Oral and Maxillofacial Pathology (Augusta University, 2019)
      Purpose of this research is: to perform DNA sequencing on a group of previously diagnosed OKC of the jaws which demonstrated clinical aggressive behavior; Compare the genetic profile of the aggressive OKC cases with the genetic profile of a similar number of OKC cases which did not demonstrate aggressive clinical behavior; Evaluate the possibility of therapeutic implications of genetic mutations noted in OKCs
    • Does Time to the Operating Room Affect Outcomes in Odontogenic Infection Patients?

      Brown, Kiara; James, Jeffery; Department of Oral and Maxillofacial Surgery (Augusta University, 2019)
      Diagnosis and treatments of odontogenic infections is arguably one of the most important responsibilities of the Oral and Maxillofacial Surgeon. With a command of the complex anatomy of the head and neck region and armed with knowledge of the dentition that feeds into the physiopathology of the infection, oral and maxillofacial surgeons find themselves one of the only head and neck specialists able to treat this disease. Several decades ago, odontogenic infections were a significant source of morbidity at rates greater than 50% in some reports. The current trend in an increase in unsponsored patients seeking treatment. This trend has cost hospital centers upwards of millions of dollars per year. While some factors, such as patient medical complexity and increasing antibiotic resistance are known factors in increasing costs, a surgeon and facility dependent factor- time to the operating room- has not been studied. Understanding the effect of delayed surgical intervention is critical to fully understanding ways to mitigate costs associated with odontogenic infection patients.
    • Ed Mills Interview

      Downing, Paul R (2011)
      This issue of the Palmetto Leaflet contains an interview with the Director of the MCG Dental Implant Maxi Course, Dr. Ed Mills.
    • Effect of an Er,Cr:YSGG Laser on P. Gingivalis-Contaminated Titanium Alloy Dental Implant Surfaces In Vitro

      Strever, Jason; Department of Oral Biology (2016-04)
      Implant dentistry has become a widely accepted modality to replace missing teeth. However, dental implants are susceptible to biofilm-mediated inflammatory lesions (peri-implant mucositis / peri-implantitis), similar to that seen around natural teeth (gingivitis / periodontitis). These lesions, in turn, threaten the longevity of implants as anchors for dental prostheses. Because of the similarity in etiology and presentation, comparable treatment modalities are applied to resolve peri-implant and periodontal inflammatory lesions. Such a shared treatment includes mechanical debridement, with or without surgical repositioning of the soft tissue complex. However, most contemporary dental implants feature threads to engage the alveolar bone and a micro/nano-textured surface to stimulate bone-implant contact (osseointegration). Therefore, when the implant threads become exposed and contaminated by biofilm, subsequent surface debridement / decontamination becomes considerably more complex than with that of a natural tooth, which is usually debrided using a metal curette or ultrasonic device. The micro/nano-textured surface of a dental implant is easily damaged by instrumentation using a metal curette. If an efficient method of dental implant surface decontamination could be established, then clinical protocols may be developed that effectively clean the implant surface to achieve peri-implant tissue health. To this end, lasers have been introduced; however, directly applied laser energy may also affect implant surface characteristics, including micro/nano-structure and composition, essential to osseointegration. Therefore, lasers may have disadvantageous clinical effects, in turn compromising peri-implant tissue consolidation and health: the very aspects its use is attempting to provide. Commercially available Er,Cr:YSGG lasers have been used to remove such implant-attached deposits, however the efficacy in removal of bacteria and the safety to the implant surface integrity have yet to be demonstrated quantitatively.
    • Effect of b-alanine treatment on mitochondrial taurine level and 5-taurinomethyluridine content

      Jong, Chian Ju; Ito, Takashi; Mozaffari, Mahmood S.; Azuma, Junichi; Schaffer, Stephen W; Department of Oral Biology (2010-08-24)
      Background: The b-amino acid, taurine, is a nutritional requirement in some species. In these species, the depletion of intracellular stores of taurine leads to the development of severe organ dysfunction. The basis underlying these defects is poorly understood, although there is some suggestion that oxidative stress may contribute to the abnormalities. Recent studies indicate that taurine is required for normal mitochondrial protein synthesis and normal electron transport chain activity; it is known that defects in these events can lead to severe mitochondrial oxidative stress. The present study examines the effect of taurine deficiency on the first step of mitochondrial protein synthesis regulation by taurine, namely, the formation of taurinomethyluridine containing tRNA.
    • EFFECT OF MATRIX-BOUND BISPHOSPHONATES ON MONOCYTE DIFFERENTIATION AND OSTEOCLAST FUNCTION

      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.
    • Effect of Metformin on Oral Implant Healing in Type 2 Diabetic Rats

      Inouye, Kimberly Ann; Department of Oral Biology (2011-04)
      In dentistry today, endosseous implants have become a generally favorable treatment option for edentulous spaces in the oral cavity because of proven biocompatibility, potential for esthetics, and good long term prognosis.(1) However, there are risk factors to consider that may affect and impair the osseointegration of an implant. A possible risk factor is type 2 diabetes mellitus (T2DM), a metabolic disorder characterized by insulin resistance at the target tissue site and progressive destruction of the pancreatic beta cells that ultimately results in prolonged periods of hyperglycemia.(2) When the serum glucose levels were persistently high, it was shown to impair bone metabolism and thus, has the potential to impair implant osseointegration.(3)
    • 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.
    • EFFECT OF PRINT ANGULATION, MODEL RESIN, AND PRINTER ON DIMENSIONAL ACCURACY OF 3D PRINTED MODELS

      Fantaski, Lincoln; Mettenburg, D; Brenes, C; Rueggeberg, FA; Department of Restorative Sciences, Department of General Dentistry (Augusta University, 2019)
      Recent advances in the application of digital imaging of oral tissues and three-dimensional, additive fabrication techniques have led to a burgeoning industry in dentistry. Over a very short period of time, this technology has greatly improved in terms of level of surface detail reproducibility and dimensional accuracy of printed forms. Initially, thermoplastic extrusion of warmed filaments of various plastic material was used. However, the layer thickness was quite large, and surface feature reproduction was low. With advances in use of photocurable monomer resins and controlled application of photo-activating light wavelengths to provide polymerization of very thin slices of the form image, the reality of providing stoneless models of a patient’s dentition became a physical, and financial reality in private dental practices.
    • The Effect of Processing Techniques for rhBMP-2 Coated Titanium Implants on Alveolar Augmentation and Osseointegration in the Canine Supraalveolar Peri-Implant Defect Model

      Decker, John; Department of Oral Biology (9/5/2014)
      A current paradigm-shift in implant dentistry places restorative factors associated with esthetics and function in front of implant site selection based on bone quantity and quality. Marginal bone loss after implant placement, resorption of the edentulous alveolar ridge, bone defects from periodontal disease, and ridge aberrations due to trauma all challenge implant treatment driven by esthetics and function. Clinicians compensate for bone loss using bone augmentation procedures including bone grafts, bone materials, biologic mediators, barrier devices, or combinations thereof. The search for treatment modalities to address implant placement into compromised sites has lead to the development of a variety of products designed to replace or induce bone formation. Some believe an ideal material could be coated onto implants, to promote osseointegration, induce local bone formation, while not requiring adjunctive biomaterials, or procedures including placement of allogeneic and xenogeneic biomaterials, or autograft bone.
    • The Effect of Solvent Type and Content on Monomer Conversion of a Model Resin System and 5th Generation Dentin Bonding Agents

      Holmes, Robert G.; Department of Oral Biology (2006-05)
      Fifth generation dentin bonding agents contain a variety of solvents. These solvents have a range of evaporation rates, which leads to differing amounts of residual solvent remaining at time of cure. Residual solvent could affect resin polymerization, and thus resultant properties of the bonded resin/dentin interface.
    • EFFECT OF TIP-TO-TARGET DISTANCE ON IRRADIANCE AMONG A VARIETY OF LED LIGHTS

      Klein, Laura; Rueggeberg, FA; Department of Restorative Sciences (Augusta University, 2019)
      Purpose of this research: To measure and compare (1) tip-to-target distance irradiance profiles (2) tip-to-target distance at which irradiance has dropped to 50% of 0-mm value (3) irradiance value at the 50% distance.
    • EFFECT OF WAVELENGTH EXPOSURE SEQUENCE ON COMPOSITE HARDNESS

      Patel, Mohit; Mettenburg, D; Rueggeberg, FA; Cellular and Molecular Biology, Department of Restorative Sciences (Augusta University, 2019)
      To measure and compare composite top and bottom surface microhardness values when using a multi-wave LED curing light emitting simultaneous blue and violet light, or when the sequence of wavelength applications was provided as separate exposures, of similar duration.
    • 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.
    • Effects of chromium picolinate on glycemic control and kidney of the obese Zucker rat.

      Mozaffari, Mahmood S.; Abdelsayed, Rafik; Liu, Jun Yao; Wimborne, Hereward J. C.; El-Remessy, Azza B.; El-Marakby, Ahmed; Department of Oral Biology; Department of Oral Health and Diagnostic Sciences (2009-12-30)
      ABSTRACT: BACKGROUND: Chromium picolinate (Cr(pic)3) is advocated as adjuvant therapy for impaired glycemic control, despite concerns for DNA damage. Potential toxicity of Cr(pic)3 should be greater for the kidney that accumulates chromium. Therefore, we tested the hypothesis that Cr(pic)3 treatment of obese Zucker rats (OZR) exacerbates renal abnormalities associated with dysglycemia. METHODS: Male OZR were treated with diets lacking or containing 5 and 10 mg/kg of chromium, as Cr(pic)3, for 20 weeks; lean Zucker rats (LZR) served as controls. Glycemic and renal effects of Cr(pic)3 were determined in the context of indices of oxidative stress and inflammation. RESULTS: The OZR displayed increased fasting plasma glucose and insulin in association with enlarged pancreatic islets exhibiting collagen and periodic acid Schiff-positive deposits compared to LZR; Cr(pic)3 treatment did not affect these parameters. The OZR, irrespective of Cr(pic)3, excreted more albumin than LZR. Also, other indices of renal function or histopathology were not affected by Cr(pic)3 treatment. Urinary excretion of 8-hydroxydeoxyguanosine (8-OHdG), an index of oxidative DNA damage, was greater in the OZR than LZR; dietary Cr(pic)3 treatment attenuated 8-OHdG excretion. However, immunostaining of kidney for 8-OHdG revealed similar staining pattern and intensity, despite significant renal accumulation of chromium in Cr(pic)3-treated groups. Finally, increased renal nitrotyrosine and cyclooxygenase-2 levels and urinary excretion of monocyte chemoattractant protein-1 of OZR were partially reversed by Cr(pic)3 treatment. CONCLUSION: Dietary Cr(pic)3 treatment of OZR does not beneficially influence glycemic status or increase the risk for oxidative DNA damage; rather, the treatment attenuates indices of oxidative stress and inflammation.