• In Vitro mechanical Analysis of Full-Arch Mandibular Implant-Supported, Complete Fixed Prosthesis Retainer Screws After Cyclic Loading

      Sananez, Andreina J.; Department of Oral Biology (2012-04)
      The use of implant-retained and supported prostheses has become a very successful treatment for completely edentulous patients. One of the most common fixed solutions involving implants consists of 5 to 7 implants supporting a framework upon which either porcelain or prefabricated acrylic resin denture teeth are added. A screw is utilized to attach the framework/prosthesis to the implants. Screw loosening is the second most common clinical complication in the implant-prosthesis system. If clinicians fail to detect worn or loose retaining screws, prosthetic fracture could occur, leading to more complicated, time consuming, and expensive repairs. Unfortunately, there is no established parameter that indicates when to expect these complications, and there is no proven recall-maintenance protocol to prevent them. The aim of this study is to examine and compare differences among de-torque values and prosthetic retention screws, using a simulated 5 implant-supported, mandibular complete fixed prosthesis. Material and Methods: Nine groups, each with its respective control, using five Nobel Biocare implants and a milled titanium framework were fabricated, assembled and tested. Dynamic loading was p on the performed tested groups through a custom made loading device for anterior, posterior, and distal cantilevered segments of the prosthesis, calculated to simulate clinical usage time. Removal of screws after 2 years of simulated oral function was performed. Before and after testing, screws were evaluated with a Scanning Electronic Microscope (SEM), for presence of debris, thread striations and homogeneity. Control groups remained unloaded for the same time the loaded groups were tested. Results: Comparisons of the difference between initial tightening torque and de-torque screw values were performed between loaded/unloaded groups and with respect to implant position. The interaction between loaded and position was significant (p=0.002). The comparison between loaded/unloaded groups was not statistically significant (p=0.518). Loaded and unloaded groups were compared separately at each of the 5 implants position, which showed a significant difference (p=0.0002, α=0.001). The sequencing effect was only seen in the control groups and thus would only be relative to framework insertion. The sequence effect was found to be overcome by from loading and resulted in a totally different position related to screw tightness. Within the limitations of this in vitro study, it was concluded that sequence of torque application could play a role in the preload of screws even with a passive fit, regardless the load applied.
    • In Vivo Pilot Study: Effect of Dehydration/Rehydration on Upper Anterior Tooth Color Change

      Britton, Eduardo; Nappi, A; Cao, T; Shepherd, K; Department of General Dentistry, Dental Hygiene, Department of Restorative Sciences (Augusta University Libraries, 2019)
      Isolation of tooth structure during fabrication of a bonded, direct, resin-based restoration is essential to optimizing its potential for long-term clinical success. Failure to protect etched enamel and bonding agents from contamination by saliva results in inadequate and unpredictable interfacial bonding of the restorative composite, potentially leading to marginal discoloration, open margins, recurrent decay, or ultimately to restoration loss or failure. A consequence of tooth isolation during placement of direct, esthetic restorative resins is the dehydration of enamel surfaces that will not be coated with saliva, and will, over time, lose water that has penetrated into the outer enamel layers (will dehydrate). The longer the tooth isolation time, the greater will be the subsequent loss of water from enamel. Presence of this water in enamel helps to provide for a stable tooth color. In teeth, the observed tooth color is the result of internal light penetration and interaction with tissues below the surface. Enamel is a translucent material, passing a great majority of transmitted light to fall on the more opaque and yellow-colored tissue underneath of it: dentin. In the hydrated state, enamel is more translucent than in its dehydrated state. The white opaque appearance of dehydrated enamel can be of great clinical concern, once a rubber dam has been removed, and the treated teeth with newly placed restorations are observed. Usually, because of the opaque, white nature of recently dehydrated enamel, there is an initial mismatch between an esthetic restoration just placed and its surrounding, remaining enamel. Patients are normally forwarded of this consequence, and are advised that a period of time needs to pass before the surrounding enamel becomes rehydrated, and more translucent (less opaque), before its pre-isolated color returns to a natural state. It is hoped that, at that time, the new restoration will perfectly match the color characteristics of the remaining enamel, and the recent replacement will not be visible at all, but will instead optically blend in without notice. However, prior to that time, there are definitely distinct color differences between a recently placed resin restoration and its surrounding tooth structure. To date, little-to-no information is available on the rate at which a clinician or patient can expect isolated enamel to return to its pre-isolated color, and when to expect this esthetic blending to occur.
    • Increased Expression and Activity of 12-Lipoxygenase in Oxygen-Induced Ischemic Retinopathy and Proliferative Diabetic Retinopathy

      Al-Shabrawey, Mohamed; Mussell, Rene; Kahook, Khalid; Tawfik, Amany; Eladl, Mohamed; Sarthy, Vijay; Nussbaum, Julian; El-Marakby, Ahmed; Park, Sun Young; Gurel, Zafer; et al. (2011-01-21)
      OBJECTIVE: Arachidonic acid is metabolized by 12-lipoxygenase (12-LOX) to 12-hydroxyeicosatetraenoic acid (12-HETE) and has an important role in the regulation of angiogenesis and endothelial cell proliferation and migration. The goal of this study was to investigate whether 12-LOX plays a role in retinal neovascularization (NV).
    • Induction of Hemeoxygenase-1 Reduces Renal Oxidative Stress and Inflammation in Diabetic Spontaneously Hypertensive Rats

      Elmarakby, Ahmed A.; Faulkner, Jessica; Baban, Babak; Sullivan, Jennifer C.; Department of Oral Biology; Department of Medicine (2012-02-26)
      The renoprotective mechanisms of hemeoxygenase-1 (HO-1) in diabetic nephropathy remain to be investigated. We hypothesize that HO-1 protects the kidney from diabetic insult via lowering renal oxidative stress and inflammation. We used control and diabetic SHR with or without HO-1 inducer cobalt protoporphyrin (CoPP) treatment for 6 weeks. Urinary albumin excretion levels were significantly elevated in diabetic SHR compared to control and CoPP significantly attenuated albumin excretion. Immuno-histochemical analysis revealed an elevation in TGF-b staining together with increased urinary collagen excretion in diabetic versus control SHR, both of which were reduced with CoPP treatment. Renal oxidative stress markers were greater in diabetic SHR and reduced with CoPP treatment. The increase in renal oxidative stress was associated with an elevation in renal inflammation in diabetic SHR. CoPP treatment also significantly attenuated the markers of renal inflammation in diabetic SHR. In vitro inhibition of HO with stannous mesoporphyrin (SnMP) increased glomerular NADPH oxidase activity and inflammation and blocked the anti-oxidant and anti-inflammatory effects of CoPP. These data suggest that the reduction of renal injury in diabetic SHR upon induction of HO-1 are associated with decreased renal oxidative stress and inflammation, implicating the role of HO-1 induction as a future treatment of diabetic nephropathy.
    • Inflammatory cytokines as predictive markers for early detection and progression of diabetic nephropathy

      Elmarakby, Ahmed A.; Abdelsayed, Rafik; Yao Liu, Jun; Mozaffari, Mahmood S.; Department of Oral Biology (2010-03-13)
      Keywords: Renal disease
    • 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.
    • Inherent Gene Expression and Protein Profile Differences Between Alveolar and Basal Bone

      Alotaibi, Fawwaz; Department of Oral Biology (5/1/2015)
      The mandible is composed to two bone types: alveolar and basal. Previous studies on the mandible have shown that the alveolar bone resorbs more than the basal bone after tooth extraction or as a result of tooth movement. Reasons for why the resorption rates are different is not well understood. This research begins exploring the differences of the alveolar and basal bone by using comparison characteristics such as bone mineral density (BMD), gene expression, protein profiles, and number of osteocytes. The research investigates these characteristics by using Real time RCR to study the differences in gene expression and protein profiles of the alveolar and basal bone. Micro-CT was used in comparing density and bone architecture characteristics of the alveolar and basal bone. Immunohistochemistry was used to better understand how osteocytes are different between the two bone types in hopes of later being able to understand the differences in resorption rates. The real time PCR showed that four genes are expressed significantly higher in basal bone than alveolar bone: SOST, E-11, DMP-1, MEPE. Three of which are associated with mature osteocytes indicating that basal bone has more mature osteocyte phenotypes. Micro-CT data indicated that the basal bone is denser and less porous than alveolar bone. There was no significant difference in immunohistochemistry and further quantitative testing is needed to draw and significant correlation.
    • Injection of Tumescent Solution into Maxillary Sinuses During LeFort I Osteotomies for Reduction of Intra-operative Blood Loss

      Zastrow, Stephanie; James, Jeffrey; Department of Oral and Maxillofacial Surgery (Augusta University, 2019)
      Orthognathic surgery is a treatment option for many dentofacial deformities that cannot be treated with orthodontics or minor surgeries alone. Repositioning of the maxilla, mandible, chin, or a combination of the three can have a significant effect on a patient’s occlusal function, facial appearance, and self-esteem. Successful, comprehensive treatment usually requires a collaborative approach between an orthodontist and oral and maxillofacial surgeon.
    • 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.
    • Investigation of the Clinical Feasibility of Incorporating Dexmedetomidine into the Outpatient Anesthesia Regimen of Oral & Maxillofacial Surgery

      Taylor, D. Craig; Ferguson, Henry W.; Department of Oral and Maxillofacial Surgery (Augusta University, 2019)
      The purpose of this investigation is to evaluate incorporating a Dexmedetomidine infusion into an established IV Sedation regimen in terms of clinical efficiency (Anesthesia time), Patient subjective experience, and physiologic response to the infusion in comparison to a control appointment without the infusion.
    • Marker Co-Expression Analysis of Initial Cellular Events in the Critical-Size Rat Calvarial Defect Model and the Effect of Bone Morphogenetic Protein-2 (rhBMP-2)

      Capetillo, Joseph F.; Department of Oral Biology (4/15/2016)
      Craniofacial defects can result from congenital malformations, trauma, tumor resection,periodontal disease, post-extraction ridge remodeling, and peri-implantitis. Regenerationof bone is critical to achieving functional and esthetic outcomes in the rehabilitation ofsuch defects. Traditional strategies for osseous regeneration include a multiple ofsurgical techniques utilizing autologous bone, cadaver-sourced allogeneic or xenogeneicbone, synthetic bone biomaterials, barrier membranes, or combinations thereof(Wikesjö, Qahash 2009). The need to enhance the predictability of regeneration inespecially large defects that cannot heal adequately without intervention (critical-sizedefects) has led to recent development of protein- and cell-based technologies.[Introduction, first paragraph]
    • Maxillary growth in patients with complete unilateral cleft lip and palate treated with Nasoalveolar molding

      Manente, M; Levy-Bercowski, D; Abreu, A; Fortson, W; Deleon, E; Yu, J; Looney, S; Department of Orthodontics; Department of Plastic Surgery; Department of Biostatistics and Data Science (Augusta University Libraries, 2019)
      In patients with cleft lip and/or palate (CLP), the nasolabial defect has a significant esthetic impact on the face and may impair psychosocial development. Nasoalveolar molding (NAM) is a pre-surgical orthopedic technique aimed to improve the alveolar and nasolabial morphology of patients with cleft lip and palate. This technique is used to facilitate and improve the future surgical correction in cleft lip and palate patients. Influences such as differences in patient age and gingivoperiosteoplasty procedures are among many that have made it difficult for conclusive results to be found and published on the impact of the NAM technique on maxillary growth in patients with complete unilateral cleft lip and palate (CUCLP).
    • A multidisciplinary approach to the management of a maxillary midline diastema: A clinical report

      Romero, Mario F.; Babb, C; Department of Restorative Sciences, Department of General Dentistry (Augusta University, 2019)
      Anterior maxillary spacing has been shown to be one of the most negative influences on self-perceived dental appearance, and a maxillary midline diastema (MMD) is commonly cited by patients as a primary concern during dental consultations. MMD has been defined as a space greater than 0.5 mm between the mesial surfaces of the 2 maxillary central incisors. An MMD greater than 2 mm in the mixed dentition is unlikely to spontaneously close. African Americans are more than twice as likely to have an MMD than whites or Hispanics. In esthetic situations, without a comprehensive smile analysis and proper planning, overtreatment and undesirable effects can occur. Tooth size especially has been emphasized as the primary element of an esthetic smile design. One method of establishing tooth size is tooth biometry as described by Chu. He reported that maxillary anterior tooth widths average 8.5 mm for central incisors, 6.5 mm for lateral incisors, and 7.5 mm for canines and that 80% of the patient population falls within ±0.5 mm of these values. Other important elements of smile analysis include the dental midline, tooth morphology, axial inclinations, and the soft tissue components of gingival health, levels, and harmony. The direct bonding technique is a straightforward, conservative method for diastema closure. However, artistic skills, a knowledge of tooth morphology, and the appropriate selection and use of composite resin materials are essential for success. According to Spear and Kokich, “some existing dentitions simply cannot be restored to a more pleasing appearance without the assistance of several different dental disciplines.” Therefore, complex esthetic dilemmas may require more than one dental discipline, for example, operative dentistry and orthodontics, to establish a functional, maintainable, and pleasant smile. This article illustrates a clinical situation in which an MMD was addressed by first completing a comprehensive smile analysis, followed by closure using limited orthodontics and direct composite resin restorations.
    • Murine Dendritic Cell Interactions with Minor-fimbriae P. gingivalis

      Yuan, J; Auersvald, c; Elashiry, M; Meghil, M; Elashiry, M; Finger Stadler, A; Arce, R.M.; Department of Periodontics (Augusta University, 2019)
      The objective was to determine DC maturity phenotype of murine bone marrow-derived DCs in response to wild/type (PgWT) and minor-fimbriated DPG3.
    • NOMA: A Preventable "Scourge" of African Children

      Ogbureke, Kalu U.E.; Ogbureke, Ezinne I; Department of Oral Biology; Department of Oral Health and Diagnostic Sciences (2010-10-21)
      Noma is a serious orofacial gangrene originating intraorally in the gingival-oral mucosa complex before spreading extraorally to produce a visibly destructive ulcer. Although cases of noma are now rarely reported in the developed countries, it is still prevalent among children in third world countries, notably in sub-Sahara Africa, where poverty, ignorance, malnutrition, and preventable childhood infections are still common. This review summarizes historical, epidemiological, management, and research updates on noma with suggestions for its prevention and ultimate global eradication. The global annual incidence remains high at about 140,000 cases, with a mortality rate exceeding 90% for untreated diseases. Where the patients survive, noma defects result in unsightly facial disfigurement, intense scarring, trismus, oral incompetence, and social alienation. Although the etiology has long been held to be infectious, a definitive causal role between microorganisms cited, and noma has been difficult to establish. The management of noma with active disease requires antibiotics followed by reconstructive surgery. Current research efforts are focused towards a comprehensive understanding of the epidemiology, and further elucidation of the microbiology and pathogenesis of noma.
    • Novel Therapeutic Approaches to Leishmania Infection

      Makala, Levi HC; Baban, Babak; Department of Pediatrics; Department of Oral Biology (InTech, 2014-03-19)
      Leishmaniasis is a parasitic disease transmitted by phlebotomine sandflies. Approximately 1.2 million cases of cutaneous leishmaniasis (CL) and 500,000 cases of visceral leishmaniasis (VL), which is lethal if untreated, occur annually across the globe as per world health organization (WHO) estimates [1-3]. Current statistics and information relevant to leishmaniasis are summarized in Table 1. Leishmaniasis currently affects about 12 million people and it is estimated that approximately 350 million people live in risk of infection [1-3].The number of cases of leishmaniasis is probably underestimated because only 40 of the 88 countries where diseases frequently occur report them on a regular basis [4]. Leishmaniasis, is caused by several leishmania spp., that are obligate intracellular and unicellular kinetoplastid protozoan flagellate that establish themselves within the phagolysosome of host immune competent cells, especially macrophages and dendritic cells (DCs). In 1903, W.B. Leishman and C. Donovan reported this new parasite at the turn of the century [5,6]. Ronald Ross christened the new genus leishmania and the new species donovani in year 1903 [7]. L. major infection (leishmaniasis) in mice is a widely used model of human infection that has yielded critical insights into the immunobiology of leishmaniasis [8-10]. Leishmaniasis as a parasitic disease manifests itself mainly in 3 clinical forms; visceral leishmaniasis (VL), cutaneous leishmaniasis (CL) and mucocutaneous leishmaniasis (MCL), of which VL is the most severe form of the disease. VL is lethal if untreated and spontaneous cure is extremely rare. Cutaneous leishmaniasis usually has milder course and often results into a self-healing of ulcers. Resolution of leishmanial infection is dependent on the coordinated interactions between components of cell mediated immune response, specifically the activation of targeted T-cell populations for appropriate cytokine production and activation of macrophages. L. major infection of B6 and BALB/c mouse strains drives predominantly TH1 and TH2 responses, respectively [11-14]. In murine model, the development of Th1 response is associated with control of infection, and Th2 response is associated with disease progression. However, Th1 and Th2 dichotomy in the human system is not as distinct as in mice and the murine model does not strictly apply to human leishmaniasis.
    • An ORMOSIL-Containing Orthodontic Acrylic Resin with Concomitant Improvements in Antimicrobial and Fracture Toughness Properties

      Gong, Shi-qiang; Epasinghe, Jeevani; Rueggeberg, Frederick A.; Niu, Li-na; Mettenberg, Donald; Yiu, Cynthia K. Y.; Blizzard, John D.; Wu, Christine D.; Mao, Jing; Drisko, Connie L.; et al. (2012-08-01)
      Global increase in patients seeking orthodontic treatment creates a demand for the use of acrylic resins in removable appliances and retainers. Orthodontic removable appliance wearers have a higher risk of oral infections that are caused by the formation of bacterial and fungal biofilms on the appliance surface. Here, we present the synthetic route for an antibacterial and antifungal organically-modified silicate (ORMOSIL) that has multiple methacryloloxy functionalities attached to a siloxane backbone (quaternary ammonium methacryloxy silicate, or QAMS). By dissolving the water-insoluble, rubbery ORMOSIL in methyl methacrylate, QAMS may be copolymerized with polymethyl methacrylate, and covalently incorporated in the pressure-processed acrylic resin. The latter demonstrated a predominantly contact-killing effect on Streptococcus mutans ATCC 36558 and Actinomyces naselundii ATCC 12104 biofilms, while inhibiting adhesion of Candida albicans ATCC 90028 on the acrylic surface. Apart from its favorable antimicrobial activities, QAMS-containing acrylic resins exhibited decreased water wettability and improved toughness, without adversely affecting the flexural strength and modulus, water sorption and solubility, when compared with QAMS-free acrylic resin. The covalently bound, antimicrobial orthodontic acrylic resin with improved toughness represents advancement over other experimental antimicrobial acrylic resin formulations, in its potential to simultaneously prevent oral infections during appliance wear, and improve the fracture resistance of those appliances.