• Tissue Lipid Analysis via MALDI Imaging (MALDI-IMS)

      Feldman, Steven G.; Scott, Alison June; Ernst, Robert K. (2013-04-11)
      Mammalian tissue contains a complex array of lipids and membrane components. Analysis is typically accomplished by one of many histological methods, such as Hematoxylin and Eosin (H&E) stain, immunohistochemistry (IHC) and in situ hybridization (ISH). However, a limitation of most techniques is a requirement for prior knowledge of the targets of interest. Mass spectrometry (MS) coupled assays are useful for their inherent speed and accuracy. Hyphenated MS techniques, such as MALDI-TOF MS (Matrix Assisted Laser Desorption Ionization-Time of Flight) have been developed for rapid analysis of complex biological samples. MALDI-TOF MS lends itself to tissue slices because it does not require pure samples and can offer de novo discovery of sample components. Here we show the coupling of this technique with histological staining for the investigation of lipids and their localization within mouse kidney tissue slices. This method is shown to be extensible through the incorporation of LIFT (MS/MS) wherein a specific peak of known molecular weight is exposed to a high energy laser which causes reliable and reproducible fragmentation based on bond energies within the molecule. As such, aspects of the target molecule from a class (eg phospholipids) down to side chains can be identified allowing the fullscale investigation of major tissue components. In a proof of concept study, pure standards of the major phospholipids phosphatidylethanolamine (PE) and phosphatidylglycerol (PG) were subjected to LIFT, to confirm structures. Subsequently, MALDI-IMS applied to tissue slices reveals abundant peaks in the range of predicted phospholipids. These results will be analyzed to confirm these tissue phospholipids. MALDI-TOF MS coupled with LIFT presents a novel way of looking at tissue without prior knowledge of its constituents as it allows for analysis in the absence of traditional reagents such as antibodies or nucleic acid probes.
    • An Interprofessional Collaboration To Implement Diabetes Screening In A University Dental Hygiene Clinic

      Idzik, Shannon; Hack, Gary, D.D.S.; Bode, Claire; Manski, Marion; Cartee, Deborah (2016)
      The purpose of this project was to implement diabetes screening for patients with diabetes risk factors during their hygiene appointments at the dental school clinic. Diabetes is an epidemic in the U.S. 18 Million are currently effected and it is expected to rise over the next few years. One third of those with diabetes are asymptomatic and undiagnosed. There is literature to support screening for diabetes in non-primary care settings. There is a bidirectional relationship between diabetes and periodontal disease. Many patients with diabetes have at least one diabetes risk factor. A significant number of people see the dentist at least once a year.
    • Shadow Systems: Pros and Cons

      Hoffman, William F., Jr.; Scharf, Katherine (2016)
    • Developing a 3D-Printed Peri-Implantium Based Plaque Assay (2016)

      Feldman, Steven G.; Kim, Jeffrey J. (2016-03-23)
      Objectives: Currently, there is no consensus of how to best maintain dental implants. With over 2 million dental implants placed annually, there is an urgent need for objective ways to measure plaque removal from peri-implant surfaces. Here, we developed a cost effective, fast and accurate way to measure the effectiveness of various oral hygiene products to maintain health of the implant and surrounding oral tissues using a 3D printer. Methods: Digitizations of dentoform teeth and jaws provided the basis for 3D-printed custom models. Simulated gingiva and genuine dental implants were incorporated to maximize clinical relevance. Fabricated model teeth were analyzed for consistency of cusp heights, inter-cusp distance and mass. Mass was remeasured following water immersion. An artificial plaque substrate (APS) was applied to 3D-printed and porcelain surfaces to ensure consistent performance. A standard by which toothbrush mediated APS removal from the interproximal and subgingival areas was developed, with varying brushing angle, force and toothbrush design. Results: The 3D-printed models had higher dimensional accuracy than the resolution of the 3D printer (X/Y<400μm, Z<100μm). Immersion in water yielded an increase in mass that was correlated linearly with time (r2 = .9365) and could be reversed upon desiccation. APS behaved similarly on the 3D-printed surface as porcelain. Conclusions: Lack of commercially available dentoforms with accurate dental implant anatomy limited the ability to simulate implant systems in vitro. However, the advent of low-priced commercial grade 3D printers enables individuals to create such models rapidly and at low cost. We developed highly accurate, anatomically correct, 3D-printed dental implant model systems, which mitigated flaws in extant designs and devised a high-throughput method for assessing in vitro plaque removal that is superior to existing methods. In the future, digital model files can be included in an electronic library for rapid manufacturing of identical models anywhere in the world.
    • Broad-spectrum, long-term antibiofilm features of metallic nanoparticles and antibacterial monomers on dental adhesive and resin composite surfaces

      Melo, Mary Anne; Weir, Michael D.; Cheng, Lei; Zhang, Ke; Xu, Hockin H. K. (2016-10)
      Concerns about the development of caries at the margins of restorations have been taken into consideration since the main reason for composite restoration failure in the long term is secondary caries. Restorative dental materials such as resin composite and adhesive systems are in contact with tooth and can be the ideal vehicle for delivering anticaries agents. Based on nanotechnology, silver nanoparticles (NAg) were developed and incorporated into dental resin-based materials. These nano-sized particles in the resin-based dental materials increased the ion release due to the higher surface area of the nanoparticles. Recent studies have demonstrated the capability of these materials for reduce bacterial load without detriment of their mechanical properties.
    • Use of a rubric for calibration among faculty members and as students' self-assessment tool

      Oh, Se-Lim; Liberman, Leila H. (2017)
      The practical examination is designed to evaluate periodontal instrumentation of second year dental students on typodonts before they are allowed to perform scaling and root planing for their patients. The failure rate in the practical examination ranged from 16-31% over the past three years. An average of 32 out of 130 students failed the first practical examination. The failed students were offered to take additional examinations until they passed. Although most students passed the first practical examination, they still exhibited some deficiencies in the clinic especially early in junior year. Therefore, lack of maintaining acquired skills and scarcity of self-assessing their skills have been brought up by the faculty members in the department of periodontics at The University of Maryland School of Dentistry (UMSOD). One of the most important skills for healthy care providers is the ability to self-assess one’s competence and consequently to identify individual deficiencies and the needs for further learning. Thus, the importance of self-assessment has been highlighted by the Commission on Change and Innovation in Dental Education. However, a self-assessment has not been introduced to dental students in the periodontics courses at the UMSOD. A new rubric was developed for second year dental students to define the categories for each point value and to emphasize the critical failure. If a student uses the incorrect end of the instrument at all times (without self-correction), the student will receive 0 point in that particulars instrument. The new rubric was also intended to be used as a self-assessment tool for students in preparation for the practical examination.
    • Innovative CAD/CAM Protocol for Fabricating Screw-Retained Implant Resin Provisionals

      Fay, Guadalupe Garcia; Hack, Gary, D.D.S. (2018)
      Intraoral scanners and the use of Computer-Aided Design and Manufacturing (CAD/CAM) produces dental restorations that have a high level of accuracy which equals or exceeds that achievable utilizing the conventional fabrication process. There are various ways of fabricating an implant provisional restoration, but this usually involves a multiple series of steps if done in a conventional manner. With the advent of digital dentistry there are less steps involved thus facilitating an easier process, however, if the suggested milling units are not available there is a possibility of utilizing an alternative process. The purpose of the study was to develop an innovative CAD/CAM protocol. To mill a screw-retained provisional crown using Sirona’s CAD/CAM systems, normally a Telio® CAD A16 provisional resin block and the use of an MCXL Milling Machine and Omnicam is needed. A16 are cross-linked poly methyl methacrylate (PMMA) blocks indicated for the fabrication of long-term temporaries by means of the CAD/CAM technique. These blocks have a pre-drilled, machined perforation to allow the milled block to accept a TiBase abutment on one surface, and another machined perforation on the opposing surface to allow the insertion of the implant screw. Our objective was to develop a protocol to mill a provisional screw-retained restoration using Sirona’s Compact Milling Machine (CMM) with a BlueC
    • Screening for Diabetes: The Maryland Experience

      Hack, Gary, D.D.S. (2018)
      86 million Americans are pre-diabetic, and 90% of these individuals are unaware of their condition and many will convert to frank diabetes without intervention. This looming epidemic will bankrupt our health care system without intervention. The dental office is an ideal place for diabetes monitoring and screening. It is estimated that over 28% of patients presenting to the dental office have undiagnosed diabetes or prediabetes. Preparation of oral healthcare providers to have a positive impact on this epidemic is essential along with knowledge of devices needed to screen for and monitor diabetes/prediabetes such as glucometers and HbA1C devices.
    • Effort Reporting: Understanding the Requirements

      Hoffman, William F., Jr.; Esposito, Dominic (2018-03)
    • Faculty Transfers-Hello and Goodbye !!

      Hoffman, William F., Jr.; Sack, Karen; Simons, Janet (2018-03)
    • Investigator/Faculty Onboarding: Facilitating the Transfer of Your New PI

      Hoffman, William; Sack, Karen; Simons, Janet (2019)
    • Cannabis and Dentistry

      Sheehan, Tara (2019)