• Community Dentistry and Behavioral Science
• Office of Education
• Endodontics
• Oral Biology
• Oral and Maxillofacial Diagnostic Sciences
• Oral and Maxillofacial Surgery
• Orthodontics
• Pediatric Dentistry
• Periodontology
• Restorative Dental Sciences

• Genetic epidemiology or recurrent aphthous stomatits (RAS
  in progress)
• Association between osteoimmune processes and RAS (in development)
• General interests: oral medicine, epidemiology, genetics, biostatistics, etiopathogenesis

• Clinical Aspects of taste and smell
• Health services research-access to case issues
• Etiology & prevation of dental caries

• Biological, social, and psychological factors that may influence the experience of pain
• Understanding the reasons for gender differences in pain thresholds
• Effects of pain relieving medications for women and men

• Health disparities in pain
• Ethnic and gender differences in experimental and acute post-operative pain
• Genetic and non-genetic factors that influence acute pain and analgesic responses
• Mechanisms contributing to development of chronic pain following surgical intervention
• Cancer pain (before, during and after treatment) and the interaction with psychological health, quality of life, treatment outcome and survival
• Regulatory influences on clinical and prescription practices

• Impact of stress on the physiological and psychological experience of pain among humans
• Clinical and laboratory models based on neuroendocrine and immune changes during and following painful stimuli
• Intensity of pain and the resulting neuroendocrine and immune biochemical correlates
• Neuroendocrine and immune patters in recovery following painful stimuli in the presence of a stress of relaxed state

• Behavioral factors in orofacial pain
• Specific topics of interest include:
  • The interaction between pain, negative mood, cognitive coping strategies, and treatment outcome
  • Sex differences in report of clinical and experimental pain
  • Treatment compliance
  • Health care utilization prediction

• Oral epidemiology and disease surveillance
• Dental public health
• Tobacco and oral health, including health effects, intervention, and policy
• Oral cancer epidemiology, prevention, and disparities
• Survey research

back to top

• Educational research: Teaching and learning methodologies, curriculum evaluation, evaluation of student developed tracking, and learning materials

back to top

• Instrumentation and obturation techniques for endodontic therapy
• Restoration of endodontically treated teeth

• Tissue engineering and 3D imaging of vertical root fractures

• Crosstalk between endothelial cells and tumor cells in head and neck cancer

• Pulpal Biology, Trauma, and Resorption
• Endodontic Instruments

• Appreciation of laser technology of non-surgical and surgical canal therapy

back to top

View web page

• Host-pathogen interactions
• Structure-function of streptococcal surface proteins
• Immunogenicity/vaccine development

Our research program is concerned with mucosal immunity and its role in host defense, and in the mechanisms by which pathogens subvert host defenses. One of our major areas of interest is molecular vaccines. We are investigating the use of live attenuated Salmonella strains as vehicles to deliver cloned antigens to the Peyer’s patches in the gut in order to efficiently stimulate a mucosal IgA response. Because an immune response can be elicited to a selected antigen and not to the entire organism, problems associated with undesirable and potentially dangerous side effects of whole cell vaccines can be avoided.

The primary interests in my laboratory are in the molecular mechanisms governing the ability of bacteria that are capable of causing diseases in humans to modulate their virulence in response to environmental influences. The specific projects in the lab are focused in three major areas. The first is a detailed study of the genetics and physiology of polysaccharide metabolism and its relationship to virulence and biofilm formation by oral streptococci. The second project is a molecular genetic analysis of the role of the major molecular chaperones in gene regulation and responses to environmental stresses. The third project is a broad based approach to understanding the genetics and physiology of ureases and arginine metabolism by streptococci and actinomycetes.

Our laboratory is primarily interested in autoimmunity with the focus in autoantigens and autoantibodies associated with systemic autoimmune diseases, such as Sjögren’s’ syndrome, and oral cancer. The two main directions are 1) to identify and characterize specific autoimmune target antigens and understand why autoantibodies are induced and continually produced in different disease states and 2) to use human autoantibodies as unique probes to reveal the molecular and cellular functions of interesting macromolecules and subcellular organelles that are autoimmune targets. By understanding the biology of autoantigens in health and disease states, we can appreciate the functional and pathogenic potentials of autoantibodies.

We have identified several novel autoantigens in cytoplasmic foci known as GW bodies (GWB, or RNA processing bodies, PB). Recent data from our laboratory demonstrate cellular functions for these cytoplasmic structures to include siRNA and miRNA mediated function. Specifically our current data suggest that the size and number of GW/P bodies are cellular biomarkers for the RNA interference (RNAi) pathway including both siRNA and miRNA functions. Our laboratory will continue to examine the role of GW/P bodies in cellular miRNA function, their contribution to different disease processes, and the use of RNAi for therapeutics especially in oral medicine and oral cancer.

We apply multidisciplinary approaches (morphological, physiological, pharmacological, biochemical, molecular and genetic) to study the biology of salivary glands, with an emphasis on the synthesis, secretion and functions of mucins. Mucins are major constituents of mucus layers of the body and function as a defense mechanism against invading microorganisms. These glycoproteins are secreted by the highly specialized mucous cell phenotype, which are under complex parasympathetic control. We recently discovered and characterized the gene, Muc19/Smgc, which encodes the mucin (Muc19) that is selectively expressed by mouse sublingual salivary glands. Coincidently, we genetically mapped an autosomal recessive mutation, sld, to a 1 megabase critical region of chromosome 15. The sld phenotype is characterized by the developmental delay and attenuated expression of Muc19. Interestingly, the critical region contains Muc19/Smgc. We are currently delineating whether Muc19 indeed harbors the sld mutation, through construction of knockout mouse models and by bioinformatic/gene expression analysis of the critical region. We are also investigating the associated genetic lesion to determine mechanism(s) by which steady-state levels of Muc19 transcripts are regulated. We recently initiated a project to induce distinct targeted gene deletions of specific salivary constituents (e.g., Muc19) in mice to test their functions in protecting teeth against the oral pathogen, Streptococcus mutans. Genetic manipulations of the bacteria are also being carried out to test putative S. mutans virulence factors in caries development. Determination of the influence of specific bacterial and host determinants in caries development in vivo may ultimately provide important targets for therapeutic intervention in the treatment of patients at high risk for caries.

My laboratory is interested in the study of bacterial, viral and fungal infections of humans. We are focusing on the development and the use of novel tools to study human diseases directly, rather than in potentially misleading animal models. We have developed an innovative tool termed In Vivo Induced Antigen Technology (IVIAT, Trends Microbiol. 8:336-339) that uses serum from human survivors of disease as a probe to identify those genetic factors that are uniquely active in the disease process. IVIAT is a functional genomic technology and it complements other gene sequencing and analytic techniques by very rapidly sifting through a pathogen’s genome to identify those critical genes in human infections. These genes are potentially valuable targets for novel antimicrobials, vaccine design or diagnostics.

• Periodontal disease: etiology, diagnosis, progression, prevention and therapy
• Clinical Research
• Clinical Trials

• Molecular biology of virulence of periodontal pathogens
• The molecular basis of the associations of periodontal disease and cardiovascular diseases
• Novel technologies of studying in vivo gene expression in pathogenic organisms

Porphyromonas gingivalis is an important periodontal pathogen. Recently, it has been recognized that P. gingivalis may have an important role in systemic diseases, including cardiovascular disease, prematurity, and low birth weight.

Project 1. Cardiovascular diseases are the leading cause of death in developed countries. We use human coronary artery endothelial cells as model to study the interactions of P. gingivalis with the endothelial layer of the vasculature.

Project 2. Prematurity and associated low birth weight are the leading cause of death in the first month of life. We developed a rat model to study adverse pregnancy outcomes during infection with P. gingivalis. We aim to elucidate the mechanisms by which P. gingivalis virulence factors and the host immune system interact to cause pregnancy complications.

• Mechanisms of antibiotic resistance and the transfer of resistant determinants in oral biofilms using an in vitro biofilm model
• Effects of antibiotics on biofilms relative to planktonic cultures (in broth)
• Live-dead assays of biofilms
• Matrix metalloproteinases (MMPs) levels in children with and without aggressive periodontal disease
• Characterization of subgingival flora in children with periodontitis using DNA-DNA hybridization

back to top

• Molecular basis of oral pre-cancer and cancer
• Clinical research on oral mucosal disorders such as burning mouth syndrome, lichen planus, pemphigoid, etc
• Epidemiological survey of various oral lesions submitted as biopsy specimen

• Investigation of pro-inflammatory microenvironment in the salivary glands to understand target tissue specificity in SjS: Molecular pathways involving inflammatory caspases and the inflammasome
• Investigation of molecular mechanisms of hyposalivation in SjS: Identification of altered trafficking of aquaporin-5 and calcium signaling pathways by anti-M3R autoantibodies
• Investigation of pathological roles of anti-M3R autoantibodies: Roles of different subclasses of anti-M3R antibodies, generation of monoclonal anti-M3R antibody, epitope mapping and autoantibody screening
• Identification of susceptibility genes by applying functional genomics and proteomics
• Application of receptor mediated siRNA delivery in SjS
• Development of preventive and therapeutic strategies to restore secretory function in patients with SjS.

• Molecular diagnosis of oral cancer
• Vesicullo-bullous diseases
• Outcomes research
• Lichen planus
• Unusual oral tumors

• The Oral systemic connection receptor for advanced glycation end product (RAGE) role in oral diseases

• Osteoradionecrosis
• Radiation caries
• Xerostomia, hyposalivation
• Candidiasis
• Taste and smell
• Cancer-related mucositis

• Autoimmune disorders, salivary dysfunction, HIV/AIDS, Oral Medicine – manifestations of systemic diseases

back to top

• Basic mechanisms of pain transmission focusing on the interactions of neuropeptide and excitatory amino acid receptors
• A second line of research involves probing the molecular physiology of the protein responsible for transducing the pain and heat associated with hot chili peppers

• Pain Electrophysiology: Immunocytochemistry on sensory cells. What are the properties of pain sensing fibers of the peripheral nervous system? Our lab uses electrophysiology pharmacology and immunocytochemistry to examine these questions in rat sensory cells.

• Continuous dose local anesthetics for control of surgical pain in HIP graft patients

• Studies of sensory changes during aging
• Pain assessment in humans
• Assessment of sensory changes in neuropathic pain syndromes

• Sterilizer monitoring

• Application of cone beam CT in maxillofacial diagnoses
• Evaluation of 3D image forming algorithms for the head and neck region
• Digital image processing for quantitative evaluation of osseous changes

• Dental implants
• Bone regeneration

• Bone grafting
• Osteoporosis
• Guided bone regeneration
• Dentoalveolar surgery

back to top

• Bone remodeling during orthodontic tooth movement
• Gene activation in osteoblasts in response to mechanical stimulation

• Activation of osteoclastic bone resorption
• Integrin-associated signaling in osteoclasts
• Phosphatidylinositol 3-kinase
• Cytoskeletal dynamics in osteoclasts
• Structure transport and function of vacuolar H+ ATPase
• Adeno-associated virus in the treatment of osteoclast-involved disease

• Morphogenesis and differentiation of taste-related oral structures
• Nerve muscle interaction in jaw muscle development
• Role of extracellular matrix and matrix metalloproteinases in craniofacial development

• Clinical and Basic Science
• Investigation of inflammatory and neuropathic mechanisms relating to peripheral pain
• Translating these laboratory findings into therapeutics for chronic pain sufferers
• Developing a collaborative network of research relating to temporomandibular joint disorders and other orofacial pain disorders

• Orthodontic treatment outcomes
• Orthodontic tooth movement

• Motor control mechanisms for jaw muscles
• Jaw and trigeminofacial reflexes
• Research diagnostic criteria for temporomandibular disorders and other orofacial pain conditions
• Nerve-muscle interactions during jaw muscle development
• Biological basis for masticatory muscle pain

• Pain mechanisms related to the effects of age on pain sensitivity
• the role of changes in immune function, HPA axis, and different transmitter systems on varying sensitivity to pain in animals of different ages
• How these changes are affected during normal aging, under pathological conditions and during conditions of stress are also being investigated
• Interest is in evaluating these changes using complex behavioral assessment strategies that involve cortical processing and decision making
• Plasticity and glia responses to acute and chronic pain conditions at different ages and the impact of cytokines and other inflammatory molecules in the development of chronic pain conditions

back to top

• Periodontal health and diseases in children and adolescents
• Dental education (University)
• Sedation of children for dental treatment

back to top

• Tissue regeneration biology
• Bone cell differentiation
• Extra cellular matrix biology

• The role of oral periodontal bacteria specifically Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola in the initiation, progression of periodontal disease, inflammation, immunity, gene expression, and alveolar bone resorption
• Dental or Undergraduate Student Research:
  1. Examine in vitro antimicrobial activity of Omega-3 Polyunsaturated fatty acids and other compounds against periodontal anaerobic bacteria
  2. Induction of periodontal disease and periodontal bacteria-associated atherosclerosis in ApoE+/- (Apolipoprotein E heterozygous) mice
  3. Polymicrobial periodontal disease and localization of pathogens in periodontium

• Microbiological, immunological and treatment changes in Aggressive periodontitis in children
• The relationship of Diabetes and Periodontal Disease in adults
• Biofilm development and antibiotic resistance

The broad research focus of our research is on the innate immune responses in diabetic patient populations. Importantly we focus on two classifications of diabetes, Type 1 and Type 2, with the understanding that these are similar diseases with different mechanisms leading to manifestation. Our interests involve how diabetic host immune responses differ from that of a normoglycemic host. Specifically, our current projects involve:

1. Investigation of diabetogenic gingival epithelial cell aberrant immunological functions in term of ‘hyper-responsiveness, receptor expression and signaling processes, and antigen presentation capacities.
2. Investigation of diabetogenic osteoclast functions in terms of excessive activation and bone resorption
3. The contribution of advanced glycated end products to aberrant immunological functions of gingival epithelial cells, macrophages, dendritic cells and osteoclasts
4. Investigation of regulatory mechanisms of cyto/chemokine expression which directly and indirectly contribute to tissue destruction and periodontal disease progression, using miRNA analysis

Additional ongoing studies of our laboratory are interested in how these potentially aberrant innate immune responses may affect other disease processes which have been classified as secondary complications of diabetes, such as periodontitis, cardiovascular disease, and arthritis.

P. gingivalis and host cells represent a highly structured and regulated dynamic interaction, the outcomes of which depend upon the properties of the organism and host. Our laboratory focuses on the interface between P. gingivalis and gingival epithelium, and facilitation of the bacterial colonization by studying the molecular mechanisms of gingival epithelial cell attachment-invasion, survival, and dissemination strategies employed by P. gingivalis.

The specific areas of research we are currently examining are:

1. Initial attachment mechanisms of P. gingivalis to epithelial cells with respect to complementary receptors on host cell surfaces and signal transduction events following attachment
2. Long-term outcomes of P. gingivalis infection on gingival epithelial cell status by examining host cell death-survival markers and phenotypic responses throughout the infection
3. Modulation mechanisms of gingival epithelial cell survival responses mediated by P. gingivalis through both intrinsic and extrinsic apoptotic pathways
4. Understanding of the means for P. gingivalis' ability to multiply and spread within the epithelium temporally and its relation to gingival epithelial cell survival
5. Motility: Modulation of actin cytoskeleton and associated cell structural-signaling molecules during the inter-cellular spreading of P. gingivalis in gingival epithelium

back to top

• Fracture resistance of all-ceramic restorations
• Enamel wear by ceramics
• Optimization of restoration design
• Reducing the risk of PFM failure, color analysis, caries risk assessment, decision analysis, fracture analysis, stress analysis
• Bond testing, enamel remineralization, color analysis

• Oral cancer

• Survival Analysis of Implant-Supported All-Ceramic Prostheses
• Wear of Ceramic and Enamel Antagonists
• Longevity of Dental Implants
• Surface Degradation of Ceramic Surfaces
• Fractographic Analysis of Failed Ceramic Prosthesis
• Clinical Performance of All-Ceramic Restorations

• Esthetic dentistry: Dentin/enamel bonding to different substrates, resin based composites, tooth bleaching, and alternative treatment of defective restorations

• Study of central pain modulation (sensitization and inhibition) in patients with chronic pain diseases (fibromyalgia syndrome, irritable bowel syndrome, myofascial pain syndrome) and in sufferers of traumatic brain injury.
• Research participants are exposed to series of brief thermal stimuli (thermal probe contacting the skin). They are asked to rate the intensity of the pain on a visual analog scale.
• Our protocols are designed to measure pain sensitivity and rate of change of sensitivity. The data collected provide insights into mechanisms that render patients more pain-prone and allow testing drug effects on pain modulation.
• The ultimate goal is the development of effective therapeutic strategies to return exaggerated pain sensitivity of chronic pain patients to normal.

• Microbiology of Caries Resistance

• Controlled release of therapeutic agents from dental restorative materials
• General properties of glass ionomer cements
• Fluoride release from dental materials
• Surface properties of dental restorative materials

• Composite materials, compomers, dental adhesives, and biodegradation of dental composites

• Tobacco use/attitudes

• Study of factors—including chronic pain conditions and cancer—affecting pain sensitivity in animal models and in human subjects