Post and core reconstruction for fixed prosthodontic restoration.

If the previous restorative therapy or dental caries has resulted in substantial loss of tooth structure, the abutment teeth for fixed prosthodontic restorations require a core reconstruction or a post and core. Small dentin defects can be restored with bonded cores; more extensive dentin defects that are often accompanied by previous endodontic treatment generally require additional support for the core material. A direct procedure with a bonded post is a viable treatment method.

Fracture line stability as a function of the internal fixation system: an in vitro comparison using a mandibular angle fracture model.

Purpose: This study was conducted to determine and compare the initial mechanical stability and functional capability of six contemporary internal fixation systems used to fix mandibular angle fractures.

Materials And Methods: An iterative analog of a mandibular angle fracture was developed to ensure replicability of material properties and fracture configuration across the test constructs. Each of six sets of mandible analog (1 set = 3 mandibles) was reduced according to prescribed technique by a variety of compressive and adaptive fixation systems.

Effect of whole oral bacteria and extracted lipopolysaccharides on peripheral blood leukocyte interleukin-2 receptor expression.

Expression of the interleukin-2 receptor (IL-2R) on T cells is the molecular mechanism that initiates the G0 to G1 transition and is the critical first step for T cell proliferation in response to antigen. The effect of whole periodontal bacteria and lipopolysaccharides (LPS) on peripheral blood mononuclear cell (PBMC) IL-2R expression was examined in vitro. LPS induced a modest but significant increase in high affinity IL-2R alpha/beta (p55/p75 positive) expression on PBMC over untreated cells after 48 h culture.

Immunotoxicity of cocaethylene.

This report describes the response of normal human T cells to stimulation in vitro in the presence of nano-micromolar concentrations of cocaethylene. Thymidine incorporation by concanavalin A-stimulated peripheral blood mononuclear cells was generally blunted by cocaethylene, albeit to different degrees depending upon the donor tested. The formation of concanavalin A-induced blast cells was decreased by increasing concentrations of cocaethylene.

Panoramic dental radiography as an aid in detecting patients at risk for stroke.

Purpose: Atherosclerotic lesions in the region of the bifurcation of the common carotid artery and in the internal carotid artery are the most common cause of stroke. On occasion these lesions are calcified and visible on a panoramic dental radiograph.

Methods: Six subjects receiving outpatient dental treatment and denying a history of previous transient ischemic attacks or stroke had bilateral calcified carotid arterial lesions noted on their routine panoramic dental radiograph.

Inactivation of the p53 gene by either mutation or HPV infection is extremely frequent in human oral squamous cell carcinoma cell lines.

The state of p53 tumour suppressor and the frequency of high-risk human papillomavirus (HPV) infections were studied in nine human oral cancer cell lines. Three cancer cell lines (SCC-4, Tu-177 and FaDu) had similar amounts of p53 transcripts to normal cells, but contained significantly higher levels of p53 protein than the normal control cells. Sequencing highly conserved open reading frames of the p53 gene of these cancer cells showed point mutations in the SCC-4 and Tu-177 cell lines, a base transition from CCC to TCC occurred at codon 151; and in the line FaDu, a mutation of CGG to CTG occurred at codon 248.

Radiographic secondary caries prevalence in teeth with clinically defective restorations.

Decisions to replace existing restorations are often based on clinical findings of margin discrepancies and other restoration defects. Previous studies have suggested that such findings do not correlate well with the actual presence of secondary caries, and that treatment should be deferred until caries is clinically or radiographically evident. The purpose of this study was to assess the frequency with which clinically defective restorations are associated with radiographic secondary caries.

Immunohistochemical mapping of epidermal growth-factor receptors in normal human oral soft tissue.

Epidermal growth-factor receptor (EGF-r) has been identified on basilar cells of stratified squamous epithelia and skin adnexa in man. Recent studies have mapped EGF-r to various oral cells in animals; however, complete mapping of EGF-r in normal human oral mucosa has not been done. Normal tissues from eight sites in human oral mucosa were examined for their expression of EGF-r using avidin-biotin peroxidase complex with mouse anti-EGF-r monoclonal antibody.

Cough headache presenting as a toothache: a case report.

Benign cough headache (BCH) presents as an intermittent, usually bilateral, severe bursting or explosive pain brought on by coughing. Some of the known conditions which can mimic the pain experienced in BCH are subarachnoid hemorrhage, increased intracranial pressure, intracranial tumors, and even toothache. Careful evaluation must be carried out in order to differentiate between these conditions.

CD44 and hyaluronan expression in human cutaneous scar fibroblasts.

Fibrotic disorders of skin and other organs are typically associated with an abnormal accumulation of extracellular matrix. This study focuses on a matrix constituent, hyaluronan-which is known to be altered in fibrotic disorders of skin- and on CD44, a cell adhesion molecule and putative receptor for hyaluronan. Tissue samples were obtained from biopsies of human normal skin, normal cutaneous scar; and hypertrophic cutaneous scar.

c-myc oncoprotein expression in oral precancerous and early cancerous lesions.

Squamous cell carcinoma of the oral cavity is often preceded by clinically evident precancerous lesions. These lesions exhibit progressive cytomorphologic changes connoting cellular transformation to malignant neoplasia. Molecular events underlie the microscopically identifiable cytological changes that herald transformation.

The effects of streptomycin/lidocaine block on trigeminal neuralgia: a double blind crossover placebo controlled study.

This study investigated the long term effect of a peripheral sensory block using streptomycin sulphate on trigeminal neuralgia. A total of twenty subjects, thirteen with idiopathic trigeminal neuralgia (ITN) and seven with traumatic trigeminal neuralgia (TTN) were studied. A double-blind placebo controlled randomized design was used.

In vitro antimicrobial activity of the human neutrophil cytosolic S-100 protein complex, calprotectin, against Capnocytophaga sputigena.

Calprotectin is a complex of two anionic proteins found in abundance in the cytosol of neutrophils, certain macrophages, and oral epithelial keratinocytes. Bacteria of the genus Capnocytophaga are pathogens of periodontal origin which can cause systemic infection in neutropenic subjects. Recently, it has been observed that Capnocytophaga may be internalized by neutrophils within the cytosol rather than within a membrane-delimited phagosome.

Thermographic characterization of the asymptomatic temporomandibular joint.

This study used electronic thermography, an alternative diagnostic imaging modality, to assess the thermal image characteristics of the normal TMJ in 30 asymptomatic subjects. Assessments made included: thermal pattern recognition and symmetry, absolute temperature measurements and differences in absolute temperature measurements, and mean temperature measurements and differences in five anatomic zones. Results indicated the presence of a common thermal TMJ pattern in two thirds of patients, with variations from this pattern in the remaining patients.

The degree to which attrition characterizes differentiated patient groups of temporomandibular disorders.

Dental attrition severity as the cumulative record of parafunctional and functional wear was graded from study cast analysis using established methodology. Attrition severity was compared in anterior, posterior mediotrusive, and posterior laterotrusive segments. Attrition scores in 48 female and 100 male totally asymptomatic controls were compared to 239 female and 31 male patients differentiated into five patient groups of temporomandibular disorders: (1) disc displacement with reduction, (2) disc displacement without reduction, (3) osteoarthrosis with a history of prior derangement, (4) osteoarthrosis without a history of prior derangement, and (5) myalgia only.

Shape changes due to functional appliances.

Functional appliances are now routinely used in orthodontic treatment to correct anteroposterior skeletal discrepancies, based on the assumption that existing functional patterns can be modified to yield a new morphological pattern. However, the mechanisms by which this correction occurs remain in dispute as current measurement procedures, primarily mathematical, do not adequately describe shape changes. This paper introduces a new measurement method, Fourier descriptors, to clinical dentistry.

Human neutrophil azurocidin synergizes with leukocyte elastase and cathepsin G in the killing of Capnocytophaga sputigena.

Azurocidin was purified in the presence of phenylmethylsulfonyl fluoride. Electrophoresis revealed at least seven species which exhibited N-terminal sequences consistent with azurocidin. Azurocidin exhibited no bactericidal activity against Capnocytophaga sputigena or other oral bacteria but synergized the bactericidal activity of enzymatically active elastase.

Sequential combined tumorigenic effect of HPV-16 and chemical carcinogens.

We immortalized oral keratinocytes by transfection with recombinant human papillomavirus type 16 (HPV-16) DNA and established two cell lines, human oral keratinocytes-16A (HOK-16A) and -16B (HOK-16B). These cell lines were morphologically different from the normal counterpart, contained HPV-16 DNA as integrated form and expressed numerous viral genes. However, these cells proliferated only in culture medium containing low calcium (0.

Patch-clamp study of postnatal development of CA1 neurons in rat hippocampal slices: membrane excitability and K+ currents.

1. The postnatal development of membrane properties and outward K+ currents in CA1 neurons in rat hippocampal slices was studied with the use of whole-cell patch-clamp techniques. 2.

Biomechanical validation of the solitary lag screw technique for reducing mandibular angle fractures.

The purpose of this study was to determine whether the solitary lag screw technique meets the biomechanical demands of angle fractures. Simulated angle fractures in four cadaveric mandibles were reduced using solitary lag screws and the load-displacement relationships determined under functional loading of the individual mandibles. Subsequently, an angle fracture in a photoelastic mandible analog was fixed with a lag screw and subjected to similar loading.

Orthognathic diagnosis and treatment planning: a cephalometric approach.

Cephalometric analyses have long been important diagnostic tools for the orthodontic specialist. Such analyses, as they pertain to adult skeletal problems and their consequent therapy, should also be a valuable adjunct for various dental specialties, e.g.

Differential killing of Actinobacillus actinomycetemcomitans and Capnocytophaga spp. by human neutrophil granule components.

The purpose of this study was to determine whether granule fractions of human neutrophils differentially kill Actinobacillus actinomycetemcomitans and Capnocytophaga spp. Granule extracts were subjected to gel filtration, and seven fractions (designated A through G) were obtained. Under aerobic conditions at pH 7.