Dental caries are, to this day, the most preventable disease still plaguing humankind. Since the mid 1900's, there has been little to no innovation in commercial fluoride dentifrices, in that, the active agent as a caries preventative is 0.24% sodium fluoride (0.15% fluoride ion), or 0.76% sodium monofluorophosphate. The purpose of the current work is to examine the effects of theobromine versus fluoride on the enamel surface of human teeth by use of an artificial neural network. Theobromine (3,7 dimethylxanthine) is a white crystalline powder and differs by only one methyl group to its sister molecule, caffeine (1,3,7 dimethlyxanthine). The dissertation focuses on a brief introduction to theobromine and the previous literature, the experimental materials, method, and design, and finally to the analysis of enamel surface microhardness data by the artificial neural network model. A subsequent in vivo acid dissolution also leads us to believe that theobromine might be a particularly effective agent in helping the enamel surface of human teeth resist the effects of bacterial acid demineralization The implications of the current work are that theobromine, which occurs naturally in chocolates, teas, and cocoa products worldwide, is a natural, nontoxic, more efficacious, and viable alternative to fluoride additives in commercial dentifrices / acase@tulane.edu

No description available.

The aim of this study was to investigate the hypothesis that pre-therapeutic "dispositional optimism" is associated with post-therapeutic "quality of life (QOL)" in a sample of patients with upper aerodigestive tract (UADT) cancer. A sample of 101 subjects with UADT cancer was enrolled in this cohort study. QOL was evaluated through the EORTC QLQ-H&N35 and the global domain of the EORTC QLQ C-30. Dispositional optimism was measured using the Life Orientation Test (LOT). Subjects completed these self-administered questionnaires prior to treatment and one week to one month after their treatment. Other data were gathered by interview and medical chart review. / Prior to treatment, an association between dispositional optimism and QOL was observed for the global, pain, swallowing, senses and feeling ill domains. However, no such associations were observed following treatment.

Introduction. Human papillomavirus (HPV) has been detected with varying frequency in oral cancers and in normal oral tissues. The main objective of the present study was to examine the association between HPV infection and risk of developing oral cancer. / Methodology. This investigation, as a component of an international multi-centre study coordinated by the IARC, followed a hospital-based case-control design. Cases consisted of newly diagnosed patients with primary squamous cell carcinoma of the oral cavity, including mouth and oropharynx. Controls were frequency matched to cases by sex, age, and hospital. All subjects were interviewed to elicit detail information on known and putative risk factors. / Oral exfoliated cells were collected from all subjects for detection of HPV DNA using the PGMY09/11 PCR protocol. Antibodies against HPV 16, 18, and 31 capsids were detected in patients' plasma using an immunoassay technique. Logistic regression was used for estimation of odds ratios (ORs) and 95% confidence intervals (CI) of oral cancer for HPV and other candidate risk factors. / Results. A total of 72 cases and 129 controls were recruited. HPV DNA was detected in 19% of cases (14 out of 72), and in 5% of controls (6 out of 129). Analysis for cancers related to Waldeyer's ring (palatine tonsil and base of tongue) showed that the OR of disease for detection of high risk HPV types was 19.32 (95%CI:2.3--159.5), after adjustment for socio-demographic characteristics, tobacco and alcohol consumption. The adjusted OR of disease for HPV 16 seropositivity was 31.51 (95%CI:4.5--219.7). Analysis for non tonsillar oral cancers showed that the OR for detection of high risk HPV DNA in oral cells and for seropositivity were 2.14 (95%CI:0.4--13.0) and 3.16 (95%CI:0.8--13.0), respectively. / Discussion. The results from this study provide evidence supporting a strong association between HPV infection and cancers of the oropharynx, especially those arising from Waldeyer's ring. On the other hand, the association with non tonsillar oral cancers was of much lower magnitude. The biological evidence establishing a firm etiologic link remains to be established for the latter subsites, whereas the association between HPV and Waldeyer's ring carcinomas is consistent with a causal link.

The research work presented in this thesis involved the examination of several fundamental questions concerning the role of oral anaerobic spirochetes (OAS) in the etiology of periodontal disease (PD). OAS are unusual, helical, Gram-negative bacteria that are considered putative periodontopathogens due to numerical association with diseased sites and the enzymatic arsenal available to OAS that appears consistent with disease symptoms. T. denticola is the most commonly isolated OAS from periodontal pockets and as such is the focus of most investigations into the role of OAS in PD. / As free iron is severely limited in humans the means by which OAS may obtain sufficient iron to prosper in the sub-gingiva was examined. The resultant model suggests T. denticola obtains iron through the $ beta$-hemolysis of erythrocytes and the binding of liberated hemin by a 47-kDa outer membrane sheath (OMS) protein. The kinetics of the ligand-receptor interaction are presented and the receptor has been purified to apparent homogeneity from T. denticola. $ sp3$H-labeled hemin is not transported into the cell. Evidence is presented to show that T. denticola produces an iron reductase, which may facilitate the transport of ferrous iron across biological membranes. It is also shown that T. denticola (Td), T. vincentii (Tv) and T. socranskii (Ts) do not produce siderophores. In growth assays, under conditions of iron-limitation, T. denticola may use inorganic iron, a source unlikely to be available in vivo. / Hyaluronidase (Hase) activity is elevated in the gingival crevice during episodes of disease. Hase, when injected into the periodontal cavity under experimental conditions has been shown to result in connective tissue degradation. It is also known that T. pallidum, the agent of syphilis, produces a Hase that is critical to pathogenesis. Evidence is presented herein to show that Td, Tv and Ts all produce a hyauronoglucosaminidase (HGase). The identity and specificity of the Td HGase is confirmed through the use of enzyme inhibitors and activators, by electron microscope observations of the enzyme using the Hase inhibitor gold sodium thiomalate and anti-Apis mellifera venom antibodies and examination of the purity of the HA substrate using other polysaccharide degrading enzymes. As the HGase of these OAS would not migrate through a substrate-SDS PAGE system, we have employed hyaluronate (HA)- and chondroitin sulfate (CS)-absorbed nitrocellulose membranes to visualize HGase activity. The 59 kDa HGase of Td has been purified to apparent homogeneity through the conjugation of HA and CS to Affigel 701 beads. / The last subject to be addressed by this thesis pertains to the ultrastructure of oral spirochetes. Using the copper-containing dye, Alcian blue, we have shown that T. denticola produces an exopolysaccharide layer, in an electron microscopy investigation. The development of a stain for dark-field microscopy has simplified the observation of this layer. The exopolysaccharide layer may have relevance to the evasion of phagocytosis, to protection against colicins, immunoglobulins and bacteriophages, to adherence and perhaps to the immunogenicity of OAS inhabiting the sub-gingiva.

<p> It is often observed that the slimy matrixes of various bacterial-formed biofilms can limit their disinfection. This investigation demonstrated that disinfection effectiveness by either photodynamic therapy (PDT) or chlorhexidine irrigation is significantly improved by collapse of that matrix using the non-bactericidal reagent delmopinol as part of the treatment sequence. Cyclic shear-producing conditions were used to grow 4-day, whole salivary and growth media biofilms on glow-discharge-treated polystyrene (N=46) and mini-germanium internal reflection prisms to serve in a periodontal crypt model of disinfection by either methylene-blue-mediated PDT or by chlorhexidine irrigation. Assays for bacterial viability, with and without treatments, were performed by alamarBlue^&reg; fluorescent methods, statistically applied (ANOVA, Tukey's HSD). Multiple Attenuated Internal Reflection Infrared (MAIR-IR) assays confirmed selective removal of the predominantly polysaccharide matrix materials by the delmopinol treatment, but not by equivalent water or chlorhexidine methods. Confocal-IR microscopy showed that the delmopinol reagent, alone, caused about one-third of each wet biofilm to be removed, while bacterial re-growth was confirmed by alamarBlue^&reg; assay. Chlorhexidine and PDT suppression of bacterial activity without regrowth was significantly improved with the added delmopinol treatment, and is likely to provide similarly beneficial results in the effective disinfection of diverse biofilms in many settings.</p>

<p> "<b>Healthcare organizations rely heavily on communications to deliver services and certify quality treatment outcomes. Specifically, communication and communication processes are critical determinants in whether a dental practice succeeds or fails. There has been a substantial amount of research on communication and its influence on patient satisfaction, employee morale, and work productivity within various organizations. However, limited existing qualitative research examines communication processes and their impact on health institutions. This research study explored the communication process and its influence on employee work performance within a dental practice. The researcher conducted semi-structured interviews to obtain descriptive, information-rich responses from a purposeful sample of 10 participants regarding their perception of the communication process. Utilizing an embedded, exploratory, case study research design, descriptions and experiences from leaders and employees revealed four major gaps within the organization's communication process. Consequently, six themes emerged that identified the four intricacies of an effective communication process within a private dental practice. The following complexities, lack of comprehension, lack of employee awareness, lack of precision and clarification of instruction, and inconsistent exchange of information, are crucial facets of the communication process. From the perspective of study participants, improvement in these areas would foster employee engagement, produce desirable outcomes, and enhance employee work performance</b>"</p>

<p> Secondary school students in Nigeria face challenges regarding their oral health. Few researchers have investigated oral health knowledge, attitudes, and behaviors in Nigerian populations. The purpose of this study was to assess the level of oral health knowledge, behaviors, and practices among secondary school students in Enugu State, Nigeria, in relation to their oral health status. The theoretical framework of this study was based on the health belief model. A cross-sectional study was conducted to collect data from 12 secondary schools in Enugu State, using a close-ended questionnaire as well as oral examination (dental caries and periodontal diseases) of the students who attended junior secondary (JSS) I, II, and III classes. A total stratified sample of 671 students was included in the study. Bivariate nonparametric tests and logistic regression were used to analyze the data. According to the results of the study, the levels of dental caries and periodontal diseases were relatively low. However, only one fourth of the students had received professional fluoridation, and almost 50% of the participants had never visited a dentist. Students from a missionary school had lower levels of periodontal diseases than those from public schools, with an odds ratio of 0.612 (95% CI [0.402, 0.934]). Students from JSS III class tended to have a lower level of periodontal diseases than those of JSS I class (OR: 0.567, 95% CI [0.363, 0.886]). The social change implications of this study can be the development and incorporation of oral health promotion programs into the school curriculum. These programs may increase the adoption of preventive oral health strategies by students, such as regular dental attendance, to maintain their good oral health for a life time. </p>

Objective. To investigate the effect of dental status on nutritional status in oral cancer patients. Method. A prospective study design was initially conducted on a group of post-therapeutic oral cancer patients. However, the level of compliance was low, so to ensure fullest use of the data, analyses were performed assuming a cross-sectional study design. Nutritional, dental and clinical information were analyzed at two time periods: evaluation one was at 1-6 months, and evaluation two was at 7-12 months post-therapy. Multiple linear regression analyses were used to evaluate the relationship between dental and nutritional status. Results. 44 subjects participated in evaluation one and 40 participated in evaluation two. Analyses showed that edentulism was a significant predictor for most nutritional indicators adjusting for age, gender, and C-reactive protein. Conclusion. Edentulous oral cancer patients demonstrated significantly poorer nutritional status than fully and partially dentate patients.

Objective: The goal of this project was to determine the impact of local inflammation on changes in the subgingival biofilm composition in ligature-induced periodontitis in rats using the specialized pro-resolving mediator (SPM), resolvin E1 (RvE1). Materials and Methods: The impact of RvE1 on the microbiota of ligature-induced periodontitis was assessed in two separate experiments; treatment of established periodontitis and prevention of ligature-induced periodontitis. In the treatment study, eighteen rats were separated into four groups comprising no ligature, ligature alone (no treatment), ligature with topical RvE1 treatment (ligature+RvE1) and, ligature with topical vehicle treatment (ligature + Vehicle). 3-0 silk ligatures were tied around maxillary second molars bilaterally for three weeks to induce disease. After three weeks, the treatment phase began with the application of RvE1 or vehicle (ethanol) every other day for an additional three weeks. Subgingival plaque samples were collected every four days throughout the experiment. The composition of the subgingival microbiota was initially screened by checkerboard DNA-DNA hybridization using probes on 40 subgingival species. Definitive, unbiased characterization of the subgingival microbiota was accomplished with next-generation sequencing using the Illumina MiSeq® platform. Six rats were sacrificed on Days 1, 21 and 42 and maxillae were dissected to collect samples for gingival RNA extraction, bone morphometric measurements, and histomorphometric analysis. Local tissue gene expression (Cxcl-1, Ptgs2, Nos2) was detected using qRT-PCR. Tissue specimens were prepared for histology and stained with H&E and tartrate resistant acid phosphatase (TRAP). In the prevention study, sixteen rats were separated into four groups (no ligature, ligature + RvE1 (0.1µg/µl), ligature + RvE1 (0.5 µg/µl), ligature + Vehicle). 5-0 silk ligatures were placed around maxillary second molars bilaterally to induce disease. At the time of ligature placement, animals received assigned treatment thrice weekly (M, W, F) for four weeks. Subgingival plaque samples were collected every four days (M and F). Four rats were sacrificed at baseline (Day 1) and the vehicle and two treatment groups (four each) were sacrificed at day 28 and samples processed as described above. The two-group comparisons were assessed by Student’s t-test. The multiple-group comparison was assessed by one-way ANOVA and post hoc tests. Results: In the first study (treatment), topical application of RvE1 significantly reversed the bone loss associated with periodontitis compared to the vehicle. RvE1 application significantly reduced the expression of Cxcl1 and osteoclast density compared to the vehicle application. In the prevention study, RvE1 treatment significantly prevented the bone loss during the disease progression. RvE1 application significantly reduced the expression of Ptgs2, Nos2 compared to the vehicle application. Osteoclast density and inflammatory cell infiltration in the RvE1 groups were significantly lower than these in the Vehicle group. The cell counts of bacterial species gradually increased and the subgingival microbiota shifted during the disease progression. In the treatment study, RvE1 treatment significantly reduced cell counts compared to the vehicle application at the end of treatment phase. The shift of subgingival microbiota was limited by the RvE1 treatment. In the prevention study, the taxonomic composition and diversity of subgingival microbiota was controlled by the RvE1 application. The change of subgingival microbiota appeared to be associated with the state of inflammation in the periodontal environment. Conclusion: Resolvin E1 treatment of existing ligature-induced periodontitis significantly regenerates lost alveolar bone and prevents alveolar bone loss. Resolvin E1 treatment limits microbial shifts and reduces total bacterial load by inhibiting inflammation of local environment in experimental periodontitis.