Needle stick injuries among dental students: risk factors and recommendations for prevention

Aim: To evaluate the risk factors of needle stick injuries (NSIs) sustained by undergraduate dental students and nurse students at the King's College London (KCL) Dental Institute. Materials and methods: A retrospective study evaluated the incident reports relating to NSIs reported over a period of 2 years. Factors including the dental department, study year, and when the injury took place during administration of local anaesthesia (LA) and recapping conventional syringe or clearing work surface or during disposal. Results: This report showed that students are at the highest risk of NSIs at the fourth year of their 5-year BDS course. About one-third of injuries were reported among this group of students followed by year 5 students (25%). Oral surgery clinics were the major source of incident reporting when compared with other specialised dental clinics within the institute. The left hands of the students were the most frequently affected by such injuries and then the right hands of student dental nurses. The attempt of needle recapping of conventional syringes was the least reported mechanism of injuries and constituted only 15% of the total injuries and mainly occurred in third year students. The most frequent injuries among student nurses were during disposal of the needle. Conclusion: Less NSIs occur when using safety syringes. A non-recapping policy with immediate disposal of either the conventional or safety syringe systems after injection would prevent all clearance-related NSIs sustained by nurses. To avoid NSIs, education plays a vital role particularly with effective implementation of the change to safety syringes with appropriate training

Novel experimental strategies to destroy oral cancer and precancer and residual disease

Oral cancer is a major healthy problem, with about 400,000 new cases diagnosed annually worldwide. The disease is characterised by consistently low 5-year survival rate that related to the significant recurrence rate. The recurrence may correlate to the presence of genetically and histologically altered tissues with a higher risk of malignant transformation (Dysplasia) or the residual malignant cells may remain in the body after surgery to remove a tumour (Residual disease).This thesis examines the efficacy of conditionally replicating adenoviruses (CRAds), to lyse epithelia that show mild, moderate or severe dysplasia and the ability of angiogenesis inhibitor (ZD4190) to prevent the growth of malignant cells in a rodent model of residual cancer in muscle bed. Several primary and established keratinocytes derived lesions with dysplasia were grown in monolayer and organotypical culture (QC) to establish 3D model for oral epithelia with mild, moderate and severe dysplasia. The model was characterised and used to test the efficacy of CRAds to lyse these epithelia. This model showed the ability to the cells derived from dysplastic lesions when grown in QC to recapitulate the architectural and cytological features of the parent tissues. The results show that QC dysplastic epithelia can be lysed with topical application of d/922-947 being more lytic than wild type adenovirus or the retargeted CRAds, and that normal QC oral epithelia were very resistant to this treatment. This study also found that the lytic effect was determined by the grade of the dysplasia, and the presence of suprabasal cycling cells in the epithelium. The integrity of the G1-S checkpoint, expression of the coxsackie adenovirus receptor (CAR) and the transcription cofactor p300 may also be important. For residual disease, the studies showed that when 104 squamous tumour cells were implanted, mimicking the clinical scenario where low numbers of residual tumour cells persist at the operative site, immediate treatment with ZD4190 prevented outgrowth of these cells whereas the control groups developed large tumours. When more than 105 malignant cells were implanted the tumours that developed in ZD4190-treated animals contained more areas of necrosis and fewer blood vessels than the vehicle-treated controls and there was a significant reduction in the tumour area when treatment was maintained for 3 weeks. This project shows that it is possible to recapitulate the features of dysplastic oral lesions in vitro. Moreover, QC epithelial phenotype can be modulated by modifying the culture conditions. The CRAD d/922-947 may provide a "molecular scalpel" for oral dysplastic lesions and a means to selectively eliminate dysplastic oral keratinocytes. Finally, shows that angiogenesis inhibitors have an important role to play in preventing the outgrowth of any residual tumour cells and that treatment should commence immediately after surgery when the tumour burden is as low as possible to maximise the therapeutic effect.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Can presence of oral Fordyce′s granules serve as a marker for hyperlipidemia?

Background: Hyperlipidemia is a well-documented risk factor for coronary heart disease and a great wealth of clinical trials have shown that early detection of hyperlipidemia and prescribing drugs that lower elevated lipid levels reduce serious cardiovascular events, such as myocardial infarction, heart failure and stroke. Fordyce granules (FGs) are sebaceous glands without hair follicles, most often located under the epithelium of the cheek and the vermilion border of lip. The incidence of FGs is typically high and their presence is usually regarded as a normal variation of the oral mucosa. The aim of this study was to investigate the pattern of anatomical distribution and density of FGs and also to explore any potential relationship between the detection of FGs and the state of hyperlipidemia. Materials and Methods: A cross-sectional, prospective study was designed. The participants were divided into two groups; first group consisted of individuals with FGs and the second group included those with no FGs detected. All participants were fasting 9-12 h before they were subjected to a comprehensive oral examination and their blood was sampled and tested for complete lipid profile. The presence of FGs was scored based on the number of the granules and their anatomical distribution. Chi-square test was used and P < 0.05 was considered as significant. Results: A total of 350 patients were recruited for this study, nearly 90% (n = 314) elicit detectable FGs. The FGs were mainly located on the buccal mucosa with or without labial involvement and their density tend to reduce with age and also with smoking. Individuals with elevated lipid profile tend to have the highest score of the FGs. Conclusion: According to this report, the presence of high numbers of FGs in people with high risk factors for cardiovascular disease should not be neglected

Lysis of Dysplastic but not Normal Oral Keratinocytes and Tissue-Engineered Epithelia with Conditionally Replicating Adenoviruses

There is no effective medical treatment for oral precancer, and surgery to remove these lesions is imprecise because abnormal mucosa extends beyond the visible lesion. Development of vectors for tumor-selective viral replication has been a significant advance, and viral lysis is well suited to destruction of oral precancerous mucosa. To facilitate evaluation of new treatments, we engineered dysplastic oral epithelium using keratinocytes isolated from dysplastic lesions. We show that these model systems recapitulate the key characteristics of the clinical lesions closely, and that topical delivery of the conditionally replicating adenovirus (CRAd) dl922-947 can lyse tissue-engineered epithelia that show mild, moderate, or severe dysplasia, but normal oral epithelia are very resistant to this treatment. The lytic effect is determined by various factors, including the grade and proliferation index of the dysplastic epithelia. The presence of suprabasal cycling cells, expression of the coxsackie adenovirus receptor (CAR), the transcription cofactor p300, and other aberrations that affect the regulation of the cell cycle or apoptosis and promote viral replication may also be important. The ability of dl922-947 to destroy engineered oral dysplasia was significantly greater than that observed using wild-type adenovirus, d/1520, or viruses modified to bypass cell entry dependent on the presence of CAR. Evidence of infection in clinical dysplastic lesions was also shown ex vivo using tissue explants. We conclude that dl922-947 may provide an efficient molecular cytotoxic to dissolve oral dysplastic lesions

Diagnostic Accuracy of Oral Cancer and Suspicious Malignant Mucosal Changes among Future Dentists

This study aimed to assess the ability of dental students and recent graduates to detect and recognize mucosal changes that are suggestive of oral cancer and potentially malignant disorders. In this cross-sectional study, a questionnaire was administered to dental students and recent graduates of Ajman University (n = 132). Completed questionnaires were received from 84 (63.6%) females and 48 (36.4%) males which included fifth-year students (n = 80), interns (n = 39), and dental practitioners (n = 13). This questionnaire was designed to assess the respondent’s ability to detect and recognize different types of oral lesions, as well as their knowledge of oral cancer appearance and malignancy potential. The overall accuracy of diagnosis was 46%. The participants correctly identified normal variations, benign tumors, malignant tumors, and premalignant lesions at rates of 60.3%, 31.0%, 55.7%, and 33.4%, respectively. There was no significant difference between the two genders in their ability to recognize and detect correct answers (females, 48.3%; males, 47.2%). According to education level, interns provided the highest percentage of correct answers (52.5%), followed by newly dental practitioners (51.9%) and fifth-year students (44.1%). Conclusion: The respondents of this survey did not exhibit a satisfactory diagnostic capability in recognizing mucosal changes consistent with the clinical presentation of oral cancer. Thus, a need exists for improved and updated educational methods for undergraduate students regarding oral cancer and potentially malignant disorders. Meanwhile, practitioners should look for oral abnormalities to provide better diagnosis and management. Practitioners should also stay up to date on the oral malignancy topic by attending workshops and clinicopathological conferences