Bespoke video vignettes - an approach to enhancing reflective learning developed by dental undergraduates and their clinical teachers.

This study explores the selective use of video as a medium to support reflective processes as related to dental undergraduate learning. With the objective of developing and enhancing high-quality adult dental care, the use of compiled video materials created in an undergraduate clinical setting was investigated. Video cameras were used to capture elements of reflection-in-action and reflection-on-action typically found during everyday clinical practice. 'Gold standard' or 'textbook outcomes' are rarely, if ever, fully achieved in dental practice. Real-life clinical experiences offer challenges and opportunities for both teachers and students to engage with reflective learning processes. The materials generated allowed for an experience of individual reflective learning and the creation of a data bank or archive with potential use for the benefit of a wider student cohort. Various aspects of the students' views and comments on the process of reflection were reported and explored by means of a semi-structured focus group moderated by a linked educational advisor.

A consideration of the paradigm of exercise physiology.

Exercise physiology, in terms of the history of biological sciences, is quite young and has a rather tumultuous history - as it spans physical education, health & medicine, sport science, and biology. This has led to the development of differing definitions, research approaches, practices and goals. This is easily seen in the presence of competing and non-universally adopted definitions of fitness. Such internal inconsistencies portray to the outside world a discipline experiencing the problems associated with a changing paradigm. Every science requires the presence of a paradigm that both describes and guides the evolution of thinking, experimentation, and the application of such. It is argued here that exercise physiology has been operating without benefit of a satisfactory and relevant paradigm. A further proposition is that the required disciplinary definitions derived from an articulated paradigm are also absent. A paradigmatic scheme based on biological dogma is presented along with proposed definitions.

So how do you see our teaching? Some observations received from past and present students at the Maurice Wohl Dental Centre.

This study explores student perceptions of clinical teaching delivered at the Maurice Wohl Dental Centre, King's College London Dental Institute. An on-line survey together with two paper-based questionnaires were used to invite three immediate past cohorts of final-year dental students to reflect and comment on their experiences during their year of attendance. Supporting data from current student focus group and face-to-face interviews were also included in the study. The principal findings from these triangulated methodologies were that the overwhelming majority of students felt they got on very well with their teachers. The development of a positive professional relationship with the teacher appeared to motivate students to work better. Teaching thought to be overly didactic and authoritarian would not be well received. The principal teaching style identified at the Centre was considered to be supportive and nurturing, encouraging a self-motivated and reflective approach to clinical practice.

Concentrations of salivary testosterone, cortisol, and immunoglobulin A after supra-maximal exercise in female adolescents.

The aim of this study was to examine the effect of supra-maximal exercise on circulating concentrations of salivary testosterone, salivary cortisol, and salivary immunoglobulin A in female adolescents. Nineteen apparently healthy females aged 15-16 years participated in this study. All participants completed 668 s sprints, interspersed with 30 s recovery intervals on a cycle ergometer. Salivary testosterone, cortisol, and immunoglobulin A samples were taken before and 5 min after exercise. Experimental procedures continued over two mornings, at least 3 h after a light breakfast. Participants refrained from performing any strenuous physical activity for at least 24 h prior to the exercise test. None of the participants were engaged in a structured training programme. The group mean (± s) for peak power output was 562 ± 113.0 W. Female adolescents recruited for this study showed no changes in salivary testosterone, cortisol or immunoglobulin A following repeated bouts of supra-maximal cycling (P > 0.05). To date, there has been a paucity of information concerning adolescents' hormonal and mucosal immune function responses to supra-maximal exercise. Our data provide further guidance with regard to physical activities and sports prescription for female adolescents. Further research, on a larger sample of females, is required to elucidate the physiological significance of these findings.

Management of patients at risk of bisphosphonate osteonecrosis in maxillofacial surgery units in the UK.

AIM: To establish how oral and maxillofacial surgery units in the UK manage patients requiring dental extractions who are currently taking, or have previously taken, bisphosphonates and to review current guidelines for management of these patients. METHODS: Postal questionnaire sent to 117 oral and maxillofacial surgery units in the UK. RESULTS: 63 replies were received (54% response rate). Only 8% of the units who responded have a protocol for managing these patients. The current strategies for the prevention of bisphosphonate osteonecrosis include chlorhexidene mouthwash and pre- and post-operative antibiotics. DISCUSSION: Bisphosphonate osteonecrosis (BON) is likely to become and increasing problem due to the large number of patients being prescribed drugs of this class. The aetiology and pathogenesis is BON is not clear but more similarities exist to 'phossy jaw' and osteopetrosis than to osteoradionecrosis. Where oral surgery is required, the use of mouthwash and antibiotics should be considered. The surgical technique should be atraumatic and where possible each sextant of the mouth should be treated in a staged manner.

Does chlorhexidine and povidone-iodine preoperative antisepsis reduce surgical site infection in cranial neurosurgery?

Introduction Surgical site infection (SSI) is a significant cause of postoperative morbidity and mortality. Effective preoperative antisepsis is a recognised prophylactic, with commonly used agents including chlorhexidine (CHG) and povidone-iodine (PVI). However, there is emerging evidence to suggest an additional benefit when they are used in combination. Methods We analysed data from our prospective SSI database on patients undergoing clean cranial neurosurgery between October 2011 and April 2014. We compared the case-mix adjusted odds of developing a SSI in patients undergoing skin preparation with CGH or PVI alone or in combination. Results SSIs were detected in 2.6% of 1146 cases. Antisepsis with PVI alone was performed in 654 (57%) procedures, while 276 (24%) had CHG alone and 216 (19%) CHG and PVI together. SSIs were associated with longer operating time (p<0.001) and younger age (p=0.03). Surgery type (p<0.001) and length of operation (p<0.001) were significantly different between antisepsis groups. In a binary logistic regression model, CHG and PVI was associated with a significant reduction in the likelihood of developing an SSI (adjusted odds ratio [AOR] 0.12, 95% confidence interval [CI] 0.02-0.63) than either agent alone. There was no difference in SSI rates between CHG and PVI alone (AOR 0.60, 95% CI 0.24-1.5). Conclusions Combination skin preparation with CHG and PVI significantly reduced SSI rates compared to CHG or PVI alone. A prospective, randomized study validating these findings is now warranted.

Insertion and recovery of a new retrievable vena caval filter. Work in progress.

A new retrievable inferior vena cava (IVC) filter was tested in nine pigs. Insertion was through a 14 French sheath using both the femoral and jugular approaches. All insertions were successful, and there was a 100% postinsertion IVC patency rate (8/8 pigs at one week and 1/1 pig at one month). Addition of an apical hook to the filter design allowed transjugular retrieval of two filters at one week postinsertion. Three of nine filters migrated to the upper IVC. The filter's design allows paraxial blood flow despite trapped thrombus and inhibits filter tilting. In vitro, the filter captured 95% to 100% of 5 X 5 mm clots. If problems with migration can be solved, the new filter may provide effective short- and long-term prophylaxis against pulmonary embolism.

Salivary PAF in acute myocardial infarction and angina: changes during hospital treatment and relationship to cardiac enzymes.

Salivary levels of platelet activating factor (PAF) were measured together with serum CPK and interleukin 2 receptor in 30 patients admitted to the coronary care unit, 9 patients with pulmonary tuberculosis, 10 with acute severe asthma and 8 normal controls. 16 of the 30 C.C.U. patients had sustained a acute myocardial infarction (M.I.) 5 had acute angina and the remaining 9 had non cardiac chest pain. Salivary PAF on admission was significantly higher in the M.I. Patients than in the normal subjects, asthmatics, tuberculosis patients and those with non cardiac chest pain (p < 0.001 in all cases) but not those with angina. After 48 hours PAF levels fell in the subjects with M.I. (p < 0.01) and no significant difference was seen between any group. PAF levels did not show any relationship with CPK levels or site of infarct in the M.I. patients. Interleukin 2 receptor was not significantly raised in the M.I. group as a whole but some individual patients showed markedly increased serum levels, but these levels did not correlate with either salivary PAF or serum CPK.

A controlled study of a specific MAO A reversible inhibitor (R011-1163) and amitriptyline in depressive illness.

A double blind comparative study of amitriptyline and a new reversible MAO A inhibitor R011-1163 was conducted in 25 depressed inpatients over 4 weeks. Response to treatment was assessed with the Hamilton depression rating scale, the Carroll depression self rating scale and the Visual analogue scale. Both drugs produced significant changes in depressive symptomatology (P less than 0.01, MANOVA) and there were no statistically significant differences between drugs (P greater than 0.05 MANOVA). Side effects were of mild to moderate severity with dry mouth the most commonly reported side effect of amitriptyline and vague, generalised headache in patients, treated with R011-1163.

Evaluation of the "Time to Quit" self-help smoking cessation program.

Public health and hospital nurses have widespread contact with smokers; an effective smoking cessation program administered by nurses has tremendous potential. This study evaluated: 1) the effectiveness of the self-help cessation program, "Time to Quit"/"Moi aussi, j'écrase" (TTQ), provided on a one-to-one basis; and 2) a smoking cessation training program for baccalaureate nursing students. Nursing students recruited 307 smokers who were randomly assigned to receive one of two interventions. Control smokers received a list of community smoking cessation resources and experimental subjects received this list plus TTQ. Smoking self-reports and cotinine levels were obtained at baseline, six weeks and nine months. More smokers receiving TTQ had reduced at six weeks post-intervention, while there were no differences in quit or reduction rates at the nine-month follow-up. Students were positive about learning the techniques and their knowledge scores were significantly higher than those of non-participating students.

Effects of the removal of composite resin restorations on Class II cavities.

Composite resin has such good aesthetic qualities that it is often difficult to identify the tooth-restoration interface, yet this is particularly important should the material require complete removal. Following the in-vitro removal of direct and indirect composite resin restorations from Class II cavities significant changes in cavity size and shape were recorded. Thirty-eight cavities were studied from both occlusal and proximal aspects and the final cavity size was compared to the original cavity. There was a significant increase in cavity size with a mean increase of 37% for the direct composite cavities and 35% for the indirect cavities, although the range of values is large. Following restoration removal, occlusal surfaces were seen to increase in 71% of teeth and proximal surfaces in 75% of teeth. There was no significant difference between the results for direct and indirect composite restorations. Occlusal dovetails and cavity undercuts were created in cavities which did not contain these features initially.

A survey of the effectiveness of dental light-curing units and a comparison of light testing devices.

The aims of this study were to: 1. survey the light output from 49 light-curing units in clinical use; 2. measure the effect on depth of cure of composite resin caused by a range of light outputs; 3. assess the relationship between radiometer meter readings and depth of cure of composite resin in a human tooth model and a Heliotest. The mean meter reading produced by the 49 lights surveyed using a lampChecker radiometer was 4.4 (+/-2.4 SD), range 0.3 to 10.0. The manufacturer of the radiometer considers optimal light output to provide a meter reading within the range 5.0 to 7.0. Lights of very low output (0.7 +/- 0.1 SD) were found to be capable of curing, after 20 seconds, a 1.9 (+/-0.3 SD) mm thickness of composite resin. However, only approximately 50% of this thickness can be considered fully cured. Increasing the cure time from 20 seconds to 60 seconds increased the mean depths of cure by a factor of approximately 1.4. The mean depths of cure of composite resin placed in the Heliotest were greater than those observed in the natural tooth model, by a factor of approximately 1.3. Correlation coefficients of meter readings and depth of cure were greater for the Efos Cure Rite and Demetron 100 radiometers than the lampChecker unit.

Precision ablation of dental enamel using a subpicosecond pulsed laser.

In this study we report the use of ultra-short-pulsed near-infrared lasers for precision laser ablation of freshly extracted human teeth. The laser wavelength was approximately 800nm, with pulsewidths of 95 and 150fs, and pulse repetition rates of 1kHz. The laser beam was focused to an approximate diameter of 50microm and was scanned over the tooth surface. The rise in the intrapulpal temperature was monitored by embedded thermocouples, and was shown to remain below 5 degrees C when the tooth was air-cooled during laser treatment. The surface preparation of the ablated teeth, observed by optical and electron microscopy, showed no apparent cracking or heat effects, and the hardness and Raman spectra of the laser-treated enamel were not distinguishable from those of native enamel. This study indicates the potential for ultra-short-pulsed lasers to effect precision ablation of dental enamel.

Strength of secondary-cured resin composite inlay repairs.

A study was designed to simulate the repair of an indirect resin composite restoration with conventionally cured resin composite. Two-part specimens were prepared to test the diametral tensile strength of the repair interface between the base material of an indirectly cured resin composite (Herculite XRV) and repairs carried out with three directly cured materials (Herculite XRV, TPH, and Charisma). The repairs were carried out with and without use of the bonding resin for the repair material. The diametral tensile strengths of all repaired specimens were significantly less than those of bulk unrepaired specimens. There were no significant differences between the diametral tensile strengths of repaired blocks when the repair materials were used without bonding resin. The use of an intermediate layer of bonding resin significantly increased the bond strengths obtained when Herculite XRV and TPH were used for repair. There was no significant difference between the strength values of Herculite XRV and TPH, but Charisma exhibited the lowest strengths of repaired specimens.

A survey of dental airlines and an examination of tooth-drying techniques.

The aims of this study were: 1. To assess the prevalence and severity of water and oil contamination in 20 dental airlines in clinical use, using a commercial test kit, LP Aerotest. 2. To determine the effect, in vitro, of such contamination on the shear bond strengths to etched bovine enamel, of composite resin and a dedicated bonding agent. The enamel was dried using either an oil-and-water-contaminated 3-in-1 syringe, a warm-air tooth-dryer, silica gel-dried air or blotting paper, prior to bonding. A total of 11 (5 mm diameter) composite discs were bonded in each group. The samples were shear tested 72 hours later at a cross-head speed of 50 mm/min. All airlines had > 100 mg/m3 water and traces of oil (< 0.5 mg/m3) were present in 50% of samples. The mean shear bond strengths (MPa) for the 3-in-1 syringe, tooth-dryer, dried air and blotting paper-dried teeth were 14.5 +/- 3.8, 19.0 +/- 2.6, 19.6 +/- 4.2 and 19.7 +/- 1.9 respectively. The differences between the values for the tooth dryer, dry air and blotting paper were not significant (P > 0.01) but a significant difference (P < 0.01) was observed between these and the 3-in-1 syringe.

A comparison of the shear bond strength of composite resin bonded by a fourth and a fifth generation dental adhesive to bovine teeth.

AIM: This study compared the shear bond strengths, to bovine enamel and dentine, of composite resin bonded using an established bonding agent (Syntac) and the more recent Syntac SC. METHOD: A total of 24 adult bovine incisors were divided into two equal groups and prepared by roughening the enamel surfaces with a medium-grit, high-speed diamond. The enamel was etched and 24 x 5 mm diameter composite discs were light-cured and bonded using Syntac and 24 using Syntac SC, following the manufacturer's instructions. The samples were shear tested 72 hours later at a crosshead speed of 50 mm/min using a Howden Universal Testing Machine. The labial enamel and 1 mm of dentine were removed and the experiment was repeated. RESULTS: The mean shear bond strengths (MPa) for the Syntac and Syntac SC bonded composite to enamel were 10.9 +/- 4.5 and 8.9 +/- 5.7, and to dentine 6.4 +/- 3.2 and 5.5 +/- 3.1, respectively. The differences between the values for each material on enamel and between each material on dentine were not significant (P > 0.01). However, nine (19%) Syntac SC bonded composite discs debonded during build-up and had to be remade, prior to testing. CONCLUSION: When a bond between composite and resin was achieved, no significant difference was found between the mean shear bond strengths of Syntac and Syntac SC bonded composite to either enamel or dentine. However, lack of composite adherence to the Syntac SC was noted during the preparation of specimens.

Electrosurgery in restorative Dentistry: 2. Clinical applications.

Electrosurgery techniques have been used in dentistry as an aid to soft tissue management for nearly 60 years. However, it was not until the late 1960s that the principles of electrosurgery were understood and improved equipment became available. Part 1 of the two-part series covered the theory behind using this technique. Part 2 will now discusses the clinical applications.

Electrosurgery in restorative dentistry: 1. Theory.

Electrosurgery techniques have been used in dentistry as an aid to soft tissue management for nearly 60 years. However, it was not until the late 1960s that the principles of electrosurgery were understood and improved equipment became available. Part 1 of this two-part series covers the theory behind using this technique. Part 2 will discuss the clinical applications.

Why do general dental practitioners become involved in clinical teaching? A pilot study exploring the views of part-time practitioner teachers, King's College London.

INTRODUCTION: Dental schools in the United Kingdom are becoming increasingly reliant on the services of part-time teachers to deliver the clinical educational component of the dental course. Their background is predominantly from general dental practice but the opportunities to progress in the system are limited. The aim of this study was to ascertain the views and perceptions of such teachers at a dental school. MATERIALS AND METHODS: An anonymous, non-incentivised online survey was used to obtain both qualitative and quantitative views of the part timers. RESULTS: The department has n = 40 part-time teachers and there was a response rate of 78%. Overall 73% were satisfied with their current teaching position, whereas the remaining 27% of teachers were seeking higher rewards both in terms of recognition and status. CONCLUSIONS: This study demonstrated the need for formal teaching skills and training to be made available to part-time clinical teachers. Allied to this is the requirement for a clearly defined and achievable career pathway.

Unique microstructural design of ceramic scaffolds for bone regeneration under load.

During the past two decades, research on ceramic scaffolds for bone regeneration has progressed rapidly; however, currently available porous scaffolds remain unsuitable for load-bearing applications. The key to success is to apply microstructural design strategies to develop ceramic scaffolds with mechanical properties approaching those of bone. Here we report on the development of a unique microstructurally designed ceramic scaffold, strontium-hardystonite-gahnite (Sr-HT-gahnite), with 85% porosity, 500µm pore size, a competitive compressive strength of 4.1±0.3MPa and a compressive modulus of 170±20MPa. The in vitro biocompatibility of the scaffolds was studied using primary human bone-derived cells. The ability of Sr-HT-gahnite scaffolds to repair critical-sized bone defects was also investigated in a rabbit radius under normal load, with ß-tricalcium phosphate/hydroxyapatite scaffolds used in the control group. Studies with primary human osteoblast cultures confirmed the bioactivity of these scaffolds, and regeneration of rabbit radial critical defects demonstrated that this material induces new bone defect bridging, with clear evidence of regeneration of original radial architecture and bone marrow environment.