Luke Dawson

Salivary Factors in Vomiting Bulimics with and without Pathological Tooth Wear

The increased occurrence of dental erosion from self-induced vomiting in bulimia nervosa is not linearly associated with the frequency or the duration of vomiting. Possible changes in the buffering and lubricating role of saliva in bulimia nervosa and their relationship to erosion have not been previously investigated. Chewing-gum-stimulated salivary flow rate, pH, bicarbonate concentration and viscosity were compared between two groups of vomiting bulimics and with 10 healthy controls. One bulimic group (n = 9) had pathological tooth wear present according to the criteria of the Tooth Wear Index and the other bulimic group (n = 10) did not. The influence of salivary pellicle on enamel acid dissolution by perchloric acid was also assessed by an enamel biopsy method. Bicarbonate was measured in a Natelson microgasometer. Both the bulimic groups had mean initial 3-min flow rates and overall 9-min flow rates significantly lower (p < 0.01) than the healthy subjects. The mean pH values were not significantly different between the two bulimic groups or the control group. However, the mean bicarbonate concentration in both bulimic groups was significantly less (p < 0.01) than in the control group. The mean salivary viscosity of 7.4 centipoise (cP), measured by a DV1 Brookfield viscometer, was significantly greater (p < 0.05) in the pathological tooth-wear-present group than in the tooth-wear-absent group (4.5 cP) and the control group (4.1 cP). Slightly more calcium was released from the pellicle-free surface in both groups but this was not statistically significant, whilst the dissolved calcium in enamel biopsies was significantly lower (p < 0.05) in the tooth-wear-present group.

Acetylcholine-evoked calcium mobilization and ion channel activation in human labial gland acinar cells from patients with primary Sjögren's syndrome

Recent evidence has indicated that the salivary gland dysfunction associated with Sjögrens syndrome (SjS) is not necessarily due to immune‐mediated destruction of acinar tissue. SjS sufferers may possess substantial reserves of acinar tissue but nevertheless be incapable of maintaining salivary flow rates in the normal range. We have investigated the ability of isolated labial gland acinar cells from SjS patients to fluid secrete by measuring agonist‐evoked changes in intracellular Ca2+ ([Ca2+]i) using fura‐2 microfluorimetry and activation of K+ and Cl− channels using the patch‐clamp whole cell technique. We can confirm that stimulation with a super‐maximal dose of acetylcholine (ACh) increased [Ca2+]i equally in both control acinar cells and those derived from SjS patients. However, at submaximal concentrations, the dose–response curve for ACh was shifted to the right by approximately one order of magnitude in acinar cells from SjS patients compared to control acinar cells. Patch‐clamp measurements consistent with the presence of Ca2+‐activated K+ and Cl− conductances were obtained from both control acinar cells and those obtained from SjS patients. Dose‐dependent activation of the ion channels by acetylcholine was also right‐shifted in acinar cells from SjS patients compared to control cells. Our data show that labial gland acinar cells from SjS patients were capable of responding to agonist stimulation by mobilizing [Ca2+]i and activating K+ and Cl− channels consistent with the requirements of fluid secretion. However, the persistent loss of sensitivity to ACh observed in from SjS patients may account for the lack of saliva production observed in these patients in vivo.

The TRACTISS Protocol: a randomised double blind placebo controlled clinical TRial of Anti-B-Cell Therapy In patients with primary Sjögren's Syndrome

BackgroundPrimary Sjögren’s Syndrome (PSS) mainly affects women (9:1 female:male ratio) and is one of the commonest autoimmune diseases with a prevalence of 0.1 – 0.6% of adult women. For patients with PSS there is currently no effective therapy that can alter the progression of the disease. The aim of the TRACTISS study is to establish whether in patients with PSS, treatment with rituximab improves clinical outcomes.Methods/designTRACTISS is a UK multi-centre, double-blind, randomised, controlled, parallel group trial of 110 patients with PSS. Patients will be randomised on a 1:1 basis to receive two courses of either rituximab or placebo infusion in addition to standard therapy, and will be followed up for up to 48 weeks. The primary objective is to assess the extent to which rituximab improves symptoms of fatigue and oral dryness. Secondary outcomes include ocular dryness, salivary flow rates, lacrimal flow, patient quality of life, measures of disease damage and disease activity, serological and peripheral blood biomarkers, and glandular histology and composition.DiscussionThe TRACTISS trial will provide direct evidence as to whether rituximab in patients with PSS leads to an improvement in patient symptoms and a reduction in disease damage and activity.Trial registrationUKCRN Portfolio ID:9809 ISRCTN65360827.

A role for nitric oxide-mediated glandular hypofunction in a non-apoptotic model for Sjögren's syndrome

OBJECTIVE To investigate a role for the inflammatory mediator, nitric oxide (NO) in SS, an autoimmune condition characterized by salivary and lacrimal gland hypofunction resulting from failure of acinar cells to secrete. METHODS FURA-2 microfluorimetry was used to measure agonist-evoked changes of [Ca(2+)](i) in isolated mouse and human salivary acinar cells following exposure to NO donors. RESULTS NO had a biphasic effect on salivary acinar function. Acute exposure to NO (2 min) caused a cyclic guanosine monophosphate (GMP)-dependent, 1-H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-sensitive increase in the Ca(2+) signal elicited in response to acetylcholine (ACh) stimulation, consistent with stimulation of ryanodine receptors by cyclic adenosine diphosphate ribose. Prolonged exposure to NO (>40 min) significantly reduced the ACh-evoked Ca(2+) signal by a mechanism independent of cyclic GMP. We found no differences between the responses of human and mouse acinar cells. CONCLUSION Our data show that chronic exposure to NO, which is known to be elevated in SS, could have a role in salivary gland hypofunction. We note a similarity in the response to stimulation of salivary acinar exposed to NO and that which we have previously reported in salivary acinar cells isolated from patients with SS. We speculate that NO-mediated nitrosylation of one or more elements of the signal transduction pathway could underlie down-regulation of salivary function in SS.

A generic consensus assessment of undergraduate competence in forceps exodontia in the United Kingdom

UNLABELLED The assessment of competence in clinical skills has become more frequent in published healthcare curricula and syllabuses recently. There are agreed mechanisms for the assessment of competence in the post-graduate environment, but no consensus within the undergraduate curriculum. This paper seeks to develop an agreed generic checklist for the assessment of competence in forceps exodontia. MATERIALS AND METHODS A modified Delphi process was undertaken with representatives from all UK dental schools (n = 13) to develop a generic checklist for the assessment of competence in forceps exodontia. A content analysis of the assessments employed by each school was used to help discussion and inform the Delphi process. RESULTS Seven schools currently employ a summative assessment of competence in forceps exodontia, with the majority employing a structured clinical objective test (n = 6). From the seven assessments, there were a total of 29 putative items and 10 putative domains identified for a generic checklist. These were reduced to five domains and 19 items through the content analysis and Delphi process, and a generic overarching checklist was created. CONCLUSION Using this generic checklist, it may now be possible to pool data inter-institution to perform more powerful analyses on how our students obtain, or fail to obtain competence in forceps exodontia.

Dental student suturing skills: a multicentre trial of a checklist-based assessment

BACKGROUND The assessment of clinical skills is essential to determine whether an undergraduate is competent to perform the tasks outlined in the curriculum. Such assessments in dentistry have historically not been subjected to large scale validity and reliability testing due the relatively small student numbers at each institute. The aims of this study were to test the validity and reliability of a standardised, checklist-based, suturing objective structured clinical examination (OSCE) and then to perform a multicentre trial to determine its performance over a large cohort of students. MATERIALS AND METHODS A total of seven UK schools agreed to take part in the trial. To test the validity and reliability of the checklist, the examiner at each institution reviewed and scored video footage of 10 students performing the assessment. Each institution then carried out the assessment providing a checklist score and a global score for each of their own students. RESULTS The assessment was well received by the staff, with acceptable inter-examiner variability. In total, 496 students completed the suturing OSCE with a success rate of 81% with a variation between schools of between 66% and 96%. A significant correlation was found between the checklist score and the global score (r = 0.361, P = 0.000). No one item on the checklist was found to be a determinant factor in the outcome of the OSCE. CONCLUSIONS This checklist-based assessment of suturing skills was found to have face and content validity. Its reliability was promising, but merits further investigation. There may be an argument for the standardisation of the assessment of this core surgical skill throughout several UK-based dental schools.

Calling for a re-evaluation of the data required to credibly demonstrate a dental student is safe and ready to practice

Irrespective of nationality, this statement underscores the importance of undergraduate education, and its associated assessments, because the best and most cost-effective way to protect the public is to ensure that only the right individuals go on the professional register in the first place. For providers of undergraduate education, this distils down into the problem of how to ensure and demonstrate that our graduates are competent to practice. In undergraduate dental education, common approaches for demonstration of competency are grounded in the traditions of novice to expert learning (2). In this arena, becoming an ‘expert’ requires ten or more years of experience (3). Consequently, the traditional method for determining competency is the measurement of experience through counting the number and the quality of procedures completed (4). This approach has likely become widely accepted because it appears to have face validity; it is simple to do; progression decisions can easily be defended; it has endured the test of time; and it fulfils a crucial criterion for assessment, namely it is acceptable to stakeholders (5). Data to support the latter statement can be found through reference to the latest round of inspection reports by the UK General Dental Council (GDC) where a focus on, and a drive to increase, the numbers of individual procedures performed by undergraduate learners is still very evident (6). However, is this traditional approach still the best possible way of measuring competency considering the aforementioned changes in expectation over accountability, combined with advances in our understanding of pedagogy, and available technology? This paper aims to initiate debate over what should constitute best practice in the assessment of competence. From the evidence-base available we suggest that to truly establish competency sophisticated approaches for data collection, integration, and interpretation are likely to be needed to meet the demands and expectations of the 21st century. This is because the modern healthcare setting requires its professionals to be responsive and adapt to the ever-changing needs of patients (7). We suggest that in this setting, the important evidence underpinning competency is the longitudinal demonstration of the learner’s ability to independently and simultaneously manage all aspects of the activity being assessed for each patient, over a range of contexts, rather than simply measuring the amount of a specific activity or isolated facets of competency such as communication or professionalism. Furthermore, we will contend that decisions over progression will need to be made on a leaner-specific basis through the professional judgement, and consensus of a multidisciplinary expert panel following the objective analysis of large and fully integrated data sets.

The Overseas Registration Examination of the General Dental Council

The Overseas Registration Examination is a route to entry to the UK Dentists Register for dentists who have qualified outside the European Economic Area. The role of the examination is to protect the public by ensuring that such dentists meet minimum standards of competence. Candidates invest considerable time and resource in attempting the examination. For these reasons it is essential that the examination is both robust and fair. This paper describes the fundamental principles of assessment underpinning the design of the examination and the steps taken by the General Dental Councils ORE Advisory Group to assure its ongoing quality.

Can assessment be a barrier to successful professional development

In recent years, there has been a profound shift towards objectivity in high stakes clinical assessments, to reassure the regulators and the public that our graduating clinicians are competent. However, a recent report has suggested that since the introduction of high stakes assessment the relative levels of patient harm have increased. Although, direct causation has not been claimed it is incumbent upon responsible educators to reflect on the possibility that our students are passing the assessments but the assessments are not sophisticated enough to predict real-world competency. In addition, there has been an increasing focus of the student population on seeing the purpose of their clinical education being to pass assessments, rather than to treat patients. This unfortunate focus likely stems from their school education that develops a fixed task focused mindset. In this manuscript, the authors explore the potential issues over mindset and assessment sophistication, and offer possible solutions to tackle both problems.

LiftUpp: Support to Develop Learner Performance

The last two decades have seen enormous progress in both theories and technology to support learner progress. However, many of the Artificial Intelligence in Education (AIED) techniques are difficult to apply in workplace-based educational settings, such as dentistry. Such settings put high demands on e-infrastructure, because they require intelligent systems that can be used in the workplace every day, and can also fuse many different forms of assessment data together. In addition, such systems should be able to enhance student development through personalised real time feedback (in dentistry education, for example, from both staff and patients) to drive learner self-reflection. Moreover, the information these systems provide must be reliable to facilitate defensible decisions over individual student progress to protect the public [2].