Assessing the assessors: investigating the process of marking essays.

Pressure for accountability, transparency, and consistency of the assessment process is increasing. For assessing complex cognitive achievements, essays are probably the most familiar method, but essay scoring is notoriously unreliable. To address issues of assessment process, accountability, and consistency, this study explores essay marking practice amongst examiners in a UK dental school using a qualitative approach. Think aloud interviews were used to gain insight into how examiners make judgements whilst engaged in marking essays. The issues were multifactorial. These interviews revealed differing interpretations of assessment and corresponding individualised practices which contributed to skewing the outcome when essays were marked. Common to all examiners was the tendency to rank essays rather than adhere to criterion-referencing. Whether examiners mark holistically or analytically, essay marking guides presented a problem to inexperienced examiners, who needed more guidance and seemed reluctant to make definitive judgements. The marking and re-marking of scripts revealed that only 1 of the 9 examiners achieved the same grade category. All examiners awarded different scores corresponding to at least one grade difference; the magnitude of the difference was unrelated to experience examining. This study concludes that in order to improve assessment, there needs to be a shared understanding of standards and of how criteria are to be used for the benefit of staff and students.

An evaluation of the use of caries risk/susceptibility assessment in an undergraduate dental curriculum.

There has been a paradigm shift in patient care with regards to delivering better oral health, towards a team-delivered, person-focused, risk-related model that is known as minimum intervention oral care (MIOC). Student skills should be developed within the undergraduate dental curricula to ensure that graduating dentists and other oral healthcare team members are able to provide phased personalised care plans alongside behavioural management support to patients/caregivers to prevent and manage oral disease in the long term. The purpose of this study is to establish that using an adjunctive caries risk/susceptibility assessment (CRSA) technology (PreViser) had an impact on the behaviour, perception, and knowledge of dental undergraduate students and their clinical teachers, regarding the benefits of such an oral health assessment in the management of patients. Four cohorts of students who did not have exposure to the caries risk susceptibility software were compared with those who did. This study was conducted using a mixed methods approach using a convergent parallel design consisting of collecting quantitative data through questionnaires presented to four cohorts of Year 4 dental students (n = 150 per cohort) and their clinical teachers (n = 10) and qualitative data from structured interviews with students (n = 5) and teachers (n = 7) with suitable statistical analysis and interpretation. Results: Generally, the items that exhibited statistical significance, when reviewed, showed better behaviour, perception, and knowledge towards CRSA in the Group C (BDS4-22T1) cohort in comparison with the Group A (BDS3-20T2) cohort. The Group D (BDS4-22T2) students felt more confident using the PreViser as a CRSA tool. When comparing the Group C and Group D data, we note that the students from the Group C cohort were more likely to carry out a diet analysis for their patients and were less likely to be negatively impacted by time constraints compared with the Group D students. Both cohorts were equally confident in using the PreViser for CRSA. From a qualitative perspective, although competence and confidence appeared high, the students and teachers acknowledged that they would need more support to use it chairside. The main barrier listed to using PreViser rested in the fact that clinical teachers either preferred their own ways of assessing or did not know how to use the tool and therefore did not encourage using it. Those who did use PreViser highlighted that it was straightforward to use and was a systematic approach, enabling communication with the patients as there is 'evidence' to back up the clinical recommendations. Conclusion: The cumulative benefit of training and use (even limited) had an impact on the students' knowledge, competence, and confidence regarding CRSA, ultimately facilitating the process of teaching and assisting them in effectively implementing CRSA. The importance of CRSA became more evident immediately following the training. Further research is suggested to understand the factors influencing student behaviour, perception, and knowledge regarding CRSA with the aim to make recommendations on a preferable approach and tool to help streamline CRSA education.

Measurement of surface roughness changes of unpolished and polished enamel following erosion.

OBJECTIVES: To determine if Sa roughness data from measuring one central location of unpolished and polished enamel were representative of the overall surfaces before and after erosion. METHODS: Twenty human enamel sections (4x4 mm) were embedded in bis-acryl composite and randomised to either a native or polishing enamel preparation protocol. Enamel samples were subjected to an acid challenge (15 minutes 100 mL orange juice, pH 3.2, titratable acidity 41.3mmol OH/L, 62.5 rpm agitation, repeated for three cycles). Median (IQR) surface roughness [Sa] was measured at baseline and after erosion from both a centralised cluster and four peripheral clusters. Within each cluster, five smaller areas (0.04 mm2) provided the Sa roughness data. RESULTS: For both unpolished and polished enamel samples there were no significant differences between measuring one central cluster or four peripheral clusters, before and after erosion. For unpolished enamel the single central cluster had a median (IQR) Sa roughness of 1.45 (2.58) µm and the four peripheral clusters had a median (IQR) of 1.32 (4.86) µm before erosion; after erosion there were statistically significant reductions to 0.38 (0.35) µm and 0.34 (0.49) µm respectively (p<0.0001). Polished enamel had a median (IQR) Sa roughness 0.04 (0.17) µm for the single central cluster and 0.05 (0.15) µm for the four peripheral clusters which statistically significantly increased after erosion to 0.27 (0.08) µm for both (p<0.0001). CONCLUSION: Measuring one central cluster of unpolished and polished enamel was representative of the overall enamel surface roughness, before and after erosion.

Mechanisms of action of environmental factors--tobacco smoking.

AIM: To review the potential biological mechanisms underlying the effects of tobacco smoking on periodontitis. MAIN FINDINGS: Smoking has major effects on the host response, but there are also a number of studies that show some microbiological differences between smokers and non-smokers. Smoking has a long-term chronic effect on many important aspects of the inflammatory and immune responses. Histological studies have shown alterations in the vasculature of the periodontal tissues in smokers. Smoking induces a significant systemic neutrophilia, but neutrophil transmigration across the periodontal microvasculature is impeded. The suppression of neutrophil cell spreading, chemokinesis, chemotaxis and phagocytosis have been described. Protease release from neutrophils may be an important mechanism in tissue destruction. Tobacco smoke has been found to affect both cell-mediated immunity and humoral immunity. Research on gingival crevicular fluid has demonstrated that there are lower levels of cytokines, enzymes and possibly polymorphonuclear cells in smokers. In vitro studies have shown detrimental effects of nicotine and some other tobacco compounds on fibroblast function, including fibroblast proliferation, adhesion to root surfaces and cytotoxicity. CONCLUSION: Tobacco smoking has widespread systemic effects, many of which may provide mechanisms for the increased susceptibility to periodontitis and the poorer response to treatment.

Prevention of mucosally induced uveitis with a HSP60-derived peptide linked to cholera toxin B subunit.

Oral administration of the uveitogenic peptide (aa 336-351) derived from human HSP60 induced clinical and histological manifestations of uveitis in 65.8% (48/73) of Lewis rats. Uveitis was significantly decreased to 16.7% (11/66) in parallel experiments with the peptide linked to recombinant cholera toxin B subunit (rCTB), also given by mouth (chi(2)=34.2, p<0.0001). The protective efficacy between tolerized and immunized animals was 74.7%. Adoptive transfer of mesenteric lymph node cells from tolerized rats prevented the development of uveitis. A significantly higher proportion of regulatory CD4(+)CD45RC(low)RT6(+) subset of Th2 memory cells were found in the mesenteric lymph nodes (p<0.005) and spleens (p