The construal of ‘exists’ as a first-order or real predicate is defended against prevailing orthodoxy.

Russell's theory of memory as acquaintance with the past seems to square uneasily with his definition of acquaintance as the converse of the relation of presentation of an object to a subject. We show how the two views can be made to cohere under a suitable construal of 'presentation', which has the additional appeal of bringing Russell's theory of memory closer to contemporary views on direct reference and object-dependent thinking than is usually acknowledged. The drawback is that memory as acquaintance with the past falls short of fulfilling Russell's requirement that knowledge by acquaintance be discriminating knowledge - a shortcoming shared by contemporary externalist accounts of knowledge from memory.

The mechanical control of supragingival biofilm is accepted as one of the most important measures to treat and prevent dental caries and periodontal diseases. Nevertheless, maintaining dental surfaces biofilm-free is not an easy task. In this regard, chemical agents, mainly in the form of mouthwashes, have been studied to help overcome the difficulties involved in the mechanical control of biofilm. The aim of this paper was to discuss proposals for the teaching of supragingival chemical control (SCC) in order to improve dentists' knowledge regarding this clinical issue. Firstly, the literature regarding the efficacy of antiseptics is presented, clearly showing that chemical agents are clinically effective in the reduction of biofilm and gingival inflammation when used as adjuvant agents to mechanical control. Thus, it is suggested that the content related to SCC be included in the curricular grid of dental schools. Secondly, some essential topics are recommended to be included in the teaching of SCC as follows: skills and competencies expected of a graduate dentist regarding SCC; how to include this content in the curricular grid; teaching-learning tools and techniques to be employed; and program content.

PURPOSE: The aim of the present crossover study was to evaluate professional toothbrushing as a method for diagnosing gingivitis in children. MATERIALS AND METHODS: Thirty-four preschool children who had gingival bleeding > or = 10% and without proximal restorations/carious lesions were included in the study. Examinations comprised two gingival indices recorded at a 15-min interval, in the following sequences: the Ainamo and Bay gingival bleeding index (GBI1) followed by the brushing index (BI2) and vice versa (BI1-GBI2). Half of the children started the study in the first sequence and the other half in the second. After a 3- to 4-day washout period, the indices were again recorded with individuals changing the sequences. Data analysis considered GBI as the gold standard, and sensitivity (SE), specificity (SP), positive predictive value (PPV) and negative predictive value (NPV) were also calculated. RESULTS: The overall mean value of gingival bleeding at the first examination was 18.85 +/- 9.24%. Validation of toothbrushing performed after GBI (BI2) resulted in values for SE, SP, PPV and NPV of 0.59 (95% CI, 0.55 to 0.63), 0.92 (95% CI, 0.91 to 0.93), 0.64 (95% CI, 0.60 to 0.69) and 0.90 (95% CI, 0.89 to 0.92), respectively. BI performed before GBI (BI1) resulted in similar SE, SP, PPV and NPV. Percentage agreement of GBI1-BI2 and BI1-GBI2 was 83.5% and 85.9%, respectively. CONCLUSIONS: Professional toothbrushing can be suggested as a method for the diagnosis of gingival inflammatory status in children, especially as an indicator of gingival health.

Judgments about the validity of at least some elementary inferential patterns (say modus ponens) are a priori if anything is. Yet a number of empirical conditions must in each case be satisfied in order for a particular inference to instantiate this or that inferential pattern. We may on occasion be entitled to presuppose that such conditions are satisfied (and the entitlement may even be a priori), yet only experience could tell us that such was indeed the case. Current discussion about a perceived incompatibility between content externalism and first-person authority exemplifies how damaging the neglect of such empirical presuppositions of correct reasoning can be. An externalistic view of mental content is ostensibly incompatible with the assumption that a rational subject should be able to avoid inconsistency no matter what the state of her empirical knowledge may be. That fact, however, needs not be taken (as it often is) as a reductio of externalism: alternatively, we may reject that assumption, adding to the agenda of a philosophical investigation of rationality an examination of the vicissitudes of logical luck. I offer an illustration and defense of that alternative.