Morphological, chemical and structural characterisation of deciduous enamel: SEM, EDS, XRD, FTIR and XPS analysis.

AIM: The purpose of this study was to characterise the enamel surface of sound deciduous teeth in terms of morphology, chemical composition, structure and crystalline phases. MATERIALS AND METHODS: The enamel of 30 human deciduous teeth was examined by: Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), X-ray Powder Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Photoelectron Spectroscopy (XPS). Chemical differences between incisors and canines were statistically evaluated using the Mann-Whitney U test (p ≤ 0.05). RESULTS: Three enamel patterns were observed by SEM: 'mostly smooth with some groves', 'abundant microporosities' and 'exposed prisms'. The average Ca/P molar ratios were 1.37 and 1.03 by EDS and XPS, respectively. The crystallite size determined by XRD was 210.82 ± 16.78 Å. The mean ratio between Ca bonded to phosphate and Ca bonded to hydroxyl was approximately 10:1. CONCLUSION: The enamel of sound deciduous teeth showed two main patterns: 'mostly smooth with some groves' and 'abundant microporosities'. 'Exposed prisms' was a secondary pattern. There were slight variations among the Ca/P molar ratios found by EDS and XPS, suggesting differences in the mineral content from the enamel surface to the interior. The crystalline phases found in enamel were hydroxyapatite and carbonate apatite, with major type B than type A carbonate incorporation.

Fear of visual loss in patients with diabetes: results of the prevalence of diabetic eye disease in Tayside, Scotland (P-DETS) study.

AIMS: To describe the relationship between fear of visual loss and dependent variables (visual acuity, retinopathy treatment, severity of retinopathy) in community-based diabetic patients. METHODS: Subjects were identified from the Diabetes Audit and Research in Tayside, Scotland (DARTS) diabetes register. From a total of 4825 individuals known to have diabetes and who were resident in Dundee and Perth (population 216 204; diabetes prevalence 2.23%), 586 persons with diabetes were randomly selected. Participants completed a self-administered questionnaire in Likert grade format which incorporated two items addressing presence and intensity of fear of visual loss. RESULTS: Questionnaires were returned by 61.4% of the cohort. Fear of visual loss was 'often in mind' for 37% of respondents, and that fear was intense for 47.4%. Analysis by diabetes type revealed differences in reported fear of Type 1 and Type 2 patients in relation to disease and treatment variables. Linear regression highlighted the complexity of the issue with retinal status, acuity and treatment only partly explaining reported patient concern (r(2) range: 0.051-0.125 for presence of fear; 0.026-0.04 for intensity of fear, depending on diabetes type). CONCLUSIONS: Fear of visual loss is preoccupying and intense for a substantial proportion of the diabetic population. Reasons for this are multiple and complex. Objective measures of visual impairment and retinal status are inadequate predictors of fear. Carers and researchers need to be mindful of this when approaching patients with diabetes.