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Aim: The prevalence of dental erosion is still increasing. A possible preventive approach might be rinsing with edible oils to improve the protective properties of the pellicle layer. This was tested in the present in situ study using safflower oil. Methods: Pellicle formation was carried out in situ on bovine enamel slabs fixed buccally to individual upper jaw splints (6 subjects). After 1 min of pellicle formation subjects rinsed with safflower oil for 10 min, subsequently the samples were exposed in the oral cavity for another 19 min. Enamel slabs without oral exposure and slabs exposed to the oral cavity for 30 min without any rinse served as controls. After pellicle formation in situ, slabs were incubated in HCl (pH 2; 2.3; 3) for 120 s, and kinetics of calcium and phosphate release were measured photometrically (arsenazo III, malachite green). Furthermore, the ultrastructure of the pellicles was evaluated by transmission electron microscopy (TEM). Results: Pellicle alone reduced erosive calcium and phosphate release significantly at all pH values. Pellicle modification by safflower oil resulted in an enhanced calcium loss at all pH values and caused an enhanced phosphate loss at pH 2.3. TEM indicated scattered accumulation of lipid micelles and irregular vesicle-like structures attached to the oil-treated pellicle layer. Acid etching affected the ultrastructure of the pellicle irrespective of oil rinsing. Conclusion: The protective properties of the pellicle layer against extensive erosive attacks are limited and mainly determined by pH. The protective effects are modified and reduced by rinses with safflower oil. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Patients with bulimia nervosa are at high risk for dental erosion. However, not all bulimic patients suffer from erosion, irrespective of the severity of their eating disorder. It is often speculated that differences in the saliva are important, however, little is known about salivary parameters in bulimic patients, particularly directly after vomiting. The aim of the clinical trial was to compare different salivary parameters of subjects suffering from bulimia with those of healthy controls. Twenty-eight subjects participated (14 patients with bulimia nervosa, 7 of them with erosion; 14 matched healthy controls). Resting and stimulated saliva of all participants was analysed as well as saliva collected from bulimic patients directly and 30 min after vomiting. Parameters under investigation were flow rate, pH, buffering capacity and the enzyme activities of proteases in general, collagenase, pepsin, trypsin, amylase, peroxidase, and lysozyme. Regarding flow rate, pH and buffering capacity only small differences were found between groups; buffering capacity directly after vomiting was significantly lower in bulimic subjects with erosion than in subjects without erosion. Differences in enzymatic activities were more pronounced. Activities of proteases, collagenase and pepsin in resting and proteases in stimulated saliva were significantly higher in bulimic participants with erosion than in controls. Peroxidase activity was significantly decreased by regular vomiting. Proteolytic enzymes seem to be relevant for the initiation and progression of dental erosion directly after vomiting, maybe by both hydrolysis of demineralized dentine structures as well as modulation of the pellicle layer. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract: Aim: The aim of the present in situ study was to investigate ultrastructural alterations as well as protective properties of the pellicle layer during consumption of acidic beverages. Methods: Bovine enamel slabs were fixed on buccal and palatal aspects of individual splints and exposed in the oral cavities of three subjects for 120min. In the following, the subjects drank orange juice, coke light or sprite light. Half of the specimens were removed afterwards, the others were exposed to the oral fluids for another 120min. Erosive alterations of the bovine enamel slabs were measured by determination of the Knoop-micro-hardness. In addition, the ultrastructure of the pellicle was evaluated by transmission electron microscopy (TEM). Results: Determination of Knoop-micro-hardness yielded only little reduction of the relative Knoop-hardness in situ during consumption of sprite light (−0.053±0.019) and coke light (−0.075±0.04). With orange juice nearly no change of the hardness was recorded. TEM-pictures showed that the globular outer layers of the pellicle were removed to a different extent according to the localisation of the specimens in the oral cavity, whereas the basal pellicle was not affected by the acidic beverages. On the specimens carried for another 120min after the erosive attack, lacunae filled with organic structures were observed underneath the basal side of the pellicle. Conclusion: During fast consumption of acidic beverages in situ, the erosive effects on pellicle coated bovine enamel are moderate and juices seem to be less harmful as compared with low pH soft drinks. Pellicle proteins in eroded lacunae may impact the remineralisation process. [Copyright &y& Elsevier]

The study describes the application of the Arsenazo III method for detection of minimal amounts of calcium 12.4–49.4 μmol/l in different acidic solutions (hydrochloric acid, oxalic acid, maleic acid, phosphoric acid, tartaric acid, citric acid, lactic acid and acetic acid) adjusted to pH 2.0, 2.3 and 3.0. A mixture of the respective calcium concentrations with distilled water served as control. The experiments were run with ten repeats in series. Assessment of intra- and interassay coefficient of variation, and lower limit of quantification revealed that depending on the acid used, the Arsenazo III method is a reliable tool to quantify minimal calcium contents in acidic solutions. Copyright © 2005 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]