Children and adolescents must be examined often for occlusal caries. Diagnosis of fissure caries is difficult especially when the tooth surface appears seemingly intact. It has been shown that using traditional clinical methods, as little as 20% of teeth with fissure caries under intact surfaces were correctly recognised as such. Therefore, new methods for increasing the accuracy of diagnosis have been sought for years. Recently, a new device, based on fluorescence measurements, was introduced. The purpose of this study was to test the device under in vivo conditions in order to provide recommendations for its use in the dental office. Seven general dental practitioners examined a total of 332 occlusal surfaces in 240 patients. Caries extent was determined for each site after operative intervention (='gold standard'). Clinical inspection and analysis of bitewing radiographs exhibited statistically significant lower sensitivities (31-63%) than did the DIAGNOdent device (sensitivity > or = 92%). It is recommended that the laser device is used in the decision-making process in relation to the diagnosis of occlusal caries as a second opinion in cases of doubt after visual inspection.

Excessive consumption of acidic drinks and foods contributes to tooth erosion. The aims of the present in vitro study were twofold: (1) to assess the erosive potential of different dietary substances and medications; (2) to determine the chemical properties with an impact on the erosive potential. We selected sixty agents: soft drinks, an energy drink, sports drinks, alcoholic drinks, juice, fruit, mineral water, yogurt, tea, coffee, salad dressing and medications. The erosive potential of the tested agents was quantified as the changes in surface hardness (DSH) of enamel specimens within the first 2 min (DSH 2 -0 ¼ SH 2 min 2 SH baseline ) and the second 2 min exposure (DSH 4 -2 ¼ SH 4 min 2 SH 2 min ). To characterise these agents, various chemical properties, e.g. pH, concentrations of Ca, P i and F, titratable acidity to pH 7·0 and buffering capacity at the original pH value (b), as well as degree of saturation (pK 2 pI) with respect to hydroxyapatite (HAP) and fluorapatite (FAP), were determined. Erosive challenge caused a statistically significant reduction in SH for all agents except for coffee, some medications and alcoholic drinks, and non-flavoured mineral waters, teas and yogurts (P,0·01). By multiple linear regression analysis, 52 % of the variation in DSH after 2 min and 61 % after 4 min immersion were explained by pH, b and concentrations of F and Ca (P,0·05). pH was the variable with the highest impact in multiple regression and bivariate correlation analyses. Furthermore, a high bivariate correlation was also obtained between (pK 2 pI) HAP , (pK 2 pI) FAP and DSH. There is increasing evidence, from in vitro and in situ studies, that the excessive consumption of acidic drinks and foods poses a risk to dental hard tissues (1 -8) . Tooth surface is softened in the early stage, and subsequently bulk material is dissolved, layer by layer, from the tooth surface. This type of tooth wear is defined as tooth erosion and is caused by acids (extrinsic and intrinsic) or chelating agents not involving bacterial action. There is a trend towards the increased consumption of acidic drinks and foods. In 2007, the worldwide annual consumption of soft drinks reached 552 billion litres, the equivalent of just under 83 litres/person per year, and this is projected to increase to 95 litres/person per year by 2012. However, the figure had already reached an average of 212 litres/person per year in the USA in 2009 (9) . To decrease extrinsic erosive tooth wear, the emphasis should be on preventive strategies that mainly aim at reducing the exposure of teeth to potentially erosive agents.As a prerequisite, it is essential for medical personnel and patients to have a thorough knowledge of the erosive potential of popular dietary substances. In the past several decades, studies investigating the erosive potential of different dietary substances and medications have been performed in different countries (3 -8,10) . A wide range of drinks, foods and medications, such as soft drinks, sports drinks, juices, salad dr...

The aim of this study was to compare the erosive potential of different beverages and foodstuffs in primary and permanent teeth. Sixty primary and 60 permanent human teeth were immersed for 3 min in the solution under study (5 teeth per treatment group). Surface microhardness was measured before and after exposure. Initial (baseline) surface microhardness was lower for primary teeth than for permanent teeth. In both primary and permanent teeth, Sprite showed the highest decrease in surface microhardness, whereas yogurt showed an increase in surface microhardness in the primary teeth. Overall decrease was 27.2 +/- 17.5 KHN (mean +/- SD) for primary and 25.9 +/- 15.6 KHN for permanent teeth. The comparison of the erosive susceptibility in this in vitro model showed that primary teeth were not more susceptible to erosion compared to permanent teeth.

The laser device DIAGNOdent developed for the detection of occlusal caries has limited value on approximal surfaces. The aim of this study was to develop and to test a new laser fluorescence (LF) device for the detection of approximal caries. Light with a wavelength of 655 nm was transported to the approximal surface using two different sapphire fibre tips. Seventy-five teeth were selected from a pool of extracted permanent human molars, frozen at –20°C until use. Before being measured, they were defrosted, cleaned and calculus was removed with a scaler. The molars were set in blocks simulating the contact area of adults. Bitewing radiographs were obtained using Kodak Insight films. After two independent assessments with the new LF device, the teeth were histologically prepared, and assessed for caries extension. Using the laser, specificity values for D₁ threshold (outer half of enamel), D₂ threshold (inner half of enamel), D₃ threshold (dentine) ranged between 0.81 and 0.93, sensitivity between 0.84 and 0.92 with no difference between the two tips. Bitewing radiography showed an inferior performance compared to LF (p < 0.05). Intraex aminer reproducibility was high (kappa >0.74). The new LF system might be a useful additional tool in detecting approximal caries. Because of its good reproducibility, it could be used to monitor caries regression or progression on approximal surfaces.

No abstract