Comparative evaluation of combined remineralization agents on demineralized tooth surface.

OBJECTIVES: The aim of this in vitro study was to evaluate the effects of casein phosphopeptides (CPP)-ACPF, NovaMin+ fluoride-containing toothpaste and Xylitol+ fluoride containing cream on demineralized areas on the enamel surface. MATERIALS AND METHODS: A total of 100 enamel slab samples was prepared to investigate in the laboratory experiments. For this purpose, a total of 50 freshly extracted third molar teeth which completed root formation split into two portions in the mesiodistal direction. Enamel surfaces were immersed in a pH cycling protocol as described in the literature to simulate oral conditions for 9 days in order to evaluate the effect of test materials on the artificial enamel lesions. Then the remineralization agents were applied on the enamel surfaces, and we analyzed their effects. RESULTS: We used Vickers Microhardness with the purpose of calculating the amount of lost or acquisition of minerals on the enamel surface qualitatively; inductively coupled plasma atomic emission spectroscopy (ICP-AES) to define the calcium and phosphorus ions that dissolved in acid. One-way ANOVA and Tukey's T Post-Hoc tests were performed to distinguish significant differences among groups (P < 0.05). CONCLUSIONS: Remineralization was provided in all treated groups, according to the data obtained from all tests. NovaMin was more effective in increasing acid resistance. It was also found that all three experimental groups were effective in increasing the surface hardness, but CPP-ACPF and NovaMin are more effective than Xylitol. However, there was no statistically significant difference between the experimental groups.

Microleakage of glass ionomer based restorative materials in primary teeth: An In vitro study.

AIM: Using AutoCAD, we examined the microleakage of dye at the edges of primary-teeth restorations using three glass ionomer-based restorative materials. MATERIALS AND METHODS: A total of 30 extracted noncarious primary molars were used. Class V cavities were adjusted on the buccal surfaces. The teeth were randomly divided into three groups of 10 teeth each as follows: Group A (Ketac Molar), Group B (Photac Fil), and Group C (Dyract XP). All specimens were stored for 24 h at 37°C in distilled water. The teeth were thermocycled 1000 times between 5°C ± 2°C and 55°C ± 2°C before immersion in 0.5% basic fuchsin for 24 h. Two mesiodistal cuts of each tooth were photographed under a stereomicroscope equipped with a digital camera. The dye-infiltrated surface area was measured. Statistical evaluations were performed by the Kolmogorov-Smirnov test, Levene test, one-way analysis of variance, and Tukey's honestly significant difference test. RESULTS: The mean microleakage ratio differed significantly among the groups (P < 0.05). Group C exhibited a significantly smaller area (P < 0.001) than the other groups. Group A had a nonsignificantly higher mean microleakage value than Group B (P > 0.05). CONCLUSIONS: Polyacid-modified composite resin may be a useful restorative material in primary teeth in terms of minimizing microleakage.

Spatial and temporal variations in airborne Ambrosia pollen in Europe.

The European Commission Cooperation in Science and Technology (COST) Action FA1203 "SMARTER" aims to make recommendations for the sustainable management of Ambrosia across Europe and for monitoring its efficiency and cost-effectiveness. The goal of the present study is to provide a baseline for spatial and temporal variations in airborne Ambrosia pollen in Europe that can be used for the management and evaluation of this noxious plant. The study covers the full range of Ambrosia artemisiifolia L. distribution over Europe (39°N-60°N; 2°W-45°E). Airborne Ambrosia pollen data for the principal flowering period of Ambrosia (August-September) recorded during a 10-year period (2004-2013) were obtained from 242 monitoring sites. The mean sum of daily average airborne Ambrosia pollen and the number of days that Ambrosia pollen was recorded in the air were analysed. The mean and standard deviation (SD) were calculated regardless of the number of years included in the study period, while trends are based on those time series with 8 or more years of data. Trends were considered significant at p < 0.05. There were few significant trends in the magnitude and frequency of atmospheric Ambrosia pollen (only 8% for the mean sum of daily average Ambrosia pollen concentrations and 14% for the mean number of days Ambrosia pollen were recorded in the air). The direction of any trends varied locally and reflected changes in sources of the pollen, either in size or in distance from the monitoring station. Pollen monitoring is important for providing an early warning of the expansion of this invasive and noxious plant.

Leakage testing for different adhesive systems and composites to permanent teeth.

AIM: To explore the microleakage of different adhesive systems and flowable composites to permanent teeth. SUBJECTS AND METHODS: In this study, a total of 84 human premolar teeth were used. Class V cavities were prepared on the buccal surfaces. The teeth were randomly assigned to six groups of 14 teeth each as follows: The first group - etch-rinse adhesive applied and cavities filled with flowable composite, the second group - etch-rinse adhesive applied and cavities filled with bulk-fill resin composite, the third group - one-stage self-etch (SE) adhesive applied and cavities filled with flowable composite, the fourth group - one-stage SE adhesive applied and cavities filled with bulk-fill resin composite, the fifth group - two-stage SE adhesive applied and cavities filled with flowable composite, and the sixth group - two-stage SE adhesive applied and cavities filled with bulk-fill resin composite. All specimens were then stored for 24 h at 37°C in distilled water. Teeth were then thermocycled for 500 cycles between 5°C and 55°C prior to immersion in 0.5% basic fuchsin for 24 h. Two mesiodistal cuts of each tooth were photographed for leakage with a digital camera. The dye infiltrated surface for each specimen was measured and data were collected with a software program. Statistical evaluations were done by nonparametric Kruskal-Wallis test and Mann-Whitney U-test. RESULTS: There were statistically significant differences in mean microleakage ratio among the groups (P < 0.05). The first group had shown significantly increased microleakage areas than the other four groups (third, fourth, fifth, and sixth groups) (P < 0.05), except for the second group (P > 0.05). It was also no significant different between the mean microleakage areas of group fourth and group fifth (P > 0.05). The sixth group had exhibited the lowest microleakage areas, and it was statistically significant (P < 0.05) compared to the other groups. CONCLUSION: In this study, it has been found that the use of total etch adhesive systems resulted in high leakage values.

Airborne olive pollen counts are not representative of exposure to the major olive allergen Ole e 1.

Pollen is routinely monitored, but it is unknown whether pollen counts represent allergen exposure. We therefore simultaneously determined olive pollen and Ole e 1 in ambient air in Córdoba, Spain, and Évora, Portugal, using Hirst-type traps for pollen and high-volume cascade impactors for allergen. Pollen from different days released 12-fold different amounts of Ole e 1 per pollen (both locations P < 0.001). Average allergen release from pollen (pollen potency) was much higher in Córdoba (3.9 pg Ole e 1/pollen) than in Évora (0.8 pg Ole e 1/pollen, P = 0.004). Indeed, yearly olive pollen counts in Córdoba were 2.4 times higher than in Évora, but Ole e 1 concentrations were 7.6 times higher. When modeling the origin of the pollen, >40% of Ole e 1 exposure in Évora was explained by high-potency pollen originating from the south of Spain. Thus, olive pollen can vary substantially in allergen release, even though they are morphologically identical.

Three-year clinical evaluation of endodontically treated anterior teeth restored with a polyethylene fibre-reinforced composite.

BACKGROUND: Polyethylene fibre-reinforced composites (FRCs) have been under development for some time. However, there is a lack of data on the clinical performance of these restorations. The purpose of this descriptive study was to evaluate the clinical performance of endodontically treated anterior teeth restored using polyethylene FRCs. METHODS: Eighty-seven endodontically treated anterior teeth in 65 patients were restored with polyethylene FRCs. The restorations were placed by three operators. The patients were recalled for examinations every year for up to three years. The restorations were evaluated using modified Ryge and USPHS criteria. RESULTS: A statistical analysis showed no significant difference in marginal irregularity, marginal discolouration, surface texture, wear/anatomic form, fracture and retention, radiographic appearance, or debonding between the baseline and three-year results. CONCLUSIONS: Based on our three-year examination results, polyethylene FRC restorations appear to be clinically successful.

Controlling polymerization of beta-amyloid and prion-derived peptides with synthetic small molecule ligands.

The Alzheimer beta-amyloid peptide (Abeta) and a fragment of the prion protein have the capacity of forming amyloid-like fibrils when incubated under physiological conditions in vitro. Here we show that a small amyloid ligand, RO-47-1816/001, enhances this process severalfold by binding to amyloid molecules and apparently promote formation of the peptide-to-peptide bonds that join the monomers of the amyloid fibrils. This effect could be antagonized by other ligands, including analogues of RO-47-1816/001, as well as the structurally unrelated ligand Congo red. Analogues of RO-47-1816/001 with low affinity for amyloid did not display any antagonistic effect. In conclusion, these data suggest that synthetic molecules, and possibly also small natural substances present in the brain, may act in a chaperone-like fashion, promoting Abeta polymerization and growth of amyloid fibrils in vitro and possibly also in vivo. Furthermore, we demonstrate that small organic molecules can be used to inhibit the action of amyloid-enhancing compounds.