Predictors of Dental Fear and Anxiety in 9-12-year-old Children in Bosnia and Herzegovina.

Objectives: Oral health in children is additionally burdened with the presence of dental fear and anxiety (DFA). These clinical psychologic entities in their progressive stages inevitably lead to avoidance of dental appointments, which makes prevention and therapy of oral diseases more difficult. Upon the onset of DFA in general, as one of the emotional outcomes of stress in a dental office, most children patients could define the specific stressors that were most intense for them, which could predict the presence of DFA. Aim: To examine the predictors of DFA presence in 9-12-year-old children, and investigate how they could explain the DFA occurrence in study participants. Material and Methods: The sample consisted of 200 children aged from 9 to 12 years. The DFA presence was determined by the modified version of the CFSS-DS scale. The child's behavior in the dental office during the treatment was evaluated by the trained observer using Venham anxiety and behavior rating scales. Socioeconomic status, characteristics of dental office visits, and previous caries experience were also analyzed. Results: The main DFA predictors were related to invasive dental treatments, where the behavior during dental treatment was the most accurate expression of the DFA appearance. Conclusions: Invasive dental procedures are the main stressful factor for DFA occurrence. Predisposing factors could strengthen the DFA occurrence.

Quantitative structure-activity relationships of xanthen-3-one and xanthen-1,8-dione derivatives and design of new compounds with enhanced antiproliferative activity on HeLa cervical cancer cells.

Xanthene derivatives have become a group of molecules of great importance in discovering of new anticancer drugs. Recent studies of our group performed on xanthen-3-one and xanthen-1,8-dione derivatives have shown their antiproliferative activity on HeLa cervical cell lines. Obtained IC50 values together with calculated molecular descriptors were subjected to Quantitative Structure-Activity Relationship (QSAR) study in order to identify the most relevant molecular features responsible for the observed antiproliferative activity of compounds. Partial least square statistical method and the same training and test set were used to obtain statistical parameters for internal and external validation in 2D- and 3D-QSAR study. The obtained QSAR models have shown next results: 2D-QSAR: R2 = 0.741, Q2 = 0.792, R2pred = 0.875 and 3D-QSAR: R2 = 0.951, Q2 = 0.830, R2pred = 0.769. Based on the performed QSAR analysis and calculated ADMET properties, novel xanthene derivatives with enhanced antiproliferative activity were designed. Communicated by Ramaswamy H. Sarma.

Structure of Biologically Active Benzoxazoles: Crystallography and DFT Studies.

Using X-ray single crystal diffraction, the crystal structures of biologically active benzoxazole derivatives were determined. DFT calculation was performed with standard 6-31G*(d), 6-31G** and 6-31+G* basis set to analyze the molecular geometry and compare with experimentally obtained X-ray crystal data of compounds. The calculated HOMO-LUMO energy gap in compound 2 (2-(2-hydroxynaphtalen-1-yl)-4-methyl-7-isopropyl-1,3-benzoxazol-5-ol) is 3.80 eV and this small gap value indicates that compound 2 is chemically more reactive compared to compounds 1 (4-methyl-2-phenyl-7-isopropyl-1,3-benzoxazol-5-ol) and 3 (2-(4-chlorophenyl)-4-methyl-7-isopropyl-1,3-benzoxazol-5-ol). The crystal structures are stabilized by both intra- and intermolecular hydrogen bonds in which an intermolecular O-H⋅⋅⋅N hydrogen bond generates N3 and O7 chain motif in compounds 1, 2, and 3, respectively. The calculated bond lengths and bond angles of all three compounds are remarkably close to the experimental values obtained by X-ray single crystal diffraction.

Evaluation of Solubility of Luting Cements in Different Solutions.

OBJECTIVE: To evaluate and compare the solubility of three luting cements in three different solutions: distilled water and artificial saliva with different pH values (7.4 and 3.0). MATERIALS AND METHODS: Resin-modified glass-ionomer cement (GC Fuji Plus) and two resin cements (Multilink Automix and Variolink II) were used. A total of 45 specimens, 15 specimens (15x1 mm) for each cement, were prepared according to ISO standard 4049:2009. The solubility of the cements was calculated by weighing the specimens before and after immersion and desiccation. Values of solubility in water (Wsl) in microgram/mm3 for each of the five specimens were calculated using the following formula (ISO 4049:2009): Wsl=(m1-m3)/V. The Mann-Whitney U nonparametric statistical method and Post hoc sample comparisons were applied. RESULTS: GC Fuji Plus showed statistically significant higher solubility in comparison with Variolink II and Multilink Automix in all three solutions. In acidic artificial saliva (pH 3.0) Multilink Automix showed significantly higher values of solubility compared to Variolink II (P<0.016). By studying the effect of pH value on the solubility of GC Fuji Plus cement, significantly higher values of solubility in pH 3.0 artificial saliva were confirmed (P<0.009). The influence of the surrounding pH value on the solubility of the resin cements Multilink Automix and Variolink II was researched. No statistically significant difference was found. CONCLUSION: Solubility values were mainly influenced by the proportion of hydrophilic matrix, the type and composition of filler, and the pH value of the solutions.

Occlusal Stress Distribution on the Mandibular First Premolar - FEM Analysis.

OBJECTIVE: The aim of this paper was to analyze the distribution of stress and deformation on the mandibular first premolar under two types of loading (axial and para-axial load of 200 N) using the FEM computer method. MATERIALS AND METHOD: For this research a µCT scan of the first mandibular premolar was used, and the method used in this research was FEM analysis under two types of loading. RESULTS: The values of the von Mises stress measured in the cervical part of an intact tooth under axial load were up to 12 MPa, and under paraaxial load over 50 MPa. The values of the stress measured on the bottom of the noncarious lesion are very high ≈ 240 Mpa. Stress values in the cervical part of the intact tooth are higher in the zone of the sub-surface enamel. The deformation values of the tooth under para-axial loading were ≈ 10 times higher than the value of the deformation under axial load. The greatest deformations were seen in the area of the tooth crown. CONCLUSIONS: Occlusal loading leads to significant stress in the cervical part of teeth. The values of the measured stress are greater under the action of paraxial load. The values of stress in abfraction lesions measured under a paraxial load are extremely high. Exposing the lesion to further stress will lead to its deepening. The total deformation of the entire tooth under paraxial load was ≈ 10 times higher compared to the deformation value of the tooth under axial load.

Evaluation of the water sorption of luting cements in different solutions.

OBJECTIVE: To evaluate and compare the water sorption of three luting cements in three different solutions: distilled water and artificial saliva with different pH values (7.4 and 3.0). MATERIALS AND METHODS: Resin-modified glass-ionomer cement (GC Fuji Plus) and two resin cements (Multilink Automix and Variolink II) were used. A total of 45 specimens - 15 specimens (15x1 mm) for each cement were prepared according to ISO standard 4049:2009. The water sorptions of the cements were calculated by weighing the specimens before and after immersion and desiccation. RESULTS: . Nonparametric statistic methods were applied. GC Fuji Plus cement showed significantly higher values of water sorption in all three solutions of both resin cements (p<0.009) and significantly higher values of sorption in artificial saliva pH 3.0. Multilink Automix showed significantly higher values of water sorption compared with Variolink II in artificial saliva pH 7.4, and higher values of sorption in this solution compared with pH value 3.0. CONCLUSION: Water sorption values are mainly influenced by the proportion of hydrophilic matrix, the type and composition of filler, and the pH value of solutions.