OBJECTIVES: The purpose of this study was to assess the effect of single and combined applications of fluoride on the amount of fluoride release, and the remineralization and physical properties of enamel. MATERIALS AND METHODS: Each of four fluoride varnish and gel products (Fluor Protector, FP, Ivoclar Vivadent; Tooth Mousse Plus, TM, GC; 60 Second Gel, A, Germiphene; CavityShield, CS, 3M ESPE) and two fluoride solutions (2% sodium fluoride, N; 8% tin(ii) fluoride, S) were applied on bovine teeth using single and combined methods (10 per group), and then the amount of fluoride release was measured for 4 wk. The electron probe microanalysis and the Vickers microhardness measurements were conducted to assess the effect of fluoride application on the surface properties of bovine teeth. RESULTS: The amount of fluoride release was higher in combined applications than in single application (p < 0.05). Microhardness values were higher after combined applications of N with FP, TM, and CS than single application of them, and these values were also higher after combined applications of S than single application of A (p < 0.05). Ca and P values were higher in combined applications of N with TM and CS than single application of them (p < 0.05). They were also increased after combined applications of the S with A than after single application (p < 0.05). CONCLUSIONS: Combined applications of fluoride could be used as a basis to design more effective methods of fluoride application to provide enhanced remineralization.
Dental Caries ; Dental Enamel ; Electron Probe Microanalysis ; Fluorides* ; Methods* ; Paint ; Sodium Fluoride ; Surface Properties ; Tooth

OBJECTIVETo investigate the crystallographic properties of the mineral phases of normal enamel and dentin (dental apatite) in deciduous and permanent teeth.

METHODSThree kinds of physical methods including X-ray diffraction (XRD), infrared absorption spectroscope (IR) and electron probe micro-analysis (EPMA) were utilized in this study.

RESULTSDental apatite was not uniphase, but multiphase, which could be described as carbonate-substituted hydroxyapatite. Compared to dentin apatite, the higher crystallinity and expanded a-axis lattice parameters were found in enamel. Chemical analyses demonstrated that higher concentrations of Mg and CO(3)(2-) were found in dentin than those of enamel. But enamel had higher Cl content.

CONCLUSIONSThe differences among enamel and dentin, in terms of lattice parameter and crystallinity may be partially attributed to the incorporation of Mg, CO(3)(2-) and Cl minor elements.

Dental Enamel ; chemistry ; Dentin ; chemistry ; Electron Probe Microanalysis ; methods ; Humans ; Spectrophotometry, Infrared ; methods ; Tooth ; chemistry ; X-Ray Diffraction ; methods

OBJECTIVE: To provide objective proof on diagnosis of electrical current mark in electrocution, the environmental scanning electron microscopy and energy dispersive X-ray microanalyser (ESEM-EDX) were adopted to study the microscopic morphological characteristics and elemental composition of electrical current mark. METHODS: Morphological characteristics of electrical current marks, the elemental composition and morphology of metal particles were studied with ESEM-EDX. RESULTS: The electroporation and metal melted beads could be found in the electrical current marks and skin around them. The metal melted beads mainly composed of common metal such as iron, copper, aluminum and some uncommon metal including gold, titanium and barium. CONCLUSION ESEM-EDX can be applied in forensic diagnosis of electrocution.
Autopsy ; Electric Injuries/pathology* ; Electron Probe Microanalysis/methods* ; Forensic Medicine/methods* ; Humans ; Metals, Heavy/analysis* ; Microscopy, Electron, Scanning/methods* ; Skin/pathology* ; Trace Elements/analysis* ; X-Rays

Rapid prenatal detection methods, including molecular cytogenetic analysis and ultrasonographic markers, are very important for prenatal diagnosis. The use of molecular cytogenetic techniques has significantly improved the rapid detection of aneuploidy and identification of small structural abnormalities of fetal chromosomes. At present, commonly used molecular cytogenetic techniques include fluorescence in situ hybridization (FISH), quantitative fluorescence PCR (QF-PCR), multiplex ligation-dependent probe amplification (MLPA) and microarray-based comparative genomic hybridization (array CGH). There is extensive evidence that major chromosomal abnormalities can be effectively detected by ultrasonography in the first and second trimesters of pregnancy. So we can combine molecular cytogenetic techniques with ultrasonographic markers to improve the identification of aneuploidies for chromosomes and the accuracy of prenatal diagnosis, and to reduce birth defects in newborns.
Chromosome Aberrations ; Chromosome Disorders ; diagnosis ; Cytogenetic Analysis ; Electron Probe Microanalysis ; Female ; Humans ; In Situ Hybridization, Fluorescence ; Nucleic Acid Hybridization ; Polymerase Chain Reaction ; Pregnancy ; Prenatal Diagnosis ; methods ; Protein Array Analysis ; Ultrasonography, Prenatal

Tooth bleaching agents may weaken the tooth structure. Therefore, it is important to minimize any risks of tooth hard tissue damage caused by bleaching agents. The aim of this study was to evaluate the effects of applying 45S5 bioglass (BG) before, after, and during 35% hydrogen peroxide (HP) bleaching on whitening efficacy, physicochemical properties and microstructures of bovine enamel. Seventy-two bovine enamel blocks were prepared and randomly divided into six groups: distilled deionized water (DDW), BG, HP, BG before HP, BG after HP and BG during HP. Colorimetric and microhardness tests were performed before and after the treatment procedure. Representative specimens from each group were selected for morphology investigation after the final tests. A significant color change was observed in group HP, BG before HP, BG after HP and BG during HP. The microhardness loss was in the following order: group HP>BG before HP, BG after HP>BG during HP>DDW, BG. The most obvious morphological alteration of was observed on enamel surfaces in group HP, and a slight morphological alteration was also detected in group BG before HP and BG after HP. Our findings suggest that the combination use of BG and HP could not impede the tooth whitening efficacy. Using BG during HP brought better protective effect than pre/post-bleaching use of BG, as it could more effectively reduce the mineral loss as well as retain the surface integrity of enamel. BG may serve as a promising biomimetic adjunct for bleaching therapy to prevent/restore the enamel damage induced by bleaching agents.
Animals ; Biomimetic Materials ; analysis ; therapeutic use ; Cattle ; Ceramics ; analysis ; chemistry ; Chemical Phenomena ; Color ; Colorimetry ; Dental Enamel ; drug effects ; ultrastructure ; Electron Probe Microanalysis ; Glass ; analysis ; chemistry ; Hardness ; Hydrogen Peroxide ; pharmacology ; Hydrogen-Ion Concentration ; Microscopy, Electron, Scanning ; Protective Agents ; analysis ; therapeutic use ; Random Allocation ; Solubility ; Spectroscopy, Fourier Transform Infrared ; Time Factors ; Tooth Bleaching ; methods ; Tooth Bleaching Agents ; pharmacology ; Water ; chemistry ; X-Ray Diffraction