OBJECTIVETo investigate the effect of pulse Nd: YAG laser combined with NaF on caries resistance of human enamel in vitro.

METHODS24 caries-free, constant premolares were cut into enamel mass. Surface ultrastructure and fluoride distribution of enamel in laser-NaF treated group, laser treated group, NaF treated group and control group were observed by scanning electron microscope (SEM) and electron probe microanalyzer.

RESULTS(1) SEM observation: In laser-NaF treated group, the smear layer was almost removed, the enamel surface showed partially melted-like and bubble-like appearance, diffuse white-small particles distributed on enamel surface, and melted position, microcrack and microhole appeared whitely blocking-reflection. (2) Electron probe microanalyzer analysis: In enamel samples, the highest average Ci of F- and the hightest depth which F- entered in enamel were recorded in the laser-NaF treated group. The average Ci of F- in laser-NaF treated group was significantly increased compared with that in NaF-treated group or laser-treated group or control group (P < 0.001).

CONCLUSIONThe pulsed Nd:YAG laser combined with sodium fluoride could make the enamel surface partially melt, change the structure of the crystal, enhance the absorption of fluoride, and clear smear layer. This technology may resist the caries.

Dental Enamel ; ultrastructure ; Fluorides ; chemistry ; Humans ; Lasers, Solid-State ; Smear Layer ; Sodium Fluoride ; chemistry

OBJECTIVE: The aim of the study was to compare the diagnostic performances of F-18 sodium fluoride positron emission tomography/computed tomography (bone PET/CT) and bone scintigraphy (BS) for the detection of thyroid cancer bone metastasis. MATERIALS AND METHODS: We retrospectively enrolled 6 thyroid cancer patients (age = 44.7 ± 9.8 years, M:F = 1:5, papillary:follicular = 2:4) with suspected bone metastatic lesions in the whole body iodine scintigraphy or BS, who subsequently underwent bone PET/CT. Pathologic diagnosis was conducted for 4 lesions of 4 patients. RESULTS: Of the 17 suspected bone lesions, 10 were metastatic and 7 benign. Compared to BS, bone PET/CT exhibited superior sensitivity (10/10 = 100% vs. 2/10 = 20%, p = 0.008), and accuracy (14/17 = 82.4% vs. 7/17 = 41.2%, p < 0.025). The specificity (4/7 = 57.1%) of bone PET/CT was not significantly different from that of BS (5/7 = 71.4%, p > 0.05). CONCLUSION: Bone PET/CT may be more sensitive and accurate than BS for the detection of thyroid cancer bone metastasis.
Adult ; Bone Neoplasms/*radiography/secondary ; Bone and Bones/*radiography ; Contrast Media/*chemistry ; Female ; Fluorine Radioisotopes/chemistry ; Humans ; Male ; Middle Aged ; Positron-Emission Tomography ; Retrospective Studies ; Sodium Fluoride/*chemistry ; Thyroid Neoplasms/*pathology ; Tomography, X-Ray Computed ; Whole Body Imaging

AIMThe effect of Galla chinensis on de-/re-mineralization of advanced enamel lesions was investigated by using micro-CT in a prolonged in vitro experiment.

METHODOLOGYBaseline mineral contents of sound enamels were first analyzed. Then lesions were produced in an acidic buffer solution (2.2 m mol x L(-1) Ca(NO3)2, 2.2 mmol x L(-1) KH2PO4, and pH = 4.5) for 21 days, with thrice daily three-minute treatments, divided into four groups: Group A, 4 000 ppm crude aqueous extract of Galla chinensis (GCE); Group B, 4000 ppm gallic acid; Group C, 1000 ppm F aq. (as NaF, positive control); Group D, deionized water (negative control). Next, the blocks were immersed in a remineralization solution (1.5 mmol x L(-1) CaCl2, 0.9 mmol x L(-1) KH2PO4, 0.1 ppm F, and pH = 7.0) for 200 days. Mineral loss (ML) in each region of interest (ROI) and integrated mineral loss (IML) of the lesions were calculated (comparing with baseline mineral content of sound enamel) at different time points.

RESULTSAfter 21 days demineralization, fluoride treatment showed a statistically significant demineralization-inhibiting effect among the four groups, and after 200 days of remineralization, mineral content recovery was ordered (lowest to highest) as A = C < B < D.

CONCLUSIONGCE could slow down the remineralization of enamel in the surface layer and thereby facilitate ion transport into the lesion body. The mechanism of Galla chinensis in enhancing the remineralization of dental caries is different from fluoride.

Animals ; Cariostatic Agents ; therapeutic use ; Cattle ; Dental Enamel ; chemistry ; drug effects ; Drugs, Chinese Herbal ; therapeutic use ; Gallic Acid ; therapeutic use ; Image Processing, Computer-Assisted ; Materials Testing ; Minerals ; analysis ; Plant Extracts ; therapeutic use ; Sodium Fluoride ; therapeutic use ; Time Factors ; Tooth Demineralization ; prevention & control ; Tooth Remineralization ; methods ; X-Ray Microtomography

OBJECTIVETo evaluate the anti-demineralization efficacy of Galla Chinesis in pH cycling model for elucidating the anti-root caries mechanism.

METHODAnti-demineralization efficacy evaluation of the natural medicine in the pH-cycling models was used . Sound human root blocks were pH-cycled through the treatment solution, acidic buffer and neutral buffer. The cycling times for demineralization study were 12 times, 2 times per day. The acidic buffers were retained for calcium analysis by atomic adsorption spectroscopy. The sections of blocks were analysed after pH-cycling by CLSM. Treatments were 4 g x L(-1). Galla Chinesis, 1 g x L(-1) NaF solution and distilled water.

RESULTGalla Chinesis was found to inhibit the demineralization in the pH cycling model. Although the effect was not as good as fluoride, there was no significant difference between the two groups.

CONCLUSIONThese data suggest that Galla Chinesis could modulate the mineralisation behaviour of root tissue in a defined chemical circumstance. These findings support the proposition that Galla Chinesis may be a promising anticaries natural medicine in the future.

Animals ; Calcium ; metabolism ; Cuspid ; drug effects ; pathology ; Dental Caries ; prevention & control ; Humans ; Hydrogen-Ion Concentration ; Insecta ; chemistry ; Materia Medica ; isolation & purification ; pharmacology ; Microscopy, Confocal ; Sodium Fluoride ; pharmacology ; Tooth Demineralization ; metabolism ; pathology ; prevention & control ; Tooth Remineralization ; Tooth Root ; drug effects ; metabolism ; pathology