Effects of silver diamine fluoride on demineralization protection after a secondary acid challenge

Abstract Objective This investigation describes the effects of 5% sodium fluoride varnish and 38% silver diamine fluoride on demineralization protection of human enamel lesions of three different severities after a secondary acid challenge. Study design Specimens underwent color and enamel surface microhardness change measurements after demineralization and treatment events. Transverse microradiography was conducted following the secondary demineralization. Results After treatments, enamel surface microhardness change showed that 24-hour lesions treated with fluoride varnish had less rehardening than 24-hour lesions treated with silver diamine fluoride (p<0.05), whereas 144-hour lesions from both treatment groups showed a beneficial decrease in surface microhardness change that was markedly better in samples treated with silver diamine fluoride (p<0.05). After the secondary demineralization, 24- and 144-hour lesions treated with silver diamine fluoride showed a sustained beneficial decrease in enamel surface microhardness change when compared to fluoride varnish-treated samples of the corresponding lesion severity (p<0.05). Transverse microradiography showed no difference between fluoride varnish- and silver diamine fluoride-treated samples of any corresponding lesion severity, indicating that remineralization in both fluoride varnish- and silver diamine fluoride-treated samples was proportional to each other after a secondary acid challenge. Conclusions Using silver diamine fluoride may have comparable benefits to fluoride varnish in mineral loss prevention.

Assessment of Early Dental Caries by Using Optical Coherence Tomography / 치위생과학회지

The purpose of this study was to assess the correlation between integrated mineral loss (volume % mineral×µm, ΔZ(TMR)) determined using transverse microradiography (TMR) and integrated reflectivity (dB×µm, ΔR(OCT)) determined using optical coherence tomography (OCT) for detecting early dental caries with lesion depth more than 200 µm. Sixty tooth specimens were made from sound bovine teeth. They were immersed in a demineralized solution for 20, 30, and 40 days. The ΔR(OCT) was obtained from the cross-sectional OCT image. The ΔZ(TMR) was obtained from the TMR image. The correlation between ΔR(OCT) and ΔZ(TMR) was examined using Pearson correlation. The Bland-Altman plot was constructed using the ΔR(OCT) and ΔZ(TMR) values. A significant correlation between ΔR(OCT) and ΔZ(TMR) was confirmed (r=0.491, p=0.003). Moreover, most of the difference between ΔR(OCT) and ΔZ(TMR) was included in the error section of the Bland-Altman plot. Therefore, OCT could be used as a substitute for TMR when analyzing mineral loss in early dental caries.

Effect of 10% fluoride on the remineralization of dentin in situ

ABSTRACT Objective The purpose of this randomized, cross-over, in situ study was to determine the remineralization of demineralized dentin specimens after the application of a 10% fluoride (F-) or a 1% chlorhexidine–1% thymol (CHX–thymol) varnish. Material and Methods Twelve individuals without current caries activity wore removable appliances in the lower jaw for a period of four weeks. Each appliance contained four human demineralized dentin specimens fixed on the buccal aspects. The dentin specimens were obtained from the cervical regions of extracted human third molars. After demineralization, half the surface of each specimen was covered with a nail varnish to serve as the reference surface. The dentin specimens were randomly assigned to one of the three groups: F-, CHX–thymol, and control (no treatment). Before the first treatment period and between the others, there were washout periods of one week. After each treatment phase, the changes in mineral content (vol% µm) and the lesion depths (µm) of the dentin slabs were determined by transverse microradiography (TMR). Data analysis was accomplished by the Kruskal-Wallis test and the Mann-Whitney U test (p<0.05). Results The medians (25th/75th percentile) of integrated mineral loss were 312.70 (203.0-628.7) for chlorhexidine varnish, 309.5 (109.8-665.8) for fluoride varnish, and -346.9 (-128.7 - -596.0) for the control group. The medians (25th/75th percentile) of lesion depth were 13.6 (5.7-34.5) for chlorhexidine varnish, 16.5 (5.6-38.1) for fluoride varnish, and -14.2 (-4.5- -32.9) for the control group. Use of the 10% F- or 1% CHX–1% thymol varnishes resulted in significantly decreased mineral loss and lesion depth in dentin when compared with the control group. There were no statistically significant differences among the test groups. Conclusions Within the limitations of this study, the results suggest that the effect of the treatment of demineralized dentin with 10% F- or 1% CHX–1% thymol is better than without any treatment.

Comparative analysis between breast conventional mammography and amplificatory mammography with partial compression in 65 cases of breast cancer / 中国基层医药

Objective To discuss the correlationship between the diagnosis of surgical pathology and the signs of malignancy which is both displayed by breast conventional mammography and amplificatory mammography with partial compression.Methods 65 cases with breast cancer were examined by both breast conventional mammography and amplificatory mammography with partial compression.The results of the two methods were analyzed.Results In all 65 cases of breast cancer,the comparison between breast conventional mammography and amplificatory mammography with partial compression could provide 16/60 cases in the X-ray signs of malignancy,which were in accordance with pathological examination results,19/41cases in the occurrence of calcification,13/37 cases in ductal calcification,0/4 cases in mixed type calcification,18/46 and 14/59 cases in the occurrence of lobulation and spicule signs.Conclusion Amplificatory mammography with partial compression can provide better insight in breast cancer than conventional mammography,especially in the region of dense shadow,small calcification and dense breast lesions,amplificatory mammography with partial compression can provide higher accuracy in diagnosis,especially for early breast cancer.

Anti-demineralizing Potential of Bottled Sugar-free Green Tea Beverages <i>in vitro</i> / Oral Science International

The purpose of this study was to evaluate the influence of a bottled green tea beverage on dentin demineralization with a demineralization gel system <i>in vitro</i>. Samples were cut from bovine root dentin. Each sample was immersed in 8% methylcellulose gel onto which a layer of green tea beverage was placed. For comparison, sugar-free coffee beverage, deionized water, and 0.8-ppm F solutions were used. After two weeks, the treatment solutions were replaced with demineralization solution. The mineral profiles and mineral loss values of the lesions were obtained by transversal microradiography (TMR) after one-week demineralization. The green tea, coffee, and fluoride solution treatments induced a significantly thicker surface layer when compared with the deionized water treatment. In particular, the mineral volume % of the demineralized dentin specimens treated with green tea was approximately seven times higher than that of the de-ionized water treatment. The green tea treatment showed significantly lower mineral loss than the other three treatments. TMR measurements clearly showed that the sugar-free bottled green tea beverage inhibited dentin lesion progression, presumably due to the effect of sub-ppm fluoride levels.

Phase Contrast Microradiography of Mouse Lung Using Synchrotron X-ray: Correlation with Optical Microscopy

PURPOSE: The purpose of this study is to evaluate the feasibility of phase contrast X-ray microtomography and microradiography, using a polychromatic synchrotron X-ray, for analysis of the mouse lung microstructure. MATERIALS AND METHODS: Normal mice were used for experiments. Some of the mouse lungs were prepared by the lung fixation-inflation method. The resulting sponge-like inflated lung samples were used for microtomography. The remaining mouse lungs were cut into 10 um sections and were used for microradiography and optical microscopic correlation. The experiments on mouse lung samples were performed at the 7B2 beamline of the Pohang Light Source in Korea. RESULTS: Phase contrast X-ray microtomography of inflated lung samples showed individual alveolar structure on 3-D reconstruction. Phase contrast microradiographs of thin lung samples showed microstructure of lung, such as alveoli and bronchioles, and were well correlated with optical microscopic images. CONCLUSIONS: The results indicate that the phase contrast X-ray microtomography and microradiography using polychromatic synchrotron X-ray is feasible for evaluation of microstructure of the lung.

Quantitative microradiographic analysis of remineralization of enamel lesions promoted by casein phosphopeptide amorphous calcium phosphate and fluoride / 吉林大学学报(医学版)

Objective To evaluate the remineralization effect of casein phosphopeptide amorphous calcium phosphate(CPP-ACP) and fluoride complex on artificial enamel subsurface white spot lesions in vitro in order to provide a new method to treat the postorthodontic enamel demineralization.Methods Extracted premolar teeth for orthodontic reason were immersed into lactic acid gel to prepare artificial white spot lesions.Then the specimens were randomly assigned to seven groups:5.0%CPP-ACFP group,1.0% CPP-ACP group,0.1% CPP-ACPgroup,calcium phosphate saturated solution group,calcium phosphate saturated solution plus fluorid group,deionized water group.Lesion depths and mineral loss were quantitatively determined by microradiography in various groups.Results The lesion depths and mineral loss after remineralization in each group were significantly reduced(P0.05),but the lesion depths and mineral loss in these three groups were significantly lower than those in deionized water group(P

Volume Fraction of the Human Pathologic Ossicles Destructed by Cholesteatoma Using Micro-CT / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Conventional studies for the middle ear ossicles destructed by cholesteatoma give relatively limited information on shape, mechanical strength and 3-dimensional relationship. Recently, Micro-CT scanning technology has been applied to analysis of skeletal structure. This study aims to reconstruct the 3-dimensional structure of normal ossicles and destructed ossicles by different cholesteatomas and to compare volume fraction of destructed ossicles with that of normal ossicles. MATERIALS AND METHOD: 13 pathological ossicles obtained during cholesteatoma surgery were used in this study (2 malleuses and 2 incuses from attic cholesteatoma;1 malleus and 2 incuses from sinus cholesteatoma;2 malleuses and 2 incuses from tensa retraction cholesteatoma; 2 incuses from congenital cholesteatoma). As a control, normal ossicles harvested from cadaveric temporal bone specimens were used. The structure of obtained ossicles was analyzed through Micro-CT (SkySan-1072, Belgium) by filming the 2-dimensional cross section image running perpendicular to the long axis of the ossicles. The 3-dimensional images were thereby reconstructed for each, and were analyzed using CT-Analyzer(TM) and ANTTM. Based on the results, the strength of each ossicle were measured. RESULTS: The volume fraction, indicating relative strengths of ossicles, was lower in the portion of destructed surface. The pattern of destructed ossicles by cholesteatoma was different according to pathological status of cholesteatoma. CONCLUSION: Our preliminary data of ossicular structure analyzed by Micro-CT scan will be helpful for elucidation of pathological ossicles in middle ear cholesteatoma and will make a great contribution to research of middle ear cholesteatoma.

Study on the Three Dimensional Structure of the Human Ossicle Using Micro CT / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Conventional studies of the middle ear ossicles give relatively limited information on shape, mechanical strength and 3-dimensional relationship. Recently, Micro CT scanning technology has been applied to analysis of skeletal structures. This study aims to reconstruct the 3-dimensional structure of the ossicles, including length, thickness, strength, and the angle. MATERIALS AND METHOD: The structures of ossicles obtained from 3 cadavers were analyzed through micro CT by filming the 2-dimensional cross section image running perpendicular to the long axis of the ossicles. The 3-dimensional images were thereby reconstructed for each, and were analyzed using CT-Analyzer(TM) and Ant(TM). Based on the results, the strength, length, and angle of each ossicle were measured. RESULTS: The ratio between the handle of malleus (4.413 mm) and the long process of incus (3.559 mm), which acts as a lever of the middle ear impedance transformer, was 1.24. The volume fraction, indicating relative strengths of ossicles, was higher in the portion close to the articular surface. CONCLUSION: Our preliminary data of the ossicular structure analysed by micro CT scan will be helpful for the elucidation of ossicle's structure and the further development of artificial prosthesis.

In vivo quantitative analysis of remineralization effect of remineralization solution "R" of incipient enamel dental caries / 대한치과보존학회지

Dental caries is a chronic disease that causes the destruction of tooth structure by the interaction of plaque bacteria, food debris, and saliva. There has been attempts to induce remineralization by supersaturating the intra-oral environment around the surface enamel, where there is incipient caries. In this study, supersaturated remineralized solution "R" was applied to specimens with incipient enamel caries, and the quantitative ananlysis of remineralization was evaluated using microradiography. Thirty subjects volunteered to participate in this study. Removable appliances were constructed for the subjects, and the enamel specimen with incipient caries were embedded in the appliances. The subjects wore the intra-oral appliance for 15 days except while eating and sleeping. The removable appliance were soaked in supersaturated solution "R", saline, or Senstime(R) to expose the specimen to those solutions three times a day, 5 minutes each time. After 15 days, microradiography was retaken to compare and evaluate remineralization. The results were as the following: 1. The ratio of remineralized area to demineralized area was significantly higher in the supersaturated solution "R" and Senstime(R) than in the saline. (p<0.05) 2. Remineralization in the supersaturated buffer solution "R" occurred in the significantly deeper parts of the tooth, compared to the Senstime(R) group containing high concentration of fluoride.(p<0.05) As in the above results, the remineralization effect of remineralized buffer solution "R" on incipient enamel caries has been proven. For clinical utilization, further studies on soft tissue reaction and the effect on dentin and cementum are necessary. In conclusion compared to commercially available fluoride solution, remineralization solution "R" showed better remineralization effect on early enamel caries lesion, so it is considered as effecient solution for clinical application.