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Titanium fluoride (TiF4) reduces mineral loss and lesion depth more effectively than sodium fluoride (NaF). However, the pH values of TiF4 and NaF solutions are different. This study aimed to evaluate the effects of TiF4 solution on the inhibition of demineralization and elemental distribution in root dentin in comparison with NaF solution at the same pH and fluoride concentrations. This study was conducted using 0.5% TiF4 or 0.675% NaF solution adjusted to pH 5 or pH 7. Bovine dentin specimens of 200 μ m thickness were subjected to pH cycling (pH 4.5 and 7.0; 6 cycles/day; simulated oral conditions) for eight weeks to prepare artificial carious dentin. During this cycle, the specimens were soaked in each solution once a week for 5 min. The control group involved no fluoride application during the test period. After cycling, the demineralization depth was measured and the calcium, fluorine, and titanium distributions were analyzed and calculated using an in-air micro-proton-induced X-ray emission (PIXE)/proton-induced gamma emission (PIGE) system at TIARA. At pH 7, TiF4 solution yielded a lower lesion depth than the NaF solution. The NaF solution at pH 7 showed lower fluorine concentration than that with the other fluoride solutions. Thus, TiF4 is more effective in inhibiting demineralization than NaF in a solution adjusted to pH 7. Moreover, the presence of titanium may strengthen the tooth structure. [ABSTRACT FROM AUTHOR]

Thirty-two glasses from four Byzantine fortifications located on the Danube in Serbia, dated to the sixth-century CE, are analysed by PIXE/PIGE, and their compositional types are determined. Most of the glasses belong to Late Antique type Foy 2.1 (22), the rest being Foy 3.2 (3), HIMTa (1), Levantine (2), plant-ash (3), and coloured black (1). The diversity of compositional types and provenances characterizing the same area during the third to fourth century, changed in the sixth century into uniformity of glass types and provenance: more than two-thirds of all glass types represent only one type (Foy 2.1), and at least 87% of all imports came from a single region, Egypt. Apart from two glasses reported herein, no Levantine glasses are reported from Serbia, and almost none from the inner Balkans, which is in contrast with the rest of the Mediterranean excluding Egypt. The reasons for this might be the economic aftermath of earlier Hunnic raids or possible centralization of raw glass imports during the Justinian rebuilding program. Two plant ash glasses of mixed composition, showing characteristics of Egyptian plant-ash flux and Mesopotamian sand, likely represent recycled glass originating from these two regions. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of tricalcium phosphate-containing fluoride varnish on the prevention of root caries using an in-air micro-proton induced X-ray/gamma-ray emission system and microcomputed tomography. Either fluoride varnish (FV) or tricalcium phosphate-containing fluoride varnish (WV) was applied to root dentin, whereas dentin without varnish were considered controls. After immersion in saline, dentin sections were prepared, and concentration of fluoride ion was measured. These specimens were demineralized, and the mineral loss was measured. Caries inhibition in sound and demineralized dentin was observed in both FV and WV groups compared to the control group. Significantly low mineral loss was found especially in the demineralized dentin, which is probably due to the combination effect of calcium and fluoride ions at a concentration range of 100,000 ppm, as supplied by the varnish. The use of calcium-containing fluoride varnish, especially in demineralized dentin, is effective in arresting initial dentin caries. [ABSTRACT FROM AUTHOR]

Several desensitizers routinely used clinically for dentin hypersensitivity are expected to inhibit demineralization. This study aimed to evaluate the effectiveness of sealing materials in inhibiting demineralization and increasing fluorine (F) uptake by acid-treated root surfaces. Five noncarious extracted human teeth were used to produce specimens. Three different fluoride-containing materials, namely "MS Coat F" (MS), "MS Coat Hys Block Gel" (HS), and CTX2 Varnish (FV), were used herein. Each material was applied to the demineralized root surface. Single sections were obtained from each specimen. All surfaces of each specimen, except the polished surface, were covered with wax and immersed in an automatic pH cycling system for 2 weeks. Fluorine and calcium distributions in the carious lesions of each specimen were evaluated using proton-induced gamma emission (PIGE) and X-ray (PIXE) techniques, respectively. Dentin demineralization was analyzed using transverse microradiography (TMR) before and after pH cycling. µPIXE/PIGE analysis demonstrated that all sample groups showed increased fluoride uptake on the root surface. TMR analysis revealed that both HS and FV showed significantly lower integrated mineral loss values than the control group. All three samples demonstrated a tendency towards increased fluoride uptake from fluoride-containing hypersensitivity desensitizers and a demineralization inhibition effect on root dentin. [ABSTRACT FROM AUTHOR]

This study employed an in-air micro-proton-induced X-ray/gamma-ray emission system to assess the effectiveness of fluoridecontaining materials (FCMs) incorporating calcium in preventing root caries. Dentin surfaces of human third molars were coated with one of three FCMs: fluoride-releasing glass-ionomer cement (F7) and experimental materials in which half (P1) or all (P2) of the strontium in F7 was replaced with calcium. Dentin without FCM coating served as the control. Specimens were immersed in saline at 37°C for 1 month, sectioned, and then demineralized. Calcium loss after demineralization was lower in the Ca-substituted groups than in the Ca-unsubstituted groups (p<0.05). Calcium loss was negatively correlated with fluoride uptake (p<0.01). In the F7, P1, and P2 groups, the retraction of the dentin surface was significantly suppressed as compared with the control group. FCMs incorporating calcium improved the acid resistance of root dentin and could help prevent root caries. [ABSTRACT FROM AUTHOR]

Several desensitizers routinely used clinically for dentin hypersensitivity are expected to inhibit demineralization. This study aimed to evaluate the effectiveness of sealing materials in inhibiting demineralization and increasing fluorine (F) uptake by acid-treated root surfaces. Five noncarious extracted human teeth were used to produce specimens. Three different fluoride-containing materials, namely “MS Coat F” (MS), “MS Coat Hys Block Gel” (HS), and CTX2 Varnish (FV), were used herein. Each material was applied to the demineralized root surface. Single sections were obtained from each specimen. All surfaces of each specimen, except the polished surface, were covered with wax and immersed in an automatic pH cycling system for 2 weeks. Fluorine and calcium distributions in the carious lesions of each specimen were evaluated using proton-induced gamma emission (PIGE) and X-ray (PIXE) techniques, respectively. Dentin demineralization was analyzed using transverse microradiography (TMR) before and after pH cycling. µPIXE/PIGE analysis demonstrated that all sample groups showed increased fluoride uptake on the root surface. TMR analysis revealed that both HS and FV showed significantly lower integrated mineral loss values than the control group. All three samples demonstrated a tendency towards increased fluoride uptake from fluoride-containing hypersensitivity desensitizers and a demineralization inhibition effect on root dentin.

There are many kinds of dental luting materials (cements) in the market. Some luting materials are fluoride-releasing to prevent secondary caries. The purpose of this study was to evaluate the release of fluorine from fluoride-containing luting materials to adjacent dentin by in-air micro PIXE/PIGE (µPIXE/PIGE) system at Takasaki Advanced Radiation Research Institute. Each extracted human tooth crown was cut to expose a flat dentin surface. A 2-mm thick acrylic resin plate was cemented to each tooth using one of four fluoride-containing luting materials on the dentin surface: Fuji Luting EX (FL); Fuji I (FO); SA Luting plus (SA); and BeautiCem SA (BC). The specimens were sectioned and exposed to automated pH cycling (pH 4.5 and 7.0; simulate oral condition) for 4 or 8 weeks. After pH cycling, calcium and fluorine distributions were analyzed by the µPIXE/PIGE system with a 1.7-MeV 1H+ microbeam. The cumulative fluorine concentration (fluorine uptake) and calcium concentration in each specimen was calculated at a distance of 100 µm from the outermost surface. The results of our study indicated that FL had the highest concentration of fluorine uptake among all test materials in the 8-week group. The other three materials did not differ significantly from each other in terms of fluorine uptake. FL showed higher calcium content than SA in the 8-week group. Findings from this study suggest that the amount of fluorine penetration into dentin is likely to be dependent on the amount of fluoride released from each material, and also related to the amount of calcium present. [ABSTRACT FROM AUTHOR]

The concentrations of Na, Mg, Al, Si, S, Cl, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Br, Sr, Zr, Sn, Sb and Pb in 40 archaeological glasses from the Early Byzantine Jelica site in Serbia, are determined by PIXE/PIGE. Geochemical and multivariate analysis shows it corresponds to Foy series 2.1 and 3.2. Regionally, it is similar to the contemporary 6th century composition from Lower Danube (Bulgaria), Caričin Grad (Serbia) and Butrint (Albania). The results indicate that trade routes between these inland regions and the rest of the Empire were mostly open even during turbulent times of the 6th century. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of tricalcium phosphate-containing fluoride varnish on the prevention of root caries using an in-air micro-proton induced X-ray/gamma-ray emission system and microcomputed tomography. Either fluoride varnish (FV) or tricalcium phosphate-containing fluoride varnish (WV) was applied to root dentin, whereas dentin without varnish were considered controls. After immersion in saline, dentin sections were prepared, and concentration of fluoride ion was measured. These specimens were demineralized, and the mineral loss was measured. Caries inhibition in sound and demineralized dentin was observed in both FV and WV groups compared to the control group. Significantly low mineral loss was found especially in the demineralized dentin, which is probably due to the combination effect of calcium and fluoride ions at a concentration range of 100,000 ppm, as supplied by the varnish. The use of calcium-containing fluoride varnish, especially in demineralized dentin, is effective in arresting initial dentin caries.

Roman gold jewellery, which was excavated in Ptuj (Poetovio) and consists of a necklace, earrings and a braceletwith embedded emeralds, is part of the Slovenian archaeological artefacts collections. Crystallographic characteristics,inclusions, luminous phenomena and geological characteristics were determined in order to establish theorigin of the emeralds. Chemical composition of the emeralds was determined non-destructively using the methodsof proton-induced X-rays and gamma rays (PIXE/PIGE). The results were compared with reference emeraldsfrom Habachtal in Austria and with green beryls from the Ural Mts. Literature data for emeralds from Egypt andmodern-day Afghanistan area were used to interpret the results. Specifically, these sites were known for emeraldsbeing mined for jewellery in Roman times. It was assumed that emeralds from archaeological artefacts originatedfrom Habachtal in Austria, given that this site was the nearest to the place where found. But the emeralds fromthe necklace and earrings in fact came from Egyptian deposits. The origin of emeralds from the bracelet could nothave been determined absolutely reliably due to the lack of comparative materials; they may originate from a site inmodern-day Afghanistan or from Egypt, but certainly not from the same site as the previously mentioned emeraldsin the necklace and earrings.

Perfluorinated chemicals (PFCs) have been widely used in various household products. Because of inactive C-F bond within its structure, most PFCs cannot be biologically degraded and tend to accumulate in the ecosystems once discharged into the environment through sewage effluent etc., necessitating low-cost treatment technologies for PFCs. We have worked on the electrolysis method in which PFCs in water are decomposed at moderate cost, and found that perfluorooctane sulfonate, considered to be the most recalcitrant chemical among PFCs, can be decomposed by electrolysis. The decomposition products, however, remained unknown although we used various advanced analytical techniques (mass spectrometry for analysis of organic substances in liquid and gas samples, and combustion-ion chromatography for total fluorine analysis) to identify the products. The emanation of volatile low-molecular fluorine compounds was suspected. The present report summarizes our trial to identify the unknown decomposition products by analytical instruments cited above, and the application of PIXE/PIGE analysis to track the fluorine compounds lost from the solution by concentrating the gaseous compounds in low temperature (-100°C) activated charcoal. [ABSTRACT FROM AUTHOR]

Roman gold jewellery, which was excavated in Ptuj (Poetovio) and consists of a necklace, earrings and a bracelet with embedded emeralds, is part of the Slovenian archaeological artefacts collections. Crystallographic characteristics, inclusions, luminous phenomena and geological characteristics were determined in order to establish the origin of the emeralds. Chemical composition of the emeralds was determined non-destructively using the methods of proton-induced X-rays and gamma rays (PIXE/PIGE). The results were compared with reference emeralds from Habachtal in Austria and with green beryls from the Ural Mts. Literature data for emeralds from Egypt and modern-day Afghanistan area were used to interpret the results. Specifically, these sites were known for emeralds being mined for jewellery in Roman times. It was assumed that emeralds from archaeological artefacts originated from Habachtal in Austria, given that this site was the nearest to the place where found. But the emeralds from the necklace and earrings in fact came from Egyptian deposits. The origin of emeralds from the bracelet could not have been determined absolutely reliably due to the lack of comparative materials; they may originate from a site in modern-day Afghanistan or from Egypt, but certainly not from the same site as the previously mentioned emeralds in the necklace and earrings. [ABSTRACT FROM AUTHOR]

An integrated, multi-analytical approach combining the high sensitivity of SR-μXRF, the light element capability of PIXE/PIGE under a helium flux and the spatial resolution of BSEM + EDS was used to characterize chemical composition and corrosion of glass samples (first to fourth centuries ad) from an important, but scarcely investigated, Roman region of south-west Iberia (southern Portugal). The geochemical trends and associations of major, minor and trace elements were investigated to shed light on production techniques, the provenance of raw materials and decay mechanisms. The results, while confirming a production technique common to Roman glasses throughout the Empire-that is, a silica-soda-lime low-Mg, low-K composition, with glass additives as colouring and/or decolouring agents (Fe, Cu, Mn, Sb)-show at one site high Zr-Ti contents, suggesting a more precise dating for these glasses to the second half of the fourth century. The Ti-Fe-Zr-Nb geochemical correlations in the pristine glass indicate the presence of minerals such as ilmenite, zircon, Ti-rich Fe oxides and columbite in the sands used as raw materials for the glass former: these minerals are typical of granitic-type source rocks. The unusually high K content in the corrosion layers is consistent with burial conditions in K-rich soils derived from the alteration of 2:1 clays in K-bearing rock sequences. [ABSTRACT FROM AUTHOR]

Abstract: The exact identification of the raw material used for ancient bone objects is the basis to understand the manner in which humans in ancient times chose the medium for the manufacture of objects. The material identification is not trivial in the case of highly modified surfaces – worked by man or degraded by diagenesis. Even if bone materials are morphologically quite different, they show in general a very similar chemical composition. Nevertheless, slight differences can be observed in their chemical composition on minor and trace level. These variations may be used as a marker of their exact nature, when other means such as morphological observations are limited. A large data base was built up by analysing different modern and archaeological osseous materials in order to define chemical markers for the identification of the raw materials used to manufacture objects. Micro-Proton Induced X-ray and Gamma-ray Emission (micro-PIXE/PIGE) was chosen to analyse the different bone materials as a non-invasive method is generally required for the study of ancient worked osseous objects. These analyses were performed at the particle accelerator AGLAE installed at the laboratory of the C2RMF, Paris. This paper presents the results obtained on about 150 objects made of different bone materials dating from the Palaeolithic to today and coming from various archaeological sites, mainly in France. Some chemical markers seem to be characteristic, such as the magnesium to calcium ratio for well preserved ivory on one hand and the fluorine content versus strontium to calcium ratio for bones of marine mammals on the other hand. The limits of this approach and the different parameters to consider for an identification of ancient bone and ivory material based on this method are particularly discussed in the case of Palaeolithic material from Abri Pataud and Isturitz, France. [Copyright &y& Elsevier]

Abstract: The use of fluoride for the prevention of caries is based on the transformation of hydroxylapatite to fluoroapatite in the presence of fluoride ions, thereby strengthening tooth structure. Adhesion of dentin and resin composite (tooth-colored restoration material) requires a dentin bonding system, since resin composite is not able to adhere to dentin directly. Demineralization of dentin by acid etching is an important step in the dentin bonding system, however, demineralization also introduces weaknesses in tooth structure. If the demineralized dentin could be strengthened by the application of fluoride, then the dentin–resin composite bond strength might also improve. To test this hypothesis, the present study evaluated the influence of fluoride applications on the strength of the dentin–resin composite bond by (1) tensile strength testing analyses, (2) SEM analyses of tooth structure, and (3) detection of calcium (Ca) and fluorine (F) distribution patterns by micro proton-induced X-ray emission (μ-PIXE) and micro proton-induced gamma-ray emission (μ-PIGE) analyses conducted at the Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) at the Takasaki Advanced Radiation Research Institute (TARRI). In this study, the dentin in extracted human molars was exposed by grinding and the dentin was etched with 35% phosphoric acid. Fluoride was applied at two concentrations, 0.022% (100ppm F) and 2.21% (10,000ppm F) NaF solution, for two time periods, 30 and 60s, prior to bonding the resin composite with the treated dentin. Controls were prepared in the same manner, but without the fluoride application. Bond strength was measured with a micro-tensile testing unit, and the fluorine and calcium distributions at the interface between dentin and resin composite were detected by μ-PIGE and μ-PIXE analysis, respectively. Results indicate that the 10,000ppm F applications resulted in higher bond strengths than observed in either the 100ppm F applications or the control group. In addition, PIGE analyses showed high concentrations of fluorine in the hybrid bonding layer of the 10,000ppm F samples, suggesting that the fluorine contributes to the strength of the dentin–resin composite bond. Detection of fluoroapatite within the hybrid bonding layer suggests that bond strength involves remineralization processes. [Copyright &y& Elsevier]

Abstract: Diagenetic alteration may limit the potential use of the biogenic composition of fossil bone as a reliable source of information for dietary, environmental and climatic reconstructions. One of the key parameters used to determine the state of preservation of fossil remains is their crystallinity. This can be evaluated by means of infrared spectroscopy, measuring the “splitting factor” (IRSF). However, the crystallinity may fail to describe the extent of chemical and mineralogical changes occurring during fossilization, and cannot be used alone as a reliable indicator of biogenic signal preservation. In this study, modern bones were experimentally heated in order to monitor the changes of FTIR spectral features related to an evolution of mineral properties. Further spectroscopic proxies of the mineral composition and structure were defined and calibrated. This method was then applied on unburnt, charred and calcined bones coming from three archaeological sites (Bize-Tournal, Organc 3 and Song Terus). The results obtained on modern and fossil bones demonstrate that low temperature heating and diagenetic processes may induce similar effects on bone mineral, while these processes are clearly distinct from those occurring during high temperature heating (>550 °C). The comparison between charred and calcined fossil bones shows that heating over 550 °C reduces the reactivity of the mineral phase and prevents compositional and structural characteristics from experiencing diagenetic modification. Applied to unburnt fossil bones, the proxies developed in this study, easily obtained from FTIR spectra, provide a more reliable evaluation of the degree of preservation than IRSF alone and contribute to a better understanding of the diagenetic processes. [Copyright &y& Elsevier]

Abstract: The analytical advantages and disadvantages of PIXE/PIGE spectrometry have been checked and compared with those of other X-ray techniques (XRF and EDX) for a wide set of glasses. The archaeometric study was conducted with glasses of different chronology (13th to 20th centuries AD) and different Spanish provenances. Glasses produced in Central Europe during the medieval period were submitted to severe corrosion processes, which induced conservation problems. Since this subject is directly connected with their chemical composition, a glass whose composition is considered as a representative model was melted at the laboratory and included in the samples set. In general, the results of chemical analyses undertaken with different techniques indicate that percentages for the main vitrifying agents and modifying agents are in good agreement. PIXE/PIGE spectrometry arises as a useful non-destructive analytical tool able to determine at the same time heavy and light oxides, as well as minor components (colouring agents). PIXE/PIGE spectrometry has also demonstrated its usefulness to characterise on the glass surface features concerning decorations (grisailles), glassy coloured layers, corrosion crusts and other products of weathering and aging. [Copyright &y& Elsevier]

Abstract: In this paper we compare the results of proton-induced X-ray and gamma-ray emission (PIXE/PIGE) and simultaneous inductively coupled plasma–optical emission spectrometry (ICP-OES) using a multivariate modeling approach. Paired samples from 17th century east Asian stoneware jars recovered from dated shipwrecks provide the test population. The comparison highlights similar elemental behaviors irrespective of technique but shows that the additional elements available through ICP-OES provide identification of subgroups not evident in the PIXE/PIGE dataset. This study concludes that high dimensional datasets, such as those provided by ICP-OES, are preferable for modeling compositional groups where the archaeological samples are of unknown compositional range. It also highlights the power of multivariate approaches in assessing the quality of data generated by different techniques. [Copyright &y& Elsevier]

This study employed an in-air micro-proton-induced X-ray/gamma-ray emission system to assess the effectiveness of fluoride-containing materials (FCMs) incorporating calcium in preventing root caries. Dentin surfaces of human third molars were coated with one of three FCMs: fluoride-releasing glass-ionomer cement (F7) and experimental materials in which half (P1) or all (P2) of the strontium in F7 was replaced with calcium. Dentin without FCM coating served as the control. Specimens were immersed in saline at 37°C for 1 month, sectioned, and then demineralized. Calcium loss after demineralization was lower in the Ca-substituted groups than in the Ca-unsubstituted groups (p<0.05). Calcium loss was negatively correlated with fluoride uptake (p<0.01). In the F7, P1, and P2 groups, the retraction of the dentin surface was significantly suppressed as compared with the control group. FCMs incorporating calcium improved the acid resistance of root dentin and could help prevent root caries.