Strontium-substituted hydroxyapatite nanocrystals

Bigi, Adriana; Boanini, Elisa; Capuccini, Chiara; Gazzano, Massimo

doi:10.1016/j.ica.2006.07.074

Cited by 320 publications

(223 citation statements)

References 23 publications

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“…In dentin the increase of fluorine content was related to time and reached 12,000 ppm after 4 years. Strontium is quantitatively incorporated into hydroxyapatite where its substitution for calcium provokes a linear increase in the lattice constant [19]. Strontium is added to glass-ionomer materials to confer radiopacity, but studies indicate that it may have a caries inhibitory role on both Streptccocuso mutans and Actinomyces viscosus, and its' effect may be more significant than that of fluorine [20], although Dabsie and associates [21] claimed that strontium alone showed no antibacterial effect when used as solution of strontium chloride hexahydrate directly on known bacterial inoculation for a short time of 5 minutes.…”

Section: Discussionmentioning

confidence: 99%

Ion exchanges between glass-ionomer restorative material and primary teeth components-an in vivo study

Zilberman¹

2014

Oral Biol Dent

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Objectives: To analyze the ion exchange between conventional glass-ionomer restorative material, (Fuji IX-GC Co., Japan) and tooth components in primary molars after long periods of function in vivo. Methods: Five deciduous mandibular molars were collected after normal exfoliation. An intact deciduous molar served as control, a second deciduous molar was restored occlusaly with Fuji IX in vitro, and 3 deciduous molars with occlusal restorations were collected after 18, 24, and 48 months in vivo. The molars were sectioned bucco-lingual through the restoration and the chemical analysis was performed on enamel, dentin and restorative material along parallel lines crossing from buccal to lingual, using an energy dispersive X-ray spectrometer (EDS). The data was analyzed using SPSS program. Results: In the enamel adjacent to the glass-ionomer material, calcium and phosphate showed a significant reduction related to time (P<0.05). In both enamel and dentin strontium, silica and alumina migrated from the glass-ionomer material in significant concentrations (P<0.05), and fluorine showed an increase from zero in the intact deciduous molar to 1.2% after four years in vivo. In the glass-ionomer material fluorine was reduced in relation with time in vivo, while calcium concentration increased. Conclusions: There is a constant exchange of ions between glass-ionomer restorative material and tooth components in deciduous molars. It begins as early as two weeks in vitro and is increased in vivo. Strontium, alumina and fluorine released from the glassionomer have a bactericidal effect and may affect remineralization. Calcium may enhance the glass-ionomer mineralization and transform it into enamel like material. Clinical significance: The results showed that a continuous exchange of ions between enamel and dentin and glass-ionomer material occurs in vivo and the concentration of the ions is time related. Strontium, alumina and fluorine in enamel and dentin may cause a continuous anti bacterial and anti cariogenic effect, while calcium enhance mineralization of glass-ionomer in vivo, a factor that may increase the longevity of the restoration.

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Section: Discussionmentioning

confidence: 99%

Ion exchanges between glass-ionomer restorative material and primary teeth components-an in vivo study

Zilberman¹

2014

Oral Biol Dent

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“…[15,21,22] The main difficulty in answering this question in the case of Mg-HA arises from the absence of high resolution spectroscopic data over an important range of composition, and the significant loss of crystallinity of Mg-HA compounds above ~ 20% Mg. Thus, in contrast with Sr-or Ba-substituted HA, [23,24] Rietveld analyses based on X-ray powder patterns are not conclusive for Mg-HA, and both the Ca(I) [15] and the Ca(II) [20] sites have been suggested to be the preferential site of incorporation of Mg. Such discrepancies might be due to differences in synthetic procedures (which could perhaps alter the final site for incorporated Mg), and/or to the low quality of the XRD patterns used in the Rietveld refinements.…”

Section: Introductionmentioning

confidence: 89%

Magnesium incorporation into hydroxyapatite

Laurencin¹,

Almora‐Barrios²,

Leeuw³

et al. 2011

Biomaterials

304

190

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The incorporation of Mg in hydroxyapatite (HA) was investigated using multinuclear solid state NMR, X-ray absorption spectroscopy (XAS) and computational modeling. High magnetic field 43 Ca solid state NMR and Ca K-edge XAS of a ~10% Mg-substituted HA were performed, bringing direct evidence of the preferential substitution of Mg in the Ca(II) position. 1 H and 31 P solid state NMR show that the environment of the anions is disordered in this substituted apatite phase. Both Density Functional Theory (DFT) and interatomic potential computations of Mg-substituted HA structures are in agreement with these observations. Indeed, the incorporation of low levels of Mg in the Ca(II) site is found to be more favourable energetically, and the NMR parameters calculated from these optimized structures are consistent with the experimental data. Calculations provide direct insight in the structural modifications of the HA lattice, due to the strong contraction of the M•••O distances around Mg. Finally, extensive interatomic potential calculations also suggest that a local clustering of Mg within the HA lattice is likely to occur.

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“…Note that this occupancy depends on the concentration of the oligoelements. The structure refinements obtained by Bigi et al [63] indicate that whilst in most of the range of concentration strontium displays a slight preference for the Ca[II] site coherently with its ionic radius, at very low concentrations its occupancy of the smaller Ca[I] site is slightly higher.…”

Section: Considering Substitution Processesmentioning

confidence: 97%