Apatite precipitation on a novel fast-setting calcium silicate cement containing fluoride

Figures & data

Table 1. Protooth compositions.

Additives to CSA cement^a (wt.%)	Fluoride^b	Radiocontrast	Nano-SiO2	Hydration liquid(μl/g powder)	Consistency	Setting time (min)
Protooth	3.5%	10% ZrO2	+	190	Creamy	Clay consistency: 4 − 6 Creamy consistency: 8 − 10
Ultrafast Protooth	3.5%	20% ZrO2	+	195	Creamy	1½−2
High fluoride Protooth	15%	25%(16% Bi2O3 + 9% SrF2)	−	210	Clay-like	8 − 10

^a CSA composition: tricalcium silicate, dicalcium silicate, Al₂O₃<5% (tricalcium aluminate >7%), calcium sulfate <3%, Other components incl. F, PO4. Patent Pub. No.: WO 2011/023199.

^b In all Protooth compositions with 3.5% fluoride additive hereof 1% fluoride was SrF₂, which also contributes as extra radiocontrast.

In high fluoride Protooth composition with 25% radiocontrast additive hereof 9% was SrF₂, which also contributes as fluoride additive.

Figure 1. Representative morphologic characterization of precipitations formed over Protooth surface immersed in PBS during 56 days. EDX spectrum was obtained from the precipitates in the field of view. Semiquantitative chemical composition presented in the table shows their Ca/P molar ratio.

Figure 2. Representative morphologic characterization of precipitations formed over ultrafast Protooth surface immersed in PBS during 56 days. EDX spectrum was obtained from the precipitates in the field of view. Semiquantitative chemical composition presented in the table shows their Ca/P molar ratio.

Figure 3. Representative morphologic characterization of precipitations formed over high fluoride Protooth surface immersed in PBS during 56 days. EDX spectrum was obtained from the precipitates in the field of view. Semiquantitative chemical composition presented in the table shows their Ca/P molar ratio.

Figure 4. Representative Raman spectra recorded on the surface of Protooth (a), ultrafast Protooth (b), and high fluoride Protooth (c) as the function of immersion time in PBS. The corresponding bands to apatite has been indicated with Ap and C-Ap (β-type carbonated apatite). I₉₆₅/I₈₆₀intensity ratio (apatite/belite) obtained from the spectra recorded on the surface of all Protooth compositions immersed in PBS as a function of time (d). A higher intensity ratio is related to thicker apatite deposition. * denotes a significant difference between Protooth and high fluoride Protooth at each time point. § denotes a significant difference between ultrafast Protooth and high fluoride Protooth at each time point. All cements showed statistically significant increase after 56 days compared to day 1 (p < 0.0001).

Table 2. Raman shift wavenumbers (cm⁻¹) and bands assignments of apatite recorded on the surface of the cements after 56 days.

Wavenumber (cm^−1)	Vibrational mode	Crystal phase	Cement
1077	ν1 CO3^2-symmetric stretching	β-type carbonated apatite	Protooth Ultrafast Protooth High fluoride Protooth
1048	ν3 PO4^3- asymmetric stretching	Apatite	Protooth Ultrafast Protooth High fluoride Protooth
1022	ν3 PO4^3- asymmetric stretching	Apatite	Protooth Ultrafast Protooth High fluoride Protooth
965	ν1 PO4^3- symmetric stretching	Apatite	Protooth Ultrafast Protooth High fluoride Protooth
609	ν4 PO4^3- bending	Apatite	High fluoride (superimposed with zirconium oxide  in Protooth and ultrafast Protooth)
592	ν4 PO4^3- bending	Apatite	High fluoride (superimposed with zirconium oxide  in Protooth and ultrafast Protooth)
580	ν4 PO4^3- bending	Apatite	High fluoride (superimposed with zirconium oxide  in Protooth and ultrafast Protooth)
435	ν2 PO4^3- bending	Apatite	Protooth Ultrafast Protooth (superimposed with bismuth oxide in high fluoride  Protooth)