Cyclodextrins as dental cleaning powders

Abstract

The invention relates to the use of a powder in a powder jet device for cleaning tooth surfaces by powder spraying, wherein the powder comprises cyclodextrin. The invention also relates to a process for cleaning tooth surfaces with a powder jet device, wherein the powder comprises cyclodextrin and the invention relates to a powder or powder mixture for use in a powder jet device, wherein the powder or powder mixture comprises cyclodextrin.

Claims

1. A powder for use in a powder jet device for cleaning tooth surfaces by powder spraying, the powder comprising one or more cyclodextrins.

2. The powder according to claim 1, wherein the cyclodextrin is a-cyclodextrin, b-cyclodextrin, g-cyclodextrin or mixtures thereof.

3. The powder according to claim 1, wherein the powder further comprises 0.5 to 3 wt.-% amorphous silicon dioxide.

4. The powder according to claim 1, wherein the powder comprises at least 10 wt-% cyclodextrin, based on the total weight of the powder.

5. The powder according to claim 1, wherein the average particle size of the powder is 5 to 40 pm.

6. The powder according to claim 1, wherein the maximum particle size of the powder is <200 pm.

7. The powder according to claim 1, wherein the powder further comprises glycine, sodium hydrogen carbonate, erythritol, a bactericide, a bleaching agent and/or an analgesic.

8. The powder according to claim 1, wherein the powder comprises 10 to 80 wt.-% cyclodextrin and 90 to 20 wt. % glycine, sodium hydrogen carbonate, tagatose, trehalose and/or alditols.

9. The powder according to claim 1, wherein the powder comprises granules having an average particle size of 20 pm to 220 pm, wherein the granules comprise primary particles and a binder, wherein the primary particles have an average particle size smaller than the average particle size of the granules and wherein the binder comprises cyclodextrin.

10. The powder according to claim 9, wherein the powder comprises 1 to 2.0 wt.-% cyclodextrin as a binder and 99 to 80 wt. % glycine, sodium hydrogen carbonate, tagatose, trehalose and/or alditols.

11. A process for cleaning tooth surfaces, wherein a powder according to claim 1 is sprayed with a powder jet device onto a tooth surface together with a gaseous or liquid carrier medium.

12. A powder or powder mixture for use in a powder jet device for cleaning tooth surfaces by powder spraying, wherein the powder or powder mixture comprises a-cyclodextrin or b-cyclodextrin.

13. The powder or powder mixture according to claim 12, wherein the powder or powder mixture comprises 10 to 99.5 wt.-% cyclodextrin, based on the total weight of the powder, 0.5 to 2 wt.-% amorphous silicon dioxide, based on the total weight of the powder, the maximum particle size of the powder is <120 μm and average particle size of the powder is 5 to 40 pm.

14. The powder or powder mixture according to claim 12, wherein the powder additionally comprises glycine, sodium hydrogen carbonate, tagatose, trehalose and/or alditols.

15. The powder or powder mixture according to claim 12, wherein the powder comprises granules having an average particle size of 20 pm to 220 pm, wherein the granules comprise primary particles and a binder, wherein the primary particles have an average particle size smaller than the average particle size of the granules and wherein the binder comprises cyclodextrin.

Description

EXAMPLES

Example 1: α-Cyclodextrin

[0047] α-cyclodextrin was grinded and sieved at 120 μm, so that d.sub.100 was ≤120 μm. The powder was mixed with about 2 wt.-% amorphous silicon dioxide (silica). The average particle size of this powder was 30 μm.

Example 2: β-Cyclodextrin

[0048] β-cyclodextrin was grinded and sieved at 120 μm, so that d.sub.100 was ≤120 μm. The powder was mixed with about 2 wt.-% amorphous silicon dioxide (silica). The average particle size d.sub.50 of this powder was 20 μm.

[0049] The two powders according to Example 1 and Example 2 were tested regarding cleaning efficiency and abrasiveness. The results are shown in FIGS. 1 to 3 in comparison to known cleaning powders.

[0050] The abrasiveness is measured by projecting powder with a powder jet device directly on a surface at 45° and 2 mm of projected distance using an EMS Airflow® prophylaxis master device. This surface is made of pure aluminium (99.5%). The application time is 30 seconds. The plate is put on an elevator to reach the distance of 2 mm. The nozzle is fixed in a resin mould in order to fix well the nozzle position. The mass is known by weighing the powder chamber before and after the test. Every measurement is repeated at least three times and the average is taken as abrasiveness. The depth of the holes was measured by a laser profilometer. The efficiency or cleaning efficiency is the surface that is cleaned per gram of the powder.

[0051] The average particle size (d.sub.50) of the powders according to the invention is determined with a Malvern Mastersizer 2000 (Malvern Instruments Ltd., Malvern, UK) with a Scirocco Dispersing Unit at a dispersion pressure of 1.5 bar.

Example 3: Erythritol Granulated with α-Cyclodextrin

[0052] The experiment was carried out in a pilot batch fluidized bed of conical shape. Initial particle mass 1 kg, inlet air temperature 60-90° C., liquid feed rate 5-20 ml min.sup.−1 and relative air spraying pressure 1-2.5 bar were chosen as process parameters. A solution of α-cyclodextrin was sprayed for 20 min. During the experiment, all process parameters (air inlet temperature, air flow rate, liquid feed rate and spraying pressure) were kept constant. At the end of the experiment the granulated powder was removed and the solid content checked to be more than 98%. The amount of α-cyclodextrin added to the powder was between 5-10%.

[0053] The invention is described further below with reference to FIGS. 1 to 3.

[0054] FIG. 1 shows the abrasiveness [μm/g] of the α-cyclodextrin and β-cyclodextrin powder according to Example 1 compared to powders of erythritol, glycine, trehalose and tagatose.

[0055] FIG. 2 shows the cleaning efficiency [mm.sup.2/g] of α-cyclodextrin and β-cyclodextrin compared to powders of erythritol and glycine.

[0056] FIG. 3 shows the abrasiveness [μm/g] of erythritol powder granulated with the α-cyclodextrin as a binder. The comparison is between the initial powder of Erythritol and the granulated powder.

[0057] The above examples demonstrate that the powders according to invention comprising cyclodextrins have a reduced abrasiveness and still a high cleaning efficiency compared to commercially available dental cleaning powders.