1. A dental ceramic article comprising,
a dental support structure, wherein the dental support structure comprises zirconium oxide and at least two different coloring substances A and B, substance A showing a light emission in the range from about 470 nm to about 510 nm and substance B showing a light absorption in the range from about 520 nm to about 750 nm, wherein the dental support structure does not comprise a glass or glass ceramic material in an amount above about 10 wt.-% and wherein substance A is from about 3 wt.-% to about 7.5 wt.-%.
2. The dental ceramic article according to claim 1, substance A being selected from components comprising dysprosium.
3. The dental ceramic article according to claim 1, substance B being selected from components comprising neodymium.
4. The dental ceramic article according to claim 1, substance A being present in an amount in the range of about 0.1 to about 5 mol-% and substance B being present in an amount in the range of about 0.01 to about 1 mol-%, wherein the amounts of the substances are calculated as molar amounts of the cations.
5. The dental ceramic article according to claim 1 being characterized by at least one of the following features:
breaking resistance: at least about 400 MPa,
density: from about 5.9 to about 6.1 gcm3, and
light emission in the region of about 470 nm to about 510 nm.
6. The dental ceramic article according to claim 1 comprising:
ZrO2: from about 80 wt.-% to about 99 wt.-%,
Y2O3: from about 0.5 wt.-% to about 10 wt.-%,
Dy2O3: from about 2 wt.-% to about 7.5 wt.-%,
Nd2O3: from about 0.014 wt.-% to about 1.4 wt.-%, and
Additives: from about 0.0001 wt.-% to about 1 wt.-%.
7. The dental ceramic article according to claim 1 fixed in or to a holding device.
8. A process of producing the dental ceramic article according to claim 1, the process comprising the steps of
a) providing a composition comprising zirconium oxide, a liquid, substance A, substance B and optionally a binder,
b) casting the composition in a mould to obtain a 3-dimensional article,
c) pre-sintering the 3-dimensional article to obtain a pre-sintered article,
d) machining the 3-dimensional article obtained in step b) or the pre-sintered article obtained in step c), and firing the article from step b), step c) or step d).
9. A process of producing the dental ceramic article according to claim 1, the process comprising the steps of
a) providing a composition comprising zirconium oxide, substance A and substance B,
b) applying pressure andor temperature to the composition to obtain a 3-dimensional article,
c) optionally machining the 3-dimensional article, and optionally firing the 3-dimensional article from step b) or step c).
10. A process of producing the dental ceramic article according to claim 1, the process comprising the steps of
a) providing a dental article comprising zirconium oxide,
b) optionally machining the dental article of step a),
c) applying a composition containing substance B and substance A to the dental article, and
d) optionally firing the dental article.
11. A process of producing the dental ceramic article according to claim 1, the process comprising the steps of
a) providing a composition comprising zirconium oxide and substance A or substance B,
b) applying pressure andor temperature to the composition to obtain a 3-dimensional article,
c) optionally machining the 3-dimensional article,
d) applying a composition containing a substance which has not been used in step a), the substance being selected from substance B or substance A, to the article obtained in step b) or step c), and
e) optionally firing the article from step d).
12. A method of producing a dental restoration or a part thereof, the method comprising
providing the dental ceramic article according to claim 1; and
machining the dental ceramic article.
13. A process for producing a dental ceramic article as described in claim 1, the process comprising applying to the dental ceramic article a composition comprising
a solvent in an amount of about 20 to about 99 wt.-%,
substance A and substance B, and
optionally additives in an amount of about 0.1 wt.-% to about 10 wt.-%,
wherein substance A is present in an amount of about 3 wt.-% to about 7.5 wt.-%, and substance B is present in an amount of about 0.1 wt.-% to about 20 wt.-%, wt.-% with respect to the weight of the whole composition.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for drilling a bore through a target including a ready made through bore, the method comprising:
advancing a drill bit into the target along the ready made through bore in a direction of advancement from a region where a drill device arranged to drive the drill bit is located to a further region;
injecting a directing gas through at least one aperture in the drill bit so that gas ejected therefrom is directed in the direction of advancement; and
as the bore is drilled, directing substantially all waste material along the ready made through bore in the direction of advancement via the gas to the further region, wherein the waste material is substantially prevented from moving in a direction opposite the direction of advancement.
2. The method as claimed in claim 1 wherein at least one cutting element of the drill bit defines an internal diameter of the bore developed in the target as the bit advances.
3. The method as claimed in claim 2 further comprising:
providing the ready made bore having an existing diameter less than the internal diameter in the target; and
directing waste material along the ready made bore during the step of advancing the drill bit.
4. The method as claimed in claim 1 wherein substantially all of the waste material is directed in the direction of advancement.
5. The method as claimed in claim 1 comprising dry drilling.
6. The method as claimed in claim 1 further comprising simultaneously drilling through at least two different materials.
7. The method as claimed in claim 1 wherein the target comprises a wall composed of a first material and a pipe composed of a different material extending through the wall, the internal bore of the pipe defining a ready made bore along which the drill bit is advanced.
8. The method as claimed in claim 1 further comprising:
selecting the dimensions of the drill tip for providing consistent particle size, having a largest cross-section below a predetermined threshold limit, of ejected waste material.
9. A drill bit for drilling a bore through a target via a drilling process, comprising:
at least one cutting surface arranged to cut a bore having an internal diameter through the target as the drill bit advances into the target from a region where a drill device arranged to drive the drill bit is located to a further region; and
at least one aperture in the drill bit for permitting a directing gas to be injected in a direction of advancement of the drill bit to thereby direct substantially all waste material, formed as the bore is drilled, in the direction of advancement to the further region; wherein
the drill bit further comprises a drill tip including the cutting surface and a shaft portion for connecting the drill tip to a drill device and the at least one aperture is formed radially outwardly in the shaft portion, wherein the at least one aperture in the drill bit is configured to direct gas in the direction of advancement of the drill bit such that the waste material is substantially prevented from moving in a direction opposite the direction of advancement.
10. The drill bit as claimed in claim 9 wherein the cutting surface is arranged for cutting a bore having an internal diameter wider than an existing bore in the target and along which the drill bit is advanced.
11. The drill bit as claimed in claim 9 further comprising a pilot tip, having an outer diameter arranged to closely match an internal diameter of a ready made bore formed in the target, extending from a body portion of the drill bit.
12. The drill bit as claimed in claim 11 wherein the pilot tip is disposed at a forward end region of the body portion of the drill bit.
13. The drill bit as claimed in claim 9 further comprising at least one chip breaker tip disposed at a forward region of a body portion of the drill bit.
14. The drill bit as claimed in claim 9 further comprising:
at least one air passage extending longitudinally through the drill bit for providing a route for gas to flow along from a rear portion of the drill bit to the at least one aperture.
15. The drill bit as claimed in claim 9 wherein the shaft portion comprises a cylindrical shell body portion and includes at least one further aperture therein, for providing a route for gas to flow from an internal region of the cylindrical shell to an external region formed between the outer diameter of the cylindrical shell and the inner diameter of the drilled bore.
16. The drill bit as claimed in claim 9 further comprising:
connecting means on at least one of a rear portion of the drill tip andor a forward region of the shaft portion for securably connecting the tip and shaft portion together.
17. A drill, for use with a drill bit arranged for drilling a bore through a target, comprising:
a drill bit comprising:
at least one cutting surface arranged to cut a bore having an internal diameter through the target as the drill bit advances into the target from a region where a drill device arranged to drive the drill bit is located to a further region; and
at least one aperture in the drill bit for permitting a directing gas to be injected in a direction of advancement of the drill bit to thereby direct substantially all waste material, formed as the bore is drilled, in the direction of advancement to the further region; wherein
the drill bit further comprises a drill tip including the cutting surface and a shaft portion for connecting the drill tip to a drill device and the at least one aperture is formed radially outwardly in the shaft portion;
a rotor shaft arranged to rotate when driven;
a motor arranged to drive the shaft;
connection means for connecting the drill bit to the rotor shaft;
a gas inlet arranged to receive pressurised gas from a pressurised gas source; and
gas directing means arranged to inject gas from the inlet to the drill bit thereby providing a directing gas flow in a direction of advancement as the drill bit drills the bore, wherein the at least one aperture in the drill bit is configured to direct gas in the direction of advancement of the drill bit such that the waste material is substantially prevented from moving in a direction opposite the direction of advancement.