GB2416310A - Dental tray for teeth whitening - Google Patents

Abstract

A tray, 1, for dental use comprises at least one dam or protrusion, 2, 3, on the tooth-facing surface of the tray to limit, in use, the spread of a composition placed in the tray. In particular the composition is a whitening agent and the dam faces the front surface of the teeth, preferably at the gingival margin. The dam, 3, facing the rear surface is preferably remote from the gingival margin. Also described are methods for making the tray and a model used for making the tray.

Description

TRAY FOR DENTAL USE

The present invention relates to trays for dental use. More specifically, the present invention seeks to provide an improved dental tray for various dental treatments including bleaching or application of other dental medicines, together with a method and model for making the tray.

Dental treatment to whiten teeth has become increasingly popular in recent years.

Consequently, several methods and tools have been developed to improve both the effectiveness and the convenience of traditional techniques. In the past, such treatments were performed in the dentist's office, but today home treatment alternatives are available.

One such treatment comprises fitting a dental tray containing oxidising or whitening gel, such as hydrogen or carbamide peroxide, to one arch of a patient's teeth (i.e. the top teeth or the bottom teeth) thereby maintaining the whitening gel in contact with the teeth. The top and bottom arches can also be whitened simultaneously using two trays. Also, the or each tray can be formed for use in relation to particular teeth. For example, to minimise cost, a patient may decide to simply whiten teeth which are most visible. It is even possible to fashion a tray for only one tooth, which may be desirable if, for example, a single tooth had been discoloured by injury. The tray may be made of soft plastics material and is usually custom moulded to fit the patient's teeth.

There are a number of known methods for making a custom fit tray. One popular method includes making an impression of the patient's teeth, making a plaster cast of the impression and forming a blank of sheet plastics material over the plaster cast.

US 6,848,905 discloses an alternative method of forming such a tray using the patient's own teeth as a template. The tray may subsequently be trimmed for improved comfort or use.

To carry out whitening, which can easily be done by the patient at home or elsewhere, whitening gel is placed into a dental tray which is then fitted over the patient's teeth and left for the requisite time. The tray can then be removed, cleaned and stored until the next use.

Despite the generally positive results obtained using the foregoing method, one known problem is that the whitening gel may leak from the tray onto the gums or onto areas of the teeth, close to the gums, where the enamel and dentine can be thin and/or discontinuous with exposed dentine. In this case, considerable irritation may arise or, for some individuals, pain may be experienced.

To mitigate this problem, the tray is sometimes cut back so that its margins stop short of the gums. However, this can result in too large a portion of each tooth, next to the gum, not being whitened. This may also result in a higher rate of leakage of the whitening gel in the absence of the barrier provided by the gum, and ingestion of the bleaching agent can cause a soar throat, particularly if the quantity is significant.

EP 0522087 discloses a further method of treating tooth surfaces comprising a sustained release composition used in conjunction with a dental tray to mitigate the . a. .

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ce - a r a ëa e.e aforementioned problem. This is achieved by the high viscosity of the bleaching agent, wherein reduced leakage occurs.

WO 00/28953 discloses a tooth whitening composition comprising potassium nitrate for reducing tooth sensitivity and a tackifying agent to assist the retention of a dental tray and reduce leakage of the composition.

The present invention seeks to provide an improved, simple and costeffective solution to the problem of whitening gel leakage which can be used either in the place of, or in conjunction with the aforementioned alternative dental treatment compositions.

According to one aspect of the invention, there is provided a tray for dental use comprising at least one dam on a tooth-facing surface of the tray.

Preferably, the tray is shaped to correspond to the configuration of one arch of a patient's teeth.

More preferably, the at least one dam extends along a marginal portion of the tray.

According to an optional feature of the invention, the at least one dam is positioned on the front tooth facing surface of at least one tooth.

Optionally, the at least one dam is positioned proximate to the area of the tray corresponding to the gingival margin.

According to a further optional feature of the invention, the tray may comprise a further dam positioned on the rear tooth-facing surface of at least one tooth. .& 8 8

sea as s s , s s se Optionally, the further dam on the rear tooth facing surface is positioned remote from the gingival margin.

According to a second aspect of the present invention, there is provided a bleaching tray comprising at least one dam on the tooth-facing surface of the tray.

According to a third aspect of this invention, there is provided a method for making a tray for dental use comprising: providing a model having a shape corresponding to one or more teeth, said model comprising a recess; and forming the tray on the model such that the tray comprises a dam corresponding to the recess.

According to an optional feature of the third aspect of this invention, there comprises an initial step of forming a recess in the model.

According to a further optional feature of the third aspect of this invention, there comprises an initial step of forming in the model a recess which extends laterally across at least a portion of the model.

Preferably, the method comprises making the recess with a knife or other sharp instrument.

Optionally, there may comprise an initial step of making the model.

According to a fourth aspect of this invention, there is provided a method of making a model for a tray for dental use comprising: providing a model having a shape corresponding to one or more teeth; and forming a recess in the model.

ca. e .ë ë ë. . Preferably, the method comprises forming a recess which extends laterally across at least a portion of the model.

More preferably, the method comprises making the recess with a knife or other sharp instrument.

According to a fifth aspect of this invention, there is provided a model for use in making a tray for dental use, wherein the model has a recess.

Preferably, the recess extends laterally along at least a portion of the model.

More preferably, the recess extends along a marginal portion of the area of the model corresponding to the patient's tooth.

According to an optional feature of the fifth aspect of this invention, the model is shaped to correspond to the configuration of one arch of a patient's teeth.

According to a sixth aspect of this invention there is provided a method for treating teeth comprising: providing a dental tray with a dam which defines the area of at least one tooth to be treated; placing a treatment composition into the portion of the tray that defines the area of the at least one tooth to be treated; and fitting the tray to the patient's teeth.

Optionally, the treatment composition comprises a fluoride composition.

e e e.eee e e e e e e e e eee eee ë e e e e e e e e e e ë- see e e According to a seventh aspect of this invention, there is provided a method for cosmetic whitening of teeth comprising: providing a bleaching tray with a dam which defines the area of at least one tooth to be whitened; placing a bleaching agent into the portion of the tray that defines the area of the at least one tooth to be whitened; and fitting the tray to the patient's teeth.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawing, in which: Figure 1 is a front view of the preferred embodiment of the dental tray according to this invention; Figure 2 is a side view of one of a patient's front teeth with the dental tray of Figure 1 in place; Figure 3 is a top view of a model for the dental tray in Figure 1 according to this invention; Figure 4 is a front view of the model in Figure 3; and Figure 5 is a side view of one tooth portion of the model in Figure 3 with the dental tray from Figure 1 formed on the model.

Figure 6 is a top view of an alternative embodiment of the dental tray according to this invention bee e.

he e e e Figure 7 is a cross-sectional view along line A-A of Figure 6 The dental tray 1 shown in Figure 1 is shaped to specifically correspond to the configuration of the bottom arch of an individual patient's teeth. Tray 1 is made of plastics sheet material, for example EVA with a thickness of approximately 0.8mm.

Protrusions 2 and 3 are provided on the front and rear tooth facing surfaces of tray 1 respectively.

As shown in Figure 2, when the tray 1 is fitted, the protrusions 2 and 3 abut the tooth 5 thereby creating a gap between the tray 1 and the tooth 5. The protrusions 2 and 3 are in close proximity to the patient's gum 4. The depth of each protrusion 2 and 3 is preferably between 0.1 and 0.5 mm.

Referring to Figure 3, a model 6 is provided which closely represents the shape of one arch of the patient's teeth. The model 6 comprises tooth portions 7 which correspond to the patient's teeth 5 and a gum portion 8 which corresponds to the patient's gums 4.

Narrow recesses 10 are also provided in the model 6 on the rear surfaces of tooth portions 7 in locations proximate the gum portion 8.

Referring to Figure 4, the model 6 further comprises narrow recesses 9 on the front surfaces of tooth portions 7 which are also in locations proximate to the gum portion 8.

Figure 5 shows the dental tray 1 formed on one of the tooth portions 7 with the protrusions 2 and 3 in their corresponding recesses 9 and 10.

The process of making the dental tray involves: (1) taking an impression (not shown) of one arch of the patient's teeth 5; (2) making a cast or model 6 of the impression; (3) . * e e forming narrow recesses 9 and 10 on the surfaces of the cast or model 6 which correspond to the front and rear surfaces of the patient's teeth 5; (4) forming a thin sheet of plastics material over the model 6 thereby forming the dental tray 1; and (5) trimming the tray 1 as required to fit onto the patient's teeth.

As shown in Figure 5, the formed tray comprises protrusions 2 and 3 in the front and rear tooth-facing surfaces of the tray corresponding to the recesses 9 and 10. The recesses 9 and 10 can be made, for example, using a knife of the kind known in the dental profession as an Ash No. 5 knife.

An alternative embodiment of the tray 100 is shown in Figures 6 and 7 which comprises a generic design with a substantially U-shaped cross section, and comprising a rigid or flexible protrusions 200 and 300 on the tooth facing surfaces of the tray on, at or adjacent to one or both of the free edges. The protrusion 200 and 300 may be part of the tray or a separate body, for example a rubber seal, secured to the tray.

In use, the whitening gel is placed in the base of the tray 1, 100 and the tray 1, 100 is tiffed over the teeth 5 as shown in Figure 2. The fitting of the tray 1, 100 causes the gel to spread over the tooth 5 while the protrusions 2, 200 and 3, 300 provide barriers or dams that retain the gel thereby preventing leakage. Consequently, the protrusions 2, and 3, 300 delineate areas of the tooth 5 that are exposed to the gel.

The protrusions 2, 200 and 3, 300 can be formed to isolate different areas of the tooth 5 as required. For example, the protrusions 2, 200 and 3, 300 can be formed to prevent areas where the enamel is thin or where the dentine is exposed from being contacted by the whitening gel. Alternatively, it may be desirable to position the protrusions 3, 300 - e.e e e e ee- . e . e e e ë .e e in a location proximate to the top surface of the tooth 5 to limit exposure of the rear tooth surfaces which may not require whitening.

Furthermore, the protrusions 2, 200 and 3, 300 are not limited to the position or orientation shown in this embodiment, for example they may be substantially perpendicular to the gingival margin or any other orientation as required to isolate a desired area of the tooth 5 surface.

A person skilled in the art will appreciate, and it is intended that, whilst the embodiment described herein relates to a dental bleaching tray, other dental procedures may benefit from the invention without departing from the scope of the invention, for example fluoride treatment or the application of other dental medicines.

Although the preferred embodiment comprises a tray and model shaped to correspond to the configuration of a full bottom arch of teeth, the principles of the invention may be applied to a tray and model for a full top arch of teeth, a partial top or bottom arch or any single tooth as required.

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Claims (21)

1. A tray (1,100) for dental use comprising at least one dam (2,200) on the tooth facing surface of the tray (1,100).

2. A tray (1,100) as claimed in Claim 1, shaped to correspond to the configuration of one arch of a patient's teeth (5).

3. A tray (1,100) as claimed in Claim 1 or 2, wherein the at least one dam (2,200) extends along a marginal portion of the tray (1,100).

4. A tray (1,100) as claimed in Claim 1, 2 or 3, wherein the at least one dam (2,200) is positioned on a front tooth-facing surface of at least one tooth (5).

5. A tray (1,100) as claimed in any of Claims 1 to 4, wherein the at least one dam (2,200) is positioned proximate to the area of the tray (1,100) corresponding to the gingival margin.

6. A tray (1,100) as claimed in any preceding Claim, comprising a further dam (3,300) positioned on the rear tooth-facing surface of at least one tooth (5).

7. A tray (1,100) as claimed in Claim 6, wherein the further dam (3,300) on the rear tooth-facing surface is positioned remote from the portion of the tray (1,100) corresponding to the gingival margin.

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8. A tray (1,100) as claimed in any of Claims 1 to 3, wherein the at least one dam (3,300) is positioned on a rear tooth-facing surface of the tray (1,100).

9. A bleaching tray (1,100) comprising at least one dam (2,200) on the tooth facing surface of the tray (1,100).

10. A method for making a tray for dental use comprising: providing a model having a shape corresponding to one or more teeth, said model comprising a recess; and forming the tray on the model such that the tray comprises a dam corresponding to the recess.

11. A method as claimed in Claim 10, comprising an initial step of forming a recess in the model.

12. A method as claimed in Claim 10 or 11, comprising an initial step of forming, in the model, a recess which extends laterally across at least a portion of the model.

13. A method as claimed in Claim 11 or 12, further comprising making the recess with a knife or other sharp instrument.

14. A method as claimed in any one of Claims 10 to 13, further comprising an initial step of making the model.

15. A method of making a model for a tray for dental use comprising: e e..

ae. ..

. providing a model having a shape corresponding to one or more teeth; and forming a recess in the model.

16. A method as claimed in Claim 15, comprising forming a recess which extends laterally across at least a portion of the model.

17. A method as claimed in Claim 15 or 16, comprising forming the recess with a knife or other sharp instrument.

18. A model (6) for use in making a tray (1,100) for dental use, said model (6) having a recess (9,10).

19. A model (6) as claimed in Claim 18, wherein the recess (9,10) extends laterally along at least a portion of the model (6).

20. A model (6) as claimed in Claim 18 or 19, wherein the recess (9,10) extends along a marginal portion of the area of the model (6) corresponding to the patient's tooth (5).

21. A model (6) as claimed in any one of Claims 18, 19 or 20, wherein the model (6) is shaped to correspond to the configuration of one arch of a patient's teeth (5) e - .-e .. .

. . . ..