GB2325857A

GB2325857A - Dental impression apparatus and method of use

Info

Publication number: GB2325857A
Application number: GB9711440A
Authority: GB
Inventors: Jonathan Lindsey Bill
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-06-04
Filing date: 1997-06-04
Publication date: 1998-12-09
Also published as: GB9711440D0

Abstract

Dental impression apparatus (10) is described comprising a substantially U-shaped tray (11) having a front (11a) and back (11b), a base (12) and an upstand (13) around the curve of the U defining an inside. The tray (11) further comprises retaining means (14) towards the back of the base (12) on the inside, and forward of the retaining means (14) an opening (16). The apparatus (10) further comprises a dam member (19) adapted to be received in the receiving means (14).

Description

Title: Dental Impression Apparatus and Method of Taking Dental Impressions The invention relates to apparatus for the taking of dental impressions and to a method of taking such impressions.

The taking of dental impressions is a common procedure performed by dental surgeons. The procedure involves the use of an impression tray which is filled with an impression material and inserted into the patients mouth. The patient bites on the tray thus sinking their teeth and gums into the soft impression material. That position is maintained for a short time while the impression material sets sufficiently to maintain the shape when removed from the mouth, at which point the tray is removed.

However, many patients find the procedure uncomfortable either because the impression material contacts their soft palate invoking a retching reflex, or because excess impression material moves towards the back of their mouth making them feel as though they are choking. These problems can mean that it is difficult for the patient to tolerate the tray in their mouth for long enough to provide a good impression, which may mean that the procedure has to be repeated, or that any appliance manufactured on the impressions is not a good fit.

It is an object of the invention to provide dental impression apparatus which helps to alleviate the above identified problems.

According to a first aspect of the invention there is provided dental impression apparatus comprising a substantially U-shaped tray having a front and back, a base and an upstand around the curve of the U defining an inside, retaining means towards the back of the base on the inside, and forward of the retaining means an opening and further comprising a dam member adapted to be received in the receiving means.

The retaining means preferably extends laterally across the base substantially from side to side. The opening extends also preferably laterally across the base substantially from side to side.

The tray may further comprise a shield on the outside of the base rearwardly of the opening. Preferably the shield extends laterally across the base substantially from side to side. The shield may extend downwardly and forwardly from the base.

The apparatus may further comprise one or more additional receiving means, openings and dam members. It may further comprise one or more additional shields.

The or each dam member may be made from wax.

According to a second aspect of the invention there is provided a method of taking a dental impression comprising the steps of: (a) warming a dam member to soften it; (b) fitting the dam member into receiving means in a tray; (c) inserting the tray into the patients mouth such that the dam member conforms to the patients mouth where it touches; (d) removing the tray from the patients mouth; (e) filling the tray with impression material; (f) reinserting the tray into the patients mouth such that the impression is obtained; (f) removing the tray and impression from the patients mouth.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: FIGURE 1 is a perspective exploded view of dental impression apparatus according to the invention from above; FIGURE 2 is a perspective view of the apparatus of Figure 1 from below, and FIGURE 3 is a section through the apparatus of Figure 1 along the midline front to back.

Dental impression apparatus 10 comprises a generally U-shaped tray 11 having a front ila and back lib. The tray comprises a base 12 with an upstand 13 around the curve of the U, which defines a volume, or inside, for receipt in use of impression material (not shown). The tray 11 further comprises, within the volume defined by the upstand 13, a first receiving means 14 which extends laterally across the base 12 substantially from side to side adjacent the back lib of the tray 11, and a second receiving means 15 which extends across the base 12 substantially from side to side forward of the first receiving means. The tray 11 further comprises first and second openings 16, 17 which extend across the base 12 substantially from side to side just in front of the first and second receiving means respectively. On the outside of the tray 11, below the base 12, a shield 18 is provided to the rear of the opening 16. The shield 18 is extends downwardly and forwardly from the basel2 and extends substantially across the basel2, and at least for the full width of the opening 16.

The apparatus 10 further comprises first and second dam members 19, 20 adapted to be received in the first and second receiving means 14, 15 respectively.

The tray 11 is made of a hard plastics material which can withstand autoclaving, or other sterilisation techniques for safe reuse. Alternatively it may be made of any other material which is appropriate for sterilisation and reuse, or from any other material which is appropriate for single use if disposable after such use. The dam members 19, 20 are made of wax in order that they may be shaped by the dental surgeon during use, as described below, to give optimum effect. The dam members 19,20 may be made of any other appropriate material which can be reshaped. In the alternative dam members may be made of a more rigid material which may not be reshaped but which may be sterilised for reuse, in which case they would preferably be provided in a wide range of sizes and shapes in order that appropriate members were available as required.

The tray 11 has been described with two receiving means 14, 15, with two associated openings 16, 17. However, trays according to the invention may include a single receiving means and opening, or more than two, as desired. In addition, the tray 11 has been described as incorporating a single shield 18 associated with the first opening 16. However, a shield may be provided rearwardly of each opening if preferred.

The method of use of the dental impression apparatus 10 will now be described. The dental surgeon selects a tray 11, and one or more dam members depending on experience of the patients tolerance to the procedure and the extent of the mouth for which an impression is required. The dam member(s) is heated to soften it around it's upper edge and then fitted into the receiving means and the tray 11 is put into the patients mouth. As the patient closes their mouth onto the tray 11 the soft edge of the dam member is reshaped to conform to the patients mouth were it comes into contact with it. The dam member(s) may also be adjusted in size by paring down if necessary, and increased by the addition of wax if required.

Once the dental surgeon is content with the fit of the tray 11 and dam member(s) the tray is filled with impression material and put into the patients mouth. As the patient bites into the impression material any excess which moves backwards comes up against the dam member(s) and cannot go further backwards. It is therefore forced through the adjacent opening and away from the patient's throat. If the opening has an associated shield, once through the opening, the impression material is forced forward in the mouth and thus again away from the patient's throat.

The apparatus and method described above provide the advantage that the impression material is kept away from the patient's throat making the procedure more comfortable, and more likely to be successful. In addition if an impression is only required of the front of the patient's mouth, as may be the case when making crowns or partial dentures for example, then dam members may be used to keep the impression material well away from the rear of the mouth.

The features disclosed in the foregoing description the following claims or the accompanying drawings, expressed in their specific forms or in terms of means for performing the disclosed function, or a method or process for attaining the disclosed result, or a class or group of substances or compositions, as appropriate, may, separately, or in any combination of such features be utilised for realising the invention in diverse forms thereof.

Claims

1. Dental impression apparatus comprising a substantially U-shaped tray having a front and back, a base and an upstand around the curve of the U defining an inside, retaining means towards the back of the base on the inside, and forward of the retaining means an opening and further comprising a dam member adapted to be received in the receiving means.

2. Dental impression apparatus according to claim 1 wherein the retaining means extends laterally across the base substantially from side to side.

3. Dental impression apparatus according to claim 1 or 2 wherein the opening extends laterally across the base substantially from side to side.

4. Dental impression apparatus according to any one of the preceding claims wherein the tray further comprises a shield on the outside of the base rearwardly of the opening.

5. Dental impression apparatus according to claim 4 wherein the shield extends laterally across the base substantially from side to side.

6. Dental impression apparatus according to claim 4 or 5 wherein the shield extends downwardly and forwardly from the base.

7. Dental impression apparatus according to any one of the preceding claims wherein it further comprises one or more additional receiving means, openings and dam members.

8. Dental impression apparatus according to claim 7 as dependant from any one of claims 4 to 6 wherein it further comprises one or more additional shields.

9. Dental impression apparatus according to any one of the preceding claims wherein the or each dam member is made from wax.

10. Dental impression apparatus substantially as hereinbefore described with reference to the accompanying drawings.

11. A method of taking a dental impression comprising the steps of: (a) warming a dam member to soften it; (b) fitting the dam member into receiving means in a tray; (c) inserting the tray into the patients mouth such that the dam member conforms to the patients mouth where it touches; (d) removing the tray from the patients mouth; (e) filling the tray with impression material; (f) reinserting the tray into the patients mouth such that the impression is obtained; (g) removing the tray and impression from the patients mouth.

12. A method a taking a dental impression substantially as hereinbefore described.

13. Any novel feature or novel combination of features as herein defined and/or shown in the accompanying drawings.