WO2016191826A1

WO2016191826A1 - Dental trays or mouthguards

Info

Publication number: WO2016191826A1
Application number: PCT/AU2016/050451
Authority: WO
Inventors: Geoffrey Macdonald KNIGHT
Original assignee: Nowtray Pty Ltd
Priority date: 2015-06-04
Filing date: 2016-06-03
Publication date: 2016-12-08

Abstract

A ready made dental tray moulded from resilient material, the tray being generally U- shaped and having a curved anterior portion and two relatively straight posteriorly directed arms, said anterior portion and said arms including a base, inner and outer sidewalls which define a curved trough for receipt, in use, of the teeth of a patient and wherein said inner and outer sidewalls include a plurality of resilient fingers a number of which, in use, resiliently engage the cervical margins, teeth and/or gums of a patient to thereby assist in maintaining the tray on the teeth of a patient.

Description

DENTAL TRAYS OR MOUTHGUARDS

BACKGROUND OF THE INVENTION

[0001] This invention relates to dental trays and/or mouthguards.

[0002] More particularly, the invention relates to dental trays which can be used to apply medicinal and cosmetic substances to the teeth and/or gums of a patient. The invention can also be used as a mouthguard.

[0003] In order for dental trays to be effective for medicinal or cosmetic treatment of a patient, the trays need to fit and be retained on the teeth of a patient. In most techniques this requires an initial consultation with a dentist or dental technician in order to make a dental impression of the teeth and gums from which a plaster model is made so that a custom tray or pair of trays can be made that fits the exact shape of the patient's teeth and gums. This process has the disadvantage that it normally requires the patient to make a further appointment with the dentist or dental practitioner in order to fit the tray or pair of trays to the teeth and/or gums of the patient for application of the medicinal or cosmetic substance. The substance is usually in the form of a relatively viscous gel, such as whitening gel, which is introduced into the tray and then applied to the patient's teeth. A good fit is required with the patient's teeth and gums in order for the tray or trays to be retained in position for sufficient time for the gel to be effective. After the tray or trays have been prepared, the patient can be provided with a supply of the medicinal or cosmetic gel for subsequent home treatments which do not require the presence of the dentist or dental technician. This procedure is relatively expensive and time consuming.

[0004] Recently a thin flexible walled disposable tray has been developed which is preloaded with a thick gel to hold the tray over the teeth and fixed gingivae. This tray has the appearance of a thin walled, flexible sport mouth guard and is only held in place by the thick consistency of the gel within the tray. The tray is flimsy and ill fitting predisposing to leakage of material from the tray into the oral cavity of the patient.

[0005] US Publication No. 2007/0254256 Al discloses an oral appliance which includes upper and lower base members which is used as an orthodontic appliance for assisting in correcting misalignment of teeth. The device includes teeth positioning formations which are positioned so as to bias individual teeth into their correct position on the arch of a user. The device is necessarily rigid but does include some parts of softer plastic materials to engage the teeth of the user. Another embodiment is described which is used as a sports guard but it does not have any projections which engage the teeth of a user.

[0006] There is therefore a need for a dental tray which is readily retained on the teeth of a user but does not need to be specially made or adapted for particular users.

[0007] There is also a need for a mouthguard which can be used to protect the teeth of a user when engaged in sporting events or the like. The mouthguard of the invention utilises similar principles of operation, as will be described below.

SUMMARY OF THE INVENTION

[0008] According to a first aspect of the present invention there is provided a ready made dental tray moulded from resilient material, the tray being generally U-shaped and having a curved anterior portion and two relatively straight posteriorly directed arms, said anterior portion and said arms including a base, inner and outer sidewalls which define a curved trough for receipt, in use, of the teeth of a patient and wherein said inner and outer sidewalls include a plurality of resilient fingers a number of which, in use, resiliency engage the cervical margins, teeth and/or gums of a patient to thereby assist in maintaining the tray on the teeth of a patient.

[0009] In the tray of the invention, the fingers are preferably uniformly spaced on the outer sidewalls of the tray so that a number of each of the fingers will engage the front face of the incisor teeth, canine teeth and pre-molar teeth of a user. The tray can be produced as a mass produced item which can be used on the tooth arches of a multiplicity of patients without the need to specially produce a tray for a particular patient.

[0010] The invention also provides a ready made dental tray moulded from resilient material, the tray being generally U-shaped and having a curved anterior portion and two relatively straight posteriorly directed arms, said anterior portion and said arms including a base, inner and outer sidewalls which define a curved trough for receipt, in use, of the teeth of a patient and wherein said inner and outer sidewalls include one or more preformed cut lines which are formed near the ends of said arms to enable ends of the arms to be cut at said preformed cut lines to thereby avoid sharp edges at the cut ends of the arms. [0011] Preferably, said base, inner and outer sidewalls have a generally uniform wall thickness except for lines of weakness which permit resilient flexure of the posteriorly directed arms towards or away from one another while maintaining the inner and outer sidewalls generally perpendicular relative to the base.

[0012] Preferably further, the lines of weakness are located on the base and inner sidewalls and the tray includes preformed cut lines formed on the inner and outer sidewalls and base adjacent to posterior ends of said arms.

[0013] Preferably further, the inner sidewall includes an upper edge which includes a plurality of notches which are respectively adjacent to lines of weakness in the inner sidewall.

[0014] Preferably further, the inner and outer sidewalls include upper edges which include notches respectively adjacent to the preformed cut lines, the notches being curved to provide rounded ends at the posterior ends of the arms when the arms are cut at said preformed cut lines.

[0015] Preferably further, the inner sidewall is lower in height than the outer sidewall relative to the base.

[0016] Preferably further, the inner wall decreases in height relative to the base towards the posterior ends of the arms and the outer sidewall decreases in height relative to the base toward the posterior ends of the arms.

[0017] Preferably further, said fingers are inclined relative to the inner and outer sidewalls such that the free ends of the fingers are directed generally towards the base.

[0018] Preferably further, the fingers are inclined at an angle of about 60° in cross-section through the trough.

[0019] Preferably further, the tray includes a first row of said fingers adjacent to an upper edge of the outer sidewall.

[0020] Preferably further, the tray includes a second row of said fingers beneath said first row of fingers.

[0021] Preferably further, the fingers in the first row are offset relative to fingers in the second row when looking into said trough. [0022] The invention also provides a pair of ready made dental trays comprising upper and lower trays as defined above for engaging upper and lower teeth of a patient respectively.

[0023] Preferably further, the spacing between the arms at their posterior ends is less in the upper tray than the lower tray.

[0024] Preferably further, the lower face of the base of the upper tray lies generally in a first plane except towards the posterior ends of its arms where the lower face of the base lies in a second plane which is inclined upwardly relative to said first plane.

[0025] Preferably further, the upper face of the base of the lower tray lies generally in a third plane except toward the posterior ends of its arms where the upper face of the base lies in a fourth plane which is inclined upwardly relative to said third plane.

[0026] Preferably further, the shapes of the bases of the upper and lower trays are complementary to one another.

[0027] The invention also provides a whitening kit including a package containing:

(i) a pair of ready made dental trays as defined above; and

(ii) a container of whitening material.

[0028] It will be appreciated from the above that the dental tray of the invention can be manufactured in bulk and supplied to a dentist or dental practitioner who can initially apply upper or lower trays to a patient in order to make sure they fit the teeth and/or gums of the patient. This may require bending of the arms and in some cases possible cutting of the ends of the arms in order to adjust their length according to the anatomy of the patient and where the treatment substance is to be applied.

[0029] The dental trays of the invention are able to be ready made in a single size for upper trays and a single size for lower trays and yet still be able to be utilised by the majority of patients. This is because there are only relatively small differences in the size and shape amongst corresponding teeth in the human dentition. Further, there is a universal concavity present between the teeth and fixed gingivae. The provision of multiple soft fingers fitted at a slight angle towards the occlusal surfaces (biting surface) on the internal outer and inner surfaces of the tray of the invention enables engagement with this concavity. This engagement substantially improves the retention of a tray placed over these teeth. [0030] Preferably, fingers are not provided in some areas, namely the lingual (inside) surfaces of the upper and lower incisors and canines and the outer surfaces of the second and third upper molar teeth. The upper and lower human dentition is aligned in an arch form from the third molars on one side to the third molars on the other. Arch forms may vary both in width and the angle of the arch especially in the anterior (front) sections that consist of the canine (eye) and incisor teeth. By reducing the thickness of a tray in the arms as described above allows for expansion and compression. The notches on the lingual (inside) surfaces also assist in preventing the outward or inward buckling of the sidewalls thus enabling variations in arch width and for varying angles of the arch in the anterior segments.

[0031] According to a second aspect of the invention there is provided a mouthguard which is constructed in accordance with the tray described above. It is preferred, however, that the outer sidewall and base are made somewhat thicker so as to provide more energy absorbing capabilities. Further, the fingers which extend inwardly from the outer sidewalls and engage the teeth of the wearer, provide for positive engagement of the mouthguard with the user. The fingers also advantageously function as shock absorbers or energy absorbers for impacts which are applied, in use, to the mouthguard and so assist in protecting the teeth of the wearer.

BRIEF DESCRIPTION OF DRAWINGS

[0032] The invention will now be further described with reference to the accompanying drawings, in which:

Figure 1 is a perspective view from above of a pair of dental trays of the invention;

Figure 2 is a perspective view of a pair of trays from below;

Figure 3 is a side view of a pair of trays;

Figure 4 is a frontal view of a pair of trays;

Figure 5 is a frontal view of the upper tray;

Figure 6 is a side view of the upper tray;

Figure 7 is an underside view of the upper tray;

Figure 8 is an end view of the upper tray;

Figure 9 is a cross-sectional view along the line 9-9;

Figure 10 is a plan view of the upper tray;

Figure 11 is a schematic view of the resilient fingers; Figure 12 is a schematic cross-sectional view along the line 12-12;

Figure 13 is a schematic cross-sectional view along the line 13-13;

Figure 14 is a perspective view from below of the upper tray;

Figure 15 is a frontal view of the lower tray;

Figure 16 is a side view of the lower tray;

Figure 17 is a plan view of the lower tray;

Figure 18 is an underside view of the lower tray;

Figure 19 is an end view of the lower tray;

Figure 20 is a cross-sectional view along the line 20-20;

Figure 21 is a perspective view from above of the top tray;

Figure 22 is a schematic cross-sectional view showing the top tray mounted on a tooth of a patient;

Figure 23A is a front view of an adult size mouthguard of the invention; Figure 24A is a side view of the mouthguard;

Figure 25A is a plan view of the mouthguard;

Figure 26A is an end view of the mouthguard;

Figure 27A is a cross-sectional view along the line 27A-27A;

Figure 28A is an underside view of the mouthguard;

Figure 29A is a perspective view from below a mouthguard;

Figure 30A is a schematic perspective view from above of the mouthguard; Figures 23B to 25B and 27B to 30B correspond to Figures 23A to 25A and 27A to 30A respectively for a child or teenage sized mouthguard;

Figure 31 is a schematic view of a whitening tray of the invention; and Figure 32 is a cross-sectional view along the line 32-32.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0033] Figures 1 to 4 schematically illustrate upper and lower dental trays 2 and 4. The trays 2 and 4 can be integrally moulded by injection moulding from plastics material such as silicone so as to provide resilient flexure but still enable good engagement with the teeth and gums of a patient, as will be described in more detail below.

[0034] Figures 5 to 14 illustrate in more detail the shape of the upper tray 2. It will be seen from Figures 7 and 10 that the upper tray 2 is generally U-shaped when seen in plan view having a central anterior portion 6 and right and left posteriorly extending arms 8 and 10. The upper tray 2 includes outer and inner sidewalls 12 and 14 joined by a base 16. The outer and inner sidewalls 12 and 14 and the base 16 define a trough 18 which is U-shaped as can be best seen from the underside view in Figure 7. The sidewalls 12 and 14 are generally perpendicular to the base 16 as can be seen in Figures 8 and 9.

[0035] The outer sidewall 12 is higher at the anterior portion 6 compared to its height at the posterior ends 20 and 22 of the arms 8 and 10. The upper edge 24 of the sidewall 12 is provided with a rounded notch 26 at the centre of the anterior portion 6 in order to accommodate the superior labial frenulum (not shown) of a patient. The upper edge 24 of the outer sidewall 12 includes notches 28, 30, 32 and 34 located towards the ends of the arms 8 and 10 as best seen in Figures 6 and 7. The inner sidewall 14 has an upper edge 36 which is also provided with a plurality of notches 38, as best seen in Figures 8 and 9. The notches 28, 30, 32 and 34 facilitate adjustment of the length of the arms 8 and 10 as will be described below. As also seen in Figure 9, the upper edge 36 increases in height from the anterior portion 6 towards the centre of the arms 8 and 10 and then decreases in height towards the ends 20 and 22 of the arms. It can also be appreciated from Figures 8 and 9 that overall the height of the inner wall 14 is considerably lower than that of the outer wall 12.

[0036] The base 16 is relatively narrow at the anterior portion 6 and increases in width gradually towards the posterior ends 20 and 22 of the arms, as seen in Figure 7. The variation in width is by about 50% so as to accommodate different dimensions of teeth in relative parts of the patient's oral cavity. The underside surface 40 of the base 18 lies mostly within a plane 42 as shown in Figure 9. The underside surface 44 of the base adjacent to the posterior ends 20 and 22 of the arms lies within a plane 46 which is upwardly inclined relative to the plane 42 by an angle A. Preferably the angle A is in the range from 8° to 15° and more preferably 10° so as to better correspond to the anatomical shape of the upper jaw of a patient. The upwardly inclined plane 46 gives the base a shape which roughly approximates to the Curve of Spee. It would be possible, of course, to mould the tray so that the base does more accurately follow the Curve of Spee.

[0037] The underside surface 40 of the base is provided with lines of weakness 48, as best shown in Figure 10. In the illustrated arrangement, there are six lines of weakness 48 and they generally extend transversely across the base. The lines of weakness 48 are mainly in the anterior portion 6 and adjacent parts of the arms 8 and 10. The lines of weakness are relatively wide, as seen in Figure 10. The lines of weakness 52 join with adjacent lines of weakness 54 which are provided in the inner sidewall 14, in the central anterior portion and adjacent parts of the arms 8 and 10. The lines of weakness 52 and 54 enable flexure of the arms 8 and 10 outwardly and inwardly as indicated by broken lines 56 and 58.

[0038] The provision of the lines of weakness 52 and 54 together with the notches formed in the upper edges of the inner and outer sidewalls 12 and 14 enable flexure of the arms 8 and 10 whilst maintaining the outer and inner sidewalls 12 and 14 substantially perpendicular to the base 16. This is important from a functional point of view because, in use of the tray, medicinal or cosmetic material in the form of a gel can be placed within the trough 18 and will tend to be retained therein, notwithstanding that the spacing between the arms 8 and 10 has been expanded or contracted so as to accommodate the shape of a patient's teeth and gums. Typically, an outward flexure of about 8 to 12mm can be accommodated and an inner contraction of about 8 to 12mm can also be accommodated.

[0039] In the preferred form of the invention, the arms 8 and 10 include preformed cut lines to enable the length of the arms to be adjusted by cutting with scissors or the like without leaving sharp edges. In the illustrated arrangement, the arm 10 includes preformed cut lines 27 and 29 which extend into the outer sidewall 12, base 16 and inner sidewall 14. The cut lines have tapered or rounded sides so that the dentist or dental technician can cut at these cut lines to remove part of the posterior end of the arm 10 in accordance with requirements. The arm 8 has similar preformed cut lines 31 and 33 so that the length of the arm 8 can also be adjusted. As best seen in Figure 6, the cut lines 27 and 29 join with notches 28 and 30. Similarly, cut lines 31 and 33 join with notches 32 and 34. This enables a dentist to selectively adjust the length of the arms 8 and 10 without leaving sharp edges at cut ends which would otherwise be uncomfortable for the patient. More particularly, if a cut is made at the cut lines 29 and 33, rounded upper edges will be provided by the curved shape of the notches 30 and 34 and the notches 38 on the inner sidewall 14. A further shortening can be effected by cutting along the cut lines 27 and 31. This adjustment in the size and shape of the tray enables the tray of the invention to be used with patients having a wide range of variations of sizes and shapes of teeth and gums.

[0040] In accordance with the invention, the inner faces 60 and 62 of the outer and inner arms 12 and 14 are moulded with a plurality of resilient fingers 64. The purpose of the fingers 64 is to resiliency engage the teeth and/or gums of the patient so as to assist in maintaining the tray mounted on the teeth and gums of the patient. As will be described in more detail below, the fingers 64 can also engage the concavity which is normally present between the teeth and the gums to provide a positive engagement.

[0041] In the illustrated arrangement, the fingers 64 are arranged in a number of rows which have been found to provide enhanced gripping ability with the teeth and/or gums of a patient. More particularly, in the illustrated arrangement, there is a first row 66 of the fingers 64 formed on the inner face 60 of the outer sidewall 12 adjacent to the upper edge 24 of the sidewall. As best seen in Figures 8 and 9, the first row 66 is located about 10mm above the base 16. It is preferred that the first row 66 of the fingers varies in height from the front to the back so that the fingers 64 in the row 66 will engage the cervical margins of the teeth, as will be described in more detail later. As the front teeth are generally longer than the rear teeth the first row 66 decreases slightly in height from the anterior portion 6 to the posterior ends 20 and 22. The difference in height, however, is relatively slight, say of the order of about 1mm. As can be seen in Figure 7, the first row 66 extends continuously through the anterior portion 6 and ends about midway along the arms 8 and 10. Thus, the first row 66 does not normally engage the outer surfaces of the second and third upper molar teeth of a patient. The inner face 60 of the outer sidewall 12 includes a second row 68 of fingers located just beneath the first row 66, as best seen in Figures 8 and 9. Again, the row 68 is parallel to the base 16. As best seen in Figures 7 and 12, the fingers in the first and second rows 66 and 68 are offset relative to one another as seen in plan view, i.e. looking into the trough 18. In other words, the fingers in the second row 68 are located between the gaps in the fingers in the first row 66. In the illustrated arrangement there are preferably about 24 uniformly special fingers in the first row. The fingers in the rows 66 and 68 are also inclined downwardly at an angle B as seen in Figure 11. Preferably the angle B is in the range 45 to 70° and most preferably 60°. It will also be seen from Figure 11 that the free ends of the fingers are somewhat tapered so as to give them additional resilience. Further, the fingers in the first row 66 are somewhat longer than the fingers in the second row 68. In one embodiment of the invention, the fingers in the upper row 66 are about 5.8mm in length and have a width of about 2mm and a thickness T of about lmm, as shown in Figure 11. In all of the embodiments herein the resilient fingers 64 in the rows are slightly higher above the floor of the trough of the tray at the anterior part of the tray compared to the posterior part so as to accommodate different lengths of teeth in a typical arch of a user.

[0042] The inner face 62 of the inner sidewall 14 includes third and fourth rows 70 and 72 of fingers which are located adjacent to the upper edge 36 of the inner sidewall 14. The rows 70 and 72 are comparatively short and are only located in the posteriorly extending arms 10 and 12 and do not extend into the anterior portion 6. In the illustrated arrangement the tray includes fifth and sixth rows 74 and 76 of fingers located beneath the rows 70 and 72 respectively. The rows 70, 72, 74 and 76 are generally parallel to the base 16. As seen in Figure 8, the rows 70, 72, 74 and 76 are lower than the first and second rows 66 and 68 because of the differences in height of the inner and outer sidewalls. In the illustrated arrangement, the rows 70 and 72 are about 6 and 4mm above the base 16. The fingers in the rows 70, 72, 74 and 76 engage the inner surfaces of the upper first and second molars, or such molar teeth in that position of the arch of the patient. The fingers in the rows 70, 72, 74 and 76 have similar dimensions and inclinations to the fingers in the rows 66 and 68.

[0043] Figure 22 is a schematic illustration showing the way in which the upper tray 2 engages a molar tooth 80 and gum 84 of a patient. As seen in Figure 22, at the junction between the outer face 82 of the tooth and the gum 84 is a concavity which is known as a cervical margin 86 of the tooth. A similar cervical margin 88 is formed at the inner face of the tooth. It will be appreciated that because there are many of the resilient fingers in the tray, together with their location and orientation, there is a high probability that when the tray is fitted to a patient, a plurality of the fingers will engage the cervical margins of the teeth. This provides a positive purchase for the fingers and substantially assists in retaining the tray in position on the teeth of a user. Some of the fingers may engage the side faces of teeth when fitted rather than the cervical margins, as diagrammatically illustrated by the fingers in the rows 68 and 76 in Figure 22. This engagement will be of some assistance in retaining the tray in position even though the contribution of such fingers would not be as effective as those which actually engage the cervical margins. [0044] It will be appreciated from the foregoing that because there are multiple fingers engaging the cervical margins of teeth of a user, it is not necessary that the position of the fingers is specially made for a particular patient. In other words, off-the-shelf type products can be used with a great number of patients without the need to form specialised trays for each patient. This greatly facilitates manufacturing and enables the device of the invention to be mass produced economically.

[0045] In use, a gel containing medication and/or cosmetic substance can be placed in the trough 18 so that it can treat the teeth and/or gums of the patient. After a treatment, the patient can remove the tray, wash it and retain it for subsequent treatments. The gel preferably has a viscosity of about 80,000-120,000 cP which is somewhat higher than the normal viscosity of toothpaste.

[0046] Figures 15 to 21 illustrate the lower dental tray 4 in more detail. Generally speaking, the lower dental tray 4 has similar features to the upper dental tray 2 and accordingly the same reference numerals have been used to denote corresponding parts but in the case of the lower tray, the reference numerals are followed by the letter 'a'. Because of the aforementioned similarity, only differences between the two trays need to be described. The lower tray 4 may be moulded with a wider spacing between the posterior ends 20a and 22a compared to the ends 20 and 22. Typically the spacing between the outermost parts (i.e. adjacent to the outer sidewall 12 is 63mm in the upper tray 2 whereas in the lower tray, the corresponding spacing is about 35mm. In contrast, the spacing between the parts of the inner sidewall 14 at the ends 20 and 22 in the upper tray is 35mm whereas the corresponding spacing in the lower tray 4 is very slightly smaller, that is to say 0.1mm smaller. In the upper tray 2, the height of the inner sidewall 12 at the section line 9-9 is 6mm whereas the height of the inner sidewall 14a at the same cross-section is about 7mm. The bottom tray 4 need not include a notch 26 for the frenulum because the interior labial frenulum is less prominent than the superior labial frenulum.

[0047] In the upper tray 2, the length of the tray as measured at the section line 9-9 is 52.5mm and this is the same distance in the lower tray 4. The angle of inclination of the plane 46a is the same as that of the plane 46 so that the lower faces of the bases 16 and 16a are complementary as shown in Figure 3. [0048] The configuration of the fingers 64a in the lower jaw is generally similar to that of the fingers 64 in the upper tray but the length may be made somewhat shorter, say by 0.3mm. Further, the first and second rows of fingers 66a and 68a can extend somewhat further towards the posterior ends 20a and 22a, as shown in Figure 18. Similarly, the posterior ends of the rows 70a, 72a, 74a and 76a are also located closer to the ends 20a and 22a compared to the corresponding locations in the upper tray.

[0049] In the upper tray, the rows of fingers tend to remain at the same height above the base 16. In the lower tray, however, the rows 10 tend to be inclined towards the base as they extend in the posterior direction. The heights of the rows in the anterior portion 6a is generally the same as that in the upper tray 2 but the rows gradually incline towards the base 16. In the illustrated arrangement, the posterior ends of the row 66a is about 5mm above the base whereas the row 68a is only about 2mm above the base at the posterior ends of the rows. In the case of the rows 70, 72, 74 and 76 on the inner sidewalls 14, the decrease in height above the base 16 towards the posterior ends of the arms is only very slight.

[0050] It is preferred that the trays 2 and 4 be injection moulded from a medical grade of relatively flexible plastics material such as silicone or polyurethane. One suitable form of material is a translucent silicone having a hardness in the range 60-70 duro. One suitable material is produced by Dow Corning and marketed under the trade name C-6 Series. The wall thicknesses of the sidewalls 12, 12a, 14, 14a and base 16 and 16a can be about 1.5mm and the depths of the lines of weaknesses in the sidewalls and base are of the order of 0.4mm to 0.8mm and preferably about 0.7mm. It is possible to use other flexible materials such as various thermoplastic elastomers and thermoplastic rubbers. Thermo setting elastomers can be used such as liquid silicone rubber and silicone rubber formed by compression moulding as would be understood by persons skilled in the art.

[0051] The dental tray described above could be used as a mouthguard, as would be appreciated by those skilled in the art. It is preferred, however, that where the dental tray is to be used as a mouthguard, the wall thicknesses would be increased in those areas which are more likely to be subject to impact blows in use. Figures 23 A to 30A illustrate a mouthguard 100A constructed in accordance with the invention. The mouthguard embodiment of the invention is very similar to the upper dental tray 2 described above and therefore the same reference numerals have been used to denote parts which are the same as or correspond to those of the upper dental tray 2.

[0052] The basic shape of the mouthguard 100A is essentially the same as the upper dental tray 2 described above except that some of the wall thicknesses and dimensions have been changed to enhance the capabilities of the device as a mouthguard. It is preferred that the mouthguard 100A is injection moulded from relatively flexible plastics material such as polyurethane or silicone. It would be possible to form the mouthguard 100A by co-moulding two components, the outer component being relatively tough and the inner component which includes the resilient teeth being made from more flexible material such as silicone. Such an arrangement would provide for greater protection for the teeth whilst providing comfort for the user because the softer component engages the teeth and gums of the user. In the illustrated arrangement, the mouthguard 100A is injection moulded as a single component from silicone. Again, the silicone material having a hardness in the range 60-70 duro can be used, as described above. In the dental tray 2, the wall thicknesses of the sidewalls 12, 14 and base 16 are about 1.5mm. In the mouthguard 100A, the wall thickness of the sidewall 12 is preferably in the range from 5mm to 2.5mm and most preferably about 4mm. In the upper dental tray 2 the wall thickness of the base 16 is about 1.5mm but in the mouthguard 100A, the thickness is preferably in the range from 4mm to 2.5mm and most preferably 3mm. In the dental tray 2, the maximum height of the upper edge 24 is about 17mm above the level of the underside surface 40 of the base whereas in the mouthguard 100A, the height of the upper edge 24 is about 19mm. In the upper dental tray 2, the length as measured from the anterior to the posterior direction is about 52.5mm whereas in the mouthguard 100A the corresponding distance is 55mm. In the mouthguard 100A, the lines of weakness 52 are wider and are more like shallow grooves. Also, the width between the anterior ends of the arms is greater in the mouthguard 100A compared to the upper tray 2. More particularly, in the upper dental tray 2 the distance between the outer edges of the arms is about 63mm whereas in the mouthguard 100A the distance is 66mm.

[0053] The mouthguard 100A illustrated in Figures 23A to 30A are sized for use with an adult. Figures 23B to 25B and Figures 27B to 30B show corresponding views of a mouthguard 100B which is sized for use by children or teenagers. By making mouthguards 100B in accordance with the invention is thought to be particularly advantageous because under current arrangements, it is necessary for new mouthguards to be purchased as the child or teenager grows. The mouthguard 100B can accommodate changes of the size of the arch as the child or teenager grows. Further, because they are mass produced they can be made relatively inexpensively. The mouthguard 100B is approximately about 10 to 15% smaller in terms of the dimensions of the spacing between the arms 6 and 8 and the length as measured in the anterior posterior direction. The resilient fingers 64 however can be approximately the same size as in the adult mouthguard 100A. Typically in the mouthguard 100B the distance between the outer sidewall 12 in the arms 8 and 10 is about 53mm and the distance between the inner sidewall 14 of the two arms 8 and 10 is about 17mm. The depth of the trough is about 15mm.

[0054] The mouthguards 100A and 100B offer distinct advantages over known mouthguards in that the rows of resilient fingers 64 provide enhanced engagement with the teeth of a user and assist in retaining the mouthguard in position. Second, because of the resilience of the fingers, there is a greater capacity for absorption of energy in potentially damaging blows being applied to the mouthguard in use. The length of the arms 10 and 12 can also be adjusted by cutting at the notches 28 and corresponding preformed cut lines 31.

[0055] Figures 31 and 32 schematically illustrate an upper whitening tray 200 of the invention. The upper whitening tray 200 is similar but somewhat simplified to the shape of the upper dental tray 2 illustrated in Figures 1 to 14. It would normally be used in conjunction with a lower whitening tray (not shown) which would be a simplified version of the lower tray shown in Figures 15 to 21. Because of the similarity of the upper whitening tray 200 to the upper tray 2, only the differences in detail need be described.

[0056] In the tray 200, the right and left posteriorly extending arms 108 and 110 are shorter than in the upper tray 2. This is because for whitening of teeth the front and side teeth are more important than the rear teeth of a user. Because of this, the base 116 is flat and need not include the upwardly inclined underside surface 44 of the tray 2. As in the previous embodiment, the base 116 need not be flat and can be made to follow or approximately follow the Curve of Spee. Also, there are no notches 38 in the upper edge 124. There are also no preformed cut lines 31 and 33 in the outer sidewall 112.

[0057] As can best be seen in Figure 31 , the tray 200 includes an inwardly directed flange 125 at its upper edge. The flange 125 preferably makes an angle C of about 30° relative to the outer sidewall 112, as shown in Figure 31. The flange 125 commences approximately at the level of the fingers 164 in the first row 166 of fingers, as seen in Figure 31. The free ends of the fingers 164 in the second row 168 are at a level somewhat below the level of the flange 125 relative to the base 116. The upper edge of the flange 125 can be tapered so as to facilitate resilient engagement with the gum 84 of a user. The inwardly directed flange 125 facilitates holding the tray in place and retention of whitening compound placed therein.

[0058] The number of fingers 164 in the first and second rows 166 and 168 is about 24 and these are preferably the same size and orientation of those in the previous embodiments. The material of the tray 200 is also preferably the same as that of the other embodiments.

[0059] The inner sidewall 144 again has upper and lower rows 170 and 172 of teeth but in this embodiment there are only two resilient teeth in each of the upper rows 170 and 172 and three teeth in each of the lower rows 174 and 176.

[0060] The lower tray (not shown) is made in a complementary way to that described above. The whitening tray functions in a similar manner to that shown in Figure 22 except that it would not normally engage the back teeth or molars of a patient.

[0061] In the illustrated arrangement, the length of the tray as measured in the anterior/posterior direction is about 36mm and the width at the rear of the tray is about 60mm. Also, the upper rows 170, 172 and lower rows 174 and 176 are located at about 8 and 10mm respectively above the base 116 (i.e. the upper surface of the base within the trough of the tray). In the lower tray (not shown) the rows of resilient teeth can be somewhat lower and about 5 and 7mm respectively above the upper level of the base within the trough.

[0062] The whitening tray 200 can be sold in the form of a whitening kit as a consumer package. The package would preferably contain an upper tray 200 which is marked with the words UPPER or UP so as to indicate to the user the correct tray to be used on the upper arch and a complementary lower tray (not shown) marked with the words LOWER or LO to indicate that it is to be used on the lower tray. The kit could include whitening material (not shown) of suitable viscosity and instructions for user of the kit. The whitening material is preferably in the form of a gel having a viscosity in the range 80,000-120,000 cP which is preferably packaged within a resilient plastic squeeze bottle having a nozzle for ease in applying the gel to the troughs of the trays. The upper and lower whitening trays can be located within a case (not shown). In the preferred kit, the gel would be supplied in a tube having a capacity of about 30ml which would be sufficient for about ten applications. After the treatment has finished, the user can keep the whitening trays in the case and purchase another package of whitening gel for future uses.

[0063] Many modifications will be apparent to those skilled in the art without departing from the spirit and scope of the invention.

[0064] LIST OF PARTS upper dental tray 2

lower dental tray 4

central anterior portion 6, 6a

right posteriorly extending arm 8, 8a

left posteriorly extending arm 10, 10a

outer sidewall 12, 12a

inner sidewall 14, 14a

base 16, 16a

trough 18, 18a

posterior ends 20, 22, 20a, 22a

upper edge 24, 24a

rounded notch 26

preformed cut lines 27, 29, 27a, 29a

notches 28, 30, 32, 34, 28a, 30a, 32a, 34a preformed cut lines 31, 33, 31a, 33a

upper edge 36, 36a

notches 38, 38a

underside surface 40, 40a

plane 42, 42a

underside surface 44, 44a

plane 46, 46a

lines of weakness 48, 48a

lines of weakness 52, 52a

lines of weakness 54, 54a

broken lines 56, 58

inner faces 60, 62, 60a, 62a

resilient fingers 64, 64a

first row 66, 66a

second row 68, 68a third and fourth rows 70, 72, 70a, 72a fifth and sixth rows 74, 76, 74a, 76a molar tooth 80

outer face 82

gum 84

cervical margins 86, 88 mouthguard 100A, 100B upper whitening tray 200

right posteriorly extending arms 108

left posteriorly extending arms 110

outer sidewall 112

base 116

upper edge 124

inward flange 125

inner sidewall 144

fingers 164

first row 166

second row 168

upper rows 170, 172 lower rows 174, 176

Claims

CLAIMS:

1. A ready made dental tray moulded from resilient material, the tray being generally U- shaped and having a curved anterior portion and two relatively straight posteriorly directed arms, said anterior portion and said arms including a base, inner and outer sidewalls which define a curved trough for receipt, in use, of the teeth of a patient and wherein said inner and outer sidewalls include a plurality of resilient fingers a number of which, in use, resiliency engage the cervical margins, teeth and/or gums of a patient to thereby assist in maintaining the tray on the teeth of a patient.

2. A tray as claimed in claim 1 wherein said base, inner and outer sidewalls have a generally uniform wall thickness except for lines of weakness which permit resilient flexure of the posteriorly directed arms towards or away from one another while maintaining the inner and outer sidewalls generally perpendicular relative to the base.

3. A tray as claimed in claim 2 wherein the lines of weakness are located on the base and inner sidewalls.

4. A tray as claimed in claim 3 including preformed cut lines formed on the inner and outer sidewalls and base adjacent to posterior ends of said arms.

5. A tray as claimed in claim 4 wherein the inner sidewall includes an upper edge which includes a plurality of notches which are respectively adjacent to lines of weakness in the inner sidewall.

6. A tray as claimed in any one of claims 1 to 4 wherein the width of each of said resilient fingers is about 2mm when looking into said curved trough.

7. A tray as claimed in any preceding claim wherein the inner sidewall is lower in height than the outer sidewall relative to the base.

8. A tray as claimed in any preceding claim wherein the inner wall decreases in height relative to the base towards the posterior ends of the arms and the outer sidewall decreases in height relative to the base toward the posterior ends of the arms.

9. A tray as claimed in any preceding claim wherein said fingers are inclined relative to the inner and outer sidewalls such that the free ends of the fingers are directed generally towards the base.

10. A tray as claimed in claim 9 wherein the fingers are inclined at an angle of about 60° in cross-section through the trough.

11. A tray as claimed in any preceding claim including upper and lower rows of said fingers located between upper and lower edges of the outer sidewall.

12. A tray as claimed in claim 11 wherein there are about 24 fingers in each of said upper and lower rows.

13. A tray as claimed in claim 12 wherein fingers in the upper row are offset relative to fingers in the lower row when looking into said trough.

14. A tray as claimed in claim 11, 12 or 13 including third and fourth rows of said fingers adjacent to the upper edge of the inner sidewall in respective ones of said posteriorly directed arms.

15. A tray as claimed in any one of claims 1 to 14 wherein said outer sidewalls include upper flanges which are inclined inwardly.

16. A tray as claimed in claim 15 wherein the upper flanges taper in wall thickness in a direction away from said base.

17. A tray as claimed in claim 16 as dependent on claim 11 wherein the upper row of said resilient fingers projects inwardly from the upper flange of the outer sidewall.

18. A pair of ready made dental trays comprising upper and lower trays as claimed in any one of claims 1 to 17 for engaging upper and lower teeth of a patient respectively.

19. A pair of ready made dental trays as claimed in claim 18 wherein the spacing between the arms at their posterior ends is less in the upper tray than the lower tray.

20. A pair of ready made dental trays as claimed in claim 18 or 19 wherein the lower face of the base of the upper tray lies generally in a first plane except towards the posterior ends of its arms where the lower face of the base lies in a second plane which is inclined upwardly relative to said first plane.

21. A pair of ready made dental trays as claimed in claim 20 wherein the upper face of the base of the lower tray lies generally in a third plane except toward the posterior ends of its arms where the upper face of the base lies in a fourth plane which is inclined upwardly relative to said third plane.

22. A pair of ready made dental trays as claimed in claim 18 or 19 wherein the bases of the upper and lower trays are flat and lie in respective planes.

23. A ready made dental tray moulded from resilient material, the tray being generally U- shaped and having a curved anterior portion and two relatively straight posteriorly directed arms, said anterior portion and said arms including a base, inner and outer sidewalls which define a curved trough for receipt, in use, of the teeth of a patient and wherein said inner and outer sidewalls include one or more preformed cut lines which are formed near the ends of said arms to enable ends of the arms to be cut at said preformed cut lines to thereby avoid sharp edges at the cut ends of the arms.

24. A mouthguard comprising a dental tray as claimed in any one of claims 1 to 17.

25. A mouthguard as claimed in claim 24 wherein the wall thickness of the outer sidewalls and base are in the range 5mm to 2.5mm.

26. A mouthguard as claimed in claim 25 wherein the wall thickness of the outer sidewall is 4mm and the wall thickness of the base is 3mm.

27. A mouthguard as claimed in any one of claims 24 to 26 wherein the mouthguard is injection moulded from plastics material having a hardness in the range 60 to 70 duro.

28. A mouthguard as claimed in any one of claims 24 to 27 wherein said plurality of resilient fingers function, in use, as shock absorbers to forces applied to said mouthguard.

29. A whitening kit including a package containing:

(i) a pair of ready made dental trays as claimed in any one of claims 18 to 22; and

(ii) a container of whitening material.

30. A kit as claimed in claim 29 wherein the container is a squeeze bottle or tube and the whitening material is in the form of a gel having a viscosity in the range 80,000-120,000 cP.