Dental Impression Tray

Abstract

This invention is a dental impression device for holding dental impression compound. It is a dental tray. More particularly, this invention is a dental impression tray formed of a pliable polymeric plastic material, with a relatively thick base portion and thinly tapering sidewalls; the tray being easily modified by cutting and rejoining to provide a proper fit.

Description

Numerous types of dental impression trays are known to the prior art operable to form impressions used in dental prosthetic work using a dental impression compound. However, these prior art devices must be kept in a large number of varied sizes to fit the gums of the patient because these are only slightly adjustable to the gum contour of the patient's mouth by trimming a portion of the walls thereof. Generally, the prior art devices are formed of a substantially inflexible material and feel uncomfortable to the patient's mouth. Additionally, the material which prior art devices are usually constructed does not readily adhere to the impression compound normally used, thus they must be perforated to allow the compound to be held in the tray by partially passing through it.

In one preferred specific embodiment of the improved dental impression tray of this invention, for taking impressions of the upper jaw, a maxillary type is provided which includes a base portion of generally a U-shaped planform having sidewalls extending normally upward from its outer surface, a vault shaped palatal wall joining the inner surface, dam post walls across the normally rear portion of the tray, and a handle extending from the labial portion of the tray. The sidewalls taper from a relatively thick cross-section near the base portion to a relatively thin cross-section at the edge portion. The tray is preferably constructed of a pliable polymeric plastic material, which is relatively soft, flexible, adheres to the dental impression compound, and is easily trimmed, cut and rejoined providing adjustment of the tray to conform to the mouth of the patient.

In another preferred specific embodiment of the improved dental impression tray of this invention, for taking impressions of the lower jaw, a mandibular type is provided including a base portion of generally a U-shaped planform with sidewalls depending normally and generally downward from the inner and outer edge surfaces of the tray, and a handle issuing from the central labial portion of the base portion. Sidewalls of the outer surface preferably flare outward slightly and the inner sidewalls preferably slope inward, both sidewalls desirably are nearly perpendicular to the base portion of the tray. Also, the sidewalls taper from a relatively thick section near the base portion to a thinner section near the edge portion. The tray is preferably formed of the above described plastic material and its size easily modified as in the aforedescribed embodiment to conform to the mouth of the patient.

One object of this invention is to provide a dental impression tray structure overcoming the aforementioned disadvantages of the prior art devices.

Still, one other object of this invention is to provide a dental impression tray structure which is easily adjustable in curvature and separation to make the tray conform to the patient's mouth thereby providing a better fit to the patient.

Another object of this invention is to provide a dental impression tray structure which is adjustable and can be adapted to several sizes and shapes thus reducing the number of dental impression trays a person doing dental prosthetic work would necessarily maintain at his disposal.

Still, another object of this invention is to provide a dental impression tray structure which is as comfortable as possible for a patient on whom it is being used by being soft and having a form to prevent the dental impression compound from sliding back in the throat of the patient.

Yet another object of this invention is to provide a dental impression tray structure made of thermosetting vinyl copolymer material which is relatively soft and flexible and will adhere to the impression compound thus removing the heretofore necessity of having the dental impression tray perforated.

Various other objects, advantages, and features of the invention will become apparent to those skilled in the art from the following discussion, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a fragment of a human head, the lower jaw shown dotted, in combination with a partial section of the mouth thereof with an upper or maxillary type dental tray therein in place and filled with impression compound:

FIG. 2 is a plan view of the normally upwardly facing portion of an upper or maxillary type dental tray of the invention;

FIG. 3 is a plan view of the normally upwardly facing portion of an upper or maxillary type dental tray of this invention having the labial portion cut and rejoined and the vault portion cut and rejoined;

FIG. 4 is a cross sectional view taken on line 4--4 of FIG. 3;

FIG. 5 is a cross sectional view taken on line 5--5 of FIG. 3;

FIG. 6 is a plan view of the normally downward facing portion of a lower or mandibular type dental tray of this invention;

FIG. 7 is a plan view of the normally downward facing portion of a lower or mandibular type dental tray of this invention having the buckle portion of the outer wall cut and rejoined and having a portion of the lingual sidewall cut and rejoined;

FIG. 8 is a cross sectional view taken on line 8--8 of FIG. 7;

FIG. 9 is a cross sectional view taken on line 9--9 of FIG. 7; and

FIG. 10 is a cross sectional view taken on line 10--10 of FIG. 7.

The following is a discussion and description of preferred specific embodiments of the new dental impression tray of this invention, such being made with reference to the drawings whereupon the same reference numerals are used to indicate the same or similar part and/or structure. It is to be understood that such discussion and description is not to unduly limit the scope of the invention.

Referring to the drawings in detail and in particular to FIG. 1, a human head, generally indicated at 10, is shown having a dental impression tray of this invention 12 in the mouth 14 as typically done in forming dental impressions. The dental impression tray is held in the mouth 14 around the teeth and gums and is filled with dental impression compound 16. The dental impression tray of this invention 12 includes a maxillary type tray 18 for taking impressions of the upper portion of the mouth 14, and a mandibular type tray 20 for taking impressions of the lower portion of the mouth 14. The trays 18 and 20 are preferably made of a pliable polymeric plastic material, and thermosetting vinyl polymeric plastic materials have been found particularly advantageous, ethylene, vinyl acetate copolymers working very well.

The maxillary type dental impression tray 18 includes a U-shaped base portion 22 integral with sidewall 24 around the outer surface, a vault portion 26 integral with the inner surface and a handle 28 integral with the base portion 22. It is seen the sidewall 24 curves upward from the base 22 and is angled slightly rearward in the front 30 or labial portion, and flares outward at the rear portion 32 of the base 22 on both sides thereof. The vault portion 26 curves upward from the inner surface of the base 22 in an arch like shape. Across the rear portion of the tray 18, a dam 34 is formed by the upper edge of the sidewall 24 and the vault 26; this retains the dental impression compound 16 within the tray 18 and prevents same from sliding out and down the patient's throat. The sidewalls 24 taper from a relatively thick root section 36 on the lower portion, near the base 22, to a thinner edge section 38 on the edge portion.

The tray 18 is preferably constructed of an ethylene, vinyl acetate copolymer material which is generally soft and flexible yet durable and retains its shape under pressure. Sidewalls 24, and dam 34 of the tray 18 are easily trimmed with a knife or like instrument to shape the tray 18 to the individual patient's mouth and gum contour. If trimming the edges of the tray 18 does not serve to fit the particular patient's mouth, the labial portion 30 of the tray can be cut; if necessary a section removed, and that portion rejoined by staples 40, the section generally indicated at 42. Also, the vault portion 26 can similarly be modified and rejoined as generally indicated at 44. The modification of the tray 18 is preferably done to fit it to the particular patient's mouth as best as possible, thus making the patient as comfortable as possible, and to provide for taking a clear impression and preventing the excess quantity of dental impression compound to flow about the patient's mouth and throat area.

The mandibular type dental impression tray 20 includes a generally U-shaped base portion integrally formed with a sidewall 45 on the edge surfaces of the base 43 and a handle 46 integrally attached and extending from the central exterior portion of the normally outward facing sidewall. The outer sidewall 48 is angled slightly outward and extends substantially around the outer surface of the base 43 maintaining substantially the same height therearound and sloping to the base 43 at the ends 50. The inner or lingual side 52 of the tray 20 slopes inward and maintains substantially a uniform height therearound, sloping to the base 43 at the end portions 50. The sidewalls 45 of the tray 20 taper from a thick portion 54 near the base 43 to a thin portion 56 at the edge.

The tray 20 is preferably constructed of the ethylene, vinyl acetate copolymer material described above which provides for easy modification. The tray 20 can be modified in size and shape to conform to the individual patient's mouth by trimming the sidewalls 45 on the upper surface 56 to the proper shape to fit the patient's gums. Also, the tray 20 can be modified by cutting the buckle portion 58 of the sidewall 48, removing a section if necessary, and rejoining same by staples 60 or the like; and the forward portion 62 of the lingual sidewall 52 can likewise be modified and rejoined by staples 60 or the like.

In the manufacture of the dental impression tray 12 of this invention, it can be originally formed in several sizes and be easily modified to numerous more sizes and can allow for the peculiarities in the mouth of a patient. Also, the tray 12 can be formed preferably of an ethylene, vinyl acetate copolymer material of sufficient strength to hold the dental impression compound rigid until set and by its inherent nature adhere to that compound.

In my experimentation with the new dental impression tray of this invention, various materials were tested. It was found that various vinyl acetate copolymers can be used. Usable and desirable materials are described specifically in the following table from Modern Plastics Encyclopedia, 1968, which describes their physical properties: ##SPC1##

The material found highly desirable to use in making the dental impression tray of this invention is Ethylene, Vinyl Acetate Copolymer 0319 or M-319, MARLEX (trademark) polymer, of Phillips Petroleum Company, Bartlesville, Oklahoma. It is a copolymer between ethylene and vinyl acetate with the vinyl acetate content of about 12-14 weight percent, melt index of 1.5 to 1.7 grams per 10 minutes, and density of 0.938 gms./cc.

In the use of the dental impression tray of this invention, it is seen that same provides a versatile structure for taking dental impressions of the type used in dental prosthetic work. The dental impression tray by virtue of the type of material from which it is preferably made and its variability in size and shape makes it desirable to both the patient and to the one using the dental impression tray in providing reasonable comfort and higher quality impressions.

As will become apparent from the foregoing description of the dental impression tray structure, relatively inexpensive, uncomplicated and efficient means have been provided to aid in the making of dental impressions. The dental impression tray is economical to manufacture, simple to use, adjustable to many sizes and peculiarities and provides very high quality dental impressions.

While the invention has been described in conjunction with preferred specific embodiments thereof, it will be understood that this description is intended to illustrate and not limit the scope of the invention, which is defined by the following claims.

Claims

I claim:

1. Dental impression means for holding dental impression compound until set, comprising a dental tray formed of a generally U-shaped trough in a pliable polymeric plastic material, said tray trough having a relatively thick base portion and sidewalls tapered to a relatively thin section on the crown portion thereof, said tray being easily cut and rejoined to provide in situ fit of said tray, and

said polymeric plastic material of a nature to readily adhere to numerous impression compounds utilized in said dental tray to assure precise and accurate impressions.

2. A dental impression means as described in claim 1, wherein:

a. said tray is formed of a thermosetting vinyl copolymeric plastic material.

3. A dental impression means as described in claim 1, wherein:

a. said tray is formed of ethylene, vinyl acetate copolymer material having said base portion thicker than said sidewalls and said sidewalls tapering to a smaller cross-section on the edge portion thereof, said sidewalls providing a good seal with said tray and the mouth of the patient and said tray adjustable in size and somewhat in form by means of cutting said sidewalls, removing a section if necessary, rejoining same with staples, and by means of cutting a portion from said edge portion of said sidewalls.