US 3654703 A
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 (OCR text may contain errors)
United States Patent McAdoo [451 Apr.1l, 1972  DENTAL IMPRESSION TRAY  Inventor: Harold L. McAdoo, 501-3 Union National Bank Building, Bartlesville, Okla. 74003  Assignee: Charlotte M. McAdoo  Filed: Jan. 27, 1970  Appl. No.: 6,062
 U.S. Cl ..32/l7  Int. Cl ..A6lc 9/00  Field ofSearch ..32/2l, 17
 References Cited UNITED STATES PATENTS 3,460,252 8/1969 Schneider et a1. ..32/l7 3,473,225 10/1969 Deuschle et a1. ..32/l7 Primary Examiner-Robert Peshock Attorney-John H. Widdowson [5 7] 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.
3 Claims, 10 Drawing Figures DENTAL IMPRESSION TRAY I 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 patients 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 patients 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 atthe 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 aw, 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 patients 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 ofthe 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 l8 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 patients 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 patients mouth and gum contour. If trimming the edges of the tray 18 does not serve to fit the particular patients 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 patients 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 patients mouth and throat area.
The mandibular type dental impression tray 20 includes a generally Uishaped 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 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 portion of the normally outward facing sidewall. The outer which it is preferably made and its variability in size and shape sidewall 48 is angled slightly outward and extends substanmakes it desirable to both the patient and to the one using the tially around the outer surface of the base 43 maintaining subdental impression tray in providing reasonable comfort and stantially the same height therearound and sloping to the base higher quality impressions, 43 at the ends 50. The inner or lingual side 52 of the tray 20 As will become apparent from the foregoing description of slopes inward and maintains substantially a uniform height 1 the dental im pression tray structure, relatively inexpensive therearound, sloping to the base 43 at the end portions 50. h p f and emelem meahs have been p l to f" The sidewalls 45 of the tray 20 taper from a thick portion 54 m h makmsof dental lmpressloris- The dental impression near the base 3 to a thin portion 56 at the edge tray is economical to manufacture, simple to use, ad ustable to The tray 20 is preferably constructed of the ethylene, vinyl Pecuharmes and Provldes y hlgh q y acetate copolymer material described above which provides dehtallmpreeslohsg for easy modification. The tray can be modified in size and whhe the mYehhoh e been descflbeq eohluhehoh whh Shape to conform to the individual patients mouth by preferred specific embodiments thereof, it will be understoodv trimming the sidewalls 45 on the upper Surface 56 to the that this description is intended to illustrate and not limit the proper shape to fit the patients gums. Also, the tray 20 can be W of the hvehhohi wheh defined by the followmg modified by cutting the buckle portion 58 of the sidewall 48, 20 ehhms; removing a section if necessary, and rejoining same by staples Iehhm' 60 or the like; and the forward portion 62 of the lingual 1. Dental impression means for holding dental impression sidewall 52 can likewise be modified and rejoined by staples compound uhh] eompne'hg dental formed 60 or the m generally U-shaped trough in a pliable polymeric plastic In the manufacture of the dental impression tray 12 of this h 5 hay trough hav'hg a telatlvely thleh base P invention, it can be originally formed in several sizes and be and sleewahs taperee to a relehvely F Seem eh the easily modified to numerous more sizes and can allow for the Crown P h thereefi f tray hemg eashy em and relomed peculiarities in the mouth of a patient. Also, the tray 12 can be phovlde m fit ohsald tray: and formed preferably of an ethylene, vinyl acetate copolymer Polythene P e metehal Ofa nature to Fe h l' material of sufficient strength to hold the dental impression to numerous hhpressloh compounds 531d compound rigid until set and by its inherent nature adhere to dental P assure Preelse and aeeurate f h that compound 2. A dental impression means as described in claim 1,
in my experimentation with the new dental impression tray a. said tray is formed of a thermosetting vinyl copolymeric of this invention, various materials were tested. It was found plastic material. that various vinyl acetate copolymers can be used. Usable and 3. A dental impression means as described in claim 1, desirable materials are described specifically in the following wherein: table from Modern Plastics Encyclopedia, 1968, which a. said tray is formed of ethylene, vinyl acetate copolymer describes their physical properties: material having said base portion thicker than said ASIM reference EVA EVA EVA EVA Melt Index, g./10 min D1238-65T 3.0 1.4 3.0 3.0 Density. iL/cc Dl505-63T 0.92s 0. 941 0. 050 0. 954 Tensile Strength at break, p.s.l D638-64I l 1, 100 2,000 2 1, 600 l, 700 Yield Strength, psi D635HMT1 2,000 (No Yield Points) Elongation, percent" .1. D638 641 740 780 1 700 770 Torsional Stiffness. psi. 131043-61? 14,000 5,500 2,500 2,000 Flexiiral stinhess, p.s.i 747453 11,000 4,300 1, 700 1,400 Modulus of Elasticity, 1% Secan 2,600 5,200 2, 900 2,300 \icat Softening Point, C D1525-58T 80 60 47 Low Temperature Brittleness F/50, C. D746-64T 76 76 76 76 Durometer Hardness D1706-61 Sh0reA 101700431 95 90 70 79 Shore D D1706-6l 40 37 31 30 l U ing ASTM D412 specimen.
2 Specimen does not break at maximum cross head separation.
The material found highly desirable to use in making the sidewalls and said sidewalls tapering to a smaller crossdental impression tray of this invention is Ethylene, Vinyl section on the edge portion thereof, said sidewalls provid- Acetate Copolymer 0319 or M-3 l9, MARLEX (trademark) ing a good seal with said tray and the mouth of the patient polymer, of Phillips Petroleum Company, Bartlesv lle, and said tray adjustable in size and somewhat in form by Oklahoma. It is a copolymer between ethylene and v nyl means of cutting said sidewalls, removing a section if acetate with the vinyl acetate content of about 12-14 weight necessary, rejoining same with staples, and by means of percent, melt index of 1.5 to L7 grams per 10 minutes, and cuttinga portion from said edge portion of said sidewalls. density Of gins/CC.
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,654,703 Dated April 11,1972
Inventor(s) Harold L. MCAdOO It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column 3, line 2, cancel "Uishaped" and insert U-shaped line 52, cancel "Dl706-6l" line 53, cancel "Dl706-6l". Column 4, line 23, after "a", first occurrence,
insert generally U-shaped trough in a 7 line 24, cancel "generally U-shaped trough in a" Signed and sealed this 12th day of December 1972.
EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents FORM PO-1050 (10-69) USCOMM-DC BO376-P59 fi' U.S. GOVERNMENT PRINTING OFFICE: 1939 0-356-354.