US2549636A - Artificial teeth - Google Patents

Description

April 17, 1951 w. D. RABER 2,549,636

ARTIFICIAL TEETH Filed Oct. 4, 1948 //VVE/VTO,8

WALTER D B/ZBEE.

BYM

PATENT GENT Patented Apr. 17, 951

7 ARTlFICIAL TEETH Walter Haber, Chicago, 111.

Application October 4, 1948, Serial No. 52,661

4 Claims.

The present invention pertains to the posterior or masticating teeth of artificial dentures including the upper and lowerbicuspids or premolars as well as the first and second molars and does not extend to the anterior teeth including the incisors and canine teeth.

' As is well known, users of artificial dentures are handicapped inevitably by having available masticating pressures that are only a small percentage of the corresponding pressures that can readily be developed with natural teeth; for example, with artificial dentures, the pressures usually available do not exceed from ten to forty pounds, whereas with natural teeth, pressures up to two hundred pounds and even more, may readily be developed. Obviously, occlusal, surfaces well adapted to the requirements of effective and efiicient mastication with such high pressures, as in natural teeth, cannot be relied upon and cannot produce satisfactory and eilicient results at the lower pressures referred to, where the teeth of artificial dentures are given theform of occlusal surfaces found in natural teeth. Many attempts have been made to compensate for the great diiference in pressures referred to, by making artificial teeth with occlusal surfaces that will more efficiently effect mastication at low pressures, but such attempts have been open to more or less objection, either because of complication and expense in manufacture, or ineiiiciency in use, or both. 1

It is the object of the invention-to overcome the difiiculty referred to by providing the occlusal surfaces of the posterior artificial. teeth with masticating areas much less than found'in corresponding natural teeth,.so thatthe small pressures available will cause effective penetration of said smaller areas into the food being masticated, and at the same time so firmly hold the food between the upper and lower teeth, that the mandibular action accompanying mastication; willcut, tear and shred the food, and so accomplish its maceration. To effect this result in accordancewith the invention, the occlusal surfaces of the teeth of one denture, for example, the upper denture, are each provided with spaced transverse ,ribs having cutting edges and separated'by depressions'or valleys for the reception of food pressed into them, which ribs and valleys are preferably straight and parallel to facilitate manufacture. The occlusal surfaces of the teeth of the other denture, for example, the lower denture, are each provided with a longitudinal rib spaced from the buccal surface of the tooth, and

same cuspal form as found in natural teeth.

having a longitudinal depression or valley extending medially across the occlusal surface and defining said rib or cutting edge. This depression or valley is of progressively decreasing depth from said rib towards the lingual surface of the tooth and merges with the occlusal surface thereof be- 1 fore reaching said lingual surface. Said rib'and valley are preferably straight and parallel to facilitate manufacture.

With the construction described, the buccal surfaces of the artificial teeth have substantially the sameappearance as natural teeth, and there is no increased danger of cheek bite, because the marginal portions of the occlusal surfaces of the teeth adjacent their buccal surfaces, have the Again, the lingual surfaces of the teeth of the invention, and the adjacent marginal portions of the occlusal surfacesthereof, have the same appearance and form as natural teeth, protecting the tongue from increased danger of biting, and not interfering in any way with the functioning ofthe tongue during mastication, in shifting the food from place to place between the teeth.

With the dentures of the invention coactingin use, the preferably straight ribs and valleys of the teeth of one denture cross the preferably straight ribs and valleys of the teeth of the other denture at substantially right angles, the crossed ribs of any two coacting teeth are pressed even with small pressure through the food and nearly or quite into engagement with each other over small areas, adjacent parts of the food are firmly pressed into and'held in the crossed valleys, and

the mandibular action of the teetheffectively cuts, shreds and tears the: food to efficiently masticate it. I ,Where the teeth of the invention are made of hardand wear-resistant material such as p01.-

celain, extremely hard plastic and the like, rein forcing means forfthe ribs may not be required; I it has heretofore been proposed however, to'make scribed ribs and cutting edges of the teeth, which, insertsare preferably incorporated in the teeth during their manufacture.

Any known techniques and materials may be used in making the teeth of the invention, and

in mounting them on suitable bases to form the dentures of the invention.

The invention includes teeth constructed as described and also dentures incorporating said teeth in their structures, and it is the object of the invention to produce artificial teeth and dentures having the structure, mode of operation and results described.

The invention will be best understood by reference to the accompanying drawings illustrating preferred embodiments thereof, in which Fig. 1 is an occlusal plan view of an upper denture in accordance with the invention,

Fig. 2 is an occlusal plan view of a lower den ture in accordance with the invention, adapted to cooperate with the denture shown in Fig. 1,

Fig. 3 is a vertical sectional view to an enlarged scale, through the first molar shown to the right in Fig. 1, this view being taken along the line 3-3 in Fig. 1,

Figs. 4, 5 and 6 are vertical, sectional views of the structure shown in Fig. 3, taken respectively along the lines 44, 5-5 and 6-5 in Fig. 3.

. Fig. 7 is an occlusal view of the molar shown in Fig. 3.

Fig. 8 is a vertical, sectional view to an enlarged scale, through the first molar shown to the right in Fig. 2, this view being taken along the line 8-8 in Fig. 2,

Figs. 9, 10 and 11 are vertical, sectional views of the structure shown in Fig. 8, taken respectively along the lines 93, ill-i9 and H--ll in Fig. 8, V I

Fig. 12 is a top plan view of the molarshown in Fig. 8, g 7

Figs. 13, '14 and 15 show in views respectively like Figs. 3, 4 and 7, a modified construction of upper first molar having metal inserts, and

Figs. 16 and 1'7 show in views respectively like Figs. 8 and 12, a modified construction of lower first molar having metal inserts for coaction with the first molar shown in Figs. 13, 14 and 15.

Similar numerals refer to similar parts throughout the several views.

In several of Figs. 3 to 17 inclusive, the letters L and B are employed to respectively indicate the lingual and buccal sides of the teeth illustrated. The upper denture illustrated in Fig. 1, includes a base I mounting anterior teeth including incisors 2 and canines 3, and also posterior teeth including right and left bicuspids 5a, first molars 5 and second molars 5.

The lower denture illustrated in Fig. 2, includes a base la mounting anterior teeth including incisors 2a and canines 3a, and also posterior teeth including right and left biscuspids 4a, first molars 5a and second molars 6a.

Only the .posterior teeth referred to and variants thereof, and their coaction are involved in the present invention.

As shown in Fig. 1, the first molar 5 at the right, has its occlusal surface transversely crossed by continuous straight parallel and spaced ribs '1 having a depression or valley 8 between them, similar depressions 9 being longitudinally formed in the occlusal surface of the tooth outside of Said ribs I. The occlusal surfaces of the ribs 7 are, preferably in the same plane connecting the apices of the cusps of the molar 5. lhe formation of the ribs 1 and depressions 8 and 9 is better shown in Figs. 3, 4 and '7. It will be noted that the lower edges of the ribs 7 are relatively sharp and form cutting edges for food pressed upwardly against the ribs, and that the depressions 3 and 9 form hollows or cavities for receiving without 4 undue pressure, parts of food pressed upwardly above said cutting edges (see Fig. 4).

As shown in Fig. 2, the first molar 511 at the right, has its occlusal surface longitudinally crossed by a rib la joining the apices of the cusps of the molar 5a. 0n the buccal side of the tooth, the medial portion of the occlusal surface of the molar having a longitudinal depression 8a therein extending entirely across the tooth adjacent to and parallel with the rib la and of a form making the adjacent surface of said rib substantially perpendicular to the occlusal surface of the tooth, and defining with the occlusal surface of said rib, a relatively sharp cutting edge extending longitudinally entirely across the tooth. The formation of the rib la and depression 8a and their relation to each other are more clearly shown in Figs. 8, 9 and 12.

It will be noted that the buccal margin of the occlusal surface of the rib la shown in Figs. 8 and 12, has substantial width which is unbroken longitudinally of said surface although said margin has small area. When, in the mastication of food, said marginal area coacts with the corresponding bucco-marginal area ofv the molar 5 shown in Figs. 3 and 7, which is also unbroken longitudinally, the small area'of the rib 7a with but small applied pressure, effectively penetrates a small part of the food until said rib is nearly or quite in engagement with the corresponding bucco-marginal portion of the occlusal surface of the molar 5; at the same time, the lingomarginal areas of the occlusal surfaces of the molars. 5a and 5 similarly coact on another small part of the food between said molars; by the action described, the food between said molars is firmly held against lateral displacement, and parts of said food are pressed into the depressions 8, 3 and 8a with a substantial amount of cutting thereof by the edges of the ribs 1' and 1a, which edges are thus brought nearly or quite into engagement with each other; with the food so held between the molars 5a and 5, mandibular movement of the teeth effectively cuts, shreds and tears said food by the action of said ribs, to efficiently masticate the food.

The walls and bottoms of the depressions 8, 9 and 8a are preferably inclined and rounded to avoid pockets in which the food might be tightly packed and held, to the end that during mastication the tongue may quite as effectively operate to re-distribute and move the food, as with natural teeth.

As shown in Figs. 5 and 6, the buccal and lingual aspects of the molar 5 are respectively the same as with natural teeth, and the same is true for the molar 5a as Shown in Figs. 10 and 11. This insures that the danger of check bite and tongue bite shall be no greater than with natural teeth.

Each of the other upper posterior teeth shown in Fig. 1 is constructed in the same manner as the molar 5 described in connection with Figs. 3 to 7 inclusive, and each of the other lower posterior teeth shown in Fig.2 is constructed in the same manner as the molar 5a described in connection with Figs. 8 to 12 inclusive; and the operation of each coacting pair of upper and lower posterior teeth is substantially the same as above described for the right molar 5 of Fig. 1 and the right molar 5a of Fig. 2, to produce substantially the same results.

Figs. 13, 14 and 15 illustrate the construction of a first upper molar 5b of softer material than porcelain, for example, plastic material, correwith Figs. 3 to 'I inclusive, and where it is desirable to reinforce the ribs of the molar; and

Figs. 16 and 1'7 illustrate the construction of a first lower molar 5c of material similar to the molar 517, corresponding to the molar Ed described in connection with Figs. 8-12 inclusive, and where it is desirable to reinforce the rib of the molar.

The upper molar 5b illustrated in Figs. 13, 14 and is of the same form and construction as the molar 5 shown in Figs. 3 to 7 inclusive, excepting that it may be made of material softer or Weaker than porcelain, or both, for example, plastic material, and that its ribs l0 include thin sheet metal inserts made preferably of any metal or metallic alloy that is wear resistant and free from corrosion by the secretions of the mouth, for example, old alloy, which inserts are embedded in the material of the molar 5b preferably duringv its manufacture, perpendicularly to the occlusal surface of the molar andwith their lower edges in said occlusal surface to form the cutting edges of said ribs. In all other respects the molar 5b is of the same construction and operates in the same manner as the molar 5 shown in Figs. 3 to '7 inclusive.

The lower molar 50 illustrated in Figs. 16 and 1'7 is of the same form and construction as the molar 50. shown in Figs. 8 to 12 inclusive, excepting that it may be made of material as described for the molar 5b, and that its rib is defined as to its cutting edge by a thin sheet metal insert ll of material like the inserts of the ribs l0, embedded in the material of the molar 5c preferably during its manufacture, perpendicularly to th occlusal surface of the molar and with its upper edge in said occlusal surface to form the cutting edge of the rib and to also form a side wall of the longitudinaldepression l2 adjacent said rib. In all other respects the molar 5c is of the same construction and operates in the same manner as the molar 5a shown in Figs. 8

to 12 inclusive, and the coaction of the molars 5b and 5c is the same as above described for the molars 5 and 5a shown in Figs. 3 to 12 inclusive.

Where rib reinforcements as shown in Figs. 13 to 1'7 inclusive, are desirable for all of the poste- 6 teeth of the invention are above described as being in a, horizontal plan or planes, it is to be understood that to meet'the requirements of different techniques and theories of mandibular movement, they may when desired be inclined to the horizontal or be located in curved surfaces according to the preference of the artificer, without departing from the invention.

the rib and depression structures shown in Figs.

' 3 to 7 inclusive, l3, l4 and I5 may be carried by rior teeth, each of the upper posterior teeth is constructed as described for the molar 5b, and each of the lower posterior teeth is constructed as described for the molar 5c, and each pair of coacting upper and lower posterior teeth, operates during mastication in the manner above described for a pair of coacting upper and lower molars 5 and 5a constructed as described in connection with Figs. 3 to 12 inclusive.

the lower posterior teeth, and the rib and depression structures shown in Figs. 8 to 12 inclusive, 16 and 17, may be carried by the upper posterior teeth, without departing from the invention, since the advantageous results of either relation are substantially the same as longas the tooth structure and coaction are substantially as shown and described.

While I have shown my invention in the particular embodiments above described, I do not limit myself thereto asI may employ equivalentsthereof without departing from the scope of the appended claims.

Having thus described my invention, what I claim is; v 1

1. In combination, upper and lower artificial dentures having pairs of posterior teeth the occlusal surfaces of which are formed in a manner to provide for small contact areas between pairs of coacting teeth to obtain strong cutting forces and large sluice-way areas, each of said teeth having buccal and lingual cusps disposed with their apexes-substantially in a plane, one of each pair of said teethjhaving two continuous straight parallel and spaced ribs extending tranversely of its occlusal surface intermediate the buccal and lingual cusps and terminating in cutting edges slightly above the position of natural cusp anatomy and a depression between and parallel to said ribs, the other of each pair of said teeth having a single, substantially straight rib extending longitudinally I of its occlusal surface and adjacent its buccal surface and crossing the direction of said transverse ribs and terminating in a cutting edge Thus the invention provides forms of posterior tooth structures which can readily be manufactured by known techniques, and it further procoactingupper and lower posterior teeth, that secure during mastication, effective penetration, cutting, shredding and tearing of the'food with applied pressures readily procurable with artirior teeth, without departing from the invention.

7 Whereas the occlusal surfaces of the posterior 60. vides forms of occlusal surfaces for any pair of slightly above the position of natural cusp anatomy, and a longitudinal depression adjacent said longitudinal rib and parallel therewith extending laterally across the medial portion of the occlusal surface, thereby providing contact between teeth of coacting dentures at points slightly beyond normal cusp contact.

2. In combination, upper and lower artificial dentures having pairs of posterior teeth the occlusal surfaces of which are formed in a manner to provide for small contact areas between pairs of coacting teeth to obtain strong cutting forces and large sluice-way areas, each of said teeth having buccal and lingual cusps disposed with their apexes substantially in a plane, one of each pair of said teeth having two continuous straight parallel and spaced ribs extending transversely of its occlusal surface intermediate the buccal and lingual cusps and terminating in cutting edges slightly above the position of natural cusp anatomy and a depression between and parallel to said ribs, the other of each pair of said teeth having a single, substantially straight rib extending longitudinally 7 of its nee-meal urface an adjacent its ursa-1 surface and cr sing he direction of said transverse ribs and terminating in a cutt g e sli htly above the nositionaof natural cus anatomy, and a ilon itudinal depr s ion adjacent said longitudinal rib and parallel therewith .extending laterally across the medial portion of the occlusal surface, thereby providing contact between teeth of coasting dentures at points slightly beyondnormagl cusp contact, said longitudinal depression being of progressively decreasing depth towards and terminating adjacent the lin ual surface of said other tooth, thereby providing ;for free movement of food transversely as well as longitudinally of said posterior teeth.

.13. combination, upper and lower artificial dentures having :pairs of posterior teeth the occlusal surfaces of which are :fQrmed in a manner :to provide :for small contact areas between pairs of coacting teeth to obtain strong putting ffDlCfiS and large sluiceway areas, each {of said teeth having :buccal and lingual cusps dis osed with their apexes substantially in a plane, one of each pair :of said teeth having {two Continnous straight parallel and spaced ribs extending transversely of :its occlusal surface intermediate (the :bnccal and lingual cusps and ter minating in cutting edges slightly above the position of natural cusp anatomy and a depression between and parallel to said ribs, the other of each pair of said teeth having a single, substantially straight rib extending longitudinally of its occlusal surface and adjacent its buccal surface and crossing the direction of said trans verse ribs and terminating "in a cutting edge slightly above the position of natural cusp anatonly, and a longitudinal depression adjacent said longitudinal rib and parallel therewith es;- tending laterally across the medial portion of the occlusal surface, thereby providing contact between teeth of coacting dentures at points slightly beyond normal cusp contact, said ribs forming said cutting edgescomprising metallic inserts merging at their ends into said cusps.

4 In combination, upper and lower artificial dentures having pairs of posterior teeth the oc- 16111531 surfaces of which are :formed :in :a man:-

ner -to provide for small contact :areas between pairs of coacting teeth to ,obtainpstrong cutting forces and large sluice-way areas, each of said teeth having buccal and lingual cusps disposed with their ,apexes substantially in a plane, one of each pair of said teeth having two continuous straight parallel and spaced ribs extending transversely of its occlusal surface intermediate the ;buccal and lingual cusps and iterminating in cutting edges slightly above the position of natural cusp anatomy and a depression between and parallel to said ribs, the other of each pair of said teeth having a single, substantially straight rib extending longitudinally of its occlusal surface and adjacent its buccal surface and crossing the direction 01 said transverse ribs and terminating in a cutting edge slightly above the position of natural cusp .anatmm, and a longitudinal depression adjacent said longitudinal rib and parallel therewith extending laterally across the medial portion of the occlusal surface, thereby providing contact between teeth of coacting dentures at points slightly beyond normal cusp contact, said longitudinal depression being of progressively decreasing depth towards and terminating adjacent the lingual surface of said other tooth, thereby providing for free movement of food transversely as well as longitudinally of said posterior teeth, said ribs forming said cutting edges comprising metallic inserts merging at their ends into :said cusps.

' WALTER D. *RA'BER.

(REFERENCE-S CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,095,432 Brenner Got. 12, 1937 2,141,487 Pleasure Dec. 27, 1938 2,295,864 Prange Sept. 15, 1942 2,375,509 Wiechert- May 8, 1945 2397,4107 Butler Mar. 26, 1946

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