US3228106A - Partial denture constructions - Google Patents

Description

Jan. 11, 1966 A. RITTER 3,

PARTIAL DENTURE CONSTRUGTIONS Filed May 13, 1963 INVENTOR.

ARTHUR R ITTER ATTORNEYS United States Patent Office 3,22%,lh Patented Jan. 11, 1966 3,228,106 PARTIAL DENTURE CONSTRUCTIONS Arthur Ritter, 2039 Rittenhouse Square, Philadelphia 3, Pa. Filed May 13, 1963, Ser. No. 279,738 14 Claims. (Cl. 325) This invention relates to removable partial denture constructions. More particularly it relates to dentures wherein resilient axial retainers are used to keep the denture in place and co-act with both novel guidance means and means for positioning the denture with respect to the gingiva. It also relates to crowned abutments particularly suited for use in connection with the constructions of the invention.

An object of this invention is to provide simple and effective denture supporting means which are adapted to hold a denture firmly in place, despite wear, and to permit its ready and accurate alignment.

It is also an object of the invention to provide dentures constructed in a manner which permits easy removal for oral hygiene.

It is a further object of the invention to provide dentures wherein adjustment to compensate for wear is simplified and the useful life of the denture thus extended.

Still another object of the invention is to provide a denture construction, the alignment of which is not effected by direct wear, indirect wear or at resorption.

A general object of the invention is to simplify and improve the construction of means for holding removable dentures in place.

A further object of the invention is to provide a dental construction in which a minimum amount of wear occurs due to movement of the denture in mastication such as is caused by the yielding of the gum tissue on which the denture is supported.

Still another object of the invention is to provide a denture construction wherein the connectors of the partial denture terminate in a clasp which is attached to an abutment in a manner as to be invisible from the anterior of the mouth but which, nonetheless, provides superior retention and alignment characteristics.

It is also an object of this invention to provide crowned abutments constructed in a novel manner which permit permanent spacing of the denture with respect to the gingiva and simultaneously provide for guidance and re tention thereof.

Another object of this invention is the provision of a dental prosthesis which can be anchored to permanent crowned abutments without marring the appearance of the user with visible clamps and other readily apparent structure.

Other objects of this invention are to provide improved dentures of the character described which are sturdy in construction, economical and quick to produce, and highly efficient in operation.

These and other objects of the invention will be apparent to those skilled in the dental art from the following description, when read in conjunction with the accompanying drawings, in which:

FIGURE 1 represents a fragmentary view of the human maxilla projected upon the occlusal plane illustrating a removable partial denture construction of the invention as it would appear in place, ready for use.

FIGURE 2 is a fragmentary sectional view taken along line 22 of FIGURE 1.

FIGURE 3 is a fragmentary sectional view taken along line 33 of FIGURE 1.

FIGURE 4 represents a detail of a resilient axial retainer of the invention.

FIGURE 5 represents a perspective view of a typical crowned abutment suitable for use in the invention.

FIGURE 6 represents a partial fragmentary sectional view showing a modified combined guidance-retention means of the invention.

Referring now to the figures, wherein like numerals designate like parts, and with particular attention to FIG- URE 1 it will be observed that a removable partial denture 16 is mounted in the human mandible 11 in order to provide the wearer with a complete set of teeth. Those teeth not provided by the removable denture 10 may include, for instance, the left central incisor 12, the right central incisor 13, the left lateral incisor 14, the right lateral incisor 15, the left canine 16, the right canine 17, the left first pre-molar 18, the right first pre-molar 19, and the left second pre-molar 2t}. Teeth 12 to 17 inclusive may be the wearers own natural teeth, or, depending on the case, may be crowned teeth which may, if desired, be tied together for strength. However, left first premolar 13, left second pre-molar 20 and right first pre-molar 19 are crowned teeth which, although fixed in the mouth and non-removable, are not the wearers natural teeth but have been constructed by the technician and mounted by the dentist. Because of their function in retention of the partial denture 19, these teeth are referred to as abutments. As will be fully described, abutments of the invention have special constructions which enable them to co-act with the partial denture 10. The abutments may be tied to each other and/ or to permanent natural teeth in a conventional manner such as by tying means 21.

The abutments of the invention may be best understood by a consideration of FIGURE 5 wherein a typical abutment, such as, for instance, right first pre-molar I9 is shown.

Abutment 19 which may be considered representative, comprises a biting surface 22, in the occlusal plane, and an enamel-simulating anterior facade 23, which provides the natural appearance so desirable as an object of any dental reconstruction. As previously stated, abutments such as 19 are crowned teeth and are fixedly attached by any of the conventional methods of the prior art. However, the abutments of the invention are provided with a plurality of parallel axial lingual channels which are spaced about the lingual perimeter of the tooth. As

shown in the particular embodiment being described, twoguidance channels, 24 and 25, are provided as Well as one axial retention channel 26. These channels are invisible when viewed from the exterior of the mouth. It is preferred to space channel 24 and channel 26 perimetrically about apart. The abutment is further provided with an arcuate lingual shoulder 27 shown, in this case, connecting channels 24 and 25. It is the cooperation between the guidance channels and the lingual shoulder which imparts occlusal rigidity and freedom from rotation to the dental structure and it is the shoulder which serves to keep the partial denture in spaced relationship to the gingiva 28. Consequently, rigidity is enhanced when the guidance grooves are perimetrically spaced about 180 apart and the shoulder connecting them is thus elongated to provide a longer arcuate bearing surface.

Returning now to a consideration of FIGURE 1 it will be noted that abutment 19 which has just been described in detail is but one of three abutments ( eg 18, 19 and 20). Abutment 18 is provided with a guidance channel 29 and a retention channel 30. Similarly, abutment 24 is provided with a guidance channel 31 and a retention channel 32. All of the abutments are provided with a shoulder such as 27. In brief, each abutment must comprise at least one guidance channel and at least one axial retention channel as well as an arcuate lingual shoulder.

The teeth shown in FIGURE 1 which are neither natural teeth nor crowns are supplied by the partial denture 10. These partial denture mounted teeth include, for instance, left first molar 33, right second premolar 34, right first molar 35, left second molar 36, right second molar 37, left third molar 38 and right third molar 39. These restored posterior teeth may be mounted, as is well known in the art, on a plastic saddle which is an integral part of the partial denture 10. However, the instant invention is concerned not with the manner in which the restored teeth are made and attached to the partial denture but rather is concerned with the manner in which the partial denture is held to and co-acts with the abutments.

The denture is provided with a plurality of connectors 40. A connector may be defined as a part serving to connect the body of a partial denture with those devices which grasp the abutments and hold the denture in place. The devices of the terminal end of the connectors may be broadly characterized as clasps.

The clasp which co-acts with abutment 19 is shown in FIGURES 1, 2 and 3. This clasp includes an arcuate rest portion 41, the underside of which is adapted to abut the lingual shoulder 27 and resist displacement of the denture toward the gingiva 28. The exposed surface of the clasp 42 conforms to the configuration of the abutment. One end of the rest is provided with an integral axial strut 43 which is complementary in cross-section to and adapted to be slideably received by channel or groove 24. The rest is also provided, at the other end of portion 41, with a second axial strut 44 which is complementary to channel 25. The rest terminates in an integral sleeve portion 45 (see FIG- URE 4), proximate rentention channel 26, which is concavely contoured opposite channel 26, as at 46. The sleeve is preferably formed with an enlargement 47 near its bottom which, functionally, serves as a fulcrum.

Lateral retention forces against the abutment 19 are provided by a resilient axial retainer, generally 48, which includes a lateral portion 49 permanently affixed to the denture 10 and a vertical portion 50. Retainer 48 is preferably ovular in cross-section and complements both channel 26 and portion 46 of sleeve 45. Portion 50 is unattached to denture 10 and is free to move laterally with respect to rest portion 45. In FIGURE 2 portion 50 is shown in phantom, as it would be when the denture 10 is out of the mouth. However, when the denture is in place, as shown in FIGURE 2, portion 50 is bent back over fulcrum 47 and exerts a direct lateral retention force against abutment 19 and, as indicated by the arrow, a downward reactive force on denture 10. Any wear which occurs between the denture and the abutment can be compensated for by bending of portion 50 to eliminate play.

The clasp used in connection with abutment 18 is generally similar and includes resilient axial retainer 51 and an axial strut 52. The lateral force against abutment 18 is, in this case, along a lingual-labial axis and provides indirect retention. The desideratum of 180 between channels applies to those clasps which counter-act rotational tendencies of the denture and provide direct retention but does not necessarily apply, as in this case, where indirect retention is sought.

The clasp used in connection with abutment is also similar to the clasp on abutment 19 and includes an axial strut 53 and a resilient axial retainer 54 connected by a rest portion 55. Here, however, retainer 54 doubles as a guide strut as well as a source of lateral posterioranterior retention force against abutment 20. Clasps of the invention are thus seen to require at least one axial retainer and at least one axial strut since, where but two channels are provided in the crowned abutment, the retention member also provides a guidance means.

FIGURE 6 shows another embodiment of the invention which is but a modification of the retention means of the previous embodiments. In this embodiment a 4 crowned abutment 56 is provided with a guidanceretention channel 57. Denture 58, on which is mounted false tooth 59 is provided with a connector terminating in a clasp comprising a partial axial strut 60 which complements channel 57 in cross-section. However, unlike the struts previously discussed, this partial strut extends only a short distance down from the occlusal plane. The balance of channel 57 is occupied by an aligned resilient axial retainer 61 which is horizontally fixed to denture it) but which, within channel 57, is free to exert a lateral retention force against abutment 56.

Changes in the specific forms of the invention described above may be made within the scope of what is claimed Without departing from the spirit of the invention.

Having described the invention, I claim:

1. In a partial denture construction a crowned abutment having an arcuate lingual shoulder and a plurality of parallel axial lingual channels including at least one axial retention channel and at least one guidance channel; and a connector terminating in a clasp removably mounted on said abutment which includes an arcuate rest portion abutting said lingual shoulder thus resisting displacement of the denture toward the gingiva, at least one axial strut complementary in cross-section and length to said axial guidance channel and received thereby, and at least one resilient axial retainer fitting within said axial retention channel and exerting a lateral force against said abutment.

2. The denture of claim 1 wherein said resilient retainer is ovular in cross-section.

3. The denture of claim 1 wherein a partial strut is provided on said clasp, to complement and fill any axially extending porton of said retention channel not occupied by said resilient retainer.

4. The denture of claim 3 wherein said resilient retainer is ovular in cross-section.

5. In a partial denture construction a crowned abutment including an arcuate lingual shoulder parallel to the occlusal plane and a plurality of parallel axial channels spaced about the lingual perimeter of said abutment including at least one axial retention channel and one guidanceretention channel; and a connector terminating in a clasp removably mounted on said abutment which includes an arcuate rest portion abutting said shoulder thus resisting displacement of the denture toward the gingiva; at least one axial strut complementary in crosssection and length to said axial guidance channel and slideably mounted therein, a partial strut complementing said guidance-retention channel in cross-section, occupying the portion of said channel distal the gingiva and slideably mounted therein, and a resilient axial retainer in alignment with said partial strut, occupying that portion of the length of said guidance-retention channel not occupied by said partial strut and exerting a lateral force against said abutment.

6. The denture of claim 5 wherein said resilient axial retainer is ovular in cross-section.

7. In a partial denture construction a crowned abutment including an arcuate lingual shoulder and a plurality of parallel axial lingual channels including at least one axial retention channel and at least one guidance channel perimetrically spaced about apart; and a connector terminating in a clasp removably mounted on said abutment which includes an arcuate rest portion abutting said lingual shoulder and thus resisting displacement of the denture toward the gingiva, at least one axial strut complementary in cross-section and length to said axial guidance groove and received thereby, and at least one resilient axial retainer fitting within said axial retention channel and exerting a lateral force against said abutment.

8. The denture of claim 7 wherein said resilient retainer is ovular in cross-section.

9. The denture of claim 7 wherein a partial strut is provided on said clasp, to complement and fill that axially extending portion of said retention channel not occupied by said resilient retainer.

10. The denture of claim 9 wherein said resilient retainer is ovular in cross-section.

11. A crown for use as an abutment in partial denture construction comprising a hitting surface in the occlusal plane, an enamel simulating anterior facade, a plurality of parallel axial lingual channels perimetrically spaced apart including at least one axial retention channel and at least one guidance channel and an arcuate lingual shoulder between two of said channels.

12. The crown of claim 11 wherein two of said axial channels are perimetrically spaced about 180 apart.

13. A partial denture construction including a lingual clasp having an arcuate rest and a cross-section, in a plane parallel to the occlusal plane, conforming to an abutment on which the clasp is slideably received, in a direction normal to the occlusal plane, said rest having a flat underside to juxtapose a lingual abutment shoulder, at least one integral axial strut at one extreme of said clasp and at least one resilient axial retainer at the other extreme of said clasp, said resilient retainer terminating in a portion which is free to move laterally with respect to said arcuate rest, and exert a lateral force against an abutment.

14. The partial denture construction of claim 13 wherein said resilient retainer is ovular in cross-section.

References Cited by the Examiner UNITED STATES PATENTS 1,299,067 4/1919 Underwood 325 1,591,155 7/1926 Craigo 32-5 2,631,373 3/1953 Timm 325 RICHARD A. GAUDET, Primary Examiner.

ROBERT E. MORGAN, Examiner.

Claims (1)

1. IN A PARTIAL DENTURE CONSTRUCTION A CROWNED ABUTMENT HAVING AN ARCUATE LINGUAL SHOULDER AND A PLURALITY OF PARALLEL AXIAL LINGUAL CHANNELS INCLUDING AT LEAST ONE AXIAL RETENTION CHANNEL AND AT LEAST ONE GUIDANCE CHANNEL; AND A CONNECTOR TERMINATING IN A CLASP REMOVABLY MOUNTED ON SAID ABUTMENT WHICH INCLUDES AN ARCUATE REST PORTION ABUTTING SAID LINGUAL SHOULDER THUS RESISTING DISPLACEMENT OF THE DENTURE TOWARD THE GINGIVA, AT LEAST

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