Patent Publication Number: US-2022233290-A1

Title: Secure Friction Retained Denture

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a continuation-in-part application of U.S. Non-Provisional Utility application Ser. No. 16/988,638 filed Aug. 8, 2020, which claims the benefit of priority to U.S. Provisional Application Ser. No. 62/884,254 filed Aug. 8, 2019; the contents of both are incorporated by this reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to dentistry, and more particularly, to functionally secure frictionally retained dentures. 
     BACKGROUND OF THE INVENTION 
     Dentures are typically utilized within the dental field to replace a plurality of natural teeth using a single assembly. Dentures are typically secured to a patient&#39;s jaw by use of previously installed dental implants. A number of difficulties arise with prior art dentures. One is that they may require a relatively great number of implants to be properly supported within the mouth. Another is that it may be objectionable to fasten dentures in place using screws or bolts secured to the denture and threaded directly into the implant. For one thing, the implant may be oriented at an angle unsuitable for passing into or through the denture. Another issue may be that bone tissue at any given desired implant site may be eroded or otherwise unsuitable for securely supporting an implant. 
     There exists a need for denture attachment to the patient&#39;s jaw that requires relatively few implants. Also, there is a need to reduce precision in components and component alignment to assure secure attachment to the jaw. 
     SUMMARY OF THE INVENTION 
     The present invention sets forth a construction for manually, expeditiously, and securely mounting a denture on the jaw of a patient, using implants. An anchor for receiving prongs is threaded to each of one or more implants in the mouth. A denture having prong passages is placed onto jaw bone or overlying tissue, above the implant (if the lower jaw is being treated). The anchor penetrates the denture, occupying an opening in the denture. With the denture in place and with the prong passages aligned with prong reception sites of the anchor, a pronged denture connector is installed such that the prongs pass through the prong passages of the denture and penetrate the prong reception sites of the anchor. The prongs are each frictionally secured in place by an elastic member lining the prong passages of the denture and constricting over inserted prongs. The elastic members may include a spanning member holding each parallel to the other. The denture may comprise synthetic resin reinforced by a metallic reinforcing bar. 
     The denture may include a recess configured to enable a pry tool to bear against the denture connector to remove the latter, for example, when replacing or servicing the denture. 
     The novel arrangement may be utilized with both partial and full arch dentures, the dentures stably secured using only two implants. Also, as will be further detailed hereinafter, it is not necessary to establish great precision in having the prongs and prong reception sites sized and aligned. 
     The present invention provides improved elements and arrangements thereof by apparatus for the purposes described which is inexpensive, dependable, and fully effective in accomplishing its intended purposes. 
     These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
         FIG. 1  is a side cross sectional view of a dental implant; 
         FIG. 2  shows a component added to  FIG. 1 ; 
         FIG. 3A  is a view of the implant of  FIG. 1 , with additional components shown exploded above the implant; 
         FIG. 3B  shows the components of  FIG. 3  fully assembled; 
         FIG. 4  is a perspective detail view of a component of the novel denture retention system; 
         FIG. 5  is similar to  FIG. 4 , but shows two additional components; 
         FIG. 6  is an environmental view of a patient&#39;s jaw, showing relative positions of components of  FIGS. 3A, 3B, 4, and 5  as they would be installed, with a denture which is included in the novel denture retention system omitted for clarity in showing the depicted components; 
         FIG. 7  is a bottom plan view of the denture omitted from  FIG. 6 ; 
         FIG. 8  is an environmental view of  FIG. 6 , showing the denture of  FIG. 7  in a stage of installation to the patient&#39;s jaw of  FIG. 6 ; 
         FIG. 9A  is a rear exploded perspective view of the assembly of  FIG. 8 ; 
         FIG. 9B  is a frontal perspective view showing the assembly of  FIG. 9A  now fully assembled; 
         FIG. 10  is a detail view showing a variation on the denture shown in  FIG. 8 ; 
         FIG. 11  is an exploded perspective detail view of components shown in  FIG. 5 ; 
         FIG. 12  is a side detail view of the components of  FIG. 5 , shown partially in cross section; 
         FIG. 13  is an enlarged detail view of a washer retaining groove in prongs shown in  FIGS. 11 and 12 ; 
         FIG. 14  is an exploded perspective view of an alternative embodiment of a component shown in  FIG. 5 . 
         FIG. 15  is a side detail view of the embodiment of  FIG. 14 , shown assembled; 
         FIG. 16  is a side detail view of  FIG. 15 , shown partially in cross section; 
         FIG. 17  is a side detail view of  FIG. 16 , shown partially in cross section, and showing a further alternative embodiment; 
         FIG. 18  is. a side detail view of  FIG. 17 , showing an initial stage of assembly; 
         FIG. 19  is a side detail view of  FIG. 18 , showing a further stage of assembly; and 
         FIG. 20  is a side detail view of  FIG. 19 , showing a final stage of assembly. 
     
    
    
     DETAILED DESCRIPTION 
     Referring first to  FIG. 1 , there is shown an implant  100  installed in a jaw bone  10  of a patient, with soft tissue such as gum tissue  12  overlying jaw bone  10 . Implant  100  may be conventional and may preexist installation of a denture  102  (see  FIGS. 6-9 ), or alternatively, may be fabricated and installed specifically for installation of denture  102 . As seen in  FIG. 2 , a seat  110  for seating elements of a novel denture retention system for denture  102  sits atop implant  100 . Seat  110  elevates a load bearing working surface of implant  100  from a location recessed within the jaw to a location reasonably flush with gum tissue  12 . It would be possible to omit seat  110  if implant  100  were flush with the upper surface of jaw tissue. Ordinarily, implant  100  sits recessed below such upper surface. 
     It should be noted at this point that orientational terms such as overlying, atop, laterally, vertically, and transverse refer to the subject drawing as viewed by an observer. The drawing figures depict their subject matter in orientations of normal use, which could obviously change with changes in posture and position of the novel denture retention system as installed in a patient, or with use of an opposed jaw (drawings illustrate a lower jaw). Therefore, orientational terms must be understood to provide semantic basis for purposes of description, and do not limit the invention or its component parts in any particular way. 
     Referring also to  FIGS. 3A-9 , there are additionally shown elements of the novel denture retention system for frictionally retaining denture  102  to a jaw of the patient. The denture retention system may comprise at least one prong anchor  104  (shown isolated from other elements in  FIG. 3A ) having a plurality of prong reception sites  106  and an implant connector (e.g., a screw  108 ) configured to secure prong anchor  104  to dental implant  100 . 
     The denture retention system may also comprise denture  102  comprising a base  112  ( FIGS. 8 and 9 ), at least one prosthetic tooth  114  ( FIG. 8 ) mounted to base  112 , at least one opening  116  ( FIG. 7 ) in base  112 , opening  116  dimensioned and configured to receive an exposed portion of prong anchor  104  therein, and a plurality of prong passages in base  112 . Each of the prong passages is dimensioned and configured to slidably receive a prong  118  ( FIG. 4 ) therethrough. 
     The denture retention system also includes a denture connector  120  ( FIGS. 4-6 ) having a plurality of parallel prongs  118  dimensioned and configured to pass through the prong passages of denture  102  and to be received within prong reception sites  106  ( FIGS. 3A, 3B ) of prong anchor  104 . 
     Prong reception sites  106  of prong anchor  104  and the prong passages of base  112  of denture  102  are oriented to enable parallel prongs  118  of denture connector  120  to pass through denture  102  and be received laterally within the at least one prong anchor  104  when prong anchor  104  is coupled to dental implant  100  and dental implant  100  is vertically oriented. Given potential play of prongs  118  with respect to prong passages in denture  102 , provision of two prongs  118  stabilizes coupling of denture  102  to prong anchor  104  and hence to the jaw. 
     Base  112  of denture  102  both establishes a structural member for engaging prong anchor  104  and denture connector  120 , and also is preferably configured to provide realistic visual transition from the jaw to gum tissue surrounding prosthetic teeth  114 . 
       FIG. 9A  shows denture  102  about to be lowered onto gum tissue, so that prongs  118  of denture connector  120  will enter prong reception sites  106 . It will be appreciated that prong reception sites guide prongs  118  into place, but need not receive prongs  118  with great precision or with very close fit. Desired precision is provided by elastomeric barrels  130 , to be described hereinafter.  FIG. 9B , a frontal view, shows denture  102  fully seated onto physiological features of the jaw of the patient, with denture connector  120  fully inserted. 
     In summary, denture  102  is held in place by interference fit of prongs  118  with prong reception sites  106 , in that denture  102  cannot be elevated from its seated or installed position (as shown e.g. in  FIG. 9B ). 
     Also seen in  FIG. 7 , the denture retention system may further comprise a metallic reinforcement bar  142  in base  112  of the denture, to distribute loads imposed for example by chewing when denture  102  is installed in the patient. 
       FIG. 7  depicts denture  102  in an exemplary final form; that is, with barrels  130  fixed thereto, for example, by resinous cement, and with prongs  118  of denture connector entrapped by barrels  130 , as will be described hereinafter. 
     Prong anchor  104  may include two prong reception sites  106 , with one prong reception site  106  on each side of the implant connector (e.g., screw  108 ). This arrangement symmetrically and stably distributes forces from clamping denture  102  to prong anchor  104  by using dual prong denture connector  120 . 
     Prong anchor  104  may comprise a bore  122  ( FIG. 3B ) in prong anchor  104  and a shoulder  124  in bore  122 . Shoulder  124  is dimensioned and configured to entrap a head  126  ( FIG. 3A ) of a threaded fastener (e.g., screw  108 ) when a shaft  128  ( FIG. 3A ) of the threaded fastener is passed through bore  122 . 
     Prong anchor  104  may further comprise the threaded fastener (i.e., screw  108 ) having threaded shaft  128  matingly compatible with female threads (not shown, but conventional in dental implants) of dental implant  100  and head  126  greater in a transverse dimension than threaded shaft  128 . 
     Bore  122  and its associated threaded fastener secure prong anchor  104  to implant  100 . 
     As seen in  FIG. 8 , denture  102  may be a full arch denture  102  spanning at least two dental implants  100  (as seen in  FIGS. 6 and 9 ). However, as seen in  FIG. 10 , denture  102  may be fabricated as a partial arch denture  102  spanning at least two dental implants  100 . Therefore, the novel denture retention system can be used when replacing all teeth of a dental arch, and also when replacing only some of the teeth of a dental arch. 
     Referring principally to  FIGS. 11 and 12 , each prong passage is capable of slidably receiving barrels  130  of denture  120  and are generally made of an expandable elastomeric material that acts to frictionally and releasably engage a respective prong  118  of denture connector  120  when denture connector  120  is installed through denture  102 . Alternatively, the barrel  130  may be made of a metallic material and include an inner radially mounted elastomeric ring to provide the desired friction fit. Alternatively still, the barrel may be metallic and at least one of the prongs  118  of the denture connector  120  may include radially mounted elastomeric ring to provide the desired releasable frictional fit relationship between the barrel  130  and prong  118 . 
     The denture retention and release mechanism hereto described also includes two alternative connector retention mechanisms for preventing unintended disengagement of denture connector  120  from the denture  102  when the denture is released from the mouth. 
     The first embodiment of the connector retention mechanisms is shown in  FIGS. 11-13  and the second embodiment is shown in  FIGS. 14-20 . In the first embodiment, each one of prongs  118  may have a circumferential groove  132  for receiving an internal surface of an expansible washer  134  to retain a respective prong  118  within barrel  130 . Each one of barrels  130  has an internal groove  136  ( FIG. 12 ) for receiving an outer surface of expansible washer  134 . Circumferential groove  132  may have one tapered end wall  138  ( FIG. 13 ) to facilitate expansion of washer  134  when denture connector  120  is inserted into the denture retention system, and an opposed square cut end wall  140  to oppose excessive withdrawal of denture connector  120 . Noting that washer  134  sits in circumferential groove  132  and is expanded first when encountering a blunt end of a prong  118  and remains expanded as it rides along the surface of the prong  118  as the denture is fully secured in place. To remove the denture, prong  118  is moved in the opposite direction until washer  134  contracts and again sits in circumferential groove  132  of prong  118 . At this position, further movement of prong  118  in this opposite direction is prevented as it results in the washer  134  encountering non-tapered square cut end wall  140  of the prong  118 . This encounter will not expand washer  134 , and excessive withdrawal of prongs  118  is prevented. 
     The purpose of circumferential grooves  132  is to retain denture connector  120  on denture  102 . When a prong  118  is first inserted through a corresponding barrel  130  to seat the denture, washer  134  is expanded by contact with the blunt end of each prong  118 , constricts as it passes over circumferential groove  132 . As prong  118  is pushed further through barrel  130  to enable prong  118  to penetrate prong reception site  106 , tapered end wall  138  facilitates expansion of washer  134 , the latter spreading or opening to accommodate passage of prong  118  to the fully installed position. 
     However, should a person attempt to withdraw prong  118 , travel of prong  118  is stopped as square cut end wall  140  encounters washer  134 . Because of the lack of taper, washer  134  is not urged to open or spread, and further withdrawal of prong  118  is opposed by interference with washer  134 , the latter entrapped by corresponding groove  136  of barrel  130 . Thus denture connector  120  is prevented from inadvertent loss, while still enabling sufficient withdrawal to manually remove denture  102  from the mouth. 
     The radial elastic member (e.g., barrels  130 ) frictionally retains prongs  118  in place. Prongs  118  interengage prong reception sites  106  to retain denture  102  against the jaw by interference fit. 
     Denture  102  may further comprise a recess  144  configured to provide access for a pry tool (not shown) to dislodge denture connector  120  from an installed position in the denture retention system. 
     Turning now to the second embodiment of the connector retention mechanism shown in  FIGS. 14-20 .  FIG. 14 , there is shown an alternative embodiment wherein a denture connector  150  is modified from the embodiment of denture connector  120 . In the novel denture retention system, each radially elastic member may comprise a barrel  152  slotted to accommodate radial expansion, and a bridge  154  connecting one of barrels  152  to another one of barrels  152 . Bridge  154  maintains barrels  152  parallel, with accommodation of minor squirming due to elasticity of barrels  152 . This feature facilitates simultaneous insertion of prongs  156  into reception sites  106  ( FIG. 9A ) despite minor squirming or deforming of barrels  152 . Preferably, barrels may be of synthetic resin, polymer, or elastomeric material with sufficient elasticity to accommodate temporary deformation during insertion of prongs  156  and provide for friction fit of said prongs  156 . Alternatively, barrels  152  may be of metallic constituency and an elastomeric ring or rings could be placed on the prongs to provide the friction fit. 
     A chamber  158  may be formed in bridge  154 , an expansible pin  160  may be dimensioned and configured to be received in chamber  158 . Chamber  158  has opposed openings  162  enabling expansible pin  160  to protrude beyond bridge  154  and bear against prongs  156 . Although openings  162  are visible in  FIG. 14 , their nature is better understood by examination of  FIGS. 16 and 17 . Expansible pin  160  may comprise two telescoping sections  164  and  166  ( FIG. 16 ) and a spring  168  configured to bias two telescoping sections  164  and  166  to expand. 
     The alternative embodiment of the connector retention mechanism has the same and critical function of preventing inadvertent loss of denture connector  150  when denture  102  is being removed from the mouth, and also, of preventing disengagement of denture connector  150  from barrels  152  as denture connector  150  is withdrawn to remove denture  102 . Escape of denture connector  150 , should that occur, could result in destruction (for example, if dropped onto a floor and stepped on) or loss (for example, swallowed). To this end, and as seen in  FIGS. 16 and 17 , the connector  150  is shown in the denture release position such that the denture  102  can be removed from the patient&#39;s mouth. In this released position it can be seen that the ends of sections  164  and  166  of expansible pin  160  are received in depression  170 , and more particularly, in abutment with a shoulder  188  of prong  156 . Should denture connector  150  be grasped by head  174  and pulled in a direction of removal (seen as arrow  190 ), interference of section  164  of expansible pin  160  with shoulder  188  will oppose further withdrawal of denture connector  150  from barrel  156  and hence from denture  102 , thereby retaining the connector in the denture  152  when the denture is released and readying it for reinsertion at a later time. Now also referring to  FIG. 16 , the denture retention system may further comprise a depression  170  on at least one of prongs  156 . Depression  170  faces expansible pin  160  when prongs  156  are inserted into barrels  152 , Depressions  170  are configured to limit expansion of expansible pin  160 , and to include an inclined ramp  172  enabling expansible pin  160  to be compressed as prongs  156  of denture connector  150  advance into respective barrels  152 . Thus, a head  174  of denture connector  150  can contact barrels  152  and prongs  156  thereby be fully inserted thereinto. 
     The denture retention system may further comprise a recess  176  in at least one of prongs  156 , recess  176  facing expansible pin  160  when denture connector  150  is fully inserted into barrels  152  thereby securing the denture in place. In the recess  176 , the expansible pin is able to expand in the recess  176  as a means of maintaining the position of the denture connector  150  in place. Note that recess  176  is optional and that the denture connector  150  is generally held in position based on the friction of the barrels upon prongs  156 . 
     Referring momentarily to  FIGS. 5 and 6 , denture connector  120  is shown fully inserted into prong anchor  104 . This is the fully installed condition of denture  102 . In the second embodiment, despite the presence of bridge  154 , the fully installed condition of denture  102  would appear much the same. This is reflected in  FIG. 20 . It will be seen at the right of  FIG. 18  that prongs  156  project beyond barrels  152 . The exposed portions of prongs  156  have entered reception sites  106  of prong anchor  104  (as seen in  FIGS. 3A, 3B, and 6 ) to lock denture  102  to prong anchors  104  ( FIG. 6 ). 
       FIGS. 18-20  show progressive insertion of denture connector  150  into the fully engaged position locking denture  102  to prong anchor  104  ( FIG. 6 ). Initially, and as seen in  FIG. 18 , denture connector  150  is inserted partially into barrels  152 . Barrels  152  are shown isolated from denture  102  for clarity of the view in  FIG. 18 , although again, barrels  152  are friction fit or cemented to denture  102 . As prongs  156  enter passages  180  of barrels  152 , tapered shoulders  182  of prongs  156  compress sections  164  and  166  of expansible pin  160  together. Ends of sections  164  and  166  will slide along prongs  156  as the latter continue to move in a direction of insertion (seen as arrow  184 ). 
     A further feature of the embodiment of  FIGS. 14-20  is that bridge  154  secures barrels  152  parallel to one another. This facilitates insertion of denture connector  150  into barrels  152 , and also facilitates removal. 
       FIG. 19  shows a further stage of insertion of prongs  156  into barrels  152 . It will be seen that ends of sections  164  and  166  of expansible pin  160  are sliding along a ramp  186  of depressions  170 . The role of depressions  170  will be explained hereinafter. Again, the right connector  120  of  FIG. 7  depicts full insertion of denture connector  120 , with full insertion of denture connector  150  appearing substantially similar to the position of connector  150  shown in  FIG. 20 . However, with denture connector  150 , a further feature comes into play. 
     Referring now to  FIG. 20 , with denture connector  150  fully inserted into barrels  152 , section  164  of expansible pin  16  has been received in recess  176 . This arrangement opposes casual disengagement of denture connector  150  from the fully inserted position seen in  FIGS. 6 and 20 . Resistance to engagement with recess  176  is easily overcome by finger pressure to enable denture connector  150  to be withdrawn from engagement with prong anchors  104  ( FIG. 6 ) for removal of denture  102  ( FIG. 7 ). 
     Chamber  158  of bridge  154  may be open on one side to enable insertion of expansible pin  160  into chamber  158 . The denture retention system may include a removable closure  178  configured to close the open side of chamber  158 . 
     It should be understood that denture connector  150  and barrels  152  perform similarly to their counterparts of  FIGS. 1-13 , and have similar structure to accomplish such performance, even if specific features have not been specified herein. 
     Implant  100 , prong anchor  104 , seat  110 , denture connectors  120  and  150 , and reinforcement bar  142  may be fabricated from a biocompatible metal such as titanium or titanium alloy. It is contemplated that prong anchor  104 , denture connectors  120  and  150 , and reinforcement bar  142  will be fabricated with dimensions and configuration unique to each patient. Denture  102  may utilize conventional dental resins cast around reinforcement bar  142 . 
     While the novel denture retention system has been described in terms of two prongs  118  on each denture connector  120  or  150  and two implants  100 , the number of prongs  118  and implants  100  used may be greater than two. 
     Drawings are drawn to internal scale, and also to external scale. By internal scale it is meant that the parts, components, and proportions thereof in the illustrated inventive example are drawn to scale relative to one another. As employed herein, external scale refers to scale of the illustrated example relative to scale of environmental elements or objects, regardless of whether the latter are included in the drawings. Where the inventive example claims external scale, the inventive and environmental elements may of course not be drawn to real or true life scale; rather, external scale signifies only that both the invention and environmental elements are drawn in scale to each other. 
     While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is to be understood that the present invention is not to be limited to the disclosed arrangements, but is intended to cover various arrangements which are included within the spirit and scope of the broadest possible interpretation of the appended claims so as to encompass all modifications and equivalent arrangements which are possible.