US3919772A

US3919772A - Dental implant assembly and method for attaching the same to the jaw bone

Info

Publication number: US3919772A
Application number: US366853A
Authority: US
Inventors: Joseph J Lenczycki
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-06-04
Filing date: 1973-06-04
Publication date: 1975-11-18
Anticipated expiration: 1992-11-18

Abstract

A dental implant assembly consists of one or more planar members adapted to be introduced into complementary cavities or slots formed in the jaw bone. Threaded fasteners are disposed through holes in the jaw bone and oriented in directions generally normal to the planar members. Threaded apertures are provided in the planar members which are engageable with the threaded fasteners for immobilizing the planar members within the cavities relative to the jaw bone. At least one of the fasteners includes a support portion which projects exteriorly of the jaw bone when the planar members and the fasteners are in engagement. The support portion is adapted to support a dental prosthetic device in fixed relation to the jaw bone during engagement. A dental jig for accurately drilling the holes in a jaw bone which receive the fasteners is described. The method of inserting a planar dental implant assembly member into a jaw bone includes cutting in the jaw bone a slot complementary to the planar member and drilling holes in the jaw bone between the alveolar crest and the slot under the guidance of the apertures in the jig. The planar member is inserted into the complementary slot and screws are introduced through the holes drilled in the jaw bone and engage threaded apertures provided in the planar member. At least one exposed portion associated with the threaded screws is retained exposed which is adapted to support a prosthetic device. A jig is also described for forming two slots essentially aligned in a common plane and disposed in opposite lingual sides of the jaw bone.

Description

DENTAL IMPLANT ASSEMBLY AND METHOD FOR ATTACI-IING THE SAME TO THE JAW BONE Joseph J. Lenczycki, 89 Florence Road, Riverside, Conn. 06878 Filed: June 4, 1973 Appl. No.: 366,853

[76] Inventor:

US. Cl. 32/10 A; 128/92 C Int. Cl. A61C 13/00 Field of Search 32/10 A, 14 A; 128/92 C,

References Cited UNITED STATES PATENTS 3,521,355 7/1970 Pearlman 32/14 A 3,660,899 5/1972 Linkow 32/10 A FOREIGN PATENTS OR APPLICATIONS 191,081 9/1956 Austria 128/92 C OTHER PUBLICATIONS Implant Research Corp. Publication, Oct. 1968, Significant New Concept in Endosseous Implantology.

Primary Examiner-Robert Peshock Assistant E.raminer-J. Q. Lever Attorney, Agent, or FirmFriedman & Goodman [57] ABSTRACT A dental implant assembly consists of one or more Nov. 18, 1975 planar members adapted to be introduced into complementary cavities or slots formed in the jaw bone. Threaded fasteners are disposed through holes in the jaw bone and oriented in directions generally normal to the planar members. Threaded apertures are provided in the planar members which are engageable with the threaded fasteners for immobilizing the planar members within the cavities relative to the jaw bone. At least one of the fasteners includes a support portion which projects exteriorly of the jaw bone when the planar members and the fasteners are in engagement. The support portion is adapted to support a dental prosthetic device in fixed relation to the jaw bone during engagement. A dental jig for accurately drilling the holes in a jaw bone which receive the fasteners is described. The method of inserting a planar dental implant assembly member into a jaw bone includes cutting in the jaw bone a slot complementary to the planar member and drilling holes in the jaw bone between the alveolar crest and the slot under the guidance of the apertures in the jig. The planar member is inserted into the complementary slot and screws are introduced through the holes drilled in the jaw bone and engage threaded apertures provided in the planar member. At least one exposed portion associated with the threaded screws is retained exposed which is adapted to support a prosthetic device. A jig is also described for forming two slots essentially aligned in a common plane and disposed in opposite lingual sides of the jaw bone.

11 Claims, 13 Drawing Figures U, Pmfit Nov.18,1975 Sheet10f2 3,919,772

FIG.6.

IO 42 32 2O 42 U0. Patent Nov. 18, 1975 Sheet20f2 3,919,772

DENTAL IMPLANT ASSEMBLY AND METHOD FOR ATTACHING THE SAMETO THE JAW BONE BACKGROUND OF THE INVENTION This invention generally relates to dental implants, and more specifically to dental implant assemblies having generally planar members receivable in complementary slots formed in a jaw bone and threaded'fasteners engageable with the planar members while being oriented in directions generally normal to the planes defined by the planar members. The present invention also relates to the method of establishing such implants in the jaw bone as well as the various jigs instrumental in the method.

Frequently, when the natural tooth structure has deteriorated, bridges or partial dentures may be formed and connected to the remaining natural teeth if the latter are sufficiently strong to support a denture or bridge. Frequently, however, the remaining natural teeth do not have sufficient strength upon which to base an artificial bridge. In these cases, it has become common to utilize bridge stabilizing systems which are connected in one way or another to the jaw bone. The devices utilized are generally termed dental implants and are generally securely fixed to the underlying bone structure of the jaw in order to realize the requisite strength necessary to support a bridge.

Most of the known dental implants have not been entirely satisfactory for the purposes intended. For example, some implants are in the form of pins, nails or screws which are directly urged into the jaw bone. The disadvantage of these types of implants is that they do not provide sufficient anchorage in the jaw bone under great stresses and do not evenly distribute the forces applied thereto the the jaw bone. Consequently, the danger exists that the implant will exert excessive stresses on the jaw bone which may cause the implant to separate from as well as damage the latter.

According to still other types of known implants, these are in the form of wedge members which are tapped into the jaw bone. The disadvantage with this last type of implant, which is also common with the above described known implants, is that all these implants rely for their retention in the jaw bone upon the pressure relationship which exists when the implants are urged or forced into the jaw bone. However, the jaw bone frequently deteriorates with time and the wedging relationship between the jaw bone and the implant may be lost this sometimes resulting in the implant becoming loose.

Implants gcnerally are provided with portions which extend exteriorly of the jaw bone when the implant is fully mounted therein the exposed portions being suitable for connection with dental prosthetic devices. According to one known dental implant, a transverse member passes through the jaw bone and extends to each side thereof in its permanent position. A jig, which is engageable with the exposed portions of the transverse member is utilized for drilling a hole from the alveolar crest of the jaw bone to the transverse member. However, when the jig is removed and a suitable threaded fastener passes through the hole so. drilled into engagement with the transverse member, the protruding portions of the latter remain exposed. This has the disadvantage that the extended portions of the transverse member interfere with the tissues surround- ,ing the jaw bone and hinder these tissues from growing over the opening drilled in the sides of the jaw bone through which the extended portions project.

Another disadvantage of the known implants has been the difficulty an inconvenience of establishing the latter in the jaw bone. The procedures for installing the implants are generally time consuming and uncomfortable to the patient. Implants which provide the possibility of becoming loose only necessitate further dental work at a later time.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a dental implant assembly which is not possessed of the above described disadvantages associated with prior art dental implants.

It is another object of the present invention to provide a dental implant which is simple in construction and economical to manufacture.

It is still another object of the present invention to provide a dental implant which provides the sufficient strength or support to the dental prosthetic device which is mounted thereon.

It is yet another object of the present invention to provide a dental implant which more evenly distributes the stresses supplied thereon to the surrounding jaw bone instead of concentrating those stresses over relatively small areas.

It is a further object of the present invention to provide jigs for accurately drilling holes in the jaw bone which facilitate both the drilling operation as well as the assembly of the dental implant.

It is still a further object of the present invention to provide dental implants which are provided with handles severable at weakened portions which makes the dental implants easier to manipulate inside the mouth prior to insertion of the implant inside associated complementary cavities previously formed in the jaw bone.

It is yet a further object of the present invention to provide dental implants which include one or more substantially flat plates or blades each associated with a complementary slot or cavity in the jaw bone and each arranged in cooperative relationship with threaded fastening screws oriented normal to the flat implants which are engaged in threaded apertures provided in at least one of the implants.

It is an additional object of the present invention to provide a dental jig for forming two slots aligned essentially in a common plane and disposed on opposite lingual sides of a jaw bone.

It is still an additional object of the present invention to provide planar implants associated with complementary slots or cavities in the jaw bone the implants being fully receivable interiorly of the cavities without protruding exteriorly of the latter when the dental implant is fully assembled.

It is yet an additional object of the present invention to provide a method for establishing planar implants in complementary slots formed in a jaw bone.

In order to achieve the above object, as well as others which will become apparent hereafter, the dental implant assembly for maintaining a dental prosthetic device in fixed relation with respect to a jaw bone comprises a planar member adapted to be introduced into a complementary cavity or slot formed in a jaw bone. Securing means are provided which are engageable with said planar member for immobilizing the latter within the cavity relative to the jaw bone. A portion of said securing means includes support means projecting exteri- 3 orly of the jaw bone when said planar member and said securing means are in engagement. Said support means is adapted to support a dental prosthetic device in fixed relation to the jaw bone during such engagement.

In accordance with a presently preferred embodiment, either one or two planar members may simultaneously be introduced into complementary cavities spaced from each other in the jaw bone. The planar members are in the form of flat plates having at least one threaded aperture therethrough. Said securing means comprise a threaded fastener configurated to pass through a hole drilled in the jaw bone and engageable with said threaded aperture.

Advantageously, the dental implant further comprises a gripping portion detachably connected to the planar member. In the preferred embodiments, said gripping portion is integrally formed with said planar member and meets the latter at a weakened line portion. The gripping portion facilitates manipulation of the planar member during assembly of the dental implant. Once the planar member has been received in its complementary cavity or slot, the gripping portion may be removed from said planar member at said weakened line portion to thereby leave a stub at the point of severance. Both said planar member and said stub are configurated to be fully receivable in the cavity without protruding exteriorly of the latter.

A dental jig in accordance with the present invention for drilling holes in a jaw bone which are to be aligned with apertures in a planar dental implant assembly member to be positioned in a complementary cavity of the jaw bone, comprises a first alighment member insertable into the jaw bone cavity. A second alignment member is positionable above the alveolar crest of the jaw bone. Both said alignment members are provided with at least one pair of aligned apertures one in each alignment member in which a drill bit is receivable, said pair of aligned apertures being similarly aligned with respect to the cavity as are the apertures in the planar dental implant assembly member. In this manner, holes drilled in the jaw bone by a drill bit passing through said pair of aligned apertures are simultaneously in alignment with each the apertures in the planar dental implant assembly member when the latter is positioned in the cavity. The dental jig may include a third alignment member when two spaced planar dental implant assembly members are to be positioned in respective complementary spaced cavities of the jaw bone. In such a case, first and second alignment members are insertable in to the respective jaw bone cavities while the third alignment member is positionable above the alveolar crest of the jaw bone.

A dental jig in accordance with the present invention for forming two slots aligned essentially in a common plane and disposed on opposite lingual sides of the jaw bone comprises rigid first extension member provided at one end thereof with a planar portion receivable in one slot cut on one lingual side of the jaw bone. A rigid second extension member is provided at one end thereof with a guide portion adapted to guide suitable slot cutting means. Connecting means is provided for connecting said first and second extension members to each other, said extension members being so configurated to position said guide portion adjacently to the other lingual side of the jaw bone offset from the desired opposite lingual position of the other slot when said extension members are connected to each other. Said offset is approximately equal to the height of the second slot. In this manner, said slot cutting means can be guided by said guide portion to cut the other slot in alignment and at the desired opposite lingual side of the jaw bone.

The method of inserting a planar dental implant assembly member into a jaw bone in accordance with the present invention comprises the steps of cutting a slot in the jaw bone which is complementary to the planar member. One alignment member of the jig above the alveolar crest of the jaw bone. Holes are drilled in the jaw bone between the alveolar crest and the slot under the guidance of the apertures in the alignment members. The planar member is inserted into the complementary slot. Fastener means is introduced through the holes drilled in the jaw bone and the fastener means are engaged to the planar member while a portion of the fastener means is retained exposed to make the latter adapted to support a prosthetic device.

BRIEF DESCRIPTION OF THE DRAWINGS With the above and additional objects and advantages in view, as will hereinafter appear, this invention comprises the device, combinations and arrangements of parts hereinafter described and illustrated in the accompanying drawings of a preferred embodiment in which:

FIG. 1 is a schematic perspective representation of a jaw bone section, showing the dental implant assembly structure in accordance with the present invention embedded in the jaw bone and having a post and a head or coping at one end one end thereof extending above the jaw bone adapted to support a dental prosthetic device;

FIG. 2 is a horizontal section of the jaw bone with the implant positioned therein, taken along line 22 in FIG. 1;

FIG. 3 is a cross section through the jaw bone and the dental implant in accordance with the present invention taken through a vertical section taken along line 3-3 in FIG. 2;

FIG. 4 is a schematic representation of the jaw bone of FIG. 1 prior to insertion of the dental implant, showing the initial step of the implanting procedure wherein a slot is cut on the side of the jaw bone;

FIG. 5 is a perspective view of a jig for accurately drilling aligned holes in the jaw bone after the slot shown in FIG. 4 has been cut;

FIG. 6 is a perspective view wherein the jig for drilling holes of FIG. 5 both cooperates with the slot drilled in the jaw bone and covers the alveolar crest of the jaw bone with an alignment member through which a drill bit can pass to thereby drill holes in the jaw bone which are to be aligned with corresponding apertures in the dental implant when the latter is subsequently inserted into the slots;

FIG. 7 schematically shows the jaw bone of FIG. 6 after the jig has been removed and the holes have been drilled, and also showing flat or planar implant and threaded posts or pins in positions to be inserted into the drilled holes for engagement with the implant after the latter has been fully inserted into the slots;

FIG. 8 is a perspective view of a further embodiment of a dental implant in accordance with the present invention, the second embodiment including two spaced flat or planar implants, each being similar to the implant according to the first embodiment;

FIG. 9 is similar to FIG. 4, but showing the first step of the procedure of lodging an implant as shown in FIG. 8 into the jaw bone this initially comprising the formation of two spaced slots or cavities;

FIG. is similar to FIG. 5, but showing a modified jig having an additional alignment member which is receivable in the additional slot formed in the jaw bone, as shown in FIG. 9;

FIG. 11 is similar to FIG. 6, but showing the jig of FIG. 10 cooperating with the jaw bone for drilling holes in the latter which extend or communicate with both of Y the slots;

FIG. 12 is comparable to FIG. 7, wherein the dental implant shown in FIG. 8 is positioned within the spaced slots shown in FIG. 9, and also showing the threaded posts or pins in positions just prior to passage through the holes drilled in the jaw bone and engagement with the dental implant; and

FIG. 13 is a front elevational view ofjig, wherein opposite jaw sections are shown in cross section, for forming two slots aligned essentially in a common plane and disposed on opposite lingual sides of the jaw sections.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, in which similar or identical parts have been designated by the same reference numerals, and first referring to FIG. 1, a representation of the jaw bone 10 is shown having the alveolar crest 12 disposed in the region where teeth normally arise. The reference numeral 14 represents the lingual surface of the jaw bone. The tissues which surround the jaw bone have not been shown for purposes of clarity.

Referring to FIGS. 1-3, the jaw bone 10 is provided with a slot 16, to be more fully described hereafter, in which the implant in accordance with the present invention is insertable. The dental implant assembly is shown in its fully assembled condition wherein the im plant 20 is fully positioned interiorly of the slot 16. The implant 20 is in the form ofa planar member or flat element which is provided with two end threaded apertures 24 and a central threaded aperture 26.

In the assembled condition of the implant, a central post 30, having a threaded portion 32 and a shoulder 34 at one free end thereof and a head or coping portion 36 at the other end thereof, extends through a hole in the jaw bone 10, as to be described hereafter, and threadedly engages with the central threaded aperture 26. Similarly, two lateral or side pins 40 are provided with threaded end portions 42 at one end thereof and shoulders 44 at the same end the threaded portions 42 being engageable with the threaded apertures 24 when the pins 40 pass through holes in the jaw bone 10, as to be described hereafter.

The post is selected to have a length sufficiently large so as to extend above the alveolar crest 12 to thereby expose a head portion 36 which is adapted to support a dental prosthetic device. The manner in which the prosthetic device is connected to the post 30 and head or coping portion 36 is well known in the art.

Although the first embodiment of the invention has been illustrated and described in connection with one central post 30 and two side pins 40, it should be clear that the actual number of threaded members which engage the implant 20 is not critical for the purposes of the present invention. Thus, it is possible to include as few as one and as many threaded fasteners as desired in order to secure the implant 20 and immobilize the same interiorly of the slot 16. The shoulder 34 of the post 30 and the shoulders 44 of the pins 40 are adapted to engage the top surface of the implant 20 when full threaded engagement has been achieved and prevent the threaded fasteners from excessively moving downwardly beyond the confines of the slot 16. The shoulders also serve the function of locking the post 30 and pins 40 when the latter are turned sufficiently so as to tighten the same and cause the shoulders to frictionally engage the top surface of the implant 20 to thereby prevent rotation and separation between the fasteners an the implant.

The method of inserting the implant 20 is generally illustrated in FIGS. 4-7. Although not shown, the first step of the method requires that the jaw bone be exposed as illustrated in the FIGURES. This involves refracting or folding back of the gum tissue and periosteum layers. A slot 16 is then formed in the jawbone through the lingual surface of the latter in any conventional manner. In accordance with the preferred method, a grinding tool having a shaft 82 and a grinding portion 84 is utilized. The slot 16 is formed so as to have dimensions which are complementary to those of the implant 20. In this manner, the implant 20 is insertable into the slot 16 with little clearance. Engagement with little or no clearance provides for best support.

In FIG. 5, ajig 50 for drilling holes in the jaw bone 10 is shown which is suitable for accurately centering or aligning the holes in the jaw bone to thereby facilitate and decrease the time of establishment of the implant assembly.

The drilling jig 50 includes a bottom or lower alignment member 52 and an upper or top alignment member 54. Apertures 60 are provided in the alignment member 54 while apertures 62 are provided in the alignment member 52. The apertures in each of the alignment members are arranged so as to be aligned along lines generally normal to the lower or bottom alignment member 52. As described above, the present invention discloses an implant which utilizes three fastening members, although this is not a critical feature of the present invention. Accordingly, the drilling jig 50 is provided with three apertures in each of the alignment members which are disposed relative to each other similarly as are disposed the threaded

apertures

24, 26 in the implant 20.

In FIG. 6, the jig 50 is engaged with the jaw bone 10. More specifically, the lower or bottom alignment member is positioned interiorly of the slot 16 while the top or upper alignment member 54 is disposed above the alveolar crest 12. The drilling jig 50 is provided with a gripping portion or handle 58 which facilitates the manipulation of the jig 50 inside the patients mouth.

It should be clear from the above description, that the lower alignment member 52 simulates the implant 20 for purposes of drilling holes in the jaw bone 10. Thus, advantageously, the dimensions of the bottom alignment member 52 are similar to the dimensions of the implant 20 the dimensions of each being complementary to the internal dimensions of the slot 16. In this manner, the slot 16 engages the implant 20 as well as that portion of the bottom alignment member 52 which is receivable therein with little clearance.

Since the holes or alignment apertures 60 in the upper or top alignment member 54 are in vertical alignment with the holes 62 in the lower alignment member 52, the holes 60 in FIG. 6, when the upper alignment member 54 is disposed above the alveolar crest 12, pro vides an indication of the positions of the apertures 62 in the lower alignment member when the latter is fully 7 inserted in the slot or cavity 16. Due to the closely corresponding dimensions of the implant 20 and that portion of the lower or bottom alignment member 52 which is receivable in the slot 16, the holes 60 also provide an indication of the locations of the threaded

apertures

24, 26 when the implant is received in the slot 16.

With the jig 50 in position as shown in FIG. 6, holes can now accurately be drilled in the jaw bone 10 which extend between the alveolar crest l2 and the slot 16. A drill bit 64 represents any suitable drilling machine which may be utilized and guided into the holes 60 successively to thereby form a central elongate hole 70 and two lateral elongate holes 72 one on each side of the hole 70, as shown in FIG. 7. In drilling the holes, the drill bit 64 is advantageously lowered sufficiently so that the drill bit fully passes through the holes 62 in the lower alignment member 52 to thereby form holes of uniform diameter along the entire extent thereof. This requires that the drill bit 64 be capable of passing through both holes 60 as well as the holes 72.

Once the jaw bone has been prepared, as shown in FIG. 7, the dental implant may be fully assembled in a relatively simple and quick manner. Firstly, the implant is placed on the lingual side of the jaw bone 10 so as to permit insertion of the implant 20 into the slot or cavity 16.

In accordance with the presently preferred implant configuration, the latter is provided with a handle 29 similar to handle 58 of the jig 50, which facilitates manipulation of the implant 20 inside the patients mouth. Advantageously, the handle 29 is integrally formed with the implant 20 and meets the latter at a weakened line portion or neck 28. Once the implant 20 is fully inserted in the desired position in the slot 16, the handle 28 may be severed from the implant by merely angularly moving the handle 29 relative to the implant 20 and severing the two portions at the weakened line portion 28 to thereby form a stub 22, best seen in FIGS. 1 and 2. Advantageously, the implant 20 and the weakened line portion 28 are so configurated that subsequent to severance between the handle 29 and the implant 20, the stub 22 remains fully contained within the slot 16 and does not protrude exteriorly from the latter. This represents an advantageous feature of the present invention since this minimizes engagement between the implant 20 or the stub 22 and the sensitive tissues in the vicinity of the jaw bone 10 which ultimately revert into abutment against the lingual surface 14 of the jaw bone. Such full containment of the implant 20 within the confines of the slot 16 decreases the dangers of irritation, or infection, and promotes the growth of tissues which have been damaged during oral or dental implant procedures.

A second embodiment of the implant 20 is described in connection with FIGS. 8-12. The second embodiment, shown in FIG. 8, differs from the implant 20 described above by including an upper planar member 20a and a lower planar member 20b each of the planar members being essentially constructed in a similar manner to the construction of the above described implant 20. The upper and lower planar members, in the form of flat plates, are spaced from each other and are fixed in the spaced relationship by a detachable handle 29'. As with the handle 29 in FIG. 7, the handle 29' is advantageously integral with the planar members 20a, 20b and meet the latter at a neck or weakened line portion 28'. Each of the planar members includes a central aperture 26 and two lateral apertures 24. Accordingly 8 to one possible arrangement, only the apertures in one of the planar members are threaded. However, it is equally possible to provide internal threads in all of the apertures on both of the members.

The method of inserting a dental implant as shown in FIG. 8 into a lingual side of the jaw bone will now be described. Referring to FIG. 9, a grinding tool includes two grinding

discs

84a and 84b mounted on a shaft 82. The spacing between the two grinding

discs

84a and 84b is selected to be equal to the spacing between the planar members 20a and 20b of the dental implant. Two blind slots 16a and 1617, each similar to the slot 16 described in connection with FIG. 4, are formed in the jaw bone 10. After the two slots or cavities 16a, 16b have been formed, a recess or depression 16c is provided which extends between the two slots 16a, 16b, for reasons to become apparent hereafter. The recess 16c may be formed in any conventional manner.

A drilling jig 50, not unlike the drilling bit 50 of FIG. 5, is provided for facilitating accurate alignment of holes to be drilled through the jaw bone 10. The drilling jig 50 differs from the drilling jig 50 only in that an additional alignment member 59 is disposed between the lower or bottom alignment member 52' and the top or upper alignment member 54. Now, the lower alignment member 52' and the middle alignment member 59 are each receivable in respective slots 16b and 16a. As with the first embodiment, the dimensions of the alignment members as well as of the planar members 20a, 20b are configurated and dimensioned so as to be complementary to the slots 16b, 16a. The slots are so dimensioned as to closely receive either the planar members or the alignment members with little clearance. The apertures in the planar members share common alignment patterns with the apertures in the alignment members. Thus, once holes have been drilled in the jaw bone 10 which are in alignment with the apertures in the alignment members, the same holes automatically become aligned with the holes in the planar members when the latter are appropriately positioned in the slots.

In FIG. 11, the drill jig is shown in the drill bit guiding position wherein the bottom and middle alignment members are disposed in their respective complementary slots 16a, 16b while the top alignment member is disposed above the alveolar crest 12 of the jaw bone 10. The drill bit 64 represents drilling means suitable for passage through the apertures 60 the latter apertures guiding the drill bit 64 while holes are drilled in the jaw bone in accordance with the alignment pattern of the apertures 60.

After the slots have been cut, as illustrated in FIG. 9, and the holes have been drilled, as illustrated in FIG. 1 1, the dental implant may be inserted into the respective slots 16a, 16b. To facilitate manipulation of the planar members, the handle 29' may be gripped during the insertion step. After the planar members 20a, 20b are fully received in their respective slots, it is possible to sever the handle 29' by breaking off the latter at the weakened line portion 28'. However, a stub remains which bridges the two planar members 20a, 20b. In order to prevent the stub from extending beyond the lingual surface of the jaw bone, the stub is urged into the recess or depression 16c which has been provided therefor.

Once the double-plate dental implant is fully inserted interiorly of the jaw bone 10, as shown in FIG. 12, suitable fastening means such as shouldered and threaded post 30, as well as threaded and shouldered pins 40 are inserted through the drilled

holes

70, 72 and the post and pins are threadedly engaged with the apertures in the planar members. As suggested above, both planar members a, 20b may be provided with threaded apertures. Alternately, only the bottom planar member 20b is provided with threaded apertures while the apertures in the top planar member are sufficiently oversized to permit free passage therethrough of the post and pins 40.

It should be noted from the above description of both embodiments of the dental implant, that theplanar members or flat plates comprising the dental implants positioned interiorly of the slots are disposed in generally horizontal planes while the posts and pins which threadingly engage therewith are vertically disposed. Such arrangement is merely illustrative and both the planar members as well as the fastening members may be disposed in any other advantageous orientations. The orientations of the planar members and of the fastening members may be influenced by the degree to which the jaw bone has deteriorated along one portion thereof or another.

The dental implants in accordance with the present invention eliminate many of the disadvantages described in the Background Of The Invention associated with prior art implants. Firstly, the implants are simple in construction and economical to manufacture. The procedure for establishing a dental implant in accordance with the present invention is particularly simple and requires substantially less time than that associated with prior art implantation procedures.

A further advantage of the present implant is the provision of the handles or gripping portions 29, 29' which facilitate manipulation of the implants inside a patients mouth the handles being severable from the implants after appropriate positioning thereof has been effected. The dimensions of the implants are advantageously selected so that, even with a remaining stub from a broken off handle or gripping portion, the entire implant is fully contained within an associated complementary slot or cavity without extending exteriorly therefrom. By eliminating projections which protrude beyond the original jaw bone surfaces, or by fully implanting the present implant interiorly of the jaw bone, minimum interaction is obtained between the implant and the sensitive tissues around the jaw bone. Such construction minimizes or eliminates tissue damage during and after the implantation procedures.

Of substantial important in regard to the present invehtion is the improved distribution of stresses provided by the subject implants as compared to prior art implants. It should be clear that by providing a planar or flat implant mounted in a complementary slot, stresses applied by a dental prosthetic device on a post 30 on which it is mounted, produces markedly reduced local stresses in the regions of the post 30 due to the increased surface areas of the implant over which the stresses may be distributed. Instead, the stresses applied to the post 30 are simultaneously transmitted to the

planar members

20 or 20a and 20b. In this manner, instead of the stresses being localized about the periphery of the post 30, the stresses are distributed over the surface areas of the planar member 20. By providing a double planar member implant as shown in FIG. 8, the stresses are still further distributed by virtue of the increased area which comes into contact with the jaw bone. Stated otherwise, the greater the surface area which the implant makes with the jaw bone, the less concentrated are the local stresses on the jaw bone and the less likely that damage will be caused to the latter.

When it is desired to form two slots aligned essentially in a common plane and disposed on opposite lingual sides of the jaw bone, a jig 92 shown in FIG. 13 may be utilized. The jig 92 includes a rigid first extension member 94 provided at one end thereof with a planar portion 98 receivable in a slot cut on one lingual side of the jaw bone, as described above in connection with FIGS. 4 and 9. A rigid second extension 100 is provided at one end thereof with a guide portion 104 adapted to guide suitable cutting means 106, 108. In order to compensate for different jaw bones in which oppositely disposed jaw portions are spaced different distances, each of the extension member is provided with

straight end portion

96, 102. Each of these

straight end portions

96, 102 is provided with a slot or guideway (not shown). A screw 120 having a head 122 disposed on one side of the straight end portions extends through the guideways and is threadingly engaged with a nut 124. In this manner, the

extension members

94, 100 may be moved relative to one another to thereby vary the distance between the planar and guide

portions

98, 104. The screw 120, when the nut 124 is loose, permits relative sliding of the end portions 96,

102 to change the spacing between the portions 98,

104. The extension members are so configurated so as to position the guide portion 104 adjacently to the desired lingual position of the jaw bone where the second slot is to be cut but offset therefrom a distance approximating the height of the slot 110, when the extension members are connected to each other as shown. In this manner, the grinding disc 106 can be guided by the guide portion 104 to cut the other slot 110, showed in dashed outline in FIG. 13, in alignment and at the desired opposite lingual side of the jaw bone.

Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of the invention which is for purposes of illustration only and is not to be construed as a limitation of the invention.

What is claimed is:

1. Dental implant assembly for maintaining a dental prosthetic device in fixed relation with respect to a jaw bone, the implant assembly comprising a planar member adapted to be introduced into a blind generally transverse complementary cavity formed in the jaw bone without extending exteriorly therefrom; and securing means engageable through a bore substantially normal to the cavity with said planar member for immobilizing the latter within the cavity relative to the jaw bone, a portion of said securing means including support means projecting exteriorly of the jaw bone when said planar member and said securing means are in engagement, said support means being adapted to support a dental prosthetic device in fixed relation to the jaw bone during such engagement, said planar member comprising a flat plate having at least one threaded aperture therethrough, said securing means comprising a threaded fastener configurated to pass through a hole drilled in the jaw bone and engageable with said threaded aperture, three threaded apertures being provided in said flat plate, and three threaded screws being provided each of which being engageable with a respective one of said threaded apertures subse- 1 1 quent to passage through holes drilled in the jaw bone.

2. Dental implant assembly for maintaining a dental prosthetic device in fixed relation with respect to a jaw bone, the implant assembly comprising a planar member adapted to be introduced into a blind generally transverse complementary cavity formed in the jaw bone without extending exteriorly therefrom; and securing means engageable through a bore substantially normal to the cavity with said planar member for immobilizing the latter within the cavity relative to the jaw bone, a portion of said securing means including support means projecting exteriorly of the jaw bone when said planar member and said securing means are in engagement, said support means being adapted to support a dental prosthetic device in fixed relation to the jaw bone during such engagement, a gripping portion detachably connected to said planar member, said gripping portion being integrally constructed with said planar member and meeting the latter at a weakened line portion.

3. Dental implant assembly as defined in claim 2, wherein a stub remains on said planar member when said gripping portion is removed from said planar member at said weakened line portion, both said planar member and said stub being configurated to be fully receivable in the cavity without protruding exteriorly of the latter.

4. Dental implant assembly for maintaining a dental prosthetic device in fixed relation with respect to a jaw bone, the implant assembly comprising two spaced and substantially parallel planar members connected to each other and adapted to be introduced into spaced blind complementary cavities formed in a jaw bone without extending exteriorly therefrom; and securing means engageable with at least one of said planar members for immobilizing said members within the cavities relative to the jaw bone, a portion of said securing means including support means projecting exteriorly of the jaw bone when said at least one planar member and said securing means are in engagement, said support means being adapted to support a dental prosthetic device in fixed relation to the jaw bone during such engagement.

5. Dental implant assembly as defined in claim 4, wherein each of said planar members has at least one aperture in alignment with the corresponding aperture in the other of said planar members, at least one of said apertures being threaded, said securing means compris- 12 ing a threaded fastener adapted to pass through one of said apertures and engage the threaded aperture.

6. Dental implant assembly as defined in claim 4, further comprising a gripping portion detachably connected to both of said planar members.

7. Dental implant assembly as defined in claim 6, wherein said gripping portion is integrally constructed with said planar members and is connected to the latter at a weakened line portion.

8. Dental implant assembly for maintaining a dental prosthetic device in fixed relation with respect to a jaw bone, the implant assembly comprising at least one planar member adapted to be introduced into a respective generally transverse blind complementary cavity formed in the jaw bone without extending exteriorly therefrom, said planar member being provided with at least one threaded aperture therethrough engageable by a threaded fastener disposed through a hole in the jaw bone oriented generally normally to said planar member, whereby said planar member distributes stresses applied to the fastener by a dental prosthetic device mounted on an exterior portion of the fastener, and a gripping portion detachably connected to said planar member.

9. Dental implant assembly as defined in claim 8, wherein said gripping portion is integrally constructed with said planar member and meets the latter at a weakened line portion.

10. A method of inserting a planar dental implant assembly member into a jaw bone comprising the steps of cutting a slot in the jaw bone complementary to the planar member; inserting one alignment member of a jig into the slot while positioning an associated alignment member of the jig above the alveolar crest of the jaw bone; drilling holes in the jaw bone between the alveolar crest and the slot under the guidance of the apertures in the alignment members; inserting the planar member into the complimentary slot; introducing fastener means through the holes drilled in the jaw bone; and engaging the fastener means with the planar member while retaining an exposed portion of the fastener means adapted to support a prosthetic device.

1 l. A method as defined in claim 10, wherein the planar member is provided with threaded apertures, said fastener means are threaded screws, and wherein the step of engaging comprises the step of threadedly engaging the screw threads of the apertures and the threaded screws.

Claims

1. Dental implant assembly for maintaining a dental prosthetic device in fixed relation with respect to a jaw bone, the implant assembly comprising a planar member adapted to be introduced into a blind generally transverse complementary cavity formed in the jaw bone without extending exteriorly therefrom; and securing means engageable through a bore substantially normal to the cavity with said planar member for immobilizing the latter within the cavity relative to the jaw bone, a portion of said securing means including support means projecting exteriorly of the jaw bone when said planar member and said securing means are in engagement, said support means being adapted to support a dental prosthetic device in fixed relation to the jaw bone during such engagement, said planar member comprising a flat plate having at least one threaded aperture therethrough, said securing means comprising a threaded fastener configurated to pass through a hole drilled in the jaw bone and engageable with said threaded aperture, three threaded apertures being provided in said flat plate, and three threaded screws being provided each of which being engageable with a respective one of said threaded apertures subsequent to passage through holes drilled in the jaw bone.

5. Dental implant assembly as defined in claim 4, wherein each of said planar members has at least one aperture in alignment with the corresponding aperture in the other of said planar members, at least one of said apertures being threaded, said securing means comprising a threaded fastener adapted to pass through one of said apertures and engage the threaded aperture.

11. A method as defined in claim 10, wherein the planar member is provided with threaded apertures, said fastener means are threaded screws, and wherein the step of engaging comprises the step of threadedly engaging the screw threads of the apertures and the threaded screws.