METHOD AND MEANS FOR AFFIXING A COMPONENT TO A DENTAL IMPLANT
Field Of The Invention
This invention relates to the art of restorative dentistry, and more particularly to that segment of the art which employs artificial roots to restore edentulous patients. This application is a continuation-in-part of pending U.S. patent application Serial No. 08/208,212, filed on March 10, 1994, which in turn is a continuation-in- part of U.S. patent application Serial No. 08/016,538 filed on February 11, 1993, now issued as U.S. Patent No. 5,322,443. Background Of The Invention
At the present time, owing in part to its predictable success, the endosseous dental implant fixture in cylindrical form is the artificial root most frequently chosen for restoring dentition to edentulous patients when implant treatment is selected. These and other forms of artificial tooth roots are conveniently designed to receive and retain, sometimes removably, a variety of intermediate components including abutments which prosthodontists use to support artificial dentition on artificial roots. The intermediate components are necessarily small parts which must be manipulated into sometimes deep posterior locations in the patient's mouth and there assembled on an existing implant fixture or fixtures into rigid and reliable structures which can withstand the forces of mastication. More and more commonly the implant fixtures have internally threaded bores for receiving small screws which are used to attach the intermediate components to the implant fixtures, and to each other, and they have hexagonal or other non-circular means for anti-rotationally engaging such intermediate components. For biological reasons the implant fixtures and intermediate components are most often made of titanium and its dilute alloys, while the screws are made of the same metals or of gold, for example. Typical diameters of implant fixtures are from about 3 mm. to about 5 mm. Typical screw diameters are about 2 mm. or less. Typically, intermediate components have diameters in the same range as implant fixtures, and lengths short enough to be encompassed within an artificial tooth, or shorter. The problems of carrying such components to an implant fixture installed in a patient's jawbone and there affixing a component to the implant with a screw, and rotating the components to engage or mate with anti-
rotational features on the implant fixture, without cross-threading the screw in the threaded bore of the implant fixture, are obvious.
Abutments and other intermediate components are made in a wide variety; some are small transmucosal components as small as one millimeter long, while some are several millimeters long intended to form the core of an artificial tooth; others may extend on an axis different from the longitudinal axis of the implant fixture, for adjusting the alignment of an artificial tooth relative to its neighbors; all must be affixed to the implant fixture. To do this the dental professional must hold the component in place on the implant fixture while inserting a screw through a small hole in the component and turning the screw in the threaded bore of the implant fixture until the screw is tight and the component is firmly affixed to it. This task becomes particularly onerous when the implant fixture is installed in a posterior region in the patient's mouth.
A dental clamp for gripping a cylindrical abutment is shown in U.S. Patent No. 5,120,221 dated June 9, 1992. Summary Of The Invention
In accordance with the present invention, there is provided a tool for use in manually positioning and manipulating a selected article at a prepared implant site in a bone in the mouth of a patient. The tool comprises an article holder having a lower end for engaging the top of the selected article; a fastener passing longitudinally through the article holder for cooperation with the selected article engaged by the lower end of d e article holder; a driver mounted for rotation in the article holder and extending downwardly through the article holder for engaging the top of the fastener, so that the fastener can be rotated by rotating the driver, the top of the driver extending above the top of the article holder so that the driver can be turned with the fingers of the person positioning and manipulating the selected article; and a handle attached to the top of the article holder and extending upwardly from the article holder to permit the person positioning and manipulating the selected article to simultaneously position and manipulate the holder and turn the driver with fingers of the same hand.
In one embodiment of die invention, the selected article is an implant carrier, and the fastener is a screw for attaching an implant to the implant carrier. In another
embodiment, the selected article is an implant abutment, and the fastener is a screw for attaching the abutment to an implant.
In the preferred form of the present invention for handling abutments or other intermediate components, the tool employs two telescopically-interfitting parts, the inner one removably attached to the screw head and the other removably attached to a supraginvival end of the intermediate component, for holding the screw and the component in relative positions suitable for installing them on the implant fixture and carrying them to the implant fixture in those positions, and there while holding the component in place on the implant fixture with the outer part using the inner part to turn the screw into the threaded bore of the implant fixture. Cross-threading of the screw is prevented by virtue of the fact that the component is firmly seated on the implant fixture with the aid of the outer part and die two telescopically interfϊtting parts align the screw accurately with relation to die threaded bore. The two interfϊtting parts can be designed to form an assembly including resilient means, such as a spring, to enable the inner part to press down on d e outer part while turning the inner part, so that the entire installation procedure can be completed with two fingers (e.g.: thumb and forefinger) while turning the inner part to install the screw. When the installation procedure is finished both parts can be detached from the screw and d e component simply by pulling them away in the supragingival direction. It is not necessary to tighten the screw to its final torque limit with the carrying and affixing means of the present invention; that task can be performed with a separate torque- limited driver.
The invention lends itself to packaging in a sealed container, which may be a sterile container if desired, so that a component and related screw may be delivered to a dental professional in a "ready for installation" condition. Thus, d e present invention simplifies an onerous task while improving the accuracy with which that task is done, and saves die user valuable time while reducing die risk of infection.
In the preferred form of the invention for use in handling an implant carrier to manually insert a dental implant into a prepared implant site in a bone in the mouth of a patient, die tool comprises a holder for the implant carrier, the holder having a lower end for engaging the top of the implant carrier so that the implant carrier is retained in the holder; a driver mounted for rotation in the holder and extending
downwardly tiirough the holder for engaging the top of the screw, so that the screw can be rotated by rotating the driver, die top of the driver extending above the top of die holder so that the driver can be turned with the fingers of the person installing the implant; and a handle attached to d e top of die holder and extending upwardly from the holder to permit the person installing the implant to simultaneously manipulate the holder and turn the driver witii fingers of the same hand. Mating male and female anti-rotation elements are formed on me top of said implant and die bottom of said implant carrier, and die bottom of the holder forms a socket for receiving the top of the implant carrier. The handle is formed as an integral part of said holder, and extends over die top of die driver. The top of die driver forms an enlarged head which extends laterally beyond die handle to facilitate turning of the driver witii the same fingers that grip the handle. Brief Description Of The Drawings
The appended drawings illustrate the background of die invention and exemplary embodiments of it. In tiiese drawings:
FIGURES 1 and 2 illustrate, respectively, a transmucosal component and related screw and a dental implant fixture on which they are to be installed;
FIGS. 1A and IB are end views of FIG. 1;
FIG. 3 illustrates a tubular part for holding die transmucosal component; FIG. 4 illustrates a part for holding the screw;
FIG. 5 shows the parts of FIGS. 3 and 4 telescopically interfitted and holding the transmucosal component and die screw in the relative positions tiiey will occupy for installation on d e implant fixture;
FIG. 5A is a modification of FIG. 5; FIG. 6 is a side view of anotiier embodiment of the invention;
FIG. 7 is a longitudinal section through FIG. 6 showing a spring used to aid in a two-finger installation;
FIG. 8 is an exploded view of die parts of the embodiment shown in FIGS. 6 and 7; FIG. 9 is a longitudinal view partly in sections showing the embodiment of
FIG. 6 in a sealed container;
FIG. 10 is a longitudinal section through a modified embodiment of die invention for use in handling and manipulating an implant carrier and its attachment screw;
FIG. 11 is an end view taken from the top end of die assembly shown in FIG. 10; and
FIG. 12 is a section taken generally along line 12-12 in FIG. 10. Detailed Description Of The Preferred Embodiments
FIGS. 1 and 2 show a typical transmucosal component 10 and a typical screw 12 for use to install the transmucosal component on a dental implant fixture 14 which has been installed in jawbone 16. The screw and die transmucosal component are shown in relative positions suitable for installing them on the implant fixture, which has an internally-threaded bore 18 for receiving the screw. As is typical in die art, die implant fixture may have an anti-rotation boss 20 extending supragingivally from it, and d e transmucosal component 10 may have a mating socket 22 for interfϊtting with die boss 20. In practice, the boss and die socket may be reversed. In eitiier case, the transmucosal component must be fitted to die implant fixture with these anti-rotation devices engaged one in the other, prior to turning the screw 12 into the bore 18.
FIG. 3 shows in longitudinal section a tubular holder part 28 for the transmucosal component 10. The internal diameter of this holder part is expanded at its lower end 30 to provide a recess with an internal shoulder 36 for receiving the supragingival end of die transmucosal component. The wall around d e recess can be longitudinally slotted if desired to provide a circular array of resilient fingers (see FIG. 6) for releasibly holding die transmucosal component; alternatively the holder part 28 can be made of a resilient plastic material, in which case the wall around die recess can be continuous and die normal resilience of die plastic material will suffice to do die same thing. At its other end d e holder has an expanded head 32 gripping it and a second internal shoulder 34 for a purpose to be described.
The second holder part 40 shown in FIG. 4 is cylindrical in shape for telescopically fitting within the tubular holder part 28. This second part has a socket 42 in its lower end 44 for embracing die head 13 of die screw 12. This particular screw has a hexagonally-shaped head, and d e socket 42 in the illustrated embodiment
is matingly hexagonal. This is an optional feature adopted to accommodate a particular screw; the invention is not limited to it. For example, the male-female relation of die head 13 and die socket 42 may be reversed. An annular boss 46 is also located near the lower end 44. When, as is illustrated in FIG. 5, the second holder part 40 is telescopically fitted witiύn the tubular holder part 28 the boss 46 will stop against die second shoulder 34.
Referring now to FIG. 5, the two holder parts are shown with die second part 40 telescopically interfitted in die tubular part 28. To do this, the second part with d e screw 12 engaged may be inserted through the lower end 30 of d e tubular part 28, and thereafter the transmucosal component 10 may be attached to die tubular part. This arrangement provides an assembly of the holder-carrier 28, 40 and die dental components 10, 12 which can be brought as a unit to d e dental implant fixture 14 with two fingers (e.g.: thumb and forefinger) of one hand holding die assembly by e expanded head 32. At d e implant fixture, the transmucosal component is then manipulated into place on die implant fixture and, while gently holding die transmucosal component against the implant fixture, die second holder part is turned to drive d e screw 12 into die ti readed bore 18. This assembly can be delivered as a unit to the end user, i.e.: a prosthodontist, periodontist, oral surgeon or other qualified dental professional. It lends itself to encapsulation in a sterile package, if desired.
In FIG. 5A a manipulator 130 is fixed to die upper end of d e second (driver) part 40, and holder means 132 having a bight portion 132a and two substantially parallel arms 132b and 132c is attached at the free ends of d e arms to substantially diametrically opposite sides of die head 32 of die holder part 28. The bight portion 3132a overlies the manipulator 130, and die manipulator fits between the arms 132b and 132c. In use, the holder means carries the assembled tool with the screw 12 and component 10 to a work site, where the bight portion 132a can be used to press die component to the implant with one finger while the manipulator can be turned witii two other fingers of the same hand. The embodiment of die invention tiiat is illustrated in FIGS. 6, 7 and 8 is unitary tool which includes a means to hold down die tubular part of the invention while turning the screw component with the second part of the invention. This
embodiment is also designed to be compact so that it will minimally obscure the user's view of the task being performed, and will be easy and economical to package and ship. The outer tubular part 50 has spring-fingers 52 separated by longitudinal slots 54 at its lower end 56 for holding die abutment 10. The inner second part 60 is an assembly of two members, a head member 60.2 and a screw-holder member 60.1 having a stem 60.3. The tubular part 50 has a diametrically reduced section 58 between its ends providing a first shoulder 58.1 facing die lower end 56 and a second shoulder 58.2 facing in the opposite direction. The holder member 60.1 has a socket member 60.4 of larger diameter than its stem 60.3 affixed to die lower end of die stem, and forming a shoulder 60.5 where it joins the stem. The socket member has a non-round socket 62 for holding d e matingly non-round head 64 of a screw 66 which is equivalent to the screw 12. To assemble this tool the stem 60.3 is passed through the lower end 56 of d e tubular part 50 and through the reduced section 58 so that the shoulders 58.1 and 60.5 confront each other, a coil spring 68 is fitted over d e stem 60.3 in the upper well 70 of the tubular part, and die head member 60.2 is press- fitted onto d e free end of die stem. A turning knob 72 is provided on die free end of die head member.
In use, die screw 66 is fitted into die socket 62 and die component 10 is thereafter fitted into the spring fingers 52. This assembly is then carried to die installed implant fixture and die abutment is put in place on the implant fixture witii the outer part 50. The knob 72 may then be grasped between the thumb and forefinger and pressed down toward die implant while the knob is turned to drive die screw into the implant fixture. The spring 68 provides resilient force to hold die component 10 on me implant while the screw is being turned. The tool of FIGS. 6, 7 and 8 may be made of materials such as stainless steel which can be autoclaved. No lubricant is used in its construction. Alternatively this tool can be made of disposable materials and it can be delivered to die user in a sterile package including die component and screw to be installed on an implant fixture. FIG. 9 shows die tool of FIG. 6 enclosed in a capsule 80, which may be made of glass or plastic, for example, and is closed witii a cap 82 which may be made of rubber or plastic, for example. The outer tubular part 50 is located witii an O-ring
84 within the capsule. As is shown, die abutment 10 may be held against die bottom of the capsule, to prevent it from falling away from the spring fingers 52. In use, the cap 82 is removed and die tool is removed from die capsule with the turning knob 72 which is then used to carry the abutment 10 and screw 66 directly to the dentalimplant fixture 14.
A modified embodiment of die invention, for use in handling and manipulating a dental implant carrier, is illustrated in FIGS. 10 - 12. An implant carrier is a device that is used to hold an implant as it is inserted into a patient's mourn and installed into a prepared site in the patient's jawbone. The carrier is also used to turn die implant to thread it into the jawbone.
In FIG. 10, an implant carrier 200 has a hexagonal socket 201 formed in its lower end for receiving a complementary hexagonal head 202 on die top of a dental implant 203. The implant 203 is held securely on the carrier 200 by a screw 204 which extends longitudinally dirough the hollow interior of the carrier 200 and is tiireaded into an internally threaded bore in the top of die implant. To prevent the screw 204 from escaping from the carrier 200, the screw 204 must be threaded dirough a short internally tiireaded section 205 of die carrier before the screw can be threaded into the implant. Thus die screw is captured within the carrier 200.
To permit the implant 203 to be threaded into die jawbone of the patient by turning the carrier 200, which will still extend well above the gingiva even when the implant is in its desired final position witiiin the jawbone, the carrier has a hexagonal head 206 that can be engaged by a standard wrench or otiier suitable driver. Turning d e carrier 200 causes turning of d e implant 203. After the implant has been threaded into the patient's jawbone, the screw 204 is threaded out of die implant to permit the carrier and its captive screw to be removed from the implant and d e patient's mourn.
For die purpose of facilitating the handling and placement of the carrier- implant assembly, a holder 210 has a hexagonal socket 211 in its lower end for receiving and frictionally retaining the hexagonal head 206 of die carrier 200. Captured within the holder 210 is a driver 212 having a small hexagonal head 213 on its lower end, for engagement witii a complementary haxagonal socket 214 in the top of die carrier screw 204. If desired, die driver may be designed as described in U.S.
Patent No. 5,105,690, which is incorporated herein by reference. The driver 212 can be rotated within the holder 210 for threading die screw 204 in and out of die implant 203, which is particularly useful for removal of the screw from the implant after the implant is in place in the patient's moutii. As in the case of the holder described above in connection with FIG. 5a, the holder 210 has a handle or manipulator 215 extending upwardly from, and diametrically across, die top of die holder. This handle 215 extends across die top of die driver 212, which is equipped with a knurled knob 216 which extends laterally beyond opposite sides of die handle 215 (see FIG. 11). Consequently, both die handle 215 and die knob 216 can be simultaneously gripped and manipulated with d e thumb and forefinger of the person installing the implant in the patient. This is a significant advantage when working within the close confines of a patient's mouth.
If desired, die holder 210 can also be used as die driving tool for turning die implant carrier 200, and thus die implant itself, to thread die implant into the patient's jawbone. Here again, the handle 215 on die top of die holder 210 can be used to advantage.