US3566470A - Implant method for securing artificial teeth - Google Patents

Abstract

A SELF-DRILLING IMPLANT ADAPTED TO BE DRILLED INTO THE ROOT OF A TOOTH THROUGH AN END OF A REDUCED DIAMETER WHILE ITS OUTER END IS BENT TO FORM A HEAD OVER WHICH IS FITTED AN ARTIFICIAL TOOTH. THE IMPLANT IS MADE OF A METAL SUCH AS STEEL THE VICKERS HARDNESS OF WHICH RANGES BETWEEN 300 AND 500 AND IS PREFERABLY EQUAL TO ABOVE 350.

Description

March 2, 1971 J, SC 3,566,470

IMPLANT METHOD FOR SECURING ARTIFCIAL TEETH v Filed Feb. 16. 1968 I 7 l/mar" United States Patent 3,566,470 llVIPLANT METHOD FOR SECURING ARTIFICIAL TEETH Jacques Scialom, 15 Ave. Francis Berthier, 94 Le Parc Saint-Maur, France Continuation-impart of application Ser. No. 253,113, Jan. 22, 1963. This application Feb. 16, 1968, Ser. No. 705,974 Claims priority, application France, Feb. 20, 1967,

3 The portion of the term of the patent subsequent to June 4, 1985, has been disclaimed Int. Cl. A61c 13/00 US. Cl. 32-10 1 Claim ABSTRACT OF THE DISCLOSURE A self-drilling implant adapted to be drilled into the root of a tooth through an end of a reduced diameter while its outer end is bent to form a head over which is fitted an artificial tooth. The implant is made of a metal such as steel the Vickers hardness of which ranges between 300 and 500 and is preferably equal to above 350.

The term self-drilling implan as used throughout the specification and the claims is to be understood as an implant provided at one of its ends with a cutting section such that the implant may be used to drill a hole in which it is to be lodged.

In my copending application Ser. No. 253,113, now Pat. No. 3,386,169, filed on Jan. 22, 1963 and entitled Method and Means for Attaching Teeth and the Like to the Maxillar Bone, of which the present application is a continuation-in-part, I have described a method for securing dental prostheses to the bone of the maxillary by means of self-drilling implants provided at one of their ends with a cutting edge and at their other end with a head adapted to be driven by any suitable mechanical means. The results obtained by means of such implants driven into the bone tissue have been extremely favorable since a number of very special conditions were simultaneously satisfied thereby: on the one hand the engagement inside the bone tissue becomes a very easy matter by reason of the reduced hardness and large elasticity of the latter and on the other hand, the implant is reliably and securely held in position by reason of this same elasticity and of the speedy osteosynthesis which clamps tightly the implant inside its housing and lastly the metal forming the implant is tantalum which is non-attacked by the liquids carried by the bone tissue and also is bestowed with the metallurgical properties required for executing a drill therewith.

However, the insertion of such drills into the actual tooth appeared to be impossible for difierent reasons. Firstly, the material forming the tooth or so-called dentine is neither soft nor elastic but is hard and only very slightly elastic. Under such conditions, it seemed highly improbable that a self-drilling implant of the type to be inserted into the bone tissue could be inserted through a self-drilling operation into dentine and be clamped tightly by the dentine when inserted therein without any further operation being required. Furthermore, an oblique insertion is not applicable in the case of the actual tooth, except in rare instances and no one could imagine it might be possible to obtain a reliable securing of the implant without a preliminary drilling of a cavity and without sealing the implant in such a cavity by means of cement as is the case of a conventional securing of a pivot into a tooth. Nor could any one imagine that it might be possible to resort to a metal other than tantalum for the 3,566,470 Patented Mar. 2, 1971 "ice execution of the implant and in particular to certain metals generally used by dentists, with which metals it might be possible to obtain together a sufficient sharpening for the implant to enter the tooth, an elasticity such as to cut out any risk of breaking during the drilling operation, since such a breaking would be a most serious mishap and a ductility high enough to allow the outer section of the implant including the head to be bent if required at a suitable angle, since the implant has been inserted in the root of a tooth, the artificial tooth being fitted over such a bent head.

My investigations have led me to perfect a method for securing an artificial tooth to the actual dentine of the root of a tooth and to devise a novel implant for the execution of said method.

I will now describe by way of example, reference being made to the single figure of the accompanying drawing, an implant executed in accordance with my invention and I will also disclose the method for securing an artificial tooth to the root of a tooth in accordance with my invention.

As illustrated, the implant is constituted by a substantially cylindrical stem or rod 6 of a circular or polygonal outline the diameter of which ranges between 0.3 and 1.5 mm. and preferably between 1 and 1.2 mm. One of its ends is defined by cutting edges 5 formed in the case illustrated at the end of a flattened section 3.

The section of the implant provided with cutting edges has a breadth less than or at the utmost equal to the diameter of the rod 6 forming the implant. Under such conditions, the diameter of the hole to be drilled in the root of the tooth is slightly less than or at the utmost equal to that of said rod, and consequently when the implant is accurately positioned, the self-drilling implant is tightly held inside the housing drilled by it.

At its other end, the rod 6 carries a head 7 which is not cylindrical and which serves for driving the rod into rotation, the shape of said head being such that it can be fitted in conventional rotary driving means such as the socalled contra-angles.

The implant is made of a metal such as steel for instance showing the following properties:

A hardness suflicient for its cutting edges to be capable of drilling inside the tooth dentine, said hardness ranging between 300 and 500 Vickers, preferably above 350 Vickers. However, it should not be brittle in its section 8 adjacent the head so that the operator, after urging the instrument into position, may deform it without risking a breaking or splitting of the tooth.

The artificial tooth is secured as follows in accordance with my invention:

The root of the tooth being prepared in the usual manner after removing the nerve out of the dental canal 1, 2, the self-drilling implant is fitted in a contra-angle or the like conventional rotary driving means. The implant is then caused to rotate under the action of the contra-angle and urged into the dental canal as provided by a gradually increasing pressure applied to it. Since the cutting edge of the implant drills a hole the diameter of which is not larger than that of the rod 6, at least part of the pulverulent dentine produced in the drilling remains in the gap between the outer surface of the implant rod and the inner surface of the hole which is being drilled and is highly compressed inside said gap, which ensures, taking into account the low elasticity of the dentine, carrying no cement, an excellent locking of the implant in position. The implant may extend up to the apex of the root and if the dental canal is incurved it continues progressing along a straight line as illustrated.

When the implant has been sufliciently driven into the root the operator removes the contra-angle and leaves the implant in position inside the root. He bends the'outwardly projecting end 8 of the implant so as to give it any suitable shape such as that of a hook, as illustrated. It is then an easy matter to secure the artificial tooth 10 over the head 7, 8 of the implant with the interposition of a false stump 9, as provided by conventional means.

Instead of inserting the implant into the dental canal, it may be inserted inside the solid section of the tooth. In the latter case, it is of advantage to resort to self-drilling implants of the type disclosed the diameter of which is very small and ranges between 0.3 and 0.8 mm. a preferred value being 0.5 mm. whilethe length of its rod section is small, its total length ranging between 4 and 10 mm. and a number of such implants being distributed within the periphery of the root.

It should be remarked that self-drilling implants thus inserted into a tooth cannot practically be torn out since they have been inserted with a force fit into a hole drilled by the implant itself and the diameter of which is less than or at the utmost equal to that of the implant rod.

What I'claim" is 1. A method for securing an artificial tooth on the root of a patients tooth consisting in engaging with a rotary instrumentality an implant provided at one end with a terminal cutting section of a diameter less "than the remainder of the implant, introducing during its rotation said implant without any cement into the root down to a predetermined depth, removing the rotary instrumentality, bending the other end of the implant which is opposite said one end and which projects outwardly of the root, and fitting an artificial tooth over said other end.

References Cited UNITED STATES PATENTS 3,386,169 6/1968 Scialo m' 32-10 403,428 5/1889 Hansen 3213 616,302 12/1898 'Evans 32-13 2,472,103 6/1949 Giesen '12892E ROBERT PESHOCK, Primary Examiner

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