US3279067A - Ultrasonic bonding - Google Patents

Description

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uct. w, 1966 R. HOFFMAN 3,279,067

ULTRASONIC BONDING Filed March 12, 1963 HIGH GENERATOR INVENTOR. ROBERT HOFFMAN ATTOR NEYJ United States Patent "ice 3,279,067 ULTRASONIC BONDING Robert Holfman, 9833 64th Ave., Rego Park, Queens, NY. Filed Mar. 12, 1963, Ser. No. 264,573 3 Claims. (Cl. 32-1) This invention relates generally to the medical art; more specifically it presents a novel method and process of joining and combining to human tissue; and in detail, it is concerned with the utilization of ultrasonic waves and vibrations for bonding to human tissue.

In the prior art, it is known to utilize mechanical means or at times adhesive means to bond or adhere any desired substance to human tissue. For example, in the field of dentistry, when filling cavities or in other mouth restoration work, joining materials, such as metals and the like, are utilized to fit within and around prepared surfaces. The teeth surfaces must be ground so as to permit the material such as amalgam to be wedged against portions thereof or to project partially therewithin. Although many variations and embellishments of this art are known, they all utilize the mechanical properties of the material being added to lock to the desired tooth structure. Teeth are but one example of human tissue and similar effects are utilized throughout the medical art for like purposes.

Of course, these mechanical processes suffer from several well known disadvantages. For example, the human tissue must be prepared mechanically to receive and wedge and thereby lock the material to be added in place. This is not always convenient or even possible and sometimes makes necessary the removal of excess tissue. Additionally, there is no assurance of uniform and even joining of the material being added to the tissue. In clinical applications, it is well known that a less than completely uniform joint and interface is often obtained.

This invention contemplates the utilization of ultrasonic waves and vibrations properly coupled to chemically combine the material to be added and the tissue to provide a more etficient bond and one that may be obtained directly against the tissue without the necessity of mechanical wedging, although the same may be utilized, if desired.

The above permits molecular bonding which would be useful. For example, it could be utilized to restore a hard tissue destroyed as a result of caries. This could be done without dependence upon the necessarily defective interfaces presently obtained by surface adaptation or cement. Molecular bonding of restorations would permit the penetration at the interface of the restoration material with the hard tissue and would provide a thoroughly leak-proof and permanent interface.

Additionally, the new method and process of molecular bonding would be especially useful in the treating of periodontal disease. The invention provides an improved method of affixing a stabilizing appliance.

Additional advantages would be obtained in fields such as orthodontics and prosthetics and in fact, to all of the other analogous medical arts.

It is a cardinal object of this invention, therefore, to provide a method and process for bonding a material chemically to human tissue, such as bone, cementum, dentine and enamel.

Another primary object is to set forth an apparatus for conveniently accomplishing the above.

With these objects in view, the invention consists of the novel features of construction and arrangement of parts which will appear in the following specification and recited in the appended claims, reference being had to the accompanying drawings in which the same reference 3,279,067 Patented Oct. 18, 1966 numerals indicate the same parts throughout the various figures and in which:

FIG. 1 is a view in perspective of the instant invention being utilized for the purpose of aflixing material to a tooth surface.

FIG. 2 is a diagramatic representation of one form of ultrasonic wave generator taken substantially along line 2-2 of FIG. 1.

FIG. 3 is an elevational view partially in section to illustrate the unique bonding obtained according to this invention.

This invention utilizes a high frequency generator to chemically bond to hard human tissue such as teeth.

Although the description set forth hereinafter will refer to teeth restoration, it is to be understood that this invention could equally well be utilized to bond to any hard human tissue. In such bonding, however, it is important that the material to be added strongly, bond to the tissue to prevent breakdown and resulting pain, discomfort and danger to health. For this purpose, ultrasonic vibrations are herein utilized to chemicaly mix the material to be added such as metal or the like to the tissue structure.

Elastic waves of frequencies beyond the range of audibility, called ultrasonic or supersonic waves, have been found to produce some interesting results. If the frequency of the waves is raised to a relatively high degree and coupled properly, they may produce vibration and thereby physical movement of each molecule comprising a material. Thus, at the interface of two materials in intimate contact that are supersonically vibrated to a desired extent, there may be a physical intermixing of some of the molecules of each of the materials with the other, thereby causing a chemical joinder of the two said materials.

There are several well known methods of generating ultrasonic frequency waves. For example, there are purely magnetic methods including vibratory components and electronic methods including piezo-electric or magneto-strictive vibratory systems. The frequencies generated by such systems range upward and exceed 200 or 300 kilocycles per second and often range upward into the megacycle range.

It has been found that when such vibrations are caused to exist between a material such as a metal, and human tissue, there will be a chemical mixing of the molecules comprising the metal and those of the human tissue. This is far superior to the joining of a physical nature which was heretofore possible.

It is to be emphasized that it is contemplated that the bonding herein is a true solid-state bond. The wandering of the molecules between the two materials being joined is a direct result of the introduction of elastic vibratoryenergy into the materials being joined.

The invention set forth herein may be especially useful when applied to the combination of a metal and enamel as commonly found in teeth in that both contain a definite crystalline structure.

By way of example, there is illustrated in FIG. 1 dental tissue 10, the enamel of which will require an attachment for dental treatment or restoration as set forth heretofore. The attachment will be applied to a shield which will be formed from a metal 12 and ultrasonic vibrations will be utilized to mechanically bond the same to the tooth enamel. For the purposes of this description, a hand tool 14 is shown generating the desired ultrasonic vibrations.

The operation of the exemplary hand tool 14 may be explained by reference to FIG. 2. There is shown in that figure, which is primarily diagrammatic, the section through the tool 14 showing the outer casing 15 thereof and an inner tip of a magnetically attractive material 16. The said tip 16 will extend at least partially through the longitudinal axis of the casing 15 of the hand tool 14 and will have a tip portion 16a extending partially from the front thereof. The central tip 16 will be surrounded by a plurality of evenly spaced coils of wire 18, 19 and 20. The coils of wire 18, 19 and 20 are each connected electrically to a rotating oscillator 21 which will act as a high frequency wave generator. Each of the coils 18, 19 and 20 will be connected to the oscillator 21 in a fashion electrically spaced relative to the waves generated by the oscillator 21 corresponding to the physical positioning of the said coils about the tip 16.

One end of the tip 16 may be fastened to the hand tool 14 and the remainder thereof including the extending tip portion 16a thereof will be free to vibrate.

Thus, as the high frequency waves are caused to be rotated about the magnetically attractive tip 16 they will cause the said tip 16 to correspondingly vibrate as desired. The amplitude of the viebration will be dependent upon the strength of the generated rotating magnetic field and the rigidity of the said tip 16. However, it will be seen that the extending end tip portion 160 of the hand tool 14 may be caused to vibrate ultrasonically as desired, merely by adjusting the oscillator 21.

Of course, it is to be emphasized that the generating means that is set forth herein is shown merely for exemplary purposes and any other well known high energy vibratory means may be substituted therefor.

Referring particularly to FIG. 1, there will be described a method of bonding an attachment to the enamel surface 11. A wire or the like of a material to be utilized to form the attaching plate or shield, such as of aluminum, or the like, will be placed on the said dental enamel 11. The ultrasonically vibrating extending tip portion 16a of the hand tool 14 will then be urged against the said aluminum 12. The tooth to be treated, however, will be secured in a relatively stationary manner within the mouth. If necessary, this may be accomplished by any suitable stationary and rigid clamp as at 30. Thus, at the intersection 31 of the aluminum 12 and the dental enamel 11, there will be relative vibration of the two materials at the desired supersonic frequency.

As set forth therein, this will cause a wandering of some of the molecules of each of the materials into the molecules of the other material thus causing a chemical intermixing of the aluminum 12 and the structure of the tooth 10.

This then provides a bond between the two materials to a degree never before obtainable.

In the illustrated embodiment of the invention, the aluminum material 12 will be chemically bonded in a thin film over an area of the dental enamel 11. This then presents a surface of a metal which may be utilized for any desired medical purpose such as for the attachment,

of an appliance 40 for orthodontic use.

It should again be noted that never before was such bonding to a surface of dental enamel or other similar tissue possible.

When it is desired to fill a cavity, the hand tool 14 may be held against the aluminum 12 until the said aluminimum entirely fills the cavity. The relative high frequency vibration of the aluminum 12 relative to the tooth 10 will cause portions of the said aluminum 12 to flow as would a plastic or liquid material until the said cavity 11 is entirely filled.

It should again be noted that although specific materials are mentioned to be utilized in conjunction with tooth restoration, it is not contemplated that this invention is to be so limited. It is rather contemplated that similar bonding in any similar medical application to human tissue may be accomplished.

By way of example, chemical bonding such as described hereinabove, to tooth enamel, was accomplished using aluminum of a diameter of .005 inch. The said aluminum was placed against the labial surface of a central incisor. Ultrasonic vibrations in the range of kilocycles were applied to the aluminum. A high degree of chemical bond was found to exist between the aluminum and the dental enamel.

The device utilized was basically a generator producing the desired ultrasonic frequency supplying a force insensitive transducer. The transducer was of the magneto-strictive type. In such a device, electrical waves converted to mechanical vibrations as a result of the tendency of a magnetically attractive rod to increase and decrease slightly in length as the intensity of the magnetic field varies.

Attached to the transducer was a tip acting as a coupling system to transmit the vibratory energy to the aluminum to be bonded. The tip or coupler was designed to operate at maximum cfiiciency at its resonant frequency which was approximately 60 kilocycles per second. The tooth was held in position by a fixed anvil.

While there are above described but a limited number of embodiments of the structure and product of the invention herein presented, it is possible to produce still other embodiments without departing from the inventive concept herein disclosed and it is desired, therefore, that only such limitations be imposed on the appended claims as are stated therein or required by the prior art.

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent is:

1. The method of attaching a relatively thin piece of metallic material to relatively hard animal tissue, namely teeth and bone, for medical purposes including the steps of, urging said material against said tissue, and applying ultra-high frequency vibrations to said material thereby causing said material to vibrate relative to said tissue thereby chemically bonding to said tissue.

2. The method of attaching a relatively thin piece of metallic material to relatively hard animal tissue, namely teeth and bone, for medical purposes including the steps of, urging said material against said tissue, rigidly clamping said tissue thereby preventing any vibration thereof, and applying ultra-high frequency vibrations to said material thereby causing said material to vibrate relative to said tissue thereby chemically bonding to said tissue.

3. The method of attaching a material to relatively hard animal tissue for medical purposes as set forth in claim 1, wherein said applied ultra-high frequency vibrations are in the order of sixty kilocycles.

References Cited by the Examiner UNITED STATES PATENTS 1,939,712 12/1933 Mahoux 148-129 2,651,148 9/1953 Carwile 12824 3,022,814 2/1962 Bodine 15673 3,047,942 8/1962 Schneider et al. 15673 X RICHARD A. GAUDET, Primary Examiner.

ROBERT E. MORGAN, Examiner.

Claims (1)

1. THE METHOD OF ATTACHING A RELATIVELY THIN PIECE OF METALLIC MATERIAL TO RELATIVELY HARD ANIMAL TISSUE, NAMELY TEETH AND DONE, FOR MEDICAL PURPOSES INCLUDING THE STEPS OF, URGING SAID MATERIAL AGAINST SAID TISSUE, AND APPLYING ULTRA-HIGH FREQUENCY VIBRATIONS TO SAID MATERIAL THEREBY CAUSING SAID MATERIAL TO VIBRATE RELATIVE TO SAID TISSUE THEREBY CHEMICALLY BONDING TO SAID TISSUE.

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