US2538486A

US2538486A - Reinforcement for a tooth filling

Info

Publication number: US2538486A
Application number: US1721A
Authority: US
Inventors: Benjamin F Tofflemire
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-01-12
Filing date: 1948-01-12
Publication date: 1951-01-16
Anticipated expiration: 1968-01-16

Description

Jan. 16, 1951 F. TOFFLEMIRE 2,538,486

REINFORCEMENT FOR A TOOTH FILLING 2 Sheets-Sheet 1 Filed Jan. 12, 1948 .41, I I l I I l I l INVENTOR.

' B:E.IB\I};JA;MU\I E TOFFLEMIRE ATTORNEYS 1 1951 B. F. TOFFLEMIRE V 2,538,486

REINFORCEMENT FOR A TOOTH FILLING Filed Jan. 12, 1948 2 Sheets-Sheet 2 INVENTOR. BENJAMIN FTOFFLEMIRE mizw aw ATTORNEYS matrix bands.

Fatented Jan. 16, 1951 a UNITED STATES PATENT O FFICE 2,538,486 I i V REINFORCEMENT FoRin- 'roo'rn- FILLING Benjamin F.. maem Lafayette; Calif. Application January 12, 1948'; Serial bio. 1,721

6 Claims.

, The present invention relates to improvements nearly meets the requirements of the majority of patients than any other filling material that hast been used in modern dentistry. Amalgam isu'sed' successfully by practically every dentist ingeneral practice. 7

Z; some of the most serious'objections to the use of amalgam in the past have been its lack of marginal edge-strength; its limited ability to resisti f'flow" when subjected to heavy masticatory stresses; its dimensionalinstability, particularly when the amalgam restoration is exposed to appreciable variations and elevations of mouth temperatures while eating, thereby accentuating the .spheroidal tendency'of the eutectic mixture, or low fusing alloy; and, finally, its inability to .maintain permanently well-rounded contacts.

' ln order to overcome all of these inherent weaknesses at one fell swoop, I have devised a -reinforcement for the amalgam fillings. For this "purpose, I provide specially'formed, instantly These inserts have.

adaptable, silver inserts. hardened contact points capable of withstanding permanent rugged service without either loss of the original summits of convexity of the contact points, or loss of the original normal interproxi- For restoring decayed and broken down teeth,

Jim

where the band contacts an adjoining tooth or teeth. 'IlTOn form; the matrix'band is nickel platedin sections soas to withstand chemical actionzbythe amalgam. Unplated sections-are provided on the matrix band in the region of the notch or notches. These unplated sections are disintegrated bytheamalgam, thus allowing the remaining portionsof the band to be removed mal embrasures and injury to the interseptal gingival tissues-all too often noticed in using amalgam which has not been stabilized by block silver reinforcing,

As an additional refinement in the use of reinforced amalgam work, I provide specially-formed 7 These bands may be applied readily to a tooth by the dental matrix retainer disclosed in my copending application, Serial No. 721,995, filed in the United States Patent Ofilce on January 14, 1947, now Patent. No. 2,502,903, so

-missal of the patient-an achievement hereto fore found impossible.

My matrix band adapts itself to the irregular conformation of V the tooth upon which it is placed, and is notched at the point, or points,

faces-only;

easily-1 1 In a modified form my matrix band is entirely nickelplated. The-notch, or notches, which receive the end, or ends, of the inserts during the packing and condensing of the amalgam, facilie' ta-te breaking the band into sections prior tore- 'm'oval-from thetooth. Other objects-and advantages will appear as thespecification continues, and the novel features will-be set forth in the claims hereunto-appended.- For abetter understanding of my invention, reference should behad to the accompanyingdrawings; forming part of this application m which: Y Y Figure l-is ail-isometric view of a lower right first-molar having a mesial-occlusal-distal cavity prepared therein, and further shows a matrix band clamped around'the axial contour of the teeth by one: of my dental matrix retainers;

Figure 2 is-a longitudinal sectional view taken through the samemolar fromthe mesial to. the

distal surfacesgand disclosing the cavity partially packedwithamalgam and the: insert anchored to the amalgam; Figure 3 is a top plan. view of the-completely: filled tooth asseenfrom the occlusalipl'ane;

Figure 4. is a longitudinal sectional view takenalong the line. IV'--I V of Figure 3; Figure'S is an elevation of a post-provided on the reinforcing. insert at either the distal or mesialend of the insert. Figure 6 is a face viewof. one form of my matrix band; I 5 Figure 7 is a face view of a modified. form of matrix band;-

Figure 8 is a view similar to Figure 4, but showing the cavity prepared in the distal-occlusal sure Figure 9 is a top plan vievrof Figure '8, looking from-the occlusal plane; and .1 Figure 10 isa view -milar to Figure 9, but add ing a ling-ual-occlusalIrelnforcing insert.

While I have shown only the preferred forms of my invention, it should be understood that various changes'o'r modifications, may be'made within the scope of the annexed claims without departing from th'- spirit thereof.

Referring to the drawings in detail, Figures 1 to 4', inclusive, illustrate a lower right first molar, which isfindicated generally at A. This tooth is situated between the second bicuspid B and the second molar 'C'.

In order that the terms hereinafter used may be fully understood, various parts of the lower right first molar A are designated by reference numeral as follows: |--buccal surface (toward cheek) 2-lingual surface (tongue side); 3- mesial surface (toward mesial plane of the body) 4-distal surface (remote or away from the mesial plane) 5occlusal surface; and (gum) border. This molar has a mesial-occlusaldistal cavity D therein, the various parts of which are .designated by reference numerals as follows:' 'l-fioor of cavity; 8axial walls; 9--gingival fioors; and icavo surfaces. The axial contour of the tooth is indicated at H, and this contour is conical-shapedand tapers inwardly toward the roots or fangs l2. a

Figure 1 shows a matrix band E, which encircles the molar A and is drawn tightly against the axial contour l l of the tooth by a dental matrix retainer F. This retainer is disclosed and described in detail in my copending application, Serial No. 721,995, filed January 14-, 1947, and referred to in the objects of this application.

Briefly described, the retainer F includes a barlike frame l4 on which a matrix-clampingblock I is slidably mounted. The frame M has a head It thereon, which defines four parallel and spaced-apart fingers ll, [8, l9 and 20. The ends H of the matrix band E are accommodated in a diagonally-extending slot 22 formed in the block l5, and are clamped thereto by a spindle 23 that isthreaded into the block. The spindle is rotated by an operating knob 24. A rotatable internallythreaded sleeve 25 is held against endwise move- 6-gingival ment relative to the frame l4. When this. sleeve is turned, the spindle 23 and the clamping block l5 are advanced or retracted relative to the head I6.- -In Figure l, I show the matrix band as passing between the fingers I'I-I8 and then guided through the slot providedbetween the fingers l8--20. When the block [5. is retracted, the matrix band E. will be drawn up tightly against the axial contour ll of the tooth A.

The matrix band E illustrated in Figure 6 is made of a material, such as brass, that will be. acted upon chemically byamalgam and cause the material to disintegrate. The band has nickel plated" sections 26, which will resist chemical reactionof. the amalgam. The intermediate sections 2'! of the band are unplated and areexposed to the action of the amalgam during packing of It will be noted from Figure 6 that thematrix the member toward the cavo surfaces ll).

posed at the bottom thereof. Figures 3 and 4 disclose the tops 32 of the posts as being wider than the member 29 so as to project laterally beyond The bar-like member 29 and the posts 30 preferably are made of silver so that amalgam will bond chemically thereto.

Lugs 33 of hardened material, such as gold,

project from opposing faces of the posts 30 in 7 directions to contact with the teeth B and C, which are disposed on opposite sides of the molar A in which an amalgam filling will be packed. These lugs project into the notches 28 of the matrix band E and are supported by the latter (see Figure 2).

An important structural feature of the insert G is the zig-zag configuration of the bar-like member 29. The over-all length of the insert will be made so as to correspond approximately with the distance between the teeth BandC. However, in the event that the lugs 33 do not contact with the teeth B and C, the length of the member 29 can be extended by merely gripping opposite corners 34 of the member with a pair of pliers, orthe like, and squeezing the jaws of the pliers toward one another to elongate the member 29. In case the member 29 is over-extended, the tips of the lugs 33 can be ground down. The primary point to bear in mind is that the lugs 33 must contact with the teeth that are located on opposite sides of the tooth in which the insert is applied.

Prior to introducing the insert E into the cav- V ity D, a body of amalgam H,- or partial filling, is applied over the cavity floor 1, the axial walls 8 and gingival floors 9. The body H of amalgam extends to the inner walls of the matrix band.

band E is curved lengthwise when the band is fiat.

The intermediate portion of the band will become conical-shaped when drawn tightly around a tooth (see Figure 2). The band extends downwardly at least togthe 'gingival fioor 9.

v Referring now to Figures 2 to 5, inclusive, I show an insert G, which is made for reinforcing a mesial-occlusal-distal filling. This insert includes a bar-like member 29 of zig zag configuration, as shown in Figure 3, and designed for overlying the main cavity floor 'l' in spaced relation therewith. The ends of this member have posts 30 depending therefrom. Each post tapers to a point 3.! dis-v floor I and the posts'substantially parallel relative to the axial walls 8. The lugs 33 will come to rest in the notches 28 and contact the teeth B and C. Figure 2 shows the restoration up to this point, and the matrix band B is still in place around the axial contour of the. tooth A. The body of amalgam H Will unite. chemically with theinsert.

.As the next step, an upper'layerof amalgam Jis packed and condensed over the insertfas shown in Figures 3 and 4. By this time, the unplated sections 21 of the matrix band have dis: integrated, or at least weakened, by the amalgam acting on the brass. The dental matrix retainer F is removed and the plated sections 26 of the band E are removed. The member 29 could be arranged in registry with the occlusal surfac of the amalgam filling, 'if desired. The posts 30'project laterally toward the cavo surfaces In so as to reinforce the amalgam filling disposed between the surfaces It atv the mesial and distal portions of the tooth. Normally, this is a very vulnerable part of the filling. I

Figure illustrates amodified form of a ma? trix band, which is designated at E. In this modification, the entire surface of the band is nickel plated, as suggested by the color shading. This band has the same shape as the one shown in Figure 6, and is provided with notches 28 in its upper edge. After the amalgam filling has been packed and condensed, the band E is broken at points below the notches 28, as indicated by the break lines 35 in Figure 7. This will allow the band E to be withdrawn in three sections.

, Turning now to Figures8 and 9, it will be noted that a distal-occlusal cavit D' has been prepared in a tooth A. The insert G is really one-half of the insert G previously described. Accordingly, like reference numerals will beapplied to corresponding parts. In this form, the end 29a abuts the central axial wall 35 of the cavity, while the lug 33 has contact with the tooth C. Figures 8 and 9 disclose the tooth A as contacting with an adjacent tooth B. The method of filling the cavity D in Figures 8 and 9 is identical with that described in connection with Figures 1 to 5, inclusive. Also, the insert is made of silver so that it will unite chemically with the amalgam bodies H and J. I

Figure 10 is identical with Figure 9, excepting that a lingual-occlusal cavity D" has been added in the tooth A". A silver insert G has been placed in this cavit to reinforce the amalgam filling K therein. The teeth on opposite sides of the tooth A" are designated at B" and C". The tooth A has a distal-occlusal cavity D therein in which an insert G is disposed to reinforce the amalgam filling J". The method of restoring the tooth A" is the same as that set forth in connection with Figures 8 and 9, except for the addition of the insert G".

It is obvious that the cavities in Figures 8 to 10, inclusive, could extend in a mesial-occlusal direction, if the decay in the tooth being filled required such a cavity to be prepared.

The inserts that I have disclosed may be applied readily and are provided with hardened lugs, or contact points, that will withstand rugged service without loss of the original summits of convexity of the contact points, or loss of the original normal interproximal embrasures. will prevent injury to the interseptal gingival tissues. The amalgam fillings will withstand heavy masticatory stresses, maintain their di mensions and resist spheroidal tendency. Also, they will maintain well-rounded contacts. No galvanic action will take place, and the inserts become permanentl bonded to theamalgam fillings. The hardened lugs on the inserts prevent food from packing between adjacent teeth. The strength of the fillings will be increased tremendously over ordinary amalgam fillings.

Although I have referred to using my inserts for reinforcing amalgam fillings, I wish to make it clear that other types of fillings, such as porcelain, could be reinforced with the inserts. When amalgam is employed, it is desirable to form the inserts from silver, since the amalgam and silver inserts will bond together chemically. The lug or lugs 33 may be made from any suitable hardened metal, for instance, low carat gold solder or other case-hardened metal, and I do not wish to be limitedto gold alone.

I claim:

1. As an article of manufacture: a bar-like member designed to be embedded in a filling of a tooth to reinforce the filling; a post depending from one end of the member for embedment in the filling; and a restricted lug projecting from the post on the side of the latter opposite to the member; the lug being dimensioned to extend beyond the axial contour of the tooth to provide a restricted interproximal contact point bearable against an adjacent tooth.

2. As an article of manufacture: a bar-like member designed to be embedded in a filling of a They tooth to reinforce the filling; a post depending from one end .of the member for embedment in the filling; and a restricted lug projecting from the post on the side of the latter opposite to the member; the lug being dimensioned to extend beyond the axial contour of the tooth to provide a restricted interproximal contact point bearable against an adjacent tooth; the bar-like member being zig-zag in configuration, and defining con-' volutions winding back and forth on first one side of the member and then on the other; the member being sufiiciently pliable for flattening out of its convolutions to extend the over-all length of the member.

3. As an article of manufacture: a bar-like member designed to be embedded in a filling of a tooth to reinforce the filling; a pair of posts dependingfrom opposite ends of the member for embedment in the filling; and preformed lugs projecting from the posts on the sides thereof opposite to the member; the lugs being dimensioned to extend beyond the axial contour of the tooth to provide restricted interproximal contact points bearable against teeth disposed on the mesial and distal aspects of the tooth in which the member is disposed.

4. As an article of manufacture: a bar-like member designed to be embedded in a filling of a tooth to reinforce the filling; a pair of posts depending from opposite ends of the member for embedment in the filling; and preformed lugs projecting from the posts on the sides thereof opposite to the member; the lugs being dimensioned to extend beyond the axial contour of the tooth to provide restricted interproximal contact points bearable against teeth disposed on the mesial and distal aspects of the tooth in which the member is disposed; the bar-like member being zig-zag in configuration, and defining convolutions Winding back and forth on first one side of the member and then the other; the memher being sufiiciently pliable for flattening out of its convolutions to spread the posts farther apart.

5. In combination: a looped matrix band having a notch fashioned in an upper edge thereof; and a bar-like member disposed within the loop of the matrix band; the member having a lug projecting into the notch of the matrix band and supporting one end of the member.

6. In combination: a looped matrix band having notches fashioned in an upper edge of the band at diametrically-opposed sections of the looped band; and a bar-like member disposed within the loop of the matrix band; the member having lugs projecting into the notches of the matrix band and supporting both ends of the member.

BENJAMIN F. TOFFLEMIRE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Bull May 5, 19,86