US2591744A - Anatomical contact-forming dental matrix band - Google Patents

Description

Ap 8, 1952 B. F. TOFFLEMIRE ANATOMICAL CONTACT-FURMING DENTAL MATRIX BAND Filed July 25, 1949 INVENTOR. BENJAMIN F. TOFF'FEMIRE ATTORNEYS Patented Apr. 8, 1952 ANATOMICAL CONTACT-FORMING DENTAL MATRIX BAND Benjamin F. Toiflemire, Lafayette, Calif. Application July 25, 1949, Serial No. 106,713

The present invention relates to anatomical contact-forming dental matrix bands. It embodies improvements over the dental matrix bands disclosed in my copending application, Serial No. 82,547, filed in the United States Patent Oifice on March 21, 1949.

An object of my invention is to provide adental matrix band, which is shaped in such'a manner as to restore the normal points of contact between a tooth being refilled and the adjacent teeth. Briefly stated, the tooth-embracing face of the matrix band is fashioned with indentations, or concavities, which are disposed to include the normal points of contactof the tooth being restored. These concavities are positioned and open toward interproximal cavities provided in the tooth encircled by the band, and receive extended portions of the filling being packed in the toothcavities. The extended portions of the filling project toward the adjacent teeth in the interproximal regions to reform eminences at the normal points of contacts. It will be appreciated, of course, that a single point of contact for instance, at the mesio-occlusal aspect, could be restored.

provided a single plane, straight surface form,.

on the inter-proximal surfaces of the teeth upon which they have been used. Notwithstanding the fact that an outward or occlusal flare has been secured in the matrix bands illustrated in my above-mentioned copending application, there is still lacking the necessary shape on the bands to reform the natural eminences at the points of contact between adjacent teeth.

,More specifically, I provide the bands of my copending application with substantially ovoid indentations or concavities, on the arms there- 'of. These concavities are so placed that the deepest parts of the concavities will occur at the normal points of contact between adjacent teeth. This will provide the normal, anatomical, physiological form necessary to reproduce normal dental morphology.

One of the outstanding features of the improved bands is the incorporation of suitablyformed and definitely contoured indentations, or concavities, on each band' at the locations where the band touches the contact points of the adjoining teeth, both mesial and distal to the T 4. Claims. (01. 32-63) heretofore neglected interproximal areas in operative and restorative dentistry.

Other and more detailed objects of the present invention will appear as the specification continues.

For a better understanding of my invention, reference should be had to the accompanying drawing, forming part of this application, in which:

Figure 1 is an occlusal view of a portion of the dentition in the lower right quadrant, showing my dental matrix band applied around the second bicuspid;

Figure 2 is an elevational view of the banded bicuspid, looking from the mesial aspect, as suggested by the line II-II in Figure 1, and disclosing the band in section.

Figure 3 is a view in elevation of the teeth shown in Figure 1, taken from the buccal aspect;

Figure 4 is an enlarged face view of my improved matrix band; and

Figure 5 is a vertical transverse sectional view taken along the line V-V of Figure 4.

While I have shown only the preferred form of my invention, it should be understood that various changes or modifications, may be made within the scope of the appended claims without departing from the spirit thereof.

Referring to the drawing in detail, Figures 1 to 3, inclusive, show a lower right second bicuspid, which is designated generally at A. This tooth is situated between the first bicuspid B and the first molar C of the same quadrant. In order that the terms hereinafter used may be clearly understood, the parts of the bicuspid A are indicated by reference numerals as follows: l-buccal surface (toward cheek); 2-lingual surface (tongue side) 3mesial surface (toward median plane of the body) 4-distal surface (remote or away from the median plane); 5occlusal surface; 6-gingival (gum) border; 1-normal points of contact with adjacent teeth; 8-central sulcate groove; 9-root or fang; and l0-neck of bicus- Did.

This bicuspid has a mesial-occlusal-distal cavity D prepared therein, the parts of which are designed by reference numerals as follows: Hfloor of cavity; |2-axial walls; l4-gingival floors; and |5-C2JVO surfaces. The mesio-lingual line angle is indicated at IS; the disto-lingual line angle at H; and the lingual are at l8.

It will be noted from Figure 3 that the mesial and distal surfaces 3 and 4, respectively, have a decided pitch, flaring outwardly from the neck 10 to the occlusal surface 5. In Figure 2, thebuccal and lingual surfaces I and 2, respectively, have a moderate or slight upward flare.

Human teeth are not round or circular in cross-section; but are invariably constantly and without exception characterized by a decided, definite mesio-distal flattening or constriction at the interproximal gingival curvature or border 6 (see Figure 1). They fiare outwardly toward the occlusal surface to a greater degree on the hitherto neglected interproximal areas (between adjacent teeth) (see Figure 1), and to a less degree on the buccal and lingual surfaces I and 2 (see Figure 2) This variable pitch of the occlusal-flare, manifesting itself most noticeably on the interproximal areas, which, oddly enough, are the very areas that require the additional constriction at the gingival areas 6, resulting from the mesio-distal constriction of all posterior (rear) teeth, are finally accurately and adequately fitted by my dental matrix bands E.

Fortunately, both molar and bicuspid teeth have this mesio-distal constriction in common, together with a definitely rounded area on the lingual surface 2 of each and every tooth, situated'between the mesio-lingual line angle 16 and thedisto-lingual line angle l1.

Moreover, it will be noted from Figure 1 that the eminences defining the normal points of contacts 1 between adjacent teeth are disposed somewhat to the buccal of the central sulcate groove 8. The cavity D in the bicuspid A has been packed with a filling indicated at F in Figure 1 of the drawing.

It is on the lingual are [8 (see Figure 1) that my dental matrix band E has its arcuate central portion is situated when the band is applied around the tooth A. This arcuate portion is sufiiciently long that the dot-dash line 20 in Figure 4 will register with the mesio-lingual line angle (see Figure 1) when the dot-dash line 2| registers with the disto-lingual line angle I7. In other words, the arcuate portion l9 and the lingual are 18 are coextensive in length.

Beyond the lines 20 and 2| in, Figure 4, the arms 22 of the matrix band are straight. It will be noted that these arms diverge relative to one another from the arcuate central portion I9. The band E in this View has the same width throughout its length. However, the gingivalfacing edge 23 may be modified as shown in my copending application, Serial No. 82,547., so as to have a greater width on their gingiva-facing edges in the regions .of the junctions between the central arcuate portion I 9 and the arms 22. This modification is quite obvious, and has not been illustrated.

Referring now to Figure 1, I have shown a dental matrix band retainer indicated generally at G. This retainer is the subject matter of my copending application, Serial No. 721,995, filed in the United States Patent Office on January 14, 1947 now Patent No. 2,502,903.

Briefly stated, the retainer G includes a barlike frame 24 on which a matrix-clamping block 25 is slidably mounted. The frame has a head 26 thereon, which defines four parallel and spaced-apart fingers 2'! depending therefrom. The end portions of the arms 22 of the matrix band E are guided through selected slots defined by these fingers (see Figure 1) and are adapted to be introduced edgewise into a diagonally-extending slot 28 formed in the block, and clamped thereto by a spindle 29 threaded into the block. The latter may be retracted along the bar 24 4 in the manner shown in my copending application, Serial No. 721,995, to draw the matrix band tightly against the axial contour of the tooth, as in Figure l. The frame 24 and spindle 29 extend from the oral cavity of the patient, where both are accessible for operation.

The strip of material from which the matrix band is fashioned is provided with indentations or concavities 39 on its tooth-embracing surface 3|. The deepest part of the concavities are designated at X, and register with the normal points of contact 1' when the band is applied around a tooth. The concavities are positioned and open toward the inter-proximal cavities in the tooth being restored to receive extended portions of the filling F when the latter is packed in the cavity D. These extended portions of the filling project toward the adjacent teeth to reform the eminences at the normal points of contact.

The indentations or concavities 30 present an appearance somewhat resembling the contour of the bowl of a teaspoon (see Figure 2), with the tip 39a of the spoon directed toward the gumline area, and the summit of the convexity touching the contact point of the contiguous toothsomewhat to the buccal of the central sulcate groove 8. In other words, the bowl of the spoon is so placed that the tip 30a touches the gum-line at the summit 32 of the interproximal gingival curvature (see Figure 2).

Then the handle (not shown) of the spoon is rotated buccally in such a manner that the summit of convexity (which is the same as the deepest part X of concavity) rests in the bucco occlusal quadrant of the approximating surface of the tooth; and the occlusal margin 30b of the concavity would terminate on a slope relative to the longitudinal axis of the spoon in the manner shown in Figures 2 and 4. The occlusal edge of the band is designated at 33 in the drawing.

Upon examination of this resulting contour, and comparison made with the interproximal surfaces, and contact points of the bicuspids and molars of the human dentition, it will be noted that this contour very closely approximates the normal, natural, anatomical contour or surface morphology.

Thecontact-point indentations or concavities 30 provide outward bulges from within the bandenclosed cavity preparation D at the position of each contact point 1. They provide the finished restoration with a corresponding naturallyformed anatomical bulge, or contour, in the regions which previously presented either no form at all, with a mass of uncontrolled metal overhanging the gingival margins of the cavity, and either a fiat metal contact with the adjoining tooth, or teeth, or no contact at all. This resulted in a plunger action for the reception and retention of fiberous foods, with the inevitable formation of interseptal pockets and recesses with their ultimate sequela of paradentosis and terminal loss of the involved tooth or teeth.

At best, the previously available pre-formed bands ofiered only an approximation of the anatomical form and function of theinterproximal surfaces of the restored teeth; and presented a straight-sided, funnel-shaped, or inverted cone-shaped restoration, the occlusal margin of which terminated at the point where it pressed against the adjoining tooth. This left the gingival two-thirds .of each interproximal surface devoid of self-cleansing contour, natural beauty and comfort.

The anatomical contact-forming arcuatedental matrix bands, herein disclosed, are especially designed to provide a precision-formed mould for the reception of the plastic alloy, or the wax pattern, if used for directpattern gold inlay work. The resulting restoration, in either case, presents well-rounded, snug-fitting normallycontoured contact points, as well as beautifully formed interproximal surfaces in those heretofore neglected gingival step extensions of the class II (mesial-occlusal, distal-occlusal, and

'mesial-occlusal-distal) restorations. With the I adjustment to the particular needs of the tooth upon which it is placed. It readily yields to the specific artistic and functional needs of the tooth upon which it is drawn, whether this be a bicuspid or a molar;

My improved bands E provide the necessary suitably-contoured, anatomically-formed mould into which the plastic alloy may be condensed, or the prepared inlay wax softened and-com.-

pressed, in order to secure the desired contour in.

the completed restoration, in either silver alloy, or in cast gold, as the operator may elect.

The pre-formed, contoured-mould permits the operator to ascertain in advance the degree of contour and the exact position of the height of 1 contour so that the alloy restoration is provided 7 with a normal physiological contact point at the position necessary and build the degree of snugness desired. In case the mould is used for direct wax pattern work for gold inlay construction, the wax is contoured out in the desired snugness prior to investing and casting the pattern so that neither grinding of excess gold is necessary after casting, nor the building up or the contact with gold-solder after casting-as was necessary heretofore.

The loss of time necessitated by the old trialand-error method of soldering and grinding of contact points has long been an annoying feature in gold inlay work. The occasional uncontrolled solder-jumps beyond the peripheral margin of safety has necessitated thousands of re-makes. What is infinitely worse, the all too frequent evidence of inlay failures where operators have gone ahead and cemented these solder-jump cases rather than take another wax pattern and cast a new inlay.

With my new bands, however, this embarrassing feature need never exist; the contour is predetermined, and the degree of snugness may be definitely controlled, either with or without wedging, during the wax pattern formation. Moreover, the preformed wax pattern provides a contour that is uniformly rounded, and not an abnormally formed spheroidal body of fused solder where the addition is made subsequent to casting, nor an abnormally formed spherical body of cast gold at the point where a drop of inlay wax is fused onto the wax pattern prior to investing and casting.

In either of these cases, the addition of solder to the inlay, or wax to'thepattern,.are unscientific,- uncontrolled additions; trial-and-error modifications of a pattern which should be a completed, predetermined, pre-formed, precision pattern at the time it is withdrawn from the prepared cavity, a uniformly consistent achievement with my matrix bands. 7

An added advantage of, my bands lies in the occlusal marginal curvature toward the axial center of the restoration, as shown at 34 in Figure 3, thereby definitely aiding in the carving of the freshly packed restoration F. Heretofore, the flat, funnel-shaped bands have resulted .in a bucco-lingual, triangularly-shaped (prismoidal-shaped) excess of metal at the extreme occlusal limit; which not only had to be trimmed away, but which invariably caused a frictional drag uponthe freshly condensed alloy at the time of withdrawing the band, often resulting in the breakage of the margin or displacement of the entire filling at this critical point.

. 1 ,ing, by having a suitably-shaped die and counterdie formingtool incorporated in the band-forming'dies. g

Referring to Figure 3, it will be noted the resulting convergence 34 of the band above the summit of convexity X provides a form which will follow the contour of the original tooth. As previously stated, this will materially assist the operator in carving the anatomy of the restoration. When my dental band is used, however, the-filling is practically finished as soon as the alloy is condensed, because the contour of the band conforms to the shape of the original marginal ridge and interproximal surfaces.

The curved contour of the polished matrix band provides a smooth dense surface to the alloy when the latter is packed against the wall of the band, and the rounded marginal ridge cuts down the drag of the band in removing the band from the freshly-condensed restoration. Upon releasing band E from the retainer G, the band is dilated or pressed away from the freshly-condensed restoration, thereby releasing theba'nd from the rounded contact points 1 and the contour of the tooth. This is done before attempting to withdraw the band over the rounded eminences. After the band is dilated, the band readily slips off the contact surfaces, without injury and leaves a dense, beautifully rounded contact point. The gingival extensions are easily withdrawn laterally with a slight rotating action. A smooth dense, easily polished, well-rounded occlusal marginal ridge results from the condensation of the alloy against the specially formed indentations 30 of the matrix bands E, wherein a bucco-lingual, naturally-contoured. and beautifully-rounded roll extends along the occlusal marginal ridge, without carving, and consequently smooth and dense.

It will be observed that the gingival third of the concavities 30 are quite gradual in their contour, thereby facilitating easy removal. The mesiobuccal and disto-buccal line angle contours are provided by my bands, adding beauty and utility to the restorations.

Iclaim:

1. In a dental matrix band: a strip of material having an arcuate central portion adapted to fit against the lingual are part of a tooth; the strip defining arms extending from said arcuate central portion, with the arms diverging relative to one another when the strip is flat; the arms being made to embrace and conform to interproximal axial contour parts of the tooth when the strip is looped around the tooth; the strip having a toothembracing surface; and at least one of the arms beyond the arcuate central portion having a preformed concavity in its tooth-embracing surface positioned for registration with a normal interproximal contact point between the banded tooth and an adjacent tooth.

2. In a dental matrix band: a strip of material having an arcuate central portion adapted to fit against the lingual arc part of a tooth; said arcuate central portion having a length to extend substantially between the mesio-lingual and distolingual line angles of the tooth; and arms extending from said arcuate central portion, with the arm diverging relative to one another when the strip is flat; the arms being made to embrace and conform to interproximal axial contour parts of the tooth when the strip is looped around the tooth; at least one of the arms beyond the arcuate central portion having a preformed concavity in its tooth-embracing surface, disposed to include a'normal interproximal contact point between the banded tooth and an adjacent tooth; the concavity being positioned and opening toward said normal point of contact.

3. In a dental matrix band: a strip of material having an arcuate central portion adapted to fit against the lingual are part of a tooth being restored; said arcuate central portion having a length to extend substantially between the mesiolingual and the disto-lingual line angles of the tooth; and arms extending from said central portion to embrace and conform to interproximal axial contour parts of the tooth; each arm beyond the arcuate central portion having a preformed concavity in its tooth-embracing surface; these concavities being spaced apart at a distance so that they will respectively register with the interproximal mesial and distal contact points between the banded tooth and the adjacent teeth.

4. In a dental matrix band: a strip of material defining a complete loop adaptedto entirely encircle a tooth, and having gingival-facing and occlusal-facing edges; the loop throughout its entire circumference being conical and flaring outwardly toward the, occlusal; the end portions of the strip being butted against one another, and extending buccally from the loop to provide arms adaptedfor engagement by a matrix retainer; the strip having an inner surface adapted to be positionecl around and embrace the entire axial contour of the banded tooth; the strip having a pair of preformed concavities in its tooth-embracing surface; these concavities being spaced apart at a distance so that they will respectively register with the interproximal mesial and distal contact points between the banded tooth and the adjacent teeth.

BENJAMIN F. TOFFLEMIRE.

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

UNITED STATES PATENTS Number Name Date 1,265,022 Zurbrigg May 7, 1918 1,379,489 Taylor May 24, 1921 2,310,448 Leib Feb. 9, 1943

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