US2720701A - Dental matrix band for use with contra-angle retainer - Google Patents

Description

DENTAL MATRIX BAND FOR USE WITH CONTRA-ANGLE RETAINER Filed March 1, 1954 E m R M we 0 V F m M Y .B N E B ATTORNEYS United States Patent DENTAL MATRIX BAND FOR USE WITH CONTRA-ANGLE RETAINER Benjamin F. Tofllemire, Lafayette, Calif. Application March 1, 1954, Serial No. 413,135

2 Claims. (Cl. 32-63) The present invention relates to improvements in a dental matrix band for use with a contra-angle retainer, such as shown in my United States Letters Patent No. 2,591,745, issued April 8, 1952.

In the above-mentioned patent, there is disclosed a dental matrix band retainer, including a bar-like frame having a slotted head at the forward end thereof. This head defines a plurality of guide fingers defining slots arranged for slidably-receiving intermediate portions of a looped band, the latter being adapted to encircle the axial contour of a posterior tooth.

As shown in that patent, the length of the bar is inclined relative to the lengths of the fingers so that the bar will clear incisal edges of anterior teeth, or clear the patients tongue and occlusal surfaces of posterior teeth in an opposite quadrant when the bar is directed across the patients mouth, with the finger lengths paralleling the long axis of the banded tooth in either case. Moreover, a slidable block is provided on the bar, and is adapted to have the end sections of the band anchored thereto by means of a rotatable spindle. Upon retracting this block, the band is constricted about the banded tooth.

It is important, of course, that the band be made to conform to and embrace the entire axial contour of the banded tooth; yet, at the same time, the ends of the band must be firmly anchored to the sliding block. Inasmuch as this block is drawn along an incline, the bands disclosed in the present application have been provided with terminal extensions, which correspond to the angular arrangement of the bar of the retainer. Thus a straight pull may be obtained on the ends of the band in parallel relation with the length of the bar-like frame, regardless of Whether the retainer is applied on the buccal or lingual surface of the tooth.

Another object of the invention is to provide a dental matrix band which has been specifically designed to utilize, augment and actually accentuate the advantages of the contra-angle retainer shown in my patent identified above. The terminal extensions on the band afford a positive and firm grip thereon by the retainer, and the band may be applied efiiciently from either the buccal or lingual aspect of the tooth to be restored. It is well adapted to childrens dentistry, but is not limited thereto.

The band presents many new, novel and altogether individualistic features which materially add not only to the functional efiiciency, beauty of design and ease of operation, but also to the standardization of operative technique in the use of the contra-angle retainer and its speciallydesigned band, and greatly facilitates the clinical teaching of modern techniques, methods and procedures.

Other objects and advantages will appear as the specification proceeds, and the novel features will be set forth in the claims hereunto appended.

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

Patented Oct. 18, 1955 Figure l is an occlusal view of primary or deciduous dentitions (upper or lower quadrants), illustrating my improved matrix band applied around one of the teeth, and held in place by the retainer;

Figure 2 is an elevational view of the retainer, taken along the plane IIII of Figure 1, parts being shown in section;

Figure 3 is a face view of one form of my dental matrix band;

Figure 4 is a modified embodiment thereof; and

Figure 5 discloses the first form of the band as being looped upon itself prior to being inserted into the retainer.

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

Detailed description Referring to the drawing, it will be noted that my improved dental matrix band A has been applied to a posterior (back) tooth B, and is held in encircling and embracing relation therewith by my contra-angle retainer C. This retainer has been illustrated as being disposed on the lingual (tongue) surface 10 of the banded tooth, and extending across the incisal edge 11 of an anterior (front) tooth D (see Figure 2); but, obviously, it may be applied to the buccal (cheek-side) surface 12 of the tooth being restored.

As pointed out in my United States Patent No. 2,591,745, which is directed to the details of the retainer, the mesial and distal surfaces 13 and 14, respectively, have a decided pitch, flaring outwardly from the gingival (gum) border 15 to the occlusal (grinding) surface 16. More over, the lingual and buccal surfaces 10 and 12, respectively, have a moderate or slight flare. Human teeth are not round in cross-section, but are characterized by a decided mesio-distal flattening or constriction at the interproximal (between the teeth) gingival border.

With this complex anatomical feature in mind, the dental matrix band A has been designed to embrace the entire axial contour of the banded tooth when applied thereto. Figure 3 discloses this band as being flattened out, while Figure 5 discloses it as being looped upon itself and ready to be inserted into the retainer C, prior to being engaged around the tooth.

In its structural features, the band A defines a strip of flexible material having occlusal-facing and gingivalfacing edges 17 and 18, respectively. The strip, when flat, provides an arcuate central portion 19 having straight arms 20-20 extending therefrom in opposite directions, with these arms diverging outwardly relative to one another. As shown in Figure 3, the occlusal-facing and gingival-facing edges of the central arcuate portion 19 and the arms 20-49 define convexed and concaved arches, respectively, when the strip is flat. The strip provides terminal extensions 2121, each of which extends occlusally at an obtuse angle relative to its respective arm. Each half of the strip, on opposite sides of the midportion 22, is identical with one another. The strip, when flat, defines substantially an extended W, in which the width of the W exceeds its height.

For those cases having extended interproximal cavities extending occluso-gingivally below the free marginal of the gum, a modified band A has been provided (see Figure 4). This band is essentially the same as the band A, excepting for the fact that Wider wing-like sections 23 formed on the gingival-facing edge 18. Otherwise, the two bands are identical; accordingly, like reference numerals have been applied to corresponding parts.

In order to obtain a clear understanding of my dental matrix band, and the reasons for its particular construction, the retainer C will be described briefly. It includes 3 a bar-like frame 24 on which a matrix-clamping block 25 is slidably mounted. This frame has a slotted head 26 at its forward-end, which defines four parallel and spacedapart fingers 27. The arms 20- 20 of the matrix band being used are adapted to be guided through the slots 'between these fingers, as shown in Figures 1 and 2. The terminal extensions 21-21 are adapted to be abutted together and then introduced edgewise into a diagonallyextending slot 28 formed in the block 25. Thereafter the extensions are clamped to the block by a pointed end 29 of a spindle 30, which is threaded 'into the block. This spindle may be turned by a knob 31.

As shown in Figures '1 and 2, a rotatable internallythe precision-formed band is especially designed so as to form an accurate, form-fitting mould for the reception of the plastic alloy for amalgamwork, or the ideal waxpattern form for cast-gold work.

Particular mention is made of the fact that the band shown herein is ideally designed for the restoration of an entire buccal surface, or a complete buccal cusp, by

1 'using it in the contra-angle retainer, the latter being apguide fingers 27 are inclined with respect to the length of the bar-like frame 24. This angular arrangement'will permit the fingers of the retainer to remain parallel with the long axis of the tooth B, while the retainer C may extend occlusally to clear the incisal edges of anterior teeth, or to clear the patients tongue and occlusal surfaces of posterior teeth when the retainer is directed across the mouth.

Reference is made to Figure 2, wherein it will be seen that the angularity of the terminal extensions 21 is such that they will parallel the length of the inclined bar-like frame 24. Thus the pointed end 29 of the spindle 30 will contact with the extensions '21 along their longitudinal centerline 35, when the spindle is advanced relative to the clamping block. Moreover, when the block is retracted away from the head 26, the terminal extensions will be pulled parallel with the bar 24, thus giving a good purchase on the ends of the band.

The angular arrangement of the extensions 21-21, which permits them to correspond with the inclination of theframe 24 when'the band is applied to the retainer,

permits a uniform distribution of the gripping force of the spindle end 29 on the extensions of the band. This will reduce the amount of finger pressure required in clamping the band to the block 25, and will materially reduce the mutilation of the band. The extensions 21-21 of the band occupy a centralized position in relation to the threaded spindle 30, which exerts traction along the centerline 35 of these terminalextensions in the normal'line of pull; 7

It will be noted from Figure 2 that the occlusal-facing and gingival-facing edges 17 and 18, respectively, of the looped band A define horizontal planes around the banded tooth, while the floor 28' of the slot 28 and the framelike bar 24 are disposed on an incline-a condition made necessary in order that the retainer C will clear the incisal edges 11 of the anterior teeth D. The angularity of the terminal ends 21 -21 correspond with this inclination of the retainer, thereby clearly defining the functional position of the band in relation to the banded tooth and the retainer. a

The angularity of the terminal ends of the band permit the latter to be used in the contra-angle retainer in remote areas ofthe mouth, and to be applied on the teeth which are displaced, rotated and badly, positioned. Moreover,

plied from the lingual aspect. 'There is no flattening pressure on the missing area, 'when the retainer is tightened, as the pressure from the retainer is against the remaining solid cusp or surface. same application may be made from the buccal side in those cases where the lingual surface or lingual cusp is missing.

Well-rounded and fully contoured restorations may be obtained. With cases having 'a very short musclei attachment, such as frequently seen in small-mouthed individuals, and always found in children, the band shown herein is particularly well suited for use in the contraangle retainer and is adapted to be applied from the lingual. Separating wedges 36 may be inserted from the buccal-so that the ends thereof do not protrude from the buccal, and thus the youngster cannot attain leverage for displacement of 'the band.

The band disclosed herein may be used successfully I with the contra-angle retainer on isolated third molars,

- the central long axis of which may be inclined and the coronal portion rotated, deviated or mutilated to an extent heretofore considered beyond restoration. I claim:

1. In a dental matrix band: a strip of flexible material 1 adapted to be looped around a' tooth in embracing relation with the axial contour thereof; the strip having occlusal-facing and gingival-facing edges; the strip, when fiat, defining an arcuate central portion having straight arms extending in opposite directions from said central portion, with the arms diverging outwardly relative to one another; the occlusal-facing and gingival-facing edges of said central portion and arms defining convexed and concaved arches, respectively, when the strip is flat; thestrip providing terminal extensions on the arms, each of which extends occlusally at an obtuse angle relative to its respective arm; theterminal extensionsjboth sloping toward the occlusal and being angularly related to one another when the strip is flat.

2. In a dental matrix band: a strip of flexible material adapted to be looped around a tooth in embracing relation with the axial contour thereof; the strip having 'occlusal-facing and gingival-facing edges; the strip, when flat, defining an arcuate central portion having straight v References Cited in the file of this patent UNITED STATES PATENTS 84 4,079 Armstrong Feb. 12, 1907 2,152,877

Since the band is reversible,-this Dagavarian Apr. 4, 1939

Images