Retainerless dental matrix and method of manufacture

Claim 2

A dental matrix comprising in combination, a strip of thin flexible material having one end portion curved into a loop with an intermediate portion of said strip and overlying the same to form a matrix band, and retaining means to hold said strip in said looped configuration for application around a tooth; said retaining means permitting said intermediate portion of said strip to slide relative to said one end for tightening said band around said tooth, the other end portion of said strip having the edge which is positioned nearest the gingival of a patient being tapered outwardly toward the terminal end for a predetermined distance and the opposite edge of said other end portion also being tapered outwardly toward the terminal end thereof, and said tapered end portion of said strip being precoiled a predetermined amount, whereby said tapered opposite edges of said end of said strip respectively form a concavity to facilitate the insertion of a coiling tool therein and a concavity in the end of said coil applied nearest the gingival tissue of a patient to minimize possible trauma to the patient.

Claim 3

The dental matrix according to claim 1 in which said tapered opposite edge of said strip is more sharply tapered than said first-mentioned edge of said other end portion, thereby to provide a downwardly sloping edge within said socket in said coil to provide effective means to be engaged by a winding tool.

Claim 4

A dental matrix comprising in combination, a strip of thin flexible material having one end portion curved into a loop with an intermediate portion of said strip and overlying the same to form a matrix band, and retaining means to hold said strip in said looped configuration for application around a tooth; said retaining means permitting said intermediate portion of said strip to slide relative to said one end for tightening said band around said tooth, a predetermined amount of the outermost portion of said other end portion of said band being pre-coiled to form a socket to receive a winding tool, said retaining means being adapted to be rendered inoperative to permit release of said band from clAmped engagement with said tooth, and aperture means in said band adapted to be engaged by an auxiliary tool to facilitate removal of said released band from said tooth.

Claim 5

A dental matrix comprising in combination, a strip of thin flexible material having one end portion curved into a loop with an intermediate portion of said strip and overlying the same to form a matrix band, and retaining means to hold said strip in said looped configuration for application around a tooth; said retaining means permitting said intermediate portion of said strip to slide relative to said one end for tightening said band around said tooth, a predetermined amount of the outermost portion of said other end portion of said band being pre-coiled to form a socket to receive a winding tool, said retaining means being adapted to be rendered inoperative to permit release of said band from clAmped engagement with said tooth, and aperture means in said band adapted to be engaged by an auxiliary tool to facilitate removal of said released band from said tooth.

Claim 6

A dental matrix band comprising in combination, a strip of thin flexible material formed into a loop extending from one end thereof and an intermediate portion of said strip flatly and slidably overlying said one end of said strip to form said loop which is adapted to surround a tooth for installation of filling material within a prepared cavity therein, said one end of said strip having a finger projecting laterally from one edge thereof within the plane of said end of the strip, said finger having a notch extending inwardly from the outer end thereof, and a retaining member extending around said one end of said strip and the portion of said strip which overlies it to maintain said loop of said matrix band, a portion of said retaining member extending through said notch in said ear to anchor said member against movement relative to said one end of said strip, and the opposite end portion of said strip being formed into a spiral coil adjacent said retaining member and adapted to be engaged by a coiling tool operable to tighten said loop around a tooth by additionally coiling said opposite end of the strip to draw said overlying portion of said loop past said retaining member.

Claim 7

A dental matrix band comprising in combination, a strip of thin flexible material formed into a loop extending from one end thereof and an intermediate portion of said strip flatly and slidably overlying said one end of said strip to form said loop which is adapted to surround a tooth for installation of filling material within a prepared cavity therein, said one end of said strip having a finger projecting laterally from one edge thereof within the plane of said end of the strip, said finger having a notch extending inwardly from the outer end thereof, and a retaining member extending around said one end of said strip and the portion of said strip which overlies it to maintain said loop of said matrix band, a portion of said retaining member extending through said notch in said ear to anchor said member against movement relative to said one end of said strip, and the opposite end portion of said strip being formed into a spiral coil adjacent said retaining member and adapted to be engaged by a coiling tool operable to tighten said loop around a tooth by additionally coiling said opposite end of the strip to draw said overlying portion of said loop past said retaining member.

Claim 8

The dental matrix band according to claim 4 in which the opposite edge of said strip from which said finger extends having another notch extending transversely thereinto in transverse alignment with the notch in said finger and said retaining member having a portion also extending through said another notch to facilitate said positioning and retention of said member relative to said strip.

Claim 9

The dental matrix band according to claim 4 in which the notch in said finger is disposed intermediately of the width thereof to form a pair of ears respectively disposed on opposite sides of said notch, the finger which is nearest the end of said matrix band upon which the finger is formed having a substantially straight outer side and being of a width adequate to be buckled outwardly due to coiling forces imposed upon said finger by engagement thereof by said winding member and thereby resist being pulled through said retaining member.

Claim 10

The dental matrix band according to claim 6 in which the ear on the opposite side of said notch has a downwardly and inwardly sloping outer edge to provide clearance relative to a winding tool when in engagement with the coiled end of said band.

Claim 11

The dental matrix band according to claim 4 in which the end of said strip which is adjacent said finger being substantially straight and transverse to the longitudinal axis of said band and terminating a slight distance past said ear to form a short end portion operable to facilitate removal of a used band from a tooth at the completion of a filling restoration.

Claim 12

The dental matrix band according to claim 5 in which said notch in said opposite side of said strip is spaced from the first-mentioned end of said strip a distance adequate to form an ear of sufficient strength to resist tearing and bending when forcefully engaged by said retaining member incident to tightening said matrix band around a tooth.

Claim 13

A dental matrix comprising in combination, a strip of thin flexible material having one end portion curved into a loop with an intermediate portion of said strip and overlying the same to form a matrix band, and retaining means to hold said strip in said looped configuration for application around a tooth; said retaining means permitting said intermediate portion of said strip to slide relative to said one end for tightening said band around a tooth and said retaining means comprising a lock loop extending around the overlying portions of said strip and formed from a narrow strip of material appreciably thicker than said matrix band, the other end portion of said strip being pre-coiled and positioned adjacent one side of said lock-loop, whereby when said pre-coiled end of said strip is rotated to tighten said strip around a tooth, it bears against the end portion of said strip which extends through said lock-loop and forms an offset shoulder therein adjacent one edge of said lock-loop to resist tearing of strip during such tightening operation, said matrix band further including a finger projecting laterally from one edge of said strip adjacent said first-mentioned end of said strip and said finger having a notch extending inward from the outer end of said finger, said lock-loop extending transversely along one surface of said strip from said finger toward the opposite edge of said strip and sharply around said opposite edge and along the opposite surface of said strip and finger, the terminal end of said lock-loop extending through said notch in said finger and overlapping the other end of said lock-loop for a distance substantially less than the length of said finger, whereby when said overlapping portions of said lock-loop and the outer end portion of said finger are severed and removed to permit removal of said matrix band from a tooth, said removed pieces may readily be trapped within a container on a severing tool and prevented from entry into the oral cavity of a patient.

Claim 14

A dental matrix comprising in combination, a strip of thin flexible material having one end portion curved into a loop with an intermediate portion of said strip and overlying the same to form a matrix band, and retaining means to hold said strip in said looped configuration for application around a tooth; said retaining means permitting said intermediate portion of said strip to slide relative to said one end for tightening said band around a tooth and said retaining means comprising a lock loop extending around the overlying portions of said strip and formed from a narrow strip of material appreciably thicker than said matrix band, the other end portion of said strip being pre-coiled and positioned adjacent one side of said lock-loop, whereby when said pre-coiled end of said strip is rotated to tighten said strip around a tooth, it bears against the end portion of said strip which extends through said lock-loop and forms an offset shoulder therein adjacent one edge of said lock-loop to resist tearing of strip during such tightening operation, said matrix band further including a finger projecting laterally from one edge of said strip adjacent said first-mentioned end of said strip and said finger having a notch extending inward from the outer end of said finger, said lock-loop extending transversely along one surface of said strip from said finger toward the opposite edge of said strip and sharply around said opposite edge and along the opposite surface of said strip and finger, the terminal end of said lock-loop extending through said notch in said finger and overlapping the other end of said lock-loop for a distance substantially less than the length of said finger, whereby when said overlapping portions of said lock-loop and the outer end portion of said finger are severed and removed to permit removal of said matrix band from a tooth, said removed pieces may readily be trapped within a container on a severing tool and prevented from entry into the oral cavity of a patient.