FIELD OF INVENTION:

The present invention relates to the field of dentistry, specifically an improved matrix system for posterior class Il composite resin dentistry. BACKGROUND OF THE INVENTION:

Complex cavity preparations of posterior teeth often require a supporting or retaining wall to contain the restorative materials within the confines of the tooth until the filling material achieves a setting or hardening state. The wall that dentists have traditionally used is an elongated flexible strip called a matrix band. Previous matrix bands were conceived to deal with the traditional metal-based or amalgam filling materials. They availed of amalgam ^' s physical properties of multi-directional expansion through its hardening phase. Therefore, retaining mediums separating the inter-proximal areas between a prepared tooth and its abutting neighbor could be successfully removed while ensuring that positive tooth to filling contact would ensue. One matrix band known in the art, and disclosed in U.S. Patent No. 2,591 ,744 to Tofflemire, encircles the tooth and provides a rigid wall with which to contain the amalgam restorative material. Although a separating wall remains until the filling material reaches its hardening phase, the amalgam's expansion capabilities and moderate inter-proximal wedging tooth separation maintain the desired restoration to tooth contact upon removal of the barrier wall. Thus, potential inter-proximal food impaction and subsequent gingival or gum irritation are eliminated. However, such matrix bands are not adequate when used with alternative and current restorative materials.

The advent of tooth colored restorative materials, such as composite resins, is in response to amalgam ^' s potential toxicity due to its mercury component, and the demand for aesthetics. However, composite resin materials contract rather than expand while hardening or

polymerizing. Conventional matrix retaining systems, such as the system disclosed in the '744 patent, allow for an inter-proximal gap to remain upon removal of the conventional matrix band. This exposes the inter-proximal area to the aforementioned pathology, that is, food impaction and gum irritation. In order to remedy this problem, some prior art techniques used a relatively thin metal matrix band in an attempt to reduce the thickness of the separating wall. Other techniques used non-metal or Mylar strips, in conjunction with enhanced wedging or separation between the teeth. Although such techniques potentially allow for more filling material to be introduced into the cavity preparation to compensate for anticipated shrinkage, they suffer from various drawbacks. Mylar strips lack sufficient rigidity, and their placement presents ergonomic challenges. The thinner metal matrix bands still require a barrier wall to remain during the setting phase, and therefore do not ensure a consistent desired inter-proximal contact. Such problems present a major disadvantage when using sensitive restorable material. Furthermore, many composite resins presently used have dual-cure capabilities. That is, the application of the curing light medium allows the resin to self-cure or harden and lessens its dependency on the light. This feature obviates the need for transparent retaining barriers and allows the dentist to use standard metal matrix retaining apparatuses.

Another conventional matrix system provides for a band with a plastic or celluloid-based inter-proximal contact area, which is attached between adjacent metal lateral extensions. However, such plastic bands lack sufficient rigidity, and therefore complicate the band's insertion. They also do not adequately prevent the escape of filling material into unwanted areas. In addition, composite resin ^' s dual curing properties eliminate the need for transparency in a matrix system. The band can also contraindicate the employment of a rubber dam or isolation barrier often essential for successful placement of current moisture sensitive composite resins.

Furthermore, the band ^' s retaining wall that is present at the completion of the filling's condensation and polymerization can, upon removal, result in an undesirable gap, or open contact. In addition, the band's fabrication requirements of micro-etching and epoxy adhesives to conjoin the segments can add considerably to the production costs of an essentially disposable, single use device.

Another conventional matrix system includes a longitudinally split dental matrix band with a windowed opening at the contact area. Such bands allow for extrusion of the compacted composite resin to abut directly to the adjacent tooth. However, the band's window, which is disjoined on one side, may contribute to unpredictable filling overflow, with subsequent contour and finishing challenges. This contraindicates multi-surface tooth restorations. Also, the window configuration of the band presents engagement with the polymerized resin to the extent that band removal may lacerate fragile gingival tissue thus contaminating the field of operation and contributing to unnecessary post-operative patient discomfort. Furthermore, the band's tension producing concept possesses ergonomic drawbacks presenting the clinician with insertion challenges in the posterior regions of the oral cavity. Engagement of this tension apparatus may also conflict with usage of the required rubber dam isolation.

Another conventional system includes a matrix with two elements. The first, being an area of matrix that is hammered thin to coincide with the prepared aspect of a tooth. The other element is a large hole or aperture to coincide with the opposite side of the prepared proximal surface. The idea is to have as minimal material as possible but still have a permanently fixed barrier between the tooth preparation and the abutting proximal surface of the next tooth. The hole functions to minimize tooth separation on the opposite side of the prepared tooth helping to attain better contact upon polymerization. Such systems have several problems. First, the

presence of a barrier, as with other conventional matrices, impedes contact. Secondly, the thinned out barrier is not only permanently in place, but also relatively delicate. As such, it is difficult to insert in tight proximal operative scenarios. Additionally, the hole that coincides with the opposite side of the prep is relatively weak, with little supportive metal. As a result, it is prone to crumpling in tight proximal cases. Furthermore, it is questionable whether the thickness of the first element, typically about fifteen thousandths of an inch, aids in tooth separation when removed. Such a matrix therefore present a conventional barrier similar to other matrices, wherein the matrix still employs a fixed barrier that can result in open contact. OBJECTS AND ADVANTAGES OF THE INVENTION: The present invention solves some or all of the above noted problems. Though not an exhaustive list, some of the objects and advantages of the present invention include:

(a) Band features allow for predictable and anatomically desirable inter-proximal contact.

(b) Functional attributes permit the replication of natural tooth contours and contact points.

(c) Band design eliminates occurrence of undesirable inter-proximal flash. (d) Band configuration permits for simultaneous multiple tooth surface restorations.

(e) Restorative finishing process is minimized.

(f) Restorative success rate is dramatically increased.

(g) Integrated feature saves significant chair side time.

(h) Removal system ensures that the polymerized composite extrusion will not sustain damage.

(i) Band removal is atraumatic to sensitive gingival tissue.

(j) Dual purpose design allows for usage of both composite and amalgam restorative materials, (k) Band is compatible with rubber dam isolation and moisture control barrier devices.

(1) Band design does not require the use of specialized instruments or retainers, (m) Predictable restoration to tooth inter-proximal contact allows for increased operator productivity.

Further objects and advantages are for the band to be readily incorporated into standard operative techniques while being compatible with existing chair-side armamentarium. The matrix band of the present invention eliminates the need for multiple matrix retaining systems thus providing economies of purchase. Still further objects and advantages would be apparent to one skilled in the art in light of the disclosure herein. SUMMARY OF THE INVENTION: In accordance with the present invention, a dental matrix band comprises a flexible body, at least one aperture in the body, a flat flexible guard to cover and temporarily prevent the passage of a restorative material through the aperture and an integrated system to bi-laterally split the matrix band through the aperture. BRIEF DESCRIPTION OF THE DRAWINGS: FIG. IA is a plan view of an unarticulated MO/DO single surface matrix with two apertures, aperture associated separation notches, a mirrored guard brace and a connected flash guard with guard removal aperture according to a first embodiment;

FlG. IB is a first plan view of the embodiment of FIG. IA after articulation;

FIG. 1 C is a second plan view of the embodiment of FIG. IA after articulation; FIG. 2A is a plan view of an unarticulated medial, occlusal, distal ("MOD") or bilateral surface matrix with four apertures, mirrored guard brace and two flash guards with conjoined removal tabs according to a second embodiment;

FIG. 2B is a first plan view of the embodiment of FIG. 2A after articulation;

FIG. 2C is a second plan view of the embodiment of FIG. 2A after articulation;

FlG. 3A is a plan view of an unarticulated deep prep or molar medial occlusal/medial distal (MO/DO") matrix with extended expanses of metal positioned beneath apertures according to a third embodiment;

FIG. 3B is a first plan view of the embodiment of FlG. 3A after articulation; FIG. 3C is a second plan view of the embodiment of FIG. 3A after articulation;

FIG. 4A is a plan view of an unarticulated molar MOD matrix with extended expanses of metal positioned beneath all four apertures according to a fourth embodiment;

FIG. 4B is a first plan view of the embodiment of FIG.4A after articulation;

FIG. 4C is a second plan view of the embodiment of FIG. 4A after articulation; FIG. 5A is a plan view of an unarticulated deep preparation MO/DO matrix with two inferiorly elongated apertures according to a fifth embodiment;

FIG. 5B is a first plan view of the embodiment of FIG. 5A after articulation;

FIG. 5C is a second plan view of the embodiment of FIG. 5A after articulation;

FIG. 6A is a plan view of an unarticulated deep preparation MOD matrix with four inferiorly elongated apertures according to a sixth embodiment;

FIG. 6B is a first plan view of the embodiment of FlG. 6A after articulation;

FIG. 6C is a second plan view of the embodiment of FIG. 6A after articulation;

FIG. 7A is a plan view of an unarticulated MO/DO matrix with foldable securing tabs and notched flash guard according to a seventh embodiment; FlG. 7B is a first plan view of the embodiment of FIG. 7A after articulation;

FIG. 7C is a second plan view of the embodiment of FIG. 7A after articulation;

FlG. 8A is a plan view of an unarticulated MOD matrix with inferiorly positioned securing extensions and a two notched conjoined flash guards according to an eighth embodiment;

FIG. 8B is a first plan view of the embodiment of FIG. 8A after articulation; FIG. 8C is a second plan view of the embodiment of FIG. 8A after articulation;

FIG. 9A is a plan view of an unarticulated MO/DO matrix with an applied adhesive application on two separate regions of the matrix band according to a ninth embodiment; FIG. 9B is a first plan view of the embodiment of FIG. 9A after articulation; FlG. 9C is a second plan view of the embodiment of FIG. 9A after articulation; FIG. 1 OA is a plan view of an unarticulated MOD matrix with an applied adhesive application on two separate regions of the matrix band according to a tenth embodiment; FIG. 1OB is a first plan view of the embodiment of FIG. 1OA after articulation; FIG. 1 OC is a second plan view of the embodiment of FIG. 1 OA after articulation; FIG. 1 IA is a plan view of an unarticulated MO/DO vertically compressed space-saving matrix having compensating retainer grip extensions according to an eleventh embodiment; FIG. 1 IB is a first plan view of the embodiment of FIG. 1 IA after articulation; FIG. 1 IC is a second plan view of the embodiment of FlG. 1 IA after articulation; FlG. 12A is a plan view of an unarticulated MOD vertically compressed space -aving matrix having compensating retainer grip extensions according to a twelfth embodiment; FIG. 12B is a first plan view of the embodiment of FIG. 12A after articulation;

FIG. 12C is a second plan view of the embodiment of FIG. I2A after articulation;

FlG. 13A is a plan view of an unarticulated MO/DO matrix with an inferiorly contoured section of band on the aspect of the matrix opposed to the apertures to aid insertion according to a thirteenth embodiment;

FlG. 13B is a first plan view of the embodiment of FlG. 13A after articulation; FlG. 13C is a second plan view of the embodiment of FIG. 13A after articulation;

FlG. 14A is a plan view of an unarticulated MO/DO matrix with ovoid apertures according to a fourteenth embodiment;

FIG. 14B is a first plan view of the embodiment of FIG. 14A after articulation;

FIG. 14C is a second plan view of the embodiment of FlG. 14A after articulation; FIG. 15A is a plan view of an unarticulated MOD matrix with equally sized ovoid windows and disconnected flash guard removal tabs according to a fifteenth embodiment;

FIG. 15B is a first plan view of the embodiment of FIG. 15A after articulation;

FIG. 15C is a second plan view of the embodiment of FIG. 15A after articulation;

FIG. 16A is a plan view of an unarticulated MO/DO matrix with offset sized ovoid apertures according to a sixteenth embodiment;

FIG. 16B is a first plan view of the embodiment of FIG. 16A after articulation;

FIG. 16C is a second plan view of the embodiment of FlG- 16A after articulation;

FIG. 17A is a plan view of an unarticulated MO/DO matrix with a laterally shortened guard brace, guard brace aperture, and a superiorly connected flash guard according to a seventeenth embodiment;

FlG. 17B is a first plan view of the embodiment of FIG. 17A after articulation;

FIG. 17C is a second plan view of the embodiment of FIG. 17A after articulation;

FlG. 18A is a plan view of an unarticulated matrix with one aperture, a centrally connected flash guard, and two flash guard extensions according to an eighteenth embodiment;

FlG. 18B is a first plan view of the embodiment of FlG. 18A after articulation;

FlG. 18C is a second plan view of the embodiment of FlG. 18A after articulation; FIG. 19A is a plan view of an unarticulated matrix with a connected flash guard and smaller wing-like guard braces according to a nineteenth embodiment;

FIG. 19B is a first plan view of the embodiment of FIG. 19A after articulation;

FIG. 19C is a second plan view of the embodiment of FIG. 19A after articulation;

FlG. 2OA is a plan view of an unarticulated matrix with a double connected flash guard and two removal tabs according to a twentieth embodiment;

FIG. 20B is a first plan view of the embodiment of FIG. 2OA after articulation;

FIG. 2OC is a second plan view of the embodiment of FIG. 2OA after articulation;

FIG. 21 A is a plan view of an unarticulated matrix with a double connected flash guard and two removal tabs and smaller semi-circular inferior guard braces according to a twenty-first embodiment;

FlG. 21 B is a first plan view of the embodiment of FIG. 21 A after articulation;

FIG. 21 C is a second plan view of the embodiment of FIG. 21 A after articulation;

FlG. 22 is a perspective view of a matrix according to the present invention showing a flash guard partially folded toward the guard brace; FlG. 23 is a perspective view of the matrix of FIG. 22 with the folded flash guard and guard brace partially folded toward the remaining matrix to form an articulated matrix;

FlG. 24 is an elevational view of an articulated matrix according to the present invention, with a user's finger tip burnishing the articulated matrix folding points flat before insertion into a matrix retainer;

FlG. 25 is a perspective view of an articulated matrix according to the present invention inserted into a matrix retainer;

FlG. 26 is a perspective view of the articulated matrix and matrix retainer of FIG. 25 placed on a first prepared tooth and a second tooth;

FIG. 27 is a perspective view of the matrix, retainer, first prepared tooth and second tooth of FlG. 26, and wedge prior to insertion; FlG. 28 is a perspective view of the matrix, retainer, teeth and wedge after the wedge has been inserted inter-proximally;

FlG. 29 is a perspective view of composite resin being packed into a first prepared tooth against an articulated matrix's flash guard according to the present invention;

FIG. 30 is a perspective view of the first prepared tooth and matrix according to the present invention, showing a shaping instrument creating a marginal ridge;

FlG. 31 is a perspective view of the first prepared tooth and matrix according to the present invention, showing scissors cutting the severance junction with evacuation apparatus in place;

FlG. 32 is a perspective view of the first prepared tooth and matrix according to the present invention, showing a probe extracting a severed flash guard from the articulated matrix;

FIG. 33 is a perspective view of the first prepared tooth and matrix according to the present invention, showing a probe engaging the flash guard's removal aperture without pre- severing the flash guard/matrix juncture;

FIG. 34 is a perspective view of the first prepared tooth and matrix according to the present invention, showing a probe removing the flash guard by an upward rotational motion;

FIG. 35 is a perspective view of the first prepared tooth and matrix according to the present invention showing a probe displacing composite resin; FIG. 36 is an elevational view of teeth treated with a light pressure application displacing composite resin to create a gently contoured proximal surface with higher inter-proximal contact;

FIG. 37 is an elevational view of teeth treated with a heavier pressure application displacing composite resin to create a pronounced proximal surface contour with lower interproximal contact; FIG. 38 is a perspective view of the matrix, retainer, teeth, and an apparatus for occlusal polymerization or light curing of composite resin;

FIG. 39 is a perspective view of the matrix, retainer, and teeth showing the apparatus for polymerizing or curing composite resin through the matrix apertures;

FIG. 40 is a perspective view of the matrix, retainer, teeth and a hand piece with diamond burr severing the rounded bridge extension to the visible notch;

FIG. 41 is a perspective view of the matrix, retainer, and teeth, showing the matrix band being released after the retainer has been tightened; and

FlG. 42 is a plan view of matrix band showing exemplary dimensions thereof. DETAILED DESCRIPTION OF THE INVENTION: A first embodiment of the invention is best shown in Figures 1 A-I C. FIG. IA shows a matrix band 1 before articulation. The matrix band 1 is preferably a flexible, mirrored band design, with a diamond-like shape. The matrix 1 can be die stamped, laser cut, chemically etched, or machine cut into configuration. The matrix band 1 may be fabricated from a biocompatible material such as stainless steel, plastic, or other semi-rigid material. Preferably,

the matrix band is fabricated from a single piece of stainless steel uniformly thick. For medical grade 302 full hard stainless steel, the thickness of matrix band 1 is preferably between about 0.0010 inch to about 0.0015 inch, more preferably about 0.0010 inch.

As shown in Figure IA, the matrix band 1 is comprised of a body. Preferably the body has a first portion, which is a boomerang shaped brace 2 having a left end 3a, and a right end 3b, and a second portion, which is a boomerang-shaped guard brace 22, having a left end 5a and a right end 5b. Each of said left ends 3a, 5a and right ends 3b, 5b are joined to form a diamond shaped opening or aperture7. Preferably, matrix band 1 is formed from a single piece of material, so that the connection between brace 2 and guard brace 22 at the left and right ends 3a, 5a and 3b, 5b, respectively, are integrally formed during fabrication. However, it should be understood that brace 2 and guard brace 22 may also be fabricated separated, and thereafter adjoined, such as by welding, gluing, or crimping.

Located within the medial region of the brace 2 interior is a hole, aperture, or extrusion window 4. The window 4 is shaped and sized to position within the inter-proximal space between the contact areas of a prepped first tooth 42 and a second tooth 44, such as shown in Figure 26. Referring again to Figures IA-I C, the window 4 preferably includes three straight areas, two radiated corners, and a curved, semi-elliptical superior aspect. The three straight aspects, two lateral, one inferior assume a rectangular dimension to approximate the box shape typical of class Il inter-proximal preparations. The curved superior window 4 border is contiguous to a superiorly positioned bulge, rounded arch, or bridge 6 that extends superiorly to the restorative area. The window 4 configuration and size allows for minimal interference with a restorative area. This lessens the potential occurrence of window 4 associated impressions (formed in the uncured composite resin 48) and related inter-proximal irregularities.

Preferably, positioned directly above the window 4 is a rounded arch of continuous material or bridge 6. The bridge 6 compensates for the height of the arched upper extrusion window's 4 border (would extend beyond the confines of the brace 2 border if the bridge 6 were not present). Additionally, the bridge 6, when the matrix band 1 has been articulated and placed on a tooth, as shown in Figure 26, preferably rises above the occlusal surface or marginal ridge of the tooth being treated. Integrated on the extreme superior and inferior window 4 borders are two wedge- shaped cutouts or notches 8a, 1 Oa. The superior window notch 8a extends upwardly into the expanse of the bridge 6. It is viewable above the occlusal surfaces of two abutting teeth when the matrix band 1 is articulated as described below and placed inter-proximally between them. This notch 8a is preferably sized and shaped to permit enhanced visibility for band placement and band removal. The inferior window notch 1 Oa resides directly opposite and below superior window notch 8a on window 4, and is preferably smaller in size than the superior window notch 8a. When the articulated matrix band 1 is placed inter-proximally, the inferior window notch 1 Oa is obscured and not visible. Positioned a short distance below the inferior window notch 1 Oa is a third or gingival notch 12a that is associated with the inferior border of the brace 2. All three of notches 8a, 10a, 12a are preferably positioned in vertical, linear alignment with regard to one another, so that the linear notch alignment bi-sects the extrusion window 4.

Guard brace 22 preferably mirrors brace 2 and is identical in size and shape. The combined visual result of the connected brace 2 and guard brace 22 is a diamond shape aperture 7. There are two points of connectivity or uninterrupted expanses of metal that conjoin the guard brace 22 to the brace 2. These connective points originate at the extreme inferior lateral region of the matrix 1. Preferably, located laterally and medially between these connective aspects are four wedge shaped cutouts or folding notches 28a, 28b, 28c, 28d, which are present on both

connective aspects. The folding notches 28a-d, are preferably located at the horizontal midline of the brace 2 and the guard brace 22, so that a horizontal line connects all four folding notches 28a-d. This alignment permits for precise correlation when the brace 2 and guard brace 22 are folded or articulated, such as shown in Figures IB, 1 C. Positioned off center within the body of the guard brace 22 is an opening, aperture, or guard window 24. This window's 24 position preferably mirrors that of the brace extrusion window 4. This allows both windows 4, 24 to align when the guard brace 22 is articulated with the brace 2 (folded along the notches 28 a-d). When folded or articulated at the folding notches 28a-d, the result is a boomerang-shaped two layered band 1 having conjoined windows 4,24 that form a single aperture, which will be covered by a cover or flash guard 14, described below. The guard window 24 is preferably identical in size and dimension to the extrusion window 4. This identical sizing and correlative placement assures the windows 4, 24 will align and not interrupt one another (border overlapping) when the matrix 1 is articulated. The identical window sizing and correlative placement also permits universal compatibility with any inter-proximal contact area, because the band is reversible.

Positioned on the superior and inferior circumference of the guard brace window 24 are two wedge-shaped notches 8b, 1 Ob. These notches, 8b, 10b are preferably identical in size and mirror the placement to notches 8a, 10a. The guard brace 22 superior window notch 8b is of a size and length as to permit viewing above the occlusal surfaces of two abutting teeth when the matrix band 1 is placed inter-proximally between a prepped first tooth 42, as best shown in Fig. 26, and a second tooth 44. The guard brace 22 inferior window notch 1 Ob preferably resides directly below the superior window notch 8b and is obscured when placed inter-proximally. Positioned a short distance below the guard brace 22 inferior window notch 1 Ob is a slightly

larger or gingival notch 12b. This notch 12b extends into the inferior border of the brace 2. All of the matrix band's 1 superior 8a, 8b, inferior 10a, 10b and gingival 12a, 12b notches are preferably aligned with one another when the matrix 1 is fully articulated.

Attached to the superior border of the guard brace 22 (when the band is articulated) or directly below the guard window 24 (as seen in Fig.l A) is a flat flexible semi-rectangular cover or flash guard 14. Preferably, the flash guard 14 is an appropriately shaped continuous aspect of the guard brace 22 that has been formed from the same single piece of material as the body portions. The flash guard 14 is attached to the guard brace 22 by a narrow strip, tab, or severance junction 30. Alternatively, the flash guard may be adhesively secured to guard brace 22 through application of adhesive about the periphery of said guard window 24 in order to provide an easily removable connection. This severance junction 30 is positioned off center from the mid-point of the guard window 24. Positioned centrally on the lateral and medial aspects of the severance junction 30 are two wedge shaped cutouts or folding notches 29a, 29b. The folding notches 29a, 29b demarcate the midpoint between the bodies of the flash guard 14 and guard brace 22 to allow the two to correlate. The guard brace 22 may be folded at folding notches 29a, 29b of tab 30, so that the flash guard 14 completely covers the guard window 24. The flash guard 14 is of a length as to not interfere with the inferior border of an articulated matrix (does not reach the bottom of the guard brace 22 border or brace 2 border of an articulated matrix 1 ). This eliminates potential for gingival invasion in instances of guard 14 migration or dislodgement. The flash guard 14 width ensures adequate coverage of the lateral aspects of both apertures 24, 4. Preferably, flash guard 14 is also formed from the same piece of material as the body portions. However, the flash guard 14 could also be separately fabricated, and subsequently connected to the body by conventional means such as gluing, welding or crimping.

Alternatively, the flash guard 14 could be a completely separate piece of material inserted across the aperture.

Located on the superior border of the flash guard 14 (when folded as best shown in Figs. IB and 1 C) is an "L" shaped peninsular extended portion, extension, flap, or guard removal tab 16. The removal tab is a continuous extension of the flash guard 14. When an articulated matrix 1 is placed inter-proximally, the removal tab 16 and connective severance junction 30 are visible above the bridge 6, as shown in Figure 26. The position of the removal tab 16 and severance juncture 30 are offset as to permit (if physically cutting the juncture 30 is not desired) a rotational removal of the flash guard 14 from between the articulated matrix 1. The removal tab's 16 shape directs the tab 16 away from the severance juncture's 30 location. This shape and direction enables a rotational removal by increasing the leverage. Additionally, the tab'sl 6 extension facilitates grasping with a hemostat or cotton pliers. Preferably, positioned within the extremities of the removal tab 16 is an ovoid hole or removal aperture 18 that is not in alignment with any part of guard window 24. This aperture is sized to be engaged by a suitable instrument for pulling the flash guard 14 away from the matrix band at the appropriate time.

Fig IB (Front View of matrix/flash guard articulation) depicts a guard brace 22 view of an articulated matrix band 1. The guard brace 22 is folded upward against the brace's 2 face. The central aspect of the flash guard's body 14 is visible through the opening of the guard window 24. Visible, above the matrix band 1 bridge 6, is the "L" shaped protrusion, or removal tab 16 and the folded protrusion that is the severance juncture 30. Located within the body of the removal tab 16 is a hole, opening, or removal aperture ] 8.

Fig. 1C (Rear View of matrix/flash guard articulation) depicts a matrix 1 side view of an articulated matrix 1. The central aspect of the flash guard 14 is visible through the opening of

the brace extrusion window 4. Visible above the matrix band 2 bridge 6 is the "L" shaped removal tab 16 and the folded severance juncture 30. Visible within the confines of the visible removal tab 16 is a hole, opening, or removal aperture 18.

All of the notches described above are part of a first embodiment of the invention, and either facilitate folding of the components of the matrix band or removal of the components of the matrix band from the tooth or both folding and removal. However, such notches are not necessary to the operation of the invention. Furthermore, the specific dimensions and configuration of matrix 1 may be modified depending on the dimensions of the particular tooth being treated. For example, various configurations may be provided for molar three-surface restoration, pre-molar three-surface restoration, and either a molar or pre-molar two surface restoration.

There are a multitude of variations for the barrier free matrix band with flash guard disclosed herein. It would be apparent to one skilled in the art the disclosed matrix band 1 could be modified in order to achieve optimal restorative versatility and secure matrix band 1 , and flash guards 14, 14a articulation. Various other exemplary embodiments will now be described.

Figs. 2A-2C show another embodiment of a MOD or bilateral matrix band 1 A. This matrix IA laterally mirrors the extrusion window 4, guard window 24, bridge 6 flash guard 14, and severance juncture 30 of the preferred embodiment Figs. IA to 1 C. This bilateral duplication of the above elements is positioned within the body of the matrix 1 A to correlate with one or two prepared inter-proximal surfaces of a tooth. Both brace extrusion 4, 4a and guard brace windows 4a, 24a are sized and spaced within the matrix 1 body to sufficiently accommodate the various dimensions of posterior teeth (bicuspid or molar) and allow for the range of patient tooth size variation, and contact point locations.

The double flash guard 34,14a configuration has a connection or tab juncture 20 joining each guard's 14, 14a removal tab 16, 16a. This juncture 20 creates a continuous connection, physically joining both flash guards 14, 14a at the vertical midline of the matrix IA body. To permit proper folding articulation (without distortion), both flash guards 14, 14a have an oblique connective orientation with regard to the severance junctures 30, 30a. This oblique angle is slanted medially, toward the matrix IA vertical midline, with both flash guards 14, 14a directed or slightly tilted toward one another. The flash guards 14, 14a to severance junctures 30, 30a, relationships creates a linear folding axis by horizontally aligning the associated folding notches and foldable region of the junctures 30, 30a (A straight line can be drawn through folding region of both severance junctions 30, 30a). A horizontal folding axis allows for a vertical, simultaneous articulation of both guards 14, 14a with the matrix IA body.

The shape and positioning of the removal tabs 16, 16a and tab junction 20 forms an opening or void of metal upon articulation. This void is visible between the inferior border of the tabs 16, 16a, tab junction 20 and the superior border of the matrix body 1 A (Figs 2B and 2C). This void is sufficiently sized to allow a cutting device, such as a scissors or dental hand piece and burr, to sever the tab junction 20 region and permit independent flash guard 14, 14a withdrawals. While intact and prior to severance, the conjoined tabs 16, 16a exhibit and promote cooperative flash guard 14, 14a flexion when the articulated matrix is placed into a retaining device. Present in both flash guards 14, 14a removal tabs 16, 16a are flash guard 14, 14a removal apertures 18, 18a. These apertures 18, 18a are laterally offset from the connective tab junctures 20. This off-center placement minimizes the chance of inadvertent cutting of the removal apertures 18, 18a when severing the tab juncture 20.

Figs. 3A-3C show various views of a deep prep or molar MO/DO matrix IB with one brace extrusion window 4 and flash guard 14. Located beneath the brace extrusion 4 and guard brace extrusion 24 windows are gingival extensions 23a,b,c,d (semi-elliptical appendages or scallop- shaped expanses of metal). These extensions 23a,b,c,d are positioned directly below the brace extrusion window 4 and guard brace extrusion window 24 to accommodate sub-gingival molar preparations.

Figs 4A to 4C show various views of a deep prep MOD matrix band 1 C with two brace extrusion windows 4,4a, a guard brace 22 that mirrors the shape and position of the brace 2, two guard brace extrusion windows 24,24a, and a two connected flash guards 14,14a. Positioned beneath each of the four windows are gingival extensions 23a,b,c,d (semi-elliptical appendages or scallop shaped expanses of metal). These extensions 23a,b,c,d are positioned directly below both brace extrusion 4,4a, and guard brace 24,24a extrusion windows to accommodate subgingival molar preparations.

Figs. 5A to 5C show various views of a MO/DO matrix ID with one brace extrusion window 4, a guard brace 22 that mirrors the shape and position of the brace 2 and a flash guard 14. The inferior aspects of both the brace extrusion window 4 and guard brace window 24 are elongated for deep preparations. The inferior matrix 1 D border below the windows is bulged or convexly extended to accommodate the added length of the brace extrusion 4 and guard brace 24 windows. Figs. 6A to 6C show various views of an MOD matrix IE with two brace extrusion windows 4,4a, a guard brace 22 that mirrors the shape and position of the brace 2, two guard brace extrusion windows 24, 24a and two connected flash guards 14, 14a. The inferior aspects of both the brace extrusion windows 4, 4a and guard brace extrusion windows 24, 24a are elongated for

deep preparations. The inferior edge of the matrix IE, below each extended window, is convexly bulged to accommodate the added length.

Figs 7A to 7C show various views of a MO/DO matrix 1 F with one brace extrusion window 4, a mirrored guard brace 22, a guard brace extrusion window 24 and a flash guard 14. Located on the superior border of the brace 2 are two tab-like protrusions or buccal lingual extensions, 34, 34a. After matrix IF articulation, the extensions 34, 34a are configured to fold downward against the guard brace 22, mechanically locking them together. Incorporated into the superior and inferior aspects of the flash guard 14 are "'V" shaped cutouts or folding notches 31, 31 a. These notches 31 , 31a are oriented to facilitate maximal flash guard 14 flexion when the matrix 1 is flexed circumferentially and placed into a matrix retainer 40.

Figs.δA to 8C show various views of a MOD matrix IG having a brace 2 with two brace extrusion windows 4, 4a, a mirrored guard brace 22, two guard brace extrusion windows 24, 24a, two connected flash guards 14, 14a. Located on the inferior border of the guard brace 22 are two tab-like protrusions or buccal lingual extensions 35, 35a. After articulation, the extensions 35, 35a fold upward against the brace 2 (Fig. 8A), mechanically locking both band aspects together. Incorporated into the superior aspect of the flash guards 14a,b when the matrix 1 is articulated are "U" shaped folding notches 31,31 a. These notches 31 , 31 a, are sized and positioned to permit for both flexibility and visibility through the superior window notches 8abcd of the aligned brace extrusion window 4, 4a and guard extrusion window 24, 24a when the matrix 1 G is articulated Figs. 8B and 8C.

Figs 9 A to 9C show various views of a MO/DO matrix IH having a brace 2 with one extrusion window 4, a mirrored guard brace 22, one guard brace extrusion window 24 and a flash guard 14. Applied to the body of the guard brace 22 is an adhesive application 38, 38a that

secure the matrix 1 upon folding articulation. The positioning of the adhesive strip 38, 38a is beyond the operative region of the flash guard 14, brace extrusion window 4 and guard brace extrusion window 24. This prevents any adhesive related complications during operative employment. Although two adhesive strips 38, 38a are shown in FIG. 9A, matrix IH may include only one strip 38 or 38a, or more than two adhesive strips 38, 38a. Adhesive strips 38, 38a may be a two- sided adhesive tape or other such strips having release paper covering each adherable side thereof, as known in the art. One side of strips 38, 38a may then be secured to brace 22 after removal of the release paper on the inwardly facing side, with the release paper being maintained on the outwardly facing side of strips 38, 38a until articulation of matrix IH. In addition, it should be understood that adhesive strips 38, 38a could be applied to the body of brace 2 instead of, or in addition to, guard brace 22.

Alternatively, matrix IH may be articulated at the time of manufacture, wherein braces 2, 22 and flash guard 14 are formed, adhesive is applied to either brace 2 and/or brace 22, and then matrix 1 H is articulated thereby securing brace 2 to brace 22. For example, adhesive could be mechanically applied, such as by spray coating, at the time of fabrication and before articulation.

Figs 10 A to 1 OC show various views of a MOD matrix 11 having a brace 2 with two brace extrusion windows 4,4a, a guard brace 22 that mirrors the shape and position of the brace 2, two guard brace extrusion windows 24,24a, and two connected flash guards 14,14a. Applied to the body of the guard brace 22 are adhesive applications 38, 38a that secure the matrix upon articulation. The positioning of the adhesive strips 38 are preferably beyond the functional regions of the flash guards 14,14a, brace extrusion windows 4,4a and guard brace extrusion windows 24,24a. This prevents any adhesive related complication during operative employment.

Figs. 1 IA -11C show various views of a vertically compressed MO/DO matrix band IJ, having a brace 2, two extrusion apertures 4, 24 , a mirrored guard brace 22, a flash guard 14 and compensating retainer grip extensions 36a,b,c,d. The vertically compressed configuration is designed for teeth having reduced vertical dimensions. The bodies of the brace 2 and guard brace 22 are fused closer together compared to the embodiments described above. The retainer extensions 36a,b,c,d approximate the lost metal resulting from a shortened total band height to provide adequate area for a retaining device 40 to grip.

Figs 12A-12C show various views of a vertically compressed MOD matrix band IK having a brace 2, two brace extrusion windows 4, 4a a mirrored guard brace 22, two guard brace extrusion windows 24, 24a two connected flash guards 14, 14a and compensating retainer grip extensions 36a,b,c,d. The vertically compressed configuration is designed for teeth having reduced vertical dimensions. The retainer extensions 36a,b,c,d approximate the lost metal to ensure a positive gripping area for the retaining device 40.

Figs 13A to 13C show various views of a MO/DO matrix IL having a brace 2 an extrusion window 4, a mirrored guard brace 22, guard window 24, and flash guard 14. Located on the body of the brace 2 opposite of the extrusion window 4 is a contoured metal section 41. The contoured region, located on the inferior brace 2 border, reduces the total band thickness when articulated that is inserted into an intact or unprepared inter-proximal contact space. This contour is of sufficient height and position as to not interfere with the initial insertion into an inter- proximal contact area.

Figs. 14A to 14C show various views of a MO/DO matrix band IM with a brace 2, extrusion window 4, a mirrored guard brace 22, one guard brace extrusion window 24, and a flash guard

14. The brace extrusion window 4 and guard brace extrusion window 24 are elliptical in shape and identical in size.

Figs. 15A to 15C show various views of a MOD matrix IN with a brace 2, two brace extrusion windows 4, 4a, a mirrored guard brace 22, two guard windows 24, 24a, and two disconnected flash guards 14, 14a. The tabs 16, 16a are not joined. The brace extrusion windows 4, 4a and guard brace windows 24, 24a are elliptical in shape and identical in size.

Figs 16A to 16C show various views of a MO/DO matrix IP with a brace 2, one brace extrusion window 4, a guard brace 22 that mirrors the shape and position of the brace2, one guard brace extrusion window 24 and a flash guard 14. The brace extrusion window 4 and guard window 24 are elliptical in shape and offset in size.

17A-17C shows a matrix IQ with brace 2, an attached flash guard 14, extrusion window 4, smaller guard brace 22 A and guard brace extrusion window 24. The guard brace's 22A connective aspects reside directly below the brace extrusion window 4 on the brace 2. The body of the guard brace 22A is sufficient in height and width to accommodate the brace extrusion window 4. When the matrix IQ is articulated, the shortened brace 22A is positioned against the prep side of a tooth.

Figs.18 A to 18C shows a matrix 1 R, a brace 2 with a connected flash guard 14 extrusion window 4, smaller guard brace 22B, and guard brace extrusion window 24. The flash guard 14 is positioned centrally above the brace extrusion window 4 and connected to the superior aspect of the bridge 6 by a severance junction 30. The flash guard 14 has two removal tabs 16a,l 6b. The guard brace 22B is positioned directly below the brace extrusion window 4 on the brace 2 and guard brace securing tabs 26a, 26b with adhesive applications 38a,38b. The guard brace 22 aspect is placed against either side of a prepared surface.

Figs 19 A to 19C show various views of MO/DO matrix band 1 S, a brace 2 with a brace extrusion window 4, a flash guard 14 and smaller wing-like inferiorly positioned guard braces 22C, 22C.

Figs.20A to 2OC shows a matrix IT, a guard brace 2 with two severance junctions 30, 30a, a flash guard 14 and two flash guard removal tabs 16, 16a.

Figs. 21 A to 21 C shows a matrix IU, a guard brace 2 with two severance junctions 30,30a connecting the flash guard 14, two flash guard removal tabs 16,16a, and semi-circular inferiorly located braces 22D, 22D'.

Operation of the barrier free matrix band 1 with flash guard 14 of the present invention will be described with reference to Figures 1 A-I C and 22-41. First, preferably an unarticulated matrix 1 as shown in Fig.l A is articulated. Preferably, the process of matrix articulation is accomplished by two separate folds that sandwich the flash guard 14 between the brace 2 and the guard-brace 22. Step one, the flash guard 14 is folded flush against the guard brace 22 and guard window 24, as shown in FIGS. 22 and 23. The fold occurs at the mid-point or notched 28 aspect of the severance junction 30. The severance junction ^' s 30 folding notches 29a, 29b serve as directional folding guides to predictably position the flash guard 14 against the guard brace 22 and window 24. The guard brace 22 and articulated flash guard 14 are folded flush against the remaining brace 2, as shown in FIG. 23. This complete matrix articulation now sandwiches the flash guard 14 directly between the brace 2, brace extrusion window 4, guard brace 22 and guard brace extrusion window 24.

Preferably, with a fingernail 76 or other sufficiently smooth hard object, the three folding aspects of the matrix 1 ; namely the severance juncture 30 and two connective aspects of the brace 2 and guard brace 28abcd, are burnished flat to promote band conformation, as shown in

Fig 24. The secured flash guard 14 is now mechanically held between the brace extrusion window 4 and guard brace window 24. This flash guard 14 serves as a temporary containing wall that will prevent the passage of a restorative material through the conjoined apertures 4a, 24a. The articulated matrix 1 may then be inserted into a retaining device 40, as shown in FIG. 25. The proper placement into the retainer 40 is determined by a prepared tooth's quadrant location and mesial or distal (front or back) inter-proximal position of a tooth. The interproximal location of a preparation determines the specific orientation of the matrix 1 in a retainer 40, since the conjoined apertures 4a, 24a and sandwiched flash guard 14 aspects of the matrix 1 must align with the preparation. Preferably, the retainer 40 and matrix band 1 are now placed around a prepared tooth, positioning the windows 4a, 24a and flash guard 14 aspects of the matrix 1 with a prepped first tooth 42, as shown Fig. 26. The brace extrusion window 4a, sandwiched flash guard 14 and guard brace extrusion window 24a are positioned directly into the inter-proximal contact area between the prepped first tooth 42 and a second tooth 44. The rounded bridge's 6 top border, the medial border aspects of the removal tab 18 and severance juncture 30, which together form a box like shape, as shown in FIG. 1 B and 1 C approximating the general shape of a preparation, are used to guide the conjoined apertures 4a, 24a into the prepared contact area of a prepped first tooth 42.

Next, the retainer 40 is tightened by an operator (not shown) to secure the matrix band 1 circumferentially around the prepped first tooth 42. To secure and seal the inferior aspects or gingival aspect of the matrix band 1 and flash guard 14, a wedge 46 is inserted into the interproximal space, as shown in FIGS. 27 and 28. Next, an appropriate amount of composite resin 48 is placed into the prepped first tooth 42. The resin 48 is subsequently bulk packed thoroughly

against the brace extrusion 4 or guard brace window 24 (proper placement into a retainer 40 determines which window 4, 24 is prep-side) and sandwiched flash guard 14 with a condensing instrument 50, as shown in FIG. 29. The resin 48 is packed up to and beyond the contact area of the prepped first tooth 42 and second tooth 44. Preferably, to expedite the restorative process and facilitate the flash guard 14 removal, a shaping instrument 52 is used to contour the resin 48 in the prepped first tooth 42, as shown in FIG. 30. While sculpting the restoration, all unnecessary composite resin 48 contacting the flash guard 14 is removed. After sufficient composite resin 48 packing, scissors 56 may be used to cut the severance junction 30, as shown in FIG. 31. Prior to cutting, an evacuation apparatus 58 is preferably placed in the mouth to catch the severed aspect of the severance junction 30. A probe 54 may then be inserted into the removal aperture 20 for a vertical extraction of the flash guard 14, as shown in FlG. 32. Alternatively, the severance junction 30 is not cut, and instead an explorer or probe 54 is used to engage the removal tab's 16 removal aperture 18, as shown in FIG. 33. An upward pulling motion rotates the flash guard 14 from between the articulated matrix 2 and the inter-proximal space of a first 42 prepared and second tooth 44, as shown in FIG. 34.

Preferably, to ensure inter-proximal contact, a probe 54 is used to penetrate the uncured resin bulk 48, as shown in FIG. 35. This probe 54 is inserted a short distance into the uncured resin 48 mass. This effects an expansive resin movement or resin displacement 62 within a prepped first tooth's 42 proximal box 66, as shown in FIGS. 36 and 37. The resin 48 is forced through the now unobstructed conjoined extrusion windows 4a, 24a. This creates direct resin contact with an adjacent second tooth 44. This direct resin contact replicates a first prepared tooth's 42 original or natural contact point 60. The expanding resin contacts the nearest surface which is the

adjacent tooth's anatomical contact point. The expansive displacement creates curvilinear or bulging replication of natural inter-proximal tooth anatomy. Natural inter-proximal contours are convexly bulged. Increased penetration or deeper probe 54 insertion in the resin mass will provide a more pronounced curvature and a lower contact point 60 with an adjacent tooth, as shown in FIG. 37. Lesser resin penetration 56 and insertion results in a higher contact point 60 and a comparatively more subtle inter-proximal contour, as shown FIG. 36.

Preferably, after sufficient resin displacement 62, a series of polymerizations occur through application of spectrum specific light that hardens uncured resin. The bulk resin mass 48 is cured by exposing the occlusal surface of a prepped tooth 42 to an appropriate exposure of polymerizing light 68, as shown in FIG. 38. Additional exposures of polymerizing light 68 are then administered to the inter-proximal region through the exposed conjoined apertures 4a, 24a, as shown in FIG. 39. The polymerizing light will reach the bottom-most aspects of the restoration by penetration through the apertures 4a, 24a and complete the curing process. After the restoration is adequately completed and polymerized, the bridge 6 is severed to the tip of the visible superior window notches 8a,b, of the brace and guard brace windows 4a, 24a with a hand piece 70 and burr, as shown in FIG. 40, or scissors (not shown). Next, progressive retainer tightening 72 applied by the operator (not shown) effects a buccal/lingual inferior matrix separation 74 along the inferior window notches 10a,b and gingival notches 12a,b, as shown in FIG. 41. The retainer constriction splits the matrix through the conjoined apertures 4a,24a for easy removal.

Exemplary dimensions of matrix are provided in FIG. 42. Referring thereto, exemplary dimensions of the disclosed matrix are set forth below in Table 1 : TABLE 1 : Matrix Band Dimensions

Preferred Max Min

H 6.35 mm 7 mm 5.5 mm 5.25 mm 7 mm 3 mm

K 3 mm 5 mm 2 mm M 1.25 mm 2 mm .75 mm N 3 mm 4 mm 2.5 mm P 1 mm 2 mm .5 mm

Q .75 mm 1.25 mm .5 mm

R 1 mm 2 mm .5 mm V 6.5 mm 8 mm 5 mm

W 63.5 mm 65.5 mm 61.5 mm

X 4.75 mm 5.75 mm 3.75 mm

Y (Radius) 6 mm 7 mm 5 mm

Z (Radius) 5 mm 7 mm 4 mm Theta 28 ° 30 ° 26 °

Phi 153 ° 155 ° 151 °

SW 9 mm 11 mm 7 mm

SH 7.5 mm 9 mm 6 mm

It should be understood that the dimensions set forth above may be modified depending on the particular application. In addition, although the method of operation is described with reference to matrix 1, operation of other matrix embodiments, or variations thereof, are performed in an identical manner after articulation, and will not be repeated hereafter.

From the description above, a number of advantages of the barrier free matrix band with flash guard become evident.

(a) The matrix produces superior contact.

(b) The matrix creates anatomically correct inter-proximal anatomy. (c) Use of band employs traditional techniques and armamentarium.

(d) This matrix is minimally technique sensitive.

(e) Band permits one-step insertion of matrix band and flash guard.

(f) The ability to have a complete barrier around the tooth permits vast restorative flexibility.

(g) The ability to remove the interim barrier will eliminate open contact. (h) Removing the barrier is accomplished with conventional armamentarium in one easy step,

(i) This matrix band can be used with or without moisture barriers. (J) Complete elimination of all inter-proximal flash when condensing resin, (k) The ability to customize the degree of contact after removal of flash guard. (1) Band's secure relationship to retainer eliminates potential for patient aspiration. (m) Post-operative visits are minimized due to band's reliability for positive contact.

(n) Conventional retainer serves also as band remover, eliminating need for additional instrumentation.

(o) Band is compatible with dual-cured and self-cured composite resins. Accordingly, it would be apparent to one skilled in the art that the disclosed barrier free matrix with flash guard promotes clean, predictable inter-proximal tooth contact. This is possible from the bands ability to control the direct contact of the polymerizing composite resin with the proximal surface of the adjacent tooth. The intuitive flash guard forms a temporary extrusion window barrier. This eliminates all inter-proximal flash and associated finishing

complications. After the initial packing of resin and subsequent removal of the flash guard, the operator is left with a smooth, flush resin face. The operator can then customize the degree of desired contact by controlled displacement of the uncured resin bulk through the band's apertures. This results in a positive contact that replicates the tooth's original contact point. The result is superior to other matrices in that resin displacement results in natural anatomical contours and will approximate the original contact point of the adjacent tooth. After the resin is cured, the notched release system allows for an atraumatic removal from the circumference of the tooth. This directly translates into a result that promotes predictable contact, minimal finishing, efficiency, vast restorative flexibility and lessened patient discomfort. Furthermore, the barrier free matrix with flash guard:

• Allows for greater daily productivity by attaining a successful first result.

• Greatly lessens chances for undesirable results by eliminating inter-proximal flash.

• Allows clinicians to customize contact by applying desired displacement through the aperture.

• Renders procedure as simple as many conventional bands.

• Eliminates inter-proximal irregularities, which reduces finishing time.

• Dual use band design accommodates both composite resin and amalgam filling procedures.

• Eliminates frustration associated with inadequate inter-proximal contact.

• Is compatible with moisture control barriers.

• Allows for convenient, atraumatic removal.

• Is compatible with existing chair side armamentarium.

• Is operator friendly and economical to use.

• Presents cost effective fabrication by utilizing traditional band design. Although the above description contains many specifications, these should not be construed as limiting the scope of the invention but merely provides presently preferred embodiments of this invention. For example, component dimensions may be altered, as need dictates. Band shape length and width can vary as future needs and procedures demand. The window's shape, size, and dimensions may be altered for optimal contact. The window can be circular or elliptical and include any degree of ellipse necessary. Geometric window apertures may also be employed. Any number of asymmetric elements may be incorporated to ensure restorative quality. The bridge features are alterable to any height dimension or shape, and can be eliminated if need determines. For example, a superficial locator notch may be scored into the bridge's apex to facilitate placement of the band's extrusion window. Additionally, the separation notches are also highly variable. The separation notches may embody any shape, height or angle as determined by optimal separation. There may be any number of notches, notch combinations, and notch configurations to create optimal band strength and separation capability.

The guard brace elements can be made to any shape, size, or be positioned anywhere on the matrix as to permit optimal performance in order to promote maximum flash guard stability, band flexibility and ease of matrix articulation. The flash guard may assume any shape that is optimally secure, ergonomic, and easy to remove. Any number of guard extensions, removal tabs or other securing features may be employed to achieve an optimal restorative result. It can be coated with an appropriate lubricating material like Teflon to ease inter-proximal removal. Grooves can be incorporated into the matrix band itself that correlate with the flash guard

extensions. These grooves serve as flash guard alignment guides, helping to determine exact flash guard/matrix band placement and flash guard extension folding points.

If optimal stability and band utility merit simplified designs, the flash guard extensions and removal tabs may be removed altogether. If necessary, any number of severance junctures may be incorporated to physically attach the band and flash guard. Juncture shape, size, width, height placement and thickness may be alterable to best promote flash guard stability and ease of junction severance with a drill or scissors. The physical locations of the severance juncture and removal tab may be altered to any configuration which permits intuitive severance and flash guard removal. To note, any number of foldable extensions may be physically incorporated onto the matrix band itself if needed to facilitate flash guard articulation and security. The use of adhesive supplements or stickers may be incorporated to all appropriate aspects of the flash guard and or matrix band to ensure stability and conformational fit. The band can be made of any biocompatible metal, synthetic or other material sufficiently rigid and thin. Such material may also be used to manufacture the barrier free dental matrix band with flash guard. The MOD or bilateral versions may allow for any degree of window width and spacing to adequately permit simultaneous alignment with two or more prepared aspects of a tooth. The double-sided configuration and severance juncture may be positioned for optimal performance. The flash guard and severance juncture can take on any shape and angled relationship that will allow ease of folding and removal. The joining tab juncture may also be made to any thickness or shape with best promotes double flash guard flexibility. Lastly, the barrier free matrix band with flash guard, can incorporate any of the above attributes in any configuration, which promotes optimal restorative results, and ease of use.

Thus, the disclosed invention has been described with reference to various embodiments for purposes of explanation only. However, it would be understood by one skilled in the art that features of one embodiment maybe incorporated into another embodiment. In addition, any preferred dimensions are exemplary, and the present invention is not so limited. Thus, it will be apparent to one of ordinary skill in the art that various modifications and variations can be made in construction or configuration of the present invention without departing from the scope or spirit of the invention. It is intended that the present invention cover such modifications and variations, and as maybe applied to the central features set forth above, provided they come within the scope of the following claims and their equivalents.