The present invention relates generally to dental apparatus. In particular, to an apparatus for isolating teeth during a dental procedure .

During root canal therapy and other dental procedures, the tooth or teeth of interest must be isolated from the rest of the oral cavity so as to provide a dry and an aseptic area free from the patient' s saliva. Existing dental apparatus employed to achieve this, such as the rubber dam assembly, typically consists of a frame, rubber sheet and clamp. However, these dental apparatus are not easily adaptable to fit every patient. Different sized clamps and damming techniques are required depending on the teeth morphology and teeth condition of the patient. In patients with little or no coronal tissue the conventional rubber dam can be difficult or impossible to use . It is also often the case that the dental practitioner requires additional components e.g. dental floss to be attached to the clamp, caulking agent, anchoring devices and napkins, thereby increasing the complexity of the procedure. If a radiograph is required the rubber dam frame must be removed and the rubber sheet adjusted to one side which renders difficultly in taking the radiograph and can reduce the diagnostic value of the radiograph.

Further, conventional clamps are metal or rigid plastic which can cause damage to the teeth and discomfort for the patient both during and after treatment. The gripping ability of these clamps is suboptimal resulting in movement and even detachment of the clamp during therapy and contamination of the isolated area with the patient' s saliva.

Further still, application of the conventional small D-shaped slot of the rubber dam clamp requires significant undercut of the forceps in order to hold the clamp securely. Subsequent removal of the forceps from the clamp can then be difficult.

An object of the present invention is to provide a dental clamp that represents at least an alternative to the above, and preferably addresses one or more of the above disadvantages. An object of specific embodiments is to provide a dental isolation apparatus, including a dental clamp, that represents an improvement on known dental clamps and apparatus.

Accordingly, the invention provides a dental clamp comprising opposing bars arranged to grip one or more teeth therebetween, wherein the opposing bars are linked by at least one resilient arch, and optionally wherein at least one of the opposing bars is flexible to enable it to conform to a curvature of a set of teeth.

Thus, the invention provides a clamp that can be applied to the one or more teeth, upper and lower in any location in the dental arch, of every patient regardless of teeth size or morphology, eliminating the need for multiple clamps of different shapes and sizes for different patients. Advantageously, the invention facilitates easy and stable application including situations where little or no coronal tissue is in place and conventional a rubber dam would be difficult or impossible to use.

The term "flexible" used in the context of the bars is understood to mean that the bars can bend/flex under reasonable force, for example under force from the resilient arch(es) pushing the bars against the natural curvature of the teeth. In one embodiment, the term "conform to a curvature of a set of teeth" is understood to mean that the curvature can accommodate the natural curve of a set of teeth, but may not necessarily be curved to the same degree of curvature as the curve of the teeth. For example the bar(s) may be arranged to flex such that the bar(s) is curved, but the degree of curvature may be less than the natural curvature of a set of teeth. In another embodiment, the curvature of the bar(s) may be arranged to substantially match the natural curvature of a set of teeth. The skilled person will understand that the curvature/arch of a set of teeth may vary between individuals and that the flexibility of the bar(s) may provide adaptability to various individuals. In one embodiment at least one of the opposing bars is flexible to enable it to conform to a curvature of a set of teeth. In one embodiment, both the opposing bars are flexible to enable them to conform to a curvature of a set of teeth. One or both opposing bars may comprise a hinge . One or each bar may comprise two hinges. One or each bar may comprise a plurality of hinges. In an alternative embodiment, one or both bars are flexible along their length. Alternatively one or both bars may be flexible at multiple sections, for example along their length.

The flexible bar(s) may flex, or be arranged to flex, in only one plane. The hinge may comprise folds. The hinge may comprise a substantially V-shaped hinge, a substantially Z-shaped hinge, a substantially S-shaped hinge or a substantially C- shaped hinge. In one embodiment the hinge is substantially V-shaped. In one embodiment the hinge comprises a V-shaped hinge. The hinge may be a region of the bar comprising a region of higher flexibility relative to the remaining bar. The hinge may be a region of the bar comprising a different, more flexible, material than the rest of the bar. The hinge may be a region of the bar comprising the same material as the rest of the bar. The hinge may comprise a region of the bar that is reduced in diameter relative to the rest of the bar. In one embodiment, the hinge comprises a V-shaped region of reduced diameter relative to the rest of the bar. The hinge may be located in the middle of the bar. The hinge may comprise a resilient material. The hinge may comprise plastic.

One or each bar may be curved to emulate the arc of the teeth. One or each bar may have a degree of curvature of between about 65 and about 85 degrees. Alternatively, one or each bar may have a degree of curvature of between about 70 and about 80 degrees. One or each bar may have a degree of curvature of about 70 degrees. One or each bar may have a degree of curvature of about 75 degrees. One or each bar may have a degree of curvature of about 80 degrees. The above degree of curvature may only be apparent in use, for example when the clamp is engaged to a set of teeth. In particular, one or each bar may be arranged to flex to a degree of curvature of between about 65 and about 85 degrees. Alternatively, one or each bar may be arranged to flex to a degree of curvature of between about 70 and about 80 degrees. One or each bar may be arranged to flex to a degree of curvature of about 70 degrees. One or each bar may be arranged to flex to a degree of curvature of about 75 degrees. One or each bar may be arranged to flex to a degree of curvature of about 80 degrees.

The bar(s) may comprise a resilient material i.e. a material capable of recoiling or springing back into shape after bending, stretching, or being compressed. The bar may comprise plastic. The bars may comprise a substantially radiolucent material. The bars may comprise a radiolucent material. Alternatively, the bars may comprise a partially radiolucent material. In one embodiment, the bar(s) may not comprise or consist of metal.

The bar(s), or at least a hinge in the bar(s), may comprise a resilient material having a Young's modulus of about 2.8 x 10 ⁹ Nm ^"2 . The bar(s), or at least a hinge in the bar(s), may comprise a resilient material having a Young's modulus of less than about 2.8 x 10 ¹¹ Nm ^"2 . The bar(s), or at least a hinge in the bar(s), may comprise a resilient material having a Young's modulus of less than about 2.8 x 10 ¹⁰ Nm ^"2 . In another embodiment, the bar(s), or at least a hinge in the bar(s) may comprise a resilient material having a Young's modulus of less than about 50 x 10 ⁹ Nm ^"2 . In another embodiment, the bar(s), or at least a hinge in the bar(s), may comprise a resilient material having a Young's modulus of less than about 8 x 10 ⁹ Nm ^"2 . The bar(s), or at least a hinge in the bar(s), may comprise a resilient material having a Young's modulus of greater than about 2.8 x 10 ⁶ Nm ^"2 greater than about 2.8 x 10 ⁷ Nm ^"2 . The bar(s), or at least a hinge in the bar(s), may comprise a resilient material having a Young's modulus of greater than about 2.8 x 10 ⁸ Nm ^"2 greater than about 1 x 10 ⁹ Nm ^{" 2} . In another embodiment, the bar(s), or at least a hinge in the bar(s), may comprise a resilient material having a Young's modulus of between about 2.8 x 10 ⁷ Nm ^"2 and about 2.8 x 10 ¹⁰ Nm ^"2 . In another embodiment, the bar(s), or at least a hinge in the bar(s), may comprise a resilient material having a Young's modulus of between about 2.8 x 10 ⁸ Nm ^"2 and about 2.8 x 10 ¹⁰ Nm ^"2 . In another embodiment, the bar(s), or at least a hinge in the bar(s), may comprise a resilient material having a Young's modulus of between about 1 x 10 ⁹ Nm ^"2 and about 10 x 10 ⁹ Nm ^"2 . In another embodiment, the bar(s), or at least a hinge in the bar(s), may comprise a resilient material having a Young's modulus of between about 2 x 10 ⁹ Nm ^"2 and about 5 x 10 ⁹ Nm ^"2 . In another embodiment, the bar(s), or at least a hinge in the bar(s), may comprise a resilient material having a Young' s modulus of between about 2 x 10 ⁹ Nm ^{" 2} and about 3 x 10 ⁹ Nm ^"2 . One or each bar may be at least 1 cm in length. One or each bar may be at least 1 .5cm in length. One or each bar may be at least 2cm in length. One or each bar may be between about 1cm and about 5cm in length. Alternatively, one or each bar may be between about 1cm and about 4cm in length. Alternatively, one or each bar may be between about 1.5cm and about 4cm in length. One or each bar may be between about 2cm and about 4.5cm in length. Alternatively, one or each bar may be between about 2cm and about 4cm in length. One or each bar may be about 3.6cm in length.

Typically, the opposing bars are parallel or generally parallel to each other.

The term "opposing bars" used herein may be directly opposing, or not directly opposing but arranged to contact opposite sides of the teeth.

The at least one resilient arch may be arranged, in use, to bridge over the teeth. The resilient arch may not contact the teeth in use or it may contact at least one tooth at the base or exposed root of the tooth. The at least one resilient arch may span a width of less than 0.5cm in resting state/closed clamp position (i.e. when not clamped onto teeth) . Alternatively, the at least one resilient arch may span a width of less than 0. 1cm in resting state/closed clamp position (i.e . when not clamped onto teeth), or they may not be contacting in resting state. In use, the at least one resilient arch may span a width of at least 3cm (i.e. when clamped onto teeth). The at least one resilient arch may be arranged to span a width of at least 3.5cm in a forced-open clamp position (for example forced open by forceps in use) . The at least one resilient arch may extend substantially perpendicularly relative to the bar(s) to which it connects. The at least one resilient arch may extend in an angular orientation relative to the bar(s) to which it connects. In an embodiment comprising two opposing resilient arches, the arches may be angled away from each other. For example, the apex of the opposing arches may be distanced further apart than the bases of each arch. The arches may be angled at between about 100° and about 150° relative to the bar(s) to which it connects. The arches may be angled at between about 100° and about 125° relative to the bar(s) to which it connects. The arches may be angled at between about 100° and about 1 10° relative to the bar(s) to which it connects. In one embodiment, the arches are angled at about 105° relative to the bar(s) to which it connects. The arches may be angled at between about 2° to about 90° away from each other. The arches may be angled at between about 2° to about 60° away from each other. The arches may be angled at between about 2° to about 40° away from each other. The arches may be angled at between about 2° to about 30° away from each other. The arches may be angled at between about 20° to about 40° away from each other. The arches may be angled at about 30° away from each other. Advantageously, providing opposing arches which are angled away from each other can provide space for access to the teeth during a dental procedure . The at least one resilient arch may comprise a ridge extending across the top of the apex of the arch. The at least one resilient arch may comprise a T-shaped cross- section.

Advantageously, a ridge or T-shaped cross section can provide an arch with improved strength and resilience relative to an equivalent arch without a ridge or T-shaped cross-section.

The at least one resilient arch may comprise a resilient material i.e . a material capable of recoiling or springing back into shape after bending, stretching, or being compressed. The at least one resilient arch may comprise the same material as the opposing bars. The at least one resilient arch may be integrally formed with the opposing bars. The at least one resilient arch may comprise plastic. The at least one resilient arch may comprise acetal (polyoxymethylene (POM)) polymer or nylon polymer, or a combination thereof. The at least one resilient arch may comprise a resilient material having a Young's modulus of about 2.8 x 10 ⁹ Nm ^"2 . The at least one resilient arch may comprise a resilient material having a Young 's modulus of less than about 2.8 x 10 ¹¹ Nm ^"2 . The at least one resilient arch may comprise a resilient material having a Young's modulus of less than about 2.8 x 10 ¹⁰ Nm ^"2 . In another embodiment, the at least one resilient arch may comprise a resilient material having a Young' s modulus of less than about 50 x 10 ⁹ Nm ^"2 . In another embodiment, the at least one resilient arch may comprise a resilient material having a Young's modulus of less than about 8 x 10 ⁹ Nm ^"2 . The at least one resilient arch may comprise a resilient material having a Young' s modulus of greater than about 2.8 x 10 ⁶ Nm ^"2 greater than about 2.8 x 10 ⁷ Nm ^"2 . The at least one resilient arch may comprise a resilient material having a Young's modulus of greater than about 2.8 x 10 ⁸ Nm ^"2 greater than about 1 x 10 ⁹ Nm ^{" 1} . In another embodiment, the at least one resilient arch may comprise a resilient material having a Young's modulus of between about 2.8 x 10 ⁷ Nm ^"2 and about 2.8 x 10 ¹⁰ Nm ^"2 . In another embodiment, the at least one resilient arch may comprise a resilient material having a Young's modulus of between about 2.8 x 10 ⁸ Nm ^"2 and about 2.8 x 10 ¹⁰ Nm ^"2 . In another embodiment, the at least one resilient arch may comprise a resilient material having a Young' s modulus of between about 1 x 10 ⁹ Nm ^{" 2} and about 10 x 10 ⁹ Nm ^"2 . In another embodiment, the at least one resilient arch may comprise a resilient material having a Young' s modulus of between about 2 x 10 ⁹ Nm ^{" 2} and about 5 x 10 ⁹ Nm ^"2 . In another embodiment, the at least one resilient arch may comprise a resilient material having a Young' s modulus of between about 2 x 10 ⁹ Nm ^{" 2} and about 3 x 10 ⁹ Nm ^"2 .

In one embodiment, the clamp comprises at least two resilient arches. The clamp may comprise two resilient arches. Alternatively, the clamp may comprise three or four resilient arches.

Two resilient arches may be located at or adjacent each end of the bars. The two resilient arches may be located at opposing ends of the bars relative to each other. For example an end of one bar may link to an arch and the opposite end of the bar may link to another second arch. The two resilient arches may be located at least 1cm apart from each other. The two resilient arches may be located at least 1.5cm apart from each other. The two resilient arches may be located at least 2cm apart from each other. The two resilient arches may be located at least 3cm apart from each other. The two resilient arches may be located at least 4cm apart from each other.

The clamp may comprise a layer of absorbent material. The layer of absorbent material may be malleable . The clamp may comprise a layer of absorbent and/or malleable material. The layer of absorbent material may be porous. The layer of absorbent material may be capable of absorbing moisture.. In one embodiment, the layer of absorbent material may comprise wadding. In one embodiment, the layer of absorbent material may comprise fibre . The fibre is preferably superabsorbent fibre. In one embodiment, the layer of absorbent material may comprise gauze, lint, cotton, wool, gel, superabsorbent polymers (e.g. hydrogel forming material) or a combination thereof. In one embodiment, the layer of malleable material may comprise superabsorbent polymers (e.g. hydrogel forming material) . In one embodiment, the layer of malleable material may comprise rubber. In one embodiment, the layer of absorbent material may comprise Sira-Care™ Saliva Absorber (Sirane Group www.sirane.com). The layer of absorbent and/or malleable material may be provided on each bar. The layer of absorbent and/or malleable material may be provided on each bar at a region arranged to contact the teeth or gum of the alveolar ridge. The layer of absorbent and/or malleable material may be arranged to grip the alveolar ridge . For example, the layer of absorbent and/or malleable material may be arranged to form a layer between one or more teeth and the bars of the clamp. The layer of absorbent and/or malleable material may be attached to the bar, for example by adhesive. The layer of absorbent and/or malleable material may be attached to the bar mechanically, for example by sonic welding or heat swaging. The layer of absorbent and/or malleable material may be provided on the surface of each bar which faces the opposing bar. The layer of absorbent and/or malleable material may be substantially L-shaped in cross-section and extend along the length of each bar. Alternatively, the layer of absorbent and/or malleable material may be substantially crescent in cross-section and extend along the length of each bar. The layer of absorbent and/or malleable material may additionally or alternatively be thicker nearer to the middle of the bar and taper to a thinner layer towards the bars ends. The layer of absorbent and/or malleable material may extend beyond at least one end of the bars. The layer of malleable material may be malleable sufficient to conform to the shape of the teeth/tooth surface under the pressure of the clamp resiliently pushing the bars together.

The clamp may further comprise a flexible membrane, which may be arranged to form a barrier, or at least partial barrier, between the dental procedure being carried out on a tooth, and the oral cavity of the patient. The flexible membrane may be stretchable, for example the flexible material may be elastic.

The flexible membrane may be attached to the clamp, for example attached to each opposing bar. The attachment may be via adhesive. The flexible membrane may be attached to the clamp mechanically, for example by sonic welding. The flexible membrane may be attached to the clamp as a stretch fit over the clamp. Alternatively, the flexible membrane may be arranged to fit to the clamp, for example by elastically gripping the clamp.

The flexible membrane may comprise a water-impermeable membrane . The flexible membrane may comprise an elastic membrane. The flexible membrane may not comprise latex. In one embodiment, the flexible membrane may comprise a latex-free rubber membrane. Alternatively, the flexible membrane may comprise a silicon membrane.

The flexible membrane may be at least 10cm in width or diameter. The flexible material may be at least 10cm ² in area.

The flexible membrane may comprise, or be mounted to, a frame. The frame may be rigid. The frame may define the circumference of the flexible membrane. The frame may be arranged to sit or rest upon the outside of a patient's mouth during a dental procedure. The frame may be assembled from component parts, which can fit together.

The flexible membrane may comprise one or more holes or slots for breathing or tool access through the flexible membrane . A rim may extend at least partially, or fully, around the flexible membrane. The edges of the flexible membrane may define a rim. One or more tool-clips may be provided for attachment to the flexible membrane . In another embodiment, the flexible membrane may comprise one or more tool-clips. The tool-clip(s) may comprise C- shaped jaws to enable a snap-fit onto a tube or tubular shaped tool. For example, the tool-clip may be capable of clipping a suction tool to the flexible membrane. Alternatively, the tool-clip(s) may comprise a closed loop to enable a thread-through of a tube or tubular shaped tool. Alternatively, the tool-clip(s) may comprise a loop, which can be opened and closed to enable a tube or tubular shaped tool to be secured in place. This can ensure that the tool cannot easily fall out during a dental procedure. The tool-clip may be integrally formed with the frame of the flexible membrane. The tool-clip may snap fit onto the frame so that it can be moved around the frame .

The clamp may be arranged to clamp onto at least one tooth. The clamp may be arranged to clamp to two or more teeth. The clamp may be arranged to clamp to three or more teeth. The clamp may be arranged to clamp onto between one and five teeth. The clamp may be arranged to clamp onto between one and four teeth. The clamp may be arranged to clamp onto between two and five teeth. The clamp may be arranged to clamp onto between two and four teeth. In one embodiment, the clamp is arranged to clamp to three teeth. By extending the free ends of the flexible membrane (i.e. at either ends of the clamp) more teeth can be included in the procedure by stretching the sheet over the outer teeth and securing the free ends by flossing between the outer teeth. For example 6 to 8 teeth could be accommodated. Accommodating more teeth may be useful when treating the upper anteriors, for example, for cosmetic procedures. The clamp may comprise or consist of plastic. The clamp may comprise a radiolucent material. The clamp may not comprise or consist of metal.

The clamp may comprise forceps attachment points for engaging a set of forceps to enable the clamp to be forced into an opened position. The forceps attachment points may comprise lips, edges, slots, or holes for engaging forceps. Two or more forceps attachment points may be provided on each bar. The forceps attachment points may be located on the opposing bars. For example the opposing bars may comprise holes or slots for engaging forceps. In one embodiment, each bar comprises two holes for engaging forceps, wherein the holes are located near to or at opposing ends of each bar.

The clamp may comprise a radiographic holder attachment point. The radiographic holder attachment point may be located on one or more arches. A radiographic holder attachment point may be located on each arch. The radiographic holder attachment point may be located on the apex of one or more arches. A radiographic holder attachment point may be located on the apex of each arch. In a particular embodiment of the invention, the at least one resilient arch is adapted to accommodate a radiographic holder with a radiographic holder attachment point. In another embodiment of the invention, the clamp comprises two resilient arches and each arch is adapted to accommodate a radiographic holder with a radiographic holder attachment point. The radiographic holder attachment point may comprise a rod-like extension. In one embodiment, the radiographic holder attachment point may comprise a clip capable of engaging with and holding a radiographic holder. The radiographic holder attachment point may comprise a cylindrical-shaped extension, which comprises a circumferential groove for engaging with the radiographic holder. The circumferential groove may comprise a channel with substantially parallel and flat opposing walls. The radiographic holder attachment point may comprise a lip, ledge, clip, slot, hole, or groove, capable of engaging a radiographic holder. The radiographic holder attachment point may comprise a keyhole mount. The clamp may comprise two radiographic holder attachment points for engaging with a single radiographic holder, for example at different positions on the radiographic holder.

A radiographic holder may be provided for attachment to the clamp, which is arranged to hold an intraoral radiograph film or an equivalent digital radiograph sensor. Alternatively the clamp may comprise an integrated radiographic holder extending therefrom, which is arranged to hold an intraoral radiograph film or an equivalent digital radiograph sensor. The radiographic holder may comprise a radiographic back plate arranged to hold an intraoral radiograph film or an equivalent digital radiograph sensor. The radiographic back plate may comprise a flat panel. The radiographic holder may comprise a lip, ledge, clip, slot, hole, or groove for engaging with the clamp. For example, the radiographic holder may comprise a keyhole-shaped hole arranged to engage an extension, particularly a grooved extension on the clamp (otherwise known as a keyhole mounting).

The radiographic holder may comprise one or more arms extending from the radiographic back plate to engage with the clamp. The radiographic holder may comprise two arms extending from the radiographic back plate to engage with the clamp. The arm(s) may extend perpendicularly from the radiographic back plate. The arms may engage and attach to the clamp, thereby keeping the radiographic holder at an appropriate angle and distance from the clamp . In one embodiment, the radiograph back plate may be parallel with the clamp (such that in use it is substantially parallel to the length of teeth) and perpendicular to the X-ray beam. In another embodiment, the radiograph back plate may be located up to 2.5cm away from the teeth or alveolar ridge . The radiograph back plate is preferably located 1.5cm away from the teeth or alveolar ridge . The arms may also provide a space therebetween.

The radiographic holder may comprise a radiograph beam guide attachment point. The radiograph beam guide attachment point may comprise a clip, slot, hole, groove, or extension, capable of engaging a radiograph beam guide, such as an arm of a radiograph beam guide. The radiograph beam guide attachment point may comprise ridges, lips or clips for engaging with opposing ridges on the radiograph beam guide for allowing the two components to be clipped together and held into place. Alternatively, the radiograph beam guide may be integrally formed with the X-ray holder. In one embodiment, the radiograph back plate may be hinged and/or be capable of rotation relative to the clamp and/or the radiograph beam guide.

The radiographic holder may comprise an integrated radiograph beam guide extending therefrom. Alternatively, a radiograph beam guide may be provided for attachment to the radiographic holder. The radiograph beam guide may comprise a guidance frame capable of guiding a radiograph collimator. The guidance frame may be a guidance ring. Alternatively, the guidance frame may be rectangular or square. The guidance ring may be rigid. The guidance frame may be connected to the radiographic holder by an arm. The arm of a radiograph beam guide may comprise an extension on the distal portion opposite the guidance frame, wherein the extension is for engaging with the radiographic holder. The extension may extend on both sides (e.g. flank both sides) of the arm to enable the arm to be engaged and connected in two opposing orientations ensuring the radiograph beam is accurately directed at the intraoral radiograph film or an equivalent digital radiograph sensor. The extension may be shaped to fit a slot or hole on the radiographic holder. The extension may comprise ridges for gripping in a slot or hole of the radiographic holder.

The arm may be bent, for example substantially L-shaped, in order to hold the guidance frame at an appropriate angle . When connected to the radiographic holder, the guidance frame may be held by the arm in a position that is on the opposite side of the clamp relative to the radiographic back plate . When connected to the radiographic holder, the guidance frame, such as a ring, may be held by the arm in a position that is parallel to the radiographic back plate and on the opposite side of the clamp relative to the radiographic back plate. The arm may extend from the guidance frame in a substantially perpendicular orientation. The guidance frame may be rotatable and/or may move up and down the arm.

The clamp may comprise chamfered or rounded edges and corners. In one embodiment, the bar(s) may comprise chamfered or rounded edges and corners. In another embodiment, the radiographic holder may comprise chamfered or rounded edges and corners. In another embodiment, the radiographic back plate may comprise chamfered or rounded edges and corners. In another embodiment, the radiograph guide may comprise chamfered or rounded edges and corners. In another embodiment, the radiograph guide, the clamp, and the radiographic holder may comprise chamfered or rounded edges and corners.

According to another aspect of the present invention, there is provided a kit comprising:

a clamp according to any embodiment of the invention; and

a flexible membrane according to any embodiment of the invention.

The kit may further comprise a radiographic holder according to any embodiment of the invention. In an embodiment of the kit comprising a radiographic holder, the kit may further comprise a radiograph beam guide according to any embodiment of the invention. The components of the kit may be arranged to fit or attach together to form a single dental isolation apparatus. The kit may be otherwise termed a "dental isolation apparatus", for example, when the kit is assembled.

According to another aspect of the present invention, there is provided a dental isolation apparatus comprising:

a clamp according to any embodiment of the invention; and

a flexible membrane according to any embodiment of the invention.

The apparatus may further comprise forceps arranged to engage with the clamp. The apparatus may further comprise a pair of forceps adaptions arranged to fit onto standard forceps and are engageable with the clamp. Each forceps adaption may comprise one or more apertures, rings, clips, or hooks that can attach to the grasping portion of the forceps, and one or more clamp engaging extensions, lips, hooks, ledges, arms, or apertures that can engage with a complementary feature on the clamp.

The dental isolation apparatus may further comprise a radiographic holder according to any embodiment of the invention. In an embodiment of the dental isolation apparatus comprising a radiographic holder, the dental isolation apparatus may further comprise a radiograph beam guide according to any embodiment of the invention. The components of the dental isolation apparatus may be attachable and/or detachable together to form a single dental isolation apparatus. Alternatively, the components of the dental isolation apparatus may integrally formed, or at least some components thereof are integrally formed. According to another aspect of the present invention, there is provided the use of the clamp, kit, or dental isolation apparatus, in accordance with the invention herein for a dental procedure.

The dental procedure may comprise a root canal therapy, placement of fillings (such as composite and glass ionomers), dental implantation, internal and external tooth bleaching, removal of amalgam fillings, pulpotomies and pulpectomies, resin fissure sealants, resin treatment of interproximal caries, airflow, micrabrasion, cast restorations (preparation and placement), treatment of white/brown spots. The skilled person will understand that optional features of one embodiment or aspect of the invention may be applicable, where appropriate, to other embodiments or aspects of the invention.

The invention is now described with reference to the following specific embodiments and accompanying drawings in which: -

Figure 1 shows a dental clamp of a first specific embodiment of the invention. Figure 1A shows a top and side view of the clamp. Figure IB shows an alternative view of the clamp as a line drawing, without the absorbent layer;

Figure 2 shows the clamp of Figure 1. Figure 2A shows a side view of the clamp. Figure 2B shows an alternative view of the clamp as a line drawing, without the absorbent layer; Figure 3 shows the clamp of Figure 1. Figure 3A shows a front view of the clamp. Figure 3B shows an alternative view of the clamp as a line drawing, without the absorbent layer;

Figure 4 shows the clamp of the invention (without the absorbent layer) with a radiograph holder, which is separated from the clamp. Figure 5 shows the clamp (without the absorbent layer) with a radiograph holder attached, and a radiograph beam guide, which is separated from the clamp and radiograph holder.

Figure 6 shows the same embodiment as Figure 5 with the radiograph beam guide engaged with the radiograph holder and clamp.

Figure 7 shows a separated radiograph holder in perspective view.

Figure 8 shows the clamp (with the absorbent layer) with a radiograph holder and radiograph plate attached, and a radiograph beam guide, which is engaged with the radiograph holder and clamp. Figure 9 shows a side view of an alternative clamp in accordance with the invention as clamped onto a set of teeth with an alternative radiograph holder.

Figure 10 shows a top view of an alternative clamp in accordance with the invention as clamped onto a set of teeth

Figure 11 shows the clamp and an attached flexible membrane.

Figure 12 shows the clamp (without the absorbent layer) and a pair of forceps adaptations engaged with the clamp, which are arranged to receive forceps.

Examples

Referring to the figures, a dental clamp 10 is shown comprising two opposing bars 12, 14, which are parallel to each other and the bars are joined together at either end by two resilient arches 16, 18. In this embodiment, the dental clamp 10 is approximately 36mm long.

The bars have respective upper and lower edges 20, 22 and respective inner and outer edges 24, 26. The bars also have respective first and second ends 28, 30. The lower and inner edges 22, 24 of the bars 12, 14 are each provided with an absorbent fibre layer 32. The absorbent fibre layers 32 extend along the length of the bars 12, 14 beyond the respective first and second ends 28, 30 to allow for adaptation to the size and number of teeth requiring isolation.

The bars 12, 14 are flexible allowing them to curve to emulate the natural arch of the teeth. The bars 12, 14 each have a hinge 34 located mid-way along each bar to facilitate this flexibility. The hinges 34 are flexible elements having a reduced cross- sectional diameter relative to the bars, and having a v-shaped fold to facilitate bending of the bars along one plane i.e . to allow bending of the opposing bars in a direction to and from each other.

The bars 12, 14 include respective forceps attachment points 36, 38 arranged to engage with a forceps tool for manipulating the clamp onto and off the teeth. The forceps attachment points 36, 38 are two holes on each bar, which are distanced apart and located near to the respective ends of the bars. The forceps attachment points 36, 38 of one bar are directly aligned with the forceps attachment points 36, 38 of the opposing bar. The resilient arches 16, 18 which join the opposing bars at their respective ends are spaced apart and located at or adjacent the first and second ends 28, 30 of the bars 12, 14 to allow ease of access and improved visibility for the dental practitioner. The resilient arches 16, 18 extend from the bars in an angled or substantially perpendicular orientation relative to the bars and they are angled away from each other to allow sufficient clearance space to access the teeth during a dental procedure.

The resilient arches 16, 18 are integrally formed with the bars using the same plastic material. The resilient arches 16, 18 are made from acetal (polyoxymethylene (POM)). The resilient arches 16, 18 have an inverted T-shaped cross-section across the apex of the arches forming a ridge 40 on the outside curve of the apex. This provides increased strength and flexibility to in the arches.

Referring in particular to Figures 4 to 9, the resilient arches 16, 18 can also be adapted to accommodate a radiograph holder 42 to hold a radiographic plate 44. A clip 46 is provided on the apex of each resilient arch 16, 18, which is used to attach the radiograph holder 42 to the clamp 10. The clip 46 is a cylindrical-shaped extension extending out from the apex of each resilient arch 16, 18 in a perpendicular direction relative to the bars. The cylindrical-shaped clips 46 have a groove in their circumference to form a middle portion reduced in diameter. For example the clips are like a dumbbell shape . The groove of each clip provides parallel and opposing flat surfaces within the groove of the clip.

The radiograph holder 42 has a back plate 56, which is a rectangular plate with rounded-corners and an opposing front plate 57, which is a smaller rectangular plate. A pair of frame arms 58, 60 extends perpendicularly from the back plate 56. The pair of frame arms 58, 60 have key-hole shaped slots 62 (i.e. a circular hole with a slot extending therefrom) which are located at the end of each frame-arm distal from the back plate 56. The key-hole shaped slots 62 can engage the clip 46 of the clamp 10 to secure the radiograph holder 42 in place . To aid clipping of the radiograph holder 42, the key-hole shaped slots 62 comprise pinch tabs (not shown). The pair of frame arms 58, 60 each have a supporting ridge 64 extending from the back plate 56 towards the distal end of the arm. The radiograph holder 42 further comprises a slot 66 next to the back plate 56, which is a rectangular hole arranged to receive and hold an attachable X-ray beam locator.

The radiographic plate is held between the back plate 56 and a much smaller front plate 57.

The back plate 56 of the radiograph holder 42 is wider along its top (superior) edge than its bottom (inferior) edge to securely hold larger intra-oral X-rays and prevent them from moving. However, in another embodiment, a narrower inferior edge of the back plate 56 allows the radiograph holder 42 to fit in the smaller anterior aspect of the dental arch.

An attachable X-ray beam locator 68 is also provided and may be used as an optional feature in conjunction with the radiograph holder 42 when an X-ray image is required. The X-ray beam locator 68 comprises a rigid circular ring 70 that is rotatable and slidable around an arm 72 which extends perpendicularly relative to the plane of the ring 70 and parallel to the back plate 56. The X-ray beam locator arm 72 is curved to a right angle at the distal end. The distal end of the X-ray beam locator arm 72 has a rectangular tab 74 extending laterally on both sides of the arm. The tab 74 is arranged to fit into the respective slot 66 in the radiograph holder 42, and comprises a series of ridges for gripping into the slot.

Referring to Figure 1 1 , the clamp is attached to a flexible latex-free membrane 48. The membrane 48 is attached along the lower edge 22 of both bars and is sandwiched between the lower edge 22 of the bars and the absorbent fibre layer 32. The membrane 48 surrounds the clamp 10 and provides a substantially rectangular hole in the centre between the opposing bars 12, 14 of the clamp 10 to allow teeth to protrude through. The membrane 48 traversing across either side from one bar to the opposing bar is not attached and remains free and flexible, for example to be able to stretch and floss it between gaps in the teeth. The membrane 48 is bordered by a circular frame 50 which forms a circumferential rim that can rest on, and sit outside a patient's mouth. The membrane has adequate quantity to allow the clamp to be situated in the mouth without causing tension on the membrane, clamp or frame. The frame 50 is a rigid plastic. The frame 50 can be provided with a soft lining on its underside for patient comfort.

The clamp is set just off centre in one quarter of the frame so that it may be orientated to fit any area of the upper and lower dental arches.

The frame 50 is further provided with a suction-clip or clips 52 to hold a suction tube (not shown) in place during a dental procedure . The suction-clip 52 is clipped onto the frame 50 by jaws that clamp around the rim. The suction-clip 52 is moveable around the circumference of the frame 50. The suction-clip has opposing jaws which form a substantially circular mouth arranged to fit around a tubular suction device . The edges of the membrane 48 are reinforced by thickening in order or to prevent tearing or distortion.

A hole or holes 54 is provided in the membrane 48 to facilitate breathing and suction through the membrane 48. The hole 54 enables those patients who are unable to breathe through their nose or who have a high salivary flow rate to breathe through their mouth, thus increasing patient tolerance.

The clamp 10 is as radiolucent as possible to enable radiographs of improved diagnostic value to be obtained. The back plate 56 of the radiograph holder 42 is radiolucent.

In Figure 12, the clamp 10 is shown with a pair of forceps adaptations 76 removably attached thereto. The forceps adaptations 76 are arranged to receive forceps (not shown). Each forceps adaptation 76 comprises a loop 78 to engage the gripping portions of the forceps, and extensions 80 to fit into the complimentary attachment points 36, 38 of the clamp 10.

The clamp 10 in its resting position provides the opposing bars 12, 14 in close proximity, which are held in position by the resilient arches 16, 18. For use, forceps are engaged into the forceps attachment points 36, 38 and the clamp 10 is prised into an open position by forcing the resilient arches 16, 18 to open, which increases the distance between the opposing bars 12, 14 such that they can flank a set of teeth and/or alveolar ridge. When the forceps are released, the resilient arches 16, 18 force the opposing bars 12, 14 together and towards each other. The resilient arches 16, 18 bias the bars 12, 14 toward each other. The absorbent fibre layer 32 of the clamp 10 moulds to the shape of the teeth and gingivae when the clamp 10 is in use to create a firm and close grip of the clamp 10 against the teeth/gingivae and to provide an area of isolation precluding salivary flow. The clamp 10 is resistant to falling off due to the natural neck of the tooth shape which generally increases from the gingivae and from the superabsorbent layers light adhering to the oral mucosa.

In use, the natural curvature of the teeth, differences between teeth and the varying form of the alveolar ridge is accommodated by the combination of the absorbent fibre layer 32 shape forming around the teeth, and by the bars 12, 14 flexing at the hinge 34.

The flexible membrane 48 is provided attached to the clamp 10 and can be flossed between teeth where it traverses from one bar to an opposing bar at both ends of the clamp 10. In other embodiments the flexible membrane 48 may be separate from the clamp 10 and can be applied later by stretching it over the clamp such that the membrane 48 abuts against the lower surface 22 of the opposing bars 12, 14, and is held in place elastically. The frame 50 of the membrane 48 can be rested on the patient's mouth peri-orally. Suction instruments or similar equipment is optionally clipped into the suction-clip(s) 52.

If a radiograph image is required during the dental procedure, the radiograph holder 42 can be clipped onto the clamp 10 by inserting the clips 46 of the clamp 10 into the key-hole-shaped slots 62 of the radiograph holder 42. The back plate 56 is automatically fixed in a suitable position parallel to the teeth and on the opposite side of the teeth relative to the radiograph beam. A radiograph beam locator 68 may also be attached by engaging the tab 74 of the radiograph beam locator arm 72 into the slot 66 of the radiograph holder 42. The ring 70 of the radiograph beam locator 68 guides the equipment into a correct position relative to the teeth and the back plate 56.

Once the dental procedure is finished, the clamp 10 can be removed by engaging the forceps into the forceps attachment points 36, 38 and the clamp is prised into an open position by forcing the resilient arches 16, 18 to open, which increases the distance between the opposing bars 12, 14 and releasing from the teeth.

The dental clamp and other components of the apparatus may be autoclavable for repeated use, or disposable .