1. Field of the Invention
The present invention relates generally to a dental cutting system.
2. Related Art
Various methods have been proposed to cut a patient's tooth. Some methods prepare a user's tooth or adjacent teeth to receive a crown. Some methods provide a cutting guide or template. For example, see U.S. Pat. Nos. 5,725,376 and 4,144,645; US Patent Publication Nos. 2010/0196842; 2010/0192375 and 2012/0270176; PCT Publication No. WO2012/110850; and German Patent Nos. DE 4012327 and DE 4013828. One issue with cutting guides is that the cutting tool can inadvertently cut the guide or template, resulting in an inaccurate guide or template, and inadvertent cutting of the patient's tooth, such as a nerve inside the tooth. In addition, some cutting guides can overly restrict the cutting tool. Furthermore, some cutting systems require custom cutting tools, or cutting tools with non-standard sizes and shapes.
It has been recognized that it would be advantageous to develop a system and method to cut a patient's tooth to resist inadvertent cutting of the guide or template, and thus resist medical injury. In addition, it has been recognized that it would be advantageous to develop a system and method to cut a patient's tooth with a guide or template that allows the cutting tool to be withdrawn by the dentist. Furthermore, it has been recognized that it would be advantageous to develop a system and method to cut a patient's tooth that utilized standard cutting tools with standard sizes and shapes already possessed by a dentist.
The invention provides a dental cutting system for cutting a patient's tooth. The system comprises a cutting guide having at least one cavity to match at least a portion of at least one of a patient's teeth. A cutting tool has a shank and a cutting bur configured to cut the patient's tooth. A slot in the cutting guide has a depth extending from an exterior of the cutting guide to the at least one cavity, and receives at least the shank of the cutting tool therein. Opposing channels are formed in opposing walls of the slot, and extend along a length of the slot. A sleeve is slidably disposed in the slot, and slidable along the slot. The sleeve has an enlarged collar slidably disposed in the opposing channels, and retains the sleeve in the slot with respect to an in-and-out direction with respect to the at least one cavity of the cutting guide, and limits the sleeve to movement within and along the slot. The sleeve has a bore extending axially therethrough, and removably receives the cutting tool therein. The shank of the cutting tool is rotatable therein, and the bur of the cutting tool being slidable therethrough in the in-and-out direction, and into and out of the sleeve. The cutting tool is rotatable to cut the tooth, slides laterally in the slot along with the sleeve, and displaces in the in-and-out direction with respect to the at least one cavity of the cutting guide, and into and out of the sleeve.
In addition, the invention provides a dental cutting system for cutting a patient's tooth. The system comprises at least one cutting guide with at least one slot therein, and a cutting tool guided by the slot. Opposing channels are formed in opposing walls of the slot and extend along a length of the slot. A sleeve is slidably disposed in the slot and slidable along the slot. The sleeve has an enlarged collar slidably disposed in the opposing channels, and retains the sleeve in the slot with respect to an in-and-out direction with respect to the at least one cavity of the cutting guide, and limits the sleeve to movement within and along the slot. The sleeve has a bore extending axially therethrough and removably receives the cutting tool therein. The cutting tool is rotatable therein, and slidable therethrough in the in-and-out direction, and into and out of the sleeve. The cutting tool has two transverse degrees of freedom, including laterally along the slot, and in and out of the slot and the sleeve.
Furthermore, the invention provides a method for cutting a patient's tooth, comprising: a) placing a cutting guide on at least one of the patient's teeth with a cavity of the cutting guide matching at least a portion of at least one of the patient's teeth; b) inserting a sleeve into a slot of the cutting guide and an enlarged collar of the sleeve into opposing channels in opposing walls of the slot; c) inserting a bur of a cutting tool into the sleeve with the bur passing through the sleeve and a shank of the cutting tool rotatable in the sleeve; d) displacing the cutting tool along the slot with the sleeve slidable in the slot to cut a portion of the patient's tooth with the bur; and e) selectively retracting and inserting the cutting tool in the sleeve.
In accordance with a more detailed aspect of the invention, the method can further comprise, under the control of one or more computer systems configured with executable instructions: a) obtaining a 3D image of the patient's teeth; b) digitally preparing a tooth to be cut based on the 3D image; c) digitally designing a restoration; d) digitally designing the cutting guide; and e) producing the cutting guide and the restoration.
Additional features and advantages of the invention will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the invention; and, wherein:
a is a side view of the cutting tool of
b is a schematic side view of the cutting tool of
a is a side view of another cutting tool of the dental cutting system of
b is a schematic side view of the cutting tool of
The cutting guides shown in
Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended.
The terms “buccal” and “lingual” are used herein to refer to an outside and a inside, respectively, face or side of a tooth with respect to the user's mouth, and are generally opposite one another, with “buccal” referring to an outside of the tooth generally facing the patient's check or lips, and “lingual” referring to an inside of the tooth generally facing the user's tongue. The terms buccal and lingual are also used herein to refer to directions and locations with respect to the tooth.
The terms “mesial” and “distal” are used herein to refer to a proximal side and a distal side, respectively of the tooth with respect to the user's mouth, and are generally opposite one another, with mesial referring to a front of the user's mouth and distal referring to a back of the user's mouth along a row of teeth.
The term “occlusal” is used herein to refer to a top face of a tooth that faces an opposing tooth when the patient's jaw is closed, and extends between the sides (buccal, lingual, mesial and distal) of the tooth. While the term occlusal generally refers to the posterior teeth, it is used interchangeably with the term “incisal” which generally refers to the anterior teeth.
The term “cutting tool” is used herein to refer to a tool that cuts, and has a cutting surface, such as a bur, and a shank that extends from the cutting surface to be held by a chuck or motor. The cutting surface or bur can have cutting or grinding surfaces or materials. The chuck and/or motor can be part of a dental handpiece that is held by the dentist.
As illustrated in
As described above, it is possible in some previous systems for the bur of the cutting tool to inadvertently cut the cutting guide, such as being inadvertently inserted into the slot while rotating, thus cutting the slot or guide defining the slot. Such an inadvertent cut in the cutting guide can result in an inaccurate guide or template, and inadvertent cutting of the patient's tooth, such as a nerve inside the tooth. Alternatively, it is possible in some previous systems for the shank of the cutting tool to bear against the wall of the cutting guide at high revolutions per minute, and thus grind away the wall, or create friction that could heat and melt the wall. Cutting or deforming the wall of the cutting guide or slot can cause a deviation of the cutting tool so that the dental prosthetic does not fit or match, or cutting too deep and hurt the patient.
The system and method of the invention includes a sleeve slidably disposed in the slot. The sleeve can have an enlarged collar slidably disposed in the opposing channels. In another aspect, the sleeve can have a pair of enlarged collars slidably disposed in the pair of opposing channels (such as first and second enlarged collars slidable in first and second pairs of opposing channels). The enlarged collar can have a cross-sectional shape that matches a cross-sectional shape of the opposing channels, or an outer profile that matches or mates with the inner profile of the channels. For example, the enlarged collar and the opposing channels, or cross-sections or profiles thereof, can have a round or circular shape. The sleeve can slide along the slot in the cutting guide, while the enlarged collar(s) can slide along in the opposing channel(s). The sleeve has a bore extending therethrough to removably receiving the cutting tool therein. The sleeve can be formed of metal. A bur of the cutting tool can be inserted through the bore and through the collar, while a shank of the cutting tool can be rotatable disposed in the bore of the sleeve. The bur of the cutting tool can be slidable therethrough in and out of the sleeve. Thus, the cutting tool can rotate in the sleeve as the bur rotates to cut the tooth, and the cutting tool can slide laterally in the slot along with the sleeve to displace the bur along the tooth during cutting, and the cutting tool can displace in and out of the sleeve to displace the bur in and out with respect to the tooth during cutting. The sleeve can be restrained in the slot in an in-and-out direction by the enlarged collar(s) on the sleeve. Thus, the sleeve is retained in the slot and in the cutting guide. In addition, the pair of enlarged collars can resist pivoting of the sleeve in the slot, or along the slot, thus maintaining the sleeve upright with respect to the slot. The cutting tool has two transverse degrees of freedom, or directions of motion, including laterally along the slot, and in and out of the slot.
As described above, the dental cutting system 10 for cutting a patient's tooth 14 can comprise at least one cutting guide, with at least one slot therein, and a cutting tool 18 guided by the slot. The cutting tool 18 can have a shank 22 and a cutting bur 26 configured to cut the patient's tooth 14. The shank 22 can be received by a chuck of a dental handpiece 30 (
The system 10 can include at least one cutting guide or a plurality of cutting guides. A single cutting guide may be used for cutting a tooth to receive an inlay or a veneer. Two or three (or more) cutting guides may be used for cutting a tooth to receive a crown, or for cutting adjacent teeth to receive a bridge. (Three cutting guides are shown in
In addition, each cutting guide 40 can have at least one slot, indicated generally at 48, in the cutting guide with a depth extending from an exterior of the cutting guide to the at least one cavity 44 or interior of the cutting guide. The slot 48 can receive at least the shank 22 of the cutting tool 18 therein. Again, the configuration, location and/or orientation of the slot(s) 48 can be custom made for the patient based on the prosthesis or restoration and cut model of the tooth, as described in greater detail below. The slot can define a cutting path or path of travel for the cutting tool, such that moving the cutting tool along the slot properly positions and orients the cutting tool to cut and shape the tooth to form a cut tooth in a predetermined shape and size (as previously modeled) to receive a prosthetic or restoration (also as previously modeled). The cutting guide can comprise plastic and be formed with 3D printing on a 3D printer, or milled or machined, or the like, to create the cutting guide with the slot(s) and cavity therein.
As described above, the system 10 can include at least one cutting guide or a plurality of cutting guides depending on the cut(s) to be made, and the restoration to be performed or installed. In the case of an inlay or a veneer, a single cutting guide may be used. For an inlay, a single cutting guide may be used with a single slot in the occlusal wall of the cutting guide to cut an occlusal surface or side of the tooth to receive the inlay. Similarly, for a veneer, a single cutting guide may be used with a single slot in the occlusal wall of the cutting guide to cut a buccal wall of the tooth or teeth to receive the veneer. In the case of a bridge, multiple cutting guides may be used, each with one or more slots, to cut the teeth to receive the bridge. Similarly, in the case of a crown, multiple cutting guides can be used.
The present invention will be described with respect to a crown with the understanding that such description is applicable to other cases, such as inlays, veneers and bridges. Thus, the plurality of cutting guides can include three cutting guides, namely: an occlusal cutting guide 40b for cutting an occlusal surface or side of the tooth 14, as shown in FIGS. 1 and 8-10; a buccal cutting guide 40c for cutting a buccal surface or side of the tooth 14, as shown in
The occlusal cutting guide 40b, for cutting the occlusal side or surface of the tooth, can have a pair of opposite occlusal slots 48b located laterally on the occlusal cutting guide. One of the occlusal slots can be located on the buccal side or wall of the cutting guide, while the other occlusal slot can be located on the lingual side or wall of the cutting guide, opposite or opposing one another across the cavity. The occlusal slots 48b can be oriented at an incline with an acute angle with respect to a plane of the occlusal side of the tooth, and located to extend approximately midway into the occlusal surface of the tooth, to form a V-shaped cut with an obtuse angle (for purposes of receiving a crown). In addition, the occlusal cutting guide can have an occlusal window 52 disposed in the occlusal wall of the occlusal cutting guide, and located between the pair of occlusal slots 48b. Thus, the tooth 14 can be viewed through the occlusal window 52 during cutting. Similarly, one or more such occulsal cutting guides can be used to cut adjacent but separated teeth to receive a bridge.
The buccal cutting guide 40c, for cutting the buccal side or surface of the tooth 14, can have a buccal slot 48c located in and/or on the occlusal wall of the cutting guide. In addition, the buccal cutting guide 40c can have a buccal window 58 disposed in the buccal wall of the buccal cutting guide and located proximal to the buccal slot and the tooth 14 so that the tooth can be viewed through the window during cutting. Similarly, one or more such buccal cutting guides can be used to cut adjacent but separated teeth to receive a bridge. In addition, such a buccal cutting guide can be used to cut the buccal side or surface of a tooth to receive a veneer. Furthermore, such a cutting guide can also be configured to cut the occlusal surface or side of the tooth to receive an inlay.
The lingual cutting guide 40d, for cutting the lingual side or surface of the tooth 14, can have a lingual slot 48d located in and/or on the occlusal wall of the cutting guide. In addition, the lingual cutting guide can have a lingual window 62 disposed in the lingual wall of the lingual cutting guide and located proximal to the lingual slot and the tooth 14 so that the tooth can be viewed through the window during cutting.
Each cutting guide can comprise a main body 62 configured to engage at least one of a patient's teeth, including a buccal wall 64, a lingual wall 66 and an occlusal wall 68. Each cutting guide can comprise a protrusion 70 extending from the main body 62 and having the slot (48b, 48c, 48d) therein. The protrusion 70 can have a wall 72 surrounding a majority of the slot with a constant cross-sectional shape, as shown in
The slots 48 (and 48b, 48c, 48d) have opposing channels 80 formed in opposing walls of the slots, and extending along a length of the slots, as shown in
A sleeve 84 is disposed in the slot 48 and slidable along the length of the slot. Each slot of each cutting guide can have its own sleeve so that there are multiple sleeves corresponding to multiple slots and multiple cutting guides. Alternatively, a single sleeve can be provided for use in all of the slots and cutting guides. The sleeve can be formed of metal, such as brass. The sleeve can be formed by machining or milling. As described below, the sleeve can have a bore 92 (
The sleeve 84 has an enlarged collar 88 (
The shank 22 of the cutting tool rotates (indicated by arrow 96) in the bore 92 of the sleeve 84 as the cutting tool and bur rotate to cut the tooth. The bur 26a or 26b of the cutting tool 18a or 18b is slidable or insertable through the bore 92 of the sleeve in the in-and-out direction, indicated by arrow 98, and into and out of the sleeve. Thus, the cutting tool 18 can rotate 96 to cut the tooth, slide laterally in the slot 48 along with the sleeve 84, and displace in and out of the bore 92 of the sleeve 84 in the in-and-out direction 98 with respect to the cavity of the cutting guide and the tooth, and into and out of the sleeve. Thus, the cutting tool 18a or 18b has two transverse degrees of freedom, namely longitudinally along the slot (and laterally with respect to the sleeve), and in and out of the slot (in the in-and-out direction 98), and in and out of the sleeve 84.
The cutting guide and/or the slot thereof can have an enlarged opening 102 to receive the sleeve 84, and enlarged collar 88, into the slot. The enlarged opening can be formed in an exterior of the cutting guide and over the slot or at the top or exterior of the slot, and at a location along the slot. The enlarged opening can have the same or greater diameter as the enlarged collar. In one aspect, the enlarged opening can be located at an end of the slot. In another aspect, the enlarged opening can be located intermediate the ends of the slot. In another aspect, the cutting guide can have a lateral opening, shaped as the lateral profile or cross-section of the sleeve, formed in a lateral wall thereof and extending to the slot.
The sleeve 84 can have a length and the slot can have a depth, and/or the opposing channels 80 can be located along the depth of the slot and the enlarged collar(s) 88 can be located along a length of the sleeve, so that an exterior or outer opening or end of the sleeve is visible in an open exterior of the slot, as shown in
In one aspect, the sleeve 84 can be inserted into the slot, or enlarged opening 102 thereof, of the cutting guide, prior to receiving the cutting tool. Then the cutting tool 18 can be inserted into the sleeve 84 or bore 92 thereof. Then the handpiece can be actuated and the cutting tool rotated to cut the tooth. In one aspect, the slot can be configured so that the cutting tool is initially located outside the tooth, and the cutting tool can be subsequently slid through the slot (within and along with the sleeve) to cut the tooth in a sweeping motion. The cutting tool or bur can be operated subsequent to full insertion of the bur through the bore of the cutting guide. The sleeve resists the shank from bearing against the cutting guide, and the bur from contacting the cutting guide if withdrawn. In another aspect, the slot can be configured so that the cutting tool is initially located inside the tooth, and the cutting tool can be initially slid into the sleeve and initially cut the tooth in a plunging motion, then the cutting tool can be subsequently slid through the slot (within and along with the sleeve) to cut the tooth in a sweeping motion. Thus, the cutting tool or bur thereof can be operated or rotated while in the bore of the sleeve, to resist the bur cutting the cutting guide. In one aspect, a sleeve can be provided for each slot. Thus, the cutting system can comprise a plurality of slots and a plurality of sleeves, one for each slot. In another aspect, the cutting tool can be inserted into the sleeve 84 or bore thereof, prior to insertion into the slot or enlarged opening thereof. By inserting the cutting tool and the bur thereof into the sleeve, the sleeve resists inadvertent cutting of the cutting guide. At the end of the cutting motion the cutting tool can be withdrawn from the slot of the cutting guide, and from the sleeve, with the sleeve retained in the slot and resisting cutting of the cutting guide in case the cutting tool needs to be reinserted to recut the tooth.
The an edge or lip 34 of the shank 22 of the cutting tool 18 can have a greater diameter than the bur 26, and can abut to the outer edge or opening of the sleeve 84 when fully inserted, as shown in
In one aspect, a low friction material or fluid can be applied to the interior of the sleeve and/or the shank to reduce friction between the shank and the sleeve, and thus resist the shank from imparting rotation to the sleeve. In another aspect, the enlarged collars of the sleeve can be oblong with a long dimension oriented along the slot and a small dimension oriented against the channel to resist rotation of the sleeve in the slot. In another aspect, a low friction material or fluid can be applied to the interior of the slot and/or an exterior of the sleeve to facilitate sliding of the sleeve in the slot.
The cutting guide can also comprise a window formed through the wall of the cutting guide from an exterior to the cavity, and located adjacent the tooth to be cut, so that the dentist can observe the cutting tool cutting the tooth as the shank moves with the sleeve through the slot. In one aspect, the window can be wider than the slot.
A method for cutting a patient's tooth 14 and utilizing the system 10 described above comprises: placing the cutting guide (40, 40b, 40c, 40d) on at least one of the patient's teeth 14 and 14b with the cavity 44 of the cutting guide matching at least a portion of at least one of the patient's teeth; inserting the sleeve 84 into the slot 48 of the cutting guide (48, 48b, 48c, 48d), and the enlarged collar 88 of the sleeve into the opposing channels 80 in the opposing walls of the slot; inserting the bur 26a or 26b of the cutting tool 18a or 18b into the sleeve 84 with the bur passing through the sleeve, and the shank 22 of the cutting tool rotatable in the sleeve; displacing the cutting tool 18a or 18b along the slot (48, 48b, 48c, 48d) with the sleeve 84 slidable in the slot, and the collar 88 slidable in the channels 80, to displace the bur along the patient's tooth 14 to cut a portion of the patient's tooth with the bur; and selectively retracting and inserting the cutting tool 18a or 18b in the sleeve 84. The cutting guide can be removed and a prosthetic or restoration affixed to the user's cut tooth. Another cutting guide can be subsequently placed on the patent's teeth, and subsequent cuts made. For example, the occlusal cutting guide 40b can be placed on the user's teeth to make occlusal cuts in the occlusal face of the tooth; the occlusal cutting guide can be removed and the lingual cutting guide 40c can be placed on the user's tooth to make a lingual cut in the lingual face of the tooth; and the lingual cutting guide 40c can be removed and the buccal cutting guide 40d can be placed on the user's teeth to make buccal cuts to the buccal face of the tooth. The cutting tool can be withdrawn from the sleeve and the cutting guide while the sleeve remains in the slot of the cutting guide.
As described above, and with reference to
Referring to
While the forgoing examples are illustrative of the principles of the present invention in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the invention. Accordingly, it is not intended that the invention be limited, except as by the claims set forth below.
Priority is claimed to copending U.S. Provisional Patent Application Ser. Nos. 61/754,894, filed Jan. 21, 2013, and 61/770,180, filed Feb. 27, 2013, which are hereby incorporated herein by reference in their entirety.
Number | Date | Country | |
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61754894 | Jan 2013 | US | |
61770180 | Feb 2013 | US |