Abstract: A bore is cut into bone tissue to receive an inserted pin or post (7, 23). A pilot bore (2, 22) is formed with a reamer; the post is fixed in the bore, and an enlarged region (16, 29, 30, 31, 32) is formed at the top end of the bore using a tubular cutter (10, 17, 26) which is guided on the post. The enlarged region can be accurately cut even with a hand drill due to the guidance provided by the post. The cutter may have holes (15) or channels for circulation of cooling/lubricating liquid, and a swarf-removing slot (13) may be provided. When the technique is used in dentistry for replacement of a tooth crown, a tubular support element (29a) is fixed around the post in the bore enlargement.

Abstract: A bone spreader for preparing a site for dental prosthesis implantation consists of a relatively flat, wide, blade component and a longitudinal ridge component centrally disposed on one side of the blade component. Penetration of the instrument effects spreading of cortical bone tissue and produces a recess that includes a groove portion within which the root element of a dental implant can be accommodated.

Abstract: A dental tool for use with an ultrasonic transducer, the tool being substantially elongated and defined by a shaft having a proximal end with a coupling attachment at the proximal end for attachment to an ultrasonic transducer, and a distal end having a tip configured for performing excavation, finishing, removal and a dental polishing procedures, and a fluid passage extending from the proximal end to the distal end and exiting at a port at or proximate the tip.

Abstract: A dental diamond bur is provided, which is applicable for operations including from opening of a pulp chamber to spreading of a root canal orifice to any teeth of anterior teeth and molars; does not cut out a tooth orifice portion more than needed; cuts out a tooth orifice surface into a smooth curve surface form, thereby improving the adhesion between a filler and a tooth in that cut-out site; and is free from occurrence of perforation, in the root canal treatment. The dental diamond bur includes a tip portion that is a body of revolution with a convergent smooth curve, having a diameter in a shank portion side thereof of 0.5 to 0.8 mm and a height of 0.5 to 0.85 mm; and a diamond grains-attached portion that is a body of revolution with an externally convex curve from a rear end of the front end portion toward a shank portion, a maximum diameter portion of the diamond grains-attached portion being positioned in a range of 5.0 to 10.

Abstract: An intraosseous delivery apparatus having a drilling member and a sleeve member. The drilling member includes a drill housing, a connecting portion for establishing a connection to a conventional dental drilling apparatus, and a drill extending from the drill housing. The sleeve member includes a sleeve housing, and a hollow sleeve extending from the sleeve housing. The sleeve housing is adapted to be removably engaged with the drill housing such that the drill is inserted into the hollow sleeve. The drill has a length such that when the drill is inserted into the hollow sleeve, a portion of the drill extends beyond the hollow sleeve. As a result, when the drill is used to drill a hole in bone, the drill is inserted deeper into the hole than the hollow sleeve. The hollow sleeve is adapted to be left inserted in the bone when the drill is removed therefrom.

Abstract: The invention provides a depth gauging system and a method for forming depth indicating bands on amorphous hard carbon coated dental tool bits and the like. The method uses a laser to process, treat or pseudo-etch selected surfaces of the coated tool bit. Advantageously, the laser pseudo-etching creates bands or indicia that substantially preserve or retain some or all of the desirable bulk properties of the hard carbon coating, for example, the corrosion resistance. Desirably, the bands provide visual differentiation during the preparation of an osteotomy in bone material which allows a surgeon to precisely control the depth of the osteotomy.

Abstract: The invention relates to a coated tool bit for a dental drilling/cutting system. The tool bit is used to prepare an osteotomy in the jawbone of a patient. The tool bit is coated with a hard carbon coating/film. The coating can comprise diamond-like carbon (DLC), amorphous diamond, crystalline diamond, or a combination thereof. The tool bit includes drilling bits, threadformers, counterbores, and cutting tips of osteotomes. Some of the advantages of the coated tool bit are reduced friction, enhanced cutting efficiency, improved heat dissipation, increased resistance to wear and corrosion, and reduced adhesion to bone, tissue and other debris.

Abstract: The invention relates to a device that is provided with a bone cutter to be fitted to medical, especially dental handpieces, for example angle pieces. Said cutter (1) is received with its cutter head (2) by a bushing (6) coupled to the cutter (1) so as to be rotated and so as to be displaced in the direction of its rotational axis. An arcuate knife edge is provided on the front face (7) of the bushing (6) so that the bushing forms a rotating punch, while the cutting head (2) can be extended from the plane of the front face (7) of the bushing (6).

Abstract: At an initial office visit, the dentist makes an impression of the portion of the mouth in which the tooth is located, with upper and lower occusal surfaces at or below the gum line. After preparation of a crown, the dentist presses the surface contour tool against the biting surface of the tooth to determine the depth settings for at least one burr in a surface tool that will remove the upper surface of the tooth and create a working surface for the material removal device. The dentist inserts at least one burr with the proper length in this tool so that when the tool is lowered onto the tooth, a flat surface will be created. The flat surface tool and the center hole drilling burr are operated with a device that locks onto the tooth and ensures that the top surface of the tooth will be perpendicular to the central line of the tooth. The dentist inserts the guide pin of the material removal device in the center hole and begins to remove material from the side of the tooth.

Abstract: An endodontic reamer and a method for manufacturing endodontic reamers and files, more specifically an endodontic reamer having a cylindrical shaft and a working portion extending forward from a removed end of the shaft. The working portion includes, typically, a pair of wedged shaped projecting sections that extend beyond the diameter of the shaft. Forward from the wedge shaped sections is a nose, typically non-cutting nose, that has a diameter of about equal to diameter of the shaft. There are typically two (2) wedge shaped sections projecting outward opposite one another. Applicant also provides a novel method for manufacturing an endodontic reamer, which consists of using a two piece mold and placing a wire blank between the mold, followed by forcing the mold together, under compression, against the wire blank, to deform the blank into the shape of the mold parts.

Abstract: A dental drill system for use in preparing an osteotomy of a predetermined depth and diameter sized to receive a dental implant therein is disclosed. The drill system comprises at least one elongate depth drill of a first diameter adapted to drill the osteotomy opening to the predetermined depth, and at least one elongate width increasing drill of a second greater diameter adapted to size the diameter of the osteotomy opening to the predetermined diameter. The invention also teaches a method of using the dental drill system to form the osteotomy opening, the method comprising the steps of using a starter drill to define at least a portion of the osteotomy opening, using at least one elongate depth drill of a first diameter to drill the osteotomy opening to the predetermined depth, and using at least one elongate width increasing drill of a second greater diameter greater than the first diameter to increase the diameter of the osteotomy opening to the predetermined diameter.

Abstract: A dental tool for use with an ultrasonic transducer, includes a substantially elongate shaft having a proximal end with a coupling attachment at the proximal end for attachment to an ultrasonic handpiece or transducer, and a distal end having a tip configured as a cutting blade having an elongated substantially straight cutting edge, where, upon energization of the transducer, the cutting blade vibrates in a direction substantially coplanar to its cutting edge.

Abstract: A dental implant healing screw formed from two pieces: a threaded shaft and a collar. The healing screw functions as a conventional healing cap to protect the coronal end of the dental implant and as a driver to drive the dental implant during the implantation procedure.

Abstract: This application relates to a dental apparatus for the initial and subsequent guidance of hypodermic needles, or similar drug delivery devices into the cortical plate of human mandibular and maxillary bones. The invention comprises a solid drill bit bearing a channeling groove along the majority of the shaft. The groove is scalloped at its delivery end to flex the needle tip and deflect the tip out from the drill and into the desired tissue. Variations are described, with the preferred embodiment having the circumference of the drill bit reduced in girth for the length bearing the groove. This permits an inexpensive plastic covering which serves as a practical seal against bacteria. The seal is permeable to the needle's tip and closes back on itself after withdrawal of the needle.

Abstract: A rotary osteotome for widening a dental implant site in preparation to receive a dental implant. The osteotome includes a tapered body tapered from a tip thereof to a widened intermediate region, with at least a part of the tapered body being threaded. The threads are feeding threads constructed to draw the tapered body into the implant site responsive to rotation thereof. A coupling provides detachable engagement with a surgical drill or hand wrench for forward and reverse rotation of the osteotome. A kit of such osteotomes includes osteotomes of gradually increasing diameters, with the diameter of the intermediate region of a first osteotome being slightly larger than the diameter of th tip for a subsequent osteotome, thereby providing for gradual widening of the implant site.

Abstract: This application relates to a dental apparatus for the initial and subsequent guidance of hypodermic needles, or similar drug delivery devices into the cortical plate of human mandibular and maxillary bones. The invention comprises a solid drill bit bearing a channeling groove along the majority of the shaft. The groove is scalloped at its delivery end to flex the needle tip and deflect the tip out from the drill and into the desired tissue. Variations are described, with the preferred embodiment having the circumference of the drill bit reduced in girth for the length bearing the groove. This permits an inexpensive plastic covering which serves as a practical seal against bacteria. The seal is permeable to the needle's tip and closes back on itself after withdrawal of the needle.

Abstract: A dental tool for use with an ultrasonic transducer, includes a substantially elongate shaft having a proximal end with a coupling attachment at the proximal end for attachment to an ultrasonic transducer, and a distal end having a tip configured as a cutting blade having an elongated substantially straight cutting edge.

Abstract: A dental tool for use with an ultrasonic transducer, the tool comprises a substantially elongate tool defined by a shaft having a proximal end with a coupling attachment at the proximal end for attachment to an ultrasonic transducer, and a distal end having a tip configured for performing a dental procedure, and a fluid passage extending from the proximal end to a port configured and positioned to direct fluid onto the tip.

Abstract: The invention relates to a coated tool bit for a dental drilling/cutting system. The tool bit is used to prepare an osteotomy in the jawbone of a patient. The tool bit is coated with a hard carbon coating/film. The coating can comprise diamond-like carbon (DLC), amorphous diamond, crystalline diamond, or a combination thereof. The tool bit includes drilling bits, threadformers, counterbores, and cutting tips of osteotomes. Some of the advantages of the coated tool bit are reduced friction, enhanced cutting efficiency, improved heat dissipation, increased resistance to wear and corrosion, and reduced adhesion to bone, tissue and other debris.

Abstract: A dental diamond bur is provided, which is applicable for operations including from opening of a pulp chamber to spreading of a root canal orifice to any teeth of anterior teeth and molars; does not cut out a tooth orifice portion more than needed; cuts out a tooth orifice surface into a smooth curve surface form, thereby improving the adhesion between a filler and a tooth in that cut-out site; and is free from occurrence of perforation, in the root canal treatment. The dental diamond bur includes a tip portion that is a body of revolution with a convergent smooth curve, having a diameter in a shank portion side thereof of 0.5 to 0.8 mm and a height of 0.5 to 0.85 mm; and a diamond grains-attached portion that is a body of revolution with an externally convex curve from a rear end of the front end portion toward a shank portion, a maximum diameter portion of the diamond grains-attached portion being positioned in a range of 5.0 to 10.

Abstract: The invention provides a dental drill comprising a plurality of blades each distally terminating in an end cutting edge having a positive rake angle. Advantageously, this allows for efficient, accurate and safe formation of an endosseous implant-receiving osteotomy in a patient's jawbone. Desirably, any patient trauma or discomfort during the procedure is substantially eliminated or reduced and a precision-sized osteotomy for receiving an implant of a predetermined size is created.

Abstract: The invention provides a depth gauging system and a method for forming depth indicating bands on amorphous hard carbon coated dental tool bits and the like. The method uses a laser to process, treat or pseudo-etch selected surfaces of the coated tool bit. Advantageously, the laser pseudo-etching creates bands or indicia that substantially preserve or retain some or all of the desirable bulk properties of the hard carbon coating, for example, the corrosion resistance. Desirably, the bands provide visual differentiation during the preparation of an osteotomy in bone material which allows a surgeon to precisely control the depth of the osteotomy.

Abstract: A dental bur for use in repair of a carious lesion has a working surface including cutting elements which deflect or abrade upon encountering material having a hardness at or above a preselected hardness, wherein said preselected hardness is below the hardness of normal dentin and is generally below a hardness corresponding to the lower limit of hardness of pre-carious dentin to be retained in painless procedures.

Abstract: Teeth, the hardest substance in the human body, are frequently all that remain of a mortuary population from which direct human presence can be gleaned. As such their morphology is invaluable to physical anthropologists and investigators in allied disciplines. Methods currently used for purposes of extracting DNA from dental remains—e.g. bone-milling, crushing, and sectioning—result in total destruction of the teeth. This paper introduces the Reverse-Root-Canal, a protocol by which DNA of molecular weight higher than that obtainable through traditional destructive means, can be obtained from ancient dental remains without harm to the morphologically informative crown and roots.

Abstract: A dental drill, formed of a substantially solid elongate body, includes (a) a longitudinal shank having a proximal and a distal end and having an axially disposed irrigation channel; (b) a working portion comprising (i) an annular boss integrally disposed distally of the shank; (ii) a neck of reduced radius relative to the boss, integrally disposed distally of the boss; (iii) a cutting region of uniform diameter integrally disposed distally of the neck; and (iv) a cutting region having a tapered external geometry, integrally dependant distally of the cutting region of uniform diameter, the cutting regions including at least four integral axi-symmetric flutes formed upon lateral surfaces of the regions, each of the flutes defining co-axial peripheral profiles, each of the flutes separated by substantially co-axial integral channels, each having at least one outlet therein, the working portion of the drill having an irrigation channel extending the entire length and integral with the shank irrigation, the one o

Abstract: Instead of a bunch of bristles coated with abrasive particles, the brush for surface treatments in restorative dentistry comprises one or several lamellar abrasive elements. In the manner of a lametta strip, the abrasive elements are divided by at least one incision, such that a plurality of bristle portions is obtained. Due to the planar configuration of the bristle portions themselves, the latter are easily bendable in at least one direction. If the arrangement of the abrasive elements is such that this direction of easy bending ability is approximately tangential to the intended rotational direction of the brush, the overall flexibility of the brush is substantially increased, thus allowing a substantially improved compliance with application-specific requirements.

Abstract: A periodontal surgical instrument is disclosed which includes a handle with two ends. One end comprises a shank with a first cutting head preferably comprising a thin, flexible, angled blade for insertion to separate the gingival attachment and enter the P.D.L. space. The angulation and length are preferably suited to circumscribe the entire circumference of the root structure, all the way to the root apices. The other end comprises a spatula-shaped blade. The blade creates enough space for the introduction of extraction instruments in a controlled manner, and at locations dictated by the surgeon. A method of use is also described for this periodontal surgical instrument for procedures where extraction is desired.

Abstract: The present invention relates to a dental tool, in particular for grinding teeth, comprising a grinding head and a rotatingly drivable shaft, the grinding head being provided on its surface with at least one elevated portion which, during rotation of the grinding head works a surface to be prepared and defines a circle of rotation. The invention is characterized in that the elevated portion comprises an edge, and the edge is the side line of a surface that is situated at least at the leading side of the edge and that is retracted relative to the circle of rotation defined by the edge.

Abstract: The present invention relates to a finisher set for the cosmetic aesthetic treatment of teeth, the set comprising a plurality of finishers each including a shaft (b 5) adapted to be clamped into a drive means, as well as a conical head provided with cutting edges, characterized in that a first finisher (1) comprises a head (2) with helical cutting edges and a transverse cut, and that a second finisher (3) is provided with a head (4) having helical cutting edges.

Abstract: An intraosseous delivery apparatus having a drilling member and a sleeve member. The drilling member includes a drill housing, a connecting portion for establishing a connection to a conventional dental drilling apparatus, and a drill extending from the drill housing. The sleeve member includes a sleeve housing, and a hollow sleeve extending from the sleeve housing. The sleeve housing is adapted to be removably engaged with the drill housing such that the drill is inserted into the hollow sleeve. The drill has a length such that when the drill is inserted into the hollow sleeve, a portion of the drill extends beyond the hollow sleeve. As a result, when the drill is used to drill a hole in bone, the drill is inserted deeper into the hole than the hollow sleeve. The hollow sleeve is adapted to be left inserted in the bone when the drill is removed therefrom.

Abstract: A method for the removal of broken threaded dental posts, whose heads have been sheared off, from their receiving bores by exposing the post in its bore together with its extraction, without a need for an additional pulling device. A hollow cylindrical body accommodates precisely the neck of the broken post. The cylinder has saw teeth at its lower rim and an extension of a solid shaft at its upper end by which it is attached to the head of a dental drill. The counter clockwise rotation of the cylinder cuts a circular groove around the post which facilitates its release and withdraw of the post by screwing it out of its bore.

Abstract: A dental instrument for sonic or ultrasonic treatment comprises a shank (1) to which a treatment section (2) is joined. The shank (1) and treatment section.(2) are made of matrix-bonded carbon fibers. The instrument can be machined out of a woven carbon fiber fabric or can be a compression molding or an injection molding. The mechanical properties of the instrument can be adjusted by varying the length of the carbon fibers.

Abstract: An intraosseous delivery apparatus having a drilling member and a sleeve member. The drilling member includes a drill housing, a connecting portion for establishing a connection to a conventional dental drilling apparatus, and a drill extending from the drill housing. The sleeve member includes a sleeve housing, and a hollow sleeve extending from the sleeve housing. The sleeve housing is adapted to be removably engaged with the drill housing such that the drill is inserted into the hollow sleeve. The drill has a length such that when the drill is inserted into the hollow sleeve, a portion of the drill extends beyond the hollow sleeve. As a result, when the drill is used to drill a hole in bone, the drill is inserted deeper into the hole than the hollow sleeve. The hollow sleeve is adapted to be left inserted in the bone when the drill is removed therefrom.

Abstract: A highly flexible instrument particularly useful in medical and dental applications is elongated and formed of a plurality of flexible metallic strands, at least one strand being spirally wound and having a scraping edge thereon.

Abstract: A rotary tool for material detaching work, especially in dentistry, comprising a machining portion having an outer circumferential surface coated with a nickel layer in which diamond particles are embedded, is characterized in that the nickel layer and the diamond particles protruding from it are covered by a layer of chromium nitride. The duration of the tool is considerably increased by the chromium nitride layer.

Abstract: The present invention relates to a dental tool (1) comprising a head (2) and a rotatably supported shaft (9). The head (2) comprises a first toothing (A), a second toothing (B), and a third toothing (C). Thus, different materials can be roughed and also finished by means of said triple toothing.

Abstract: A dental bur for use in examining anomalies and in restoration of decayed areas of teeth with a bur head having a generally elongate conical shaped body with a base and an opposed vertex. Cutting members are located about the outer surface of the body between the base and vertex and extend along the outer surface of the bur head which has a length of at least 1.5 millimeters.

Abstract: In the method for the manufacture of dental tools for the treatment of surfaces, a rubber core serving as a carrier layer is first applied by injection molding onto the spindle of the tool, and the abrasive layer comprising the abrasive grains is subsequently applied to the carrier layer. In another method for the manufacture of dental tools for different treatments of surfaces, more particularly for coarse grinding, finishing, and polishing, rubber-elastic masses of different degrees of hardness are used for the abrasive parts of the tools according to the intended treatment, and abrasive grains of the same size are embedded in the rubber-elastic mass of these parts.

Abstract: An intraosseous delivery apparatus having a drill coupling member and a drilling needle member. The drill coupling member includes a shaft, an open housing provided at one end of the shaft, a connecting portion provided at an opposite end of the shaft for establishing a connection to a conventional dental drill, and an anticlog needle extending from the shaft through the open housing. The drilling needle member includes a drilling needle housing and a hollow drilling needle shaft extending therefrom. The drilling needle member is adapted to be removably engaged with the drill coupling member such that the drilling needle housing of the drilling needle member is inserted into the open housing of the drill coupling member and such that the anticlog needle of the drill coupling member is inserted into the hollow drilling needle shaft of the drilling needle member.

Abstract: The invention relates to a bone recovering surgical drill comprising an active portion (A) and a non-active portion (E), having between the active and non-active portions one or more circular grooves (f) the depth and width of which are sufficient for recovering the drilled bone residues, as well as a stop with a diameter larger than that of the active portion (A), the purpose of which is to limit the penetration of the drill. The stop is a fixed stop with a coloured mark (d) on said stop.

Abstract: A dental instrument is provided for use in an endodontic procedure which has a file extending from a handle configured to enable the working length of the handle to be varied. The handle of the instrument is adapted to be received in and to be releasbly held by a chuck or collet of an endodontic handpiece head. Both the handles and chucks are adapted to enable the handles to be appropriately positioned in the chuck of a dental handpiece head at various positions to yield a desired working length and to then be secured. The rim around the chuck is preferably configured to act as a stop during use of the handpiece. The handle is most useful when configured with incremental adjustment indicators, preferably in uniform increments, such that the working length can be determined by viewing the indicators.

Abstract: A dental instrument is provided with a pivotally arranged shaft and a head mounted to the shaft. The head is equipped with a plurality of cutting blades. The cutting blades have a clearance angle of 0° and a negative cutting angle. The areas of the blades that trail the cutting edges are either planar surfaces or a partially cylindrical shape. In some embodiments, the front area of head is provided with a circumferential groove that is open at the front side, into which an annular contact element (O-ring) is inserted. The contact element can have the shape of an elastic ring.

Abstract: A pair of dental burs for shaping mandibular teeth into the proper sloped configuration for lingual occlusion or denture teeth. The first bur is provided with a non-cutting central portion that is flanked by two slightly angled cutting surfaces, and the second bur is provided with a cutting central portion that is flanked by two slightly angled non-cutting surfaces. The angulation of the two cutting surfaces on the first bur may or may not match each other on a given set of burs, and the angulation of the two non-cutting surfaces on the second bur may or may not match each other on a given set of burs, but the angles of the cutting surfaces on the first bur match the angles of the non-cuffing surfaces on the second bur. The burs are used sequentially; i.e. the first bur is used first and the second bur is used second, to achieve the desired slope and center floss for the mandibular teeth without cutting too deeply.

Abstract: A drill particularly suited for drilling holes for dental anchors. The drill has a central shaft including a proximal end having conventional connection structure for attachment to a powered rotatable appliance and a distal end bearing a forwardly projecting pin which occupies and is guided within a pilot bore. The pin has a blunt, preferably spherical, enlarged head. The blade is mounted on the central shaft between the proximal and distal ends of the shaft. The blade is preferably annular, having cutting teeth facing the distal end of the shaft. At least one relief communicates between the interior of the annular blade and the exterior thereof.

Abstract: The present invention relates to a dental drill comprising a shaft (2) and a cutting portion (3) provided with cutting edges. At the front side, the dental drill (1) comprises two main cutting edges (5) and, laterally on the cutting portion, a plurality of additional cutting edges (7). The main cutting edges (5) converge in a central axis of the dental drill and directly pass into two lateral cutting edges (8).

Abstract: A shank for a dental instrument, including instruments which are used in endodontics and in dental prophylaxis, is fitted on a contra-angle or a handpiece and is provided with a rotary drive which cooperates directly with the rotary transmission members of the kinematic chain of the contra-angle, upstream of the head of the contra-angle. Also, the head of a dental instrument which is equipped with such a shank.

Abstract: Non-traumatic expansion devices for the bone for receiving affixing means for dental prosthetics, each expansion device being formed by a one-piece component (1) having an upper base (11) formed as a prismatic screw head. A center body (3) has milled generating lines extending in axial direction. A first transition area (5) is disposed between the center body (3) and the upper base (11). A threaded end (9) has a shape of an elongated cone and a second transition area (7) has a conical shape tapering toward the threaded end (9). Each expansion device has a different thickness and length on the threaded end (9) depending on the type of required expansion. The expansion device has the function of a screw for the purposes of drilling the bone and keeping the bone mass whole.

Abstract: An apparatus for intraosseous injection for dental application comprising a hollow drill (1) having a perforation or perforations (2) along its length and a beveled cutting end (3), fitted into a hub (4) of partly circular and partly hexagonal external cross-section and provided with a circumferential lip (5) and a funnel-shaped orifice (6) giving access to the open end of the said hollow drill at its end remote from the said cutting end, and an adapter (7) removably mated with the said hub by means of a matching orifice of substantially hexagonal cross-section and having at its end remote from said orifice a shank (8) shaped to fit into the chuck of a standard contra-angle dental handpiece, and a protective cap (9) fitted over the said hollow drill.

Abstract: A dental drill is formed of a solid elongate body, having a longitudinal shank including an axially disposed irrigation channel and a working portion having an annular boss and a neck of reduced radius relative to the boss, and a cutting region disposed distally of the neck, the cutting region including at least four axi-symmetric flutes formed upon lateral surfaces of the cutting region, each of the flutes defining co-axial peripheral profiles, each of the flutes separated by substantially co-axial channels, the working portion of the drill having an irrigation channel extending the entire length and having at least one outlet within each of the channels, the one outlet of each channel located proximally to a distal tip of the working portion, the tip defining a surface formed integrally and continuously with ends of the flutes and channels.

Abstract: A dental bur has a working surface including cutting elements which deflect or abrade upon encountering material at or above the preselected hardness corresponding to the lower limit of hardness of non-carious dentin. The dental bur is constructed of metal, ceramic, or plastic.