An apparatus for pliabilizing tubular materials including a frame, a ring holder, and a mandrel assembly. The ring holder assembly is mounted to the frame and includes a circumferential ring, and a plurality of pairs of non-mechanically driven, rotatable wheels mounted around the ring and having a recess extending circumferentially around an outer edge. The mandrel assembly includes a mandrel having proximal and distal ends and a maximum outer circumference, and a plurality of non-mechanically driven, rotatable wheels spaced apart about a circumference of the mandrel and mounted thereto so as to extend radially beyond the maximum outer circumference. The wheels of the mandrel assembly are positioned between and so as to mate with respective pairs of the wheels of the ring holder assembly, and the wheels of the mandrel assembly are sized shaped to mate with the recesses of the respective pairs of wheels of the ring holder assembly.

A machine and a method for treating fabrics, comprise in combination a step of inducing substantially vertical vibrations in a quantity of fabric in the form of a substantially compact mass and a simultaneous step of drying the rest of the fabric in opened-out form.

There are described powders comprising agglomerated nanocrystals of an electroactive alloy and oxygen. The main component of the alloy can be of nickel, cobalt, iron or mixtures thereof while the alloying element is one or more transition metals such as Mo, W, V, the alloy also including oxygen. Preferably the nanocrystals will be made of an alloy of nickel, molybdenum and oxygen. An electrode which is used by compacting the powders is also disclosed. Also disclosed, is a process for producing the powders by providing particles of nickel, cobalt and iron or oxides thereof with particles of at least one transition metal, (Mo, W, V) or oxides thereof and subjecting the particles to high energy mechanical alloying such as ball milling under conditions which include oxygen and for a sufficient period of time to produce a nanocrystalline alloy. Electrodes produced from these powders have an electrocatalytic activity for the hydrogen evolution which is comparable or higher than the electrodes which are presently used in the electrochemical industry. Moreover, these materials present an excellent chemical, electrochemical and mechanical stability. When use as a cathode the powders are useful in water electrolyzers, in chlor-alkali or the like cells.

A moisture metering calibration method and system for, e.g., determining the moisture lumber within a lumber drying kiln is disclosed. Calibration of moisture indicative electrical signals obtained from, e.g., moisture sensing capacitive plates spaced apart within a stack of drying lumber is performed, wherein long lengths (e.g., up to 1000 linear feet or more) of coaxial cable can be used for transmitting the signals, and effectively removing signal anomalies induced in such cabling so that accurate lumber moisture measurements result. Such extended cable lengths provides flexibility with respect to placement of electronic moisture metering equipment. This flexibility allows such equipment to be placed in an environmentally-controlled enclosure, rather than on the weather exposed exterior of a kiln whose lumber is being monitored.

A robotic arm especially suited for laparoscopic surgery, having a torsional joint and a flexural joint forming serially arranged joints is described. The joints provide respective degrees of freedom for the arm, which further receives drive means for such joints. The robotic arm also has transmission means placed between the drive means have and the joints. The transmission means a first and a second assembly of three gear wheels, preferably conical gear wheels, and a train of three additional gear wheels, preferably straight-cut gear wheels, which couple the first and second assembly to form a differential mechanism.

A dual clutch transmission designed as a reduction gearing which has concentric central and hollow transmission shafts, exactly one layshaft, and two power shift elements. A hollow shaft is provided coaxially on the layshaft, which can be rotatably fixed to the layshaft, via one shift device, and to which at least two gears of the gear stages are rotatably fixed. A further hollow shaft is provided coaxially on either the central or the hollow transmission shaft, which can be connected, via one of the shift devices, with the central or the hollow transmission shaft and to which at least two further gears of the gear stages are rotatably fixed. At least three transmission ratios are obtainable as a result of engaging the shift element into the power flow in three of the gear stages, by which one transmission ratio results from engaging only one shift element into the power flow.

A control device for a dual clutch transmission includes a transmission control unit that determines immobility in an engaging-side clutch in a next stage as sticking and, when the engaging-side clutch in the next stage malfunctions and when a gear in a previous stage is out of engagement, engages the gear in the previous stage and thereafter controls a clutch torque capacity in the previous stage to a predetermined value, and a back torque limiter operates according to a predetermined condition to engage a release-side clutch in the previous stage.

An XY all-directional precision alignment platform is provided and includes an XY-axes moving platform including X-axis moving platform and Y-axis moving platform, the X-axis and Y-axis moving platforms being stacked together, and a θ-angle rotating platform, the θ-angle rotating platform stacked onto the carrier surface thereof; wherein the θ-angle rotating platform is driven to perform precise θ-angle rotation achieving 360° and is of a four-layered thickness only, achieving the goal of having a light and thin product.

A device for preventing an inward shifting of a brake pedal during a collision. The device includes a mounting bracket. A pedal housing is combined with the mounting bracket such that the pedal housing is movable in a rearwards direction from the mounting bracket. A pedal arm is hinge-coupled at upper and middle parts thereof with the pedal housing and a push rod, respectively. A unit for preventing the inward shifting of the pedal arm has a separating plate which, as the pedal housing is moved rearwards, presses against a fixing pin to decouple the fixing pin from the pedal arm, enabling the pedal arm to turn outwards about a hinge point at the middle part.

A housing for a transmission is disclosed. The housing may have a plurality of integrally-formed walls that together create an enclosure with an open first end and an open second end disposed axially opposite the first end. The housing may also have a first flange located at the first end of the enclosure and configured to engage an input housing of an engine, and a second flange located at the second end of the enclosure and configured to engage a differential housing. The plurality of integrally formed walls includes a lower wall having at least one impingement protection feature.

A vibratory device comprises a rotor and an eccentric weight. The eccentric weight is mounted to the shaft and has a center of mass that is offset from the shaft axis. The vibratory device is configured such that the eccentric weight is in a first rotational orientation relative to the shaft and rotates with the shaft when the shaft rotates in a first direction about the shaft axis and such that the eccentric weight is in a second rotational orientation relative to the shaft when the shaft rotates in an opposite second direction about the shaft axis. The vibratory device is further configured such that the eccentric weight automatically transitions from the first rotational orientation to the second rotational orientation when the shaft is switched from rotating in the first direction to rotating in the second direction.

A hydraulic arrangement by which a plurality of shift rails of a transmission are actuated, including one double acting cylinder per shift rail by which the respective shift rail can be moved back and forth. A first hydraulic valve is connected upstream of the plurality of shift rails and has a first output and a second output, by which a first shift pressure and a second shift pressure for actuating the shift rails can be provided. A second hydraulic valve is connected between the first hydraulic valve and two of the shift rails, and by which it is selectively possible for the first output of the first hydraulic valve to be associated with one of the double acting cylinders of the two shift rails, and the second output of the first hydraulic valve to be associated with the other double acting cylinder of the two shift rails.

A pedal apparatus for a vehicle may include a pad, a bracket which may be disposed below the pad, wherein the bracket may be coupled to the pad and a pedal arm at each opposite end of the pad and the pedal arm, respectively, a link section which may be disposed in the bracket, wherein the link section may be coupled to a lower portion of the pad and an intermediate portion of the bracket, respectively, such that the bracket may be movable in a longitudinal direction thereof, and a hinge-adjusting section which may be disposed above the link section such that an angle of the pad may be adjusted as the link section moves in the longitudinal direction thereof.

Centrifugal pendulum device including pendulum masses arranged on axial sides of a pendulum mass support rotatable about an axis of rotation to form a pendulum mass pair. To form the mass pair, the masses are fastened to each other by means of a fastener passing through a cutout in the mass support. The mass pair is pivotable relative to the mass support due to a rolling element arranged to roll in a recess of the mass support and of the mass. In a section axially covering the recess of the mass support, the rolling element has a first outer diameter. In a section axially covering the recess of the pendulum mass, the rolling element has a second outer diameter. The rolling element further comprises a section axially located between the first and second diameters and has a third diameter, which is smaller than or equal to the first outer diameter.

An electromechanical actuator for a movable flight control surface of an aircraft, the actuator comprising an electric motor having an outlet shaft with first and second directions of rotation, a movement transmission arranged to connect the outlet shaft of the motor to the movable flight control surface, and a control unit for controlling the motor. The transmission incorporates a pawl device arranged to oppose the transmission of movement in the first direction of rotation, and the control unit is connected to a pawl declutching member for declutching the pawl and enabling movement to be transmitted in the first direction of rotation.

A dual stage accelerator pedal assembly is provided that is capable of communicating various vehicle operating conditions to the driver as well as notifying the driver of a critical operating condition, such as a low battery pack level, via a change in pedal resistance. The change in pedal resistance is achieved by preloading one of the springs in the accelerator pedal's spring assembly. The spring assembly uses two springs exhibiting different spring force to achieve distinguishable first and second pedal stroke stages.

An apparatus for locating a central axis of a spinal column and method of using the same is disclosed. The apparatus and method includes one or more members capable of spanning a center line which may then be identified by at least one additional member positioned therebetween. Furthermore, the device may contain or be capable of accommodating various additional tools for marking the location of the central axis of a spinal column.

A portable articulated arm coordinate measurement machine can include a base, a manually positionable articulated arm portion having opposed first and second ends, the arm portion including a plurality of connected arm segments, an electronic circuit that receives the position signals from the transducers, a first inclinometer coupled to the base, wherein the inclinometer is configured to produce a first electrical signal responsive to an angle of tilt of the base and an electrical system configured to record a first reading of the first inclinometer and a second reading of the first inclinometer, wherein the first reading is in response to at least one of a first force applied to the base and a third force applied to the mounting structure, wherein the second reading is in response to at least one of a second force applied to the base and a fourth force applied to the mounting structure.

A centerline marker holder used for engaging and sliding along a portion of two intersecting walls and sliding along an exterior or interior rounded or bull nose corner between the walls. The marker holder uses a pencil for drawing a centerline along a length of the corner. The marker holder includes a flat, first wall engaging member attached at an angle to a flat, second wall engaging member. Along a length of an intersection of the first and second wall engaging members is a centerline hole. The centerline hole is dimensioned to receive the pencil therethrough for marking the centerline. The marker holder also includes a plurality of offset holes from the centerline hole for drawing parallel offset lines at a selected distance from the centerline.

A frame assembly for simulating topography of an existing wall portion provides points of adjustment behind a wallboard panel mounted to the frame assembly. In this manner imperfections in an existing wall can be replicated to facilitate cabinet or countertop installation.

A protractor for use with an external fixation frame is provided. The protractor may include a face having angle designations thereon and a set of opposed and extending flanges projecting from said face. The flanges may connect to a portion of an external fixation frame, such as a ring (or other component) of the frame. The face may also include a post member to which a rotatable dial is mounted. An elongate member may be pivotally connected to a portion of the post member and may include a clamp. The clamp may be used to connect to an alternate portion of an external fixation frame, such as a strut of the frame. Thus, the protractor may be connected to two points on an external fixation frame so as to measure the angle between such points. Related methods of using the aforementioned protractor are also disclosed.

A hoist alignment apparatus and a method for aligning a hoist lift arm with a particular area on a frame are provided. The apparatus comprises a base defining a plane and a light operable to emit a light beam along an axis substantially orthogonal to the plane of the base, the light being held by a light holder attached to the base. The light may be replaced by an extendable rod. The hoist lift arm may be aligned by placing the apparatus on the arm and moving the arm until the light beam shines on the particular area or the tip of the extended rod points directly to the particular area.

Systems and methods for sailboat mast alignment are provided. In some embodiments, a system for alignment of a sailboat mast comprises a mounting bracket configured for attachment to the mast, and one or more lasers pivotally connected to the mounting bracket to enable the one or more lasers to be positioned at an index angle relative to the mast on both sides of the mast.

An apparatus for securing and drawing upon a piece of paper, includes a board having a drawing surface sized to receive the paper. The drawing surface is bounded along its perimeter by a border region. An array of border pieces is fastened securely to the border region, each border piece being aligned relative to the others to establish a precisely sized drawing surface area to accommodate the paper. Each border piece has a length shorter than that of the corresponding edge of the drawing surface.

An electronic caliper generates power for measurement operations. The caliper comprises a scale member, a slider, a signal processing portion configured to measure a displacement between the scale member and slider, a power generating arrangement attached to the slider comprising a gear assembly configured to rotate in response to a force provided through a power generating handle to the gear assembly by a user moving the power generating handle relative to the gear assembly, and a power generator coupled to the gear assembly and configured to rotate in response to force provided by the rotating gear assembly and provide power to the signal processing portion. The power generating arrangement generates power as the user moves the power generating handle, and the power generating arrangement contributes a motion resistance force component of at most 20N as the user moves the power generating handle with a maximum manual acceleration.

An apparatus for measuring dimensions of a micro-scale object includes a movable stylus, a probe and at least one acoustic emissions sensor. The movable stylus is positionable to contact an object to be measured. The probe is rotatably coupled to the stylus and has a distal end that circumscribes a circle when rotated. The acoustic emissions sensor is operatively coupled to the probe. The sensor is operative to detect acoustic emissions generated from contact between the distal end of the probe and the object, thereby allowing dimensions of the object to be determined.

A physiological measurement device or wearable device simulator includes a frame and a plurality of surfaces distributed within the frame. For each surface, a surface actuator links the surface of the frame. At least one of: i) force or position imparted by the surface on a physiological feature of a subject by the surface actuator; and ii) the force imparted by the physiological feature of the subject on the surface, can be employed to modulate the positions of the surfaces relative to each other independently of the forces imparted by or on those surfaces, thereby measuring the physiological feature of the subject or simulating a wearable device interface.

A measurement gauge, comprising a pair of jaws biased in a closed position; a normalizing member surrounding one of the jaws when the pair of jaws is closed, the normalizing member biased in an extended position; a handle coupled to the pair of jaws and normalizing member such that movement from an extended handle position to an retracted handle position opens the pair of jaws and moves the normalizing member to an retracted position.

An instrument and method for determining the location of the anatomical epicondylar axis between the condyles of a femur is provided. The instrument includes first and second gauges each for measuring a radius of a femoral condyle and a frame. At least one of the gauges is movably connected to the frame. The method includes positioning the measuring end of each gauge against a separate condyle of a femur, actuating a pivoting member of each gauge to determine the radius of each condyle, measuring the distance between the condyles, and determining the location of the anatomical epicondylar axis of the femur. A measurement can be taken from a measuring scale provided on the gauge and from another scale provided on the frame. Determining the location of the axis can further include performing a calculation utilizing the radii of the condyles and the distance between the condyles.

A mechanical encoder including an assembly, a flexible element, and a signal sensing module is disclosed. The assembly has a plurality of poking/stiring structure that provides poking/stirring function. The flexible element includes a first piezoelectric layer and a second piezoelectric layer. The first piezoelectric layer and the second piezoelectric layer are stacked on each other via an attach material. The flexible element is set up so that the poking/stiring structures stir/poke a first end of the flexible element, so as to output an electrical signal responsive to deformation of the flexible element. The signal sensing module receives the electrical signal to generate a position signal and a direction signal corresponding to the movement of the poking structures.

An apparatus for aligning a wind turbine generator is disclosed. Preferably, the apparatus includes at least, but is not limited to, a support flange engaging a securement stud via a securement aperture, and a force displacement plate contacting the support flange. The preferred apparatus further includes an indexing means attached to the securement stud and force displacement plate, the indexing means configured to translate a rotational force to linear force capable of moving the support flange in relation to the securement stud.

In a method for calibrating a star probe of an image measuring machine, the star probe includes one or more probe heads. Probe configuration information for the star probe is configured when there is no probe configuration file of the star probe stored in a storage device of the image measuring machine, and one of the probe heads to be calibrated is selected from the star probe. The method calibrates a radius value of the selected probe head, and calibrates the deviation between the center point of the selected probe head and the focus of the camera lens. The method further generates a star probe model of the star probe according to the probe configuration information and the probe calibration information, and displays the star probe model of the star probe on a display device of the image measuring machine.

A disposable saliva ejector that utilizes a single planar, double leaf shaped plate design that is embossed on their inner faces with a series of arced ribs and folded about its midpoint. A tab and slot arrangement about the center of the plates, joins the two plates. The distal tips are held together by a dovetail arrangement on raised pads at the distal tips of each plate. The distal and proximal tips are also held in operational contact by the suction forces passed through the device. The arced ribs form a series of channels about perimeter of the device. A trough runs along the linear axis of both of the plates to direct any fluid and debris that is sucked into the channels into a connected suction tube. Placement of the saliva ejector within the mouth lies along the interior of the patient's cheek, keeping the oral cavity clear of viewing obstructions. The discharge end connects to a discharge tube, wrapping around the oral commissure then hooking onto the patient's outer cheek. Once properly placed within the patient's mouth the dental assistant is relieved from providing suction during various procedures.

An oral cavity suction system that incorporates a disposable saliva ejector residing along the interior of the patient's cheek that utilizes a single planar, double leaf shaped plate design that is embossed on their inner faces with a series of arced ribs and folded about its midpoint. The arced ribs form a series of channels about perimeter of the device that directs saliva into a trough running along the linear axis of both of the plates to direct this saliva into a connected “U” connector that hooks around the patient's cheek. A sterile suction tube is also connected on one end to the “U” connector suction tube and on its other end to a quick connect fitting that mates to a tube adapted with a fitting for connection to a high volume suction pump.

Ultrasound scaler tip and ultrasound scaler has high sterilization effect. Toothbrush has reduced effect on mouth interior. An ultrasound scaler tip has tip body and optical fiber. Tip body has tubular shape with pointed-end opening and rear-end opening, rear end that can be attached to ultrasound scaler body, and intermediate curved part. Optical fiber is thinner than minimum inner diameter of tip body and has rear end toward which light from light source can enter. Optical fiber is inserted from rear-end opening to pointed-end opening of tip body, and has intermediate part that is in contact with curved part, so that end is vibrated by ultrasonic vibration of tip body. Ultrasound scaler body houses liquid supply device, ultrasound-generating device, and light source, which is attached to rear end of ultrasound scaler tip. Light source causes light for sterilization in predetermined wavelength range to enter rear end of optical fiber.

To enable firm bonding to a member including a polyaryl ether ketone resin. A bonding method including: a bonding material applying step for applying, to the surface of a member including a polyaryl ether ketone resin, a bonding material including (A) a polymerizable monomer and (B) at least a portion of components for configuring a polymerization initiator, the content ratio of polymerizable monomers at least having two or more polymerizable functional groups in a (p2) molecule among all polymerizable monomers being 50% by mass or greater, and the content ratio of polymerizable monomers at least having one or more polymerizable functional groups and one or more functional groups capable of hydrogen bonding in a (p1h1) molecule being 5% by mass or greater; and a curing step for curing the bonding material. A bonding material and bonding kit using the bonding method.

The present document describes methods of use of photo activated compositions for oral disinfection and/or treatments which comprise at least one oxidant, at least one photoactivator capable of activating the oxidant, and at least one healing factor chosen from hyaluronic acid, glucosamine and allantoin, in association with a pharmacologically acceptable carrier.

A planning and guiding method and excavation guiding device correctly implant an artificial tooth root at a predetermined site, perform various excavation processes on a cortical bone section and a spongy bone section by stage-based guidance, and guide eccentric excavation of the cortical bone section and concentric excavation of the spongy bone section according to a bone pattern, such that the artificial tooth root thus implanted is not only positioned at a planned ideal site but also manifests appropriate initial stability.

An orthodontic apparatus for installation in a patient's mouth is disclosed. The orthodontic apparatus includes a first extension wire, a second extension wire, and a palatal archwire. Each of the first and second extension wires includes a proximal portion and a distal portion. The proximal and distal portions and the palatal archwire are manipulatable to apply corrective buccal, labial, and transverse forces on the patient's dento-alveolar complex (DAC), to correct the shape of the patient's palate.

The present disclosure provides methods, computing device readable medium, devices, and systems having a dental attachment placement structure. One dental attachment placement apparatus includes a body having an attachment placement surface that is to be placed on an attachment affixing surface of a tooth and wherein the attachment placement surface includes a portion that is shaped to allow placement of an attachment at a particular position on the affixing surface of the tooth and a portion of the body having a contour that is shaped to correspond with a contour of an alignment surface of a tooth and when the contour of the body and the corresponding contour is aligned, the attachment is located at the particular position and can be secured to the affixing surface of the tooth.

The present invention provides a dental implant with a post section that can be implanted in a jaw with a designated mounting component. A crown may be attached to the mounting component. The cmounted components are designed in multiple sections, preferably in two sections, in which a first mounted component with an attached formed first contact pin can be firmly inserted into an allocated recess in the post section, and a second mounted section with an attached formed second contact pin can be inserted into the recess in the second mounted section.

The present invention relates to an endosseous implant assembly adapted for treatment of peri-implantitis. The implant assembly comprises an implant core body configured to receive and couple with implant insert structures that potentially facilitate treatment of peri-implantitis.

Root canal abutment devices and methods which facilitate the adjustment or removal of an oral appliance, e.g., a crown or bridge, from a reconfigurable abutment assembly are described. The adjustable abutment assembly may be secured within a pulp chamber of a pre-existing tooth. The abutment assembly has a projecting abutment portion with one or more shape memory alloy sleeves or plates or elements extending along the abutment. Each of the sleeves has a length with at least one curved or arcuate portion. Energy may be applied to the elements such that the arcuate portion flattens to allow for the oral appliance to be placed thereupon while removal of the energy allows the elements to reconfigure into its curved configuration thereby locking the oral appliance to the abutment. Removal of the oral appliance may be effected by reapplication of energy to the elements.

A multi-layer coating of alternating titanium nitride (TiN) and titanium carbo nitride (TiCN) layers is applied to at least part of a dental device for use in attaching crowns, overdentures, and the like in a patient's jaw, where the outermost layer is TiCN with a predetermined percentage of carbon to produce a pink color. The pink outermost layer is of sufficient thickness to conceal the color of the underlying layers, and is very hard and resistant to wear and damage in use. At the same time, the outermost TiCN layer is of a color consistent with the gingival anatomy, and is very hard and resistant to wear and damage in use.

Apparatuses, components, devices, methods, and systems for determining jaw movement are provided. An example patient assembly for capturing motion data of a patient includes a clutch configured to be worn by the patient on a dentition of the patient. The clutch includes a dentition coupling device configured to couple to the dentition of the patient and includes an extension member configured to protrude through the patient's mouth. The clutch also includes a position indicating system rigidly connected to the dentition coupling device. An example position indicating system emits a plurality of light beams. Some examples also include an imaging system and a motion determining device. An example imaging system captures a plurality of image sets that each include at least one of a plurality of screens upon which the light beams project. An example motion determining device processes the captured image sets to determine the motion of the patient's dentition.

The present invention relates to oral and dental care and cleaning agents comprising an aqueous dispersion of a phosphate-containing and/or phosphonate-containing polyurethane polymer and anionic surfactant(s), to tooth cleaning methods using these agents, and to the use of oral and dental care and cleaning agents comprising an aqueous dispersion of a phosphate-containing and/or phosphonate-containing polyurethane polymer and anionic surfactant(s) to reduce the restaining of teeth and/or to reduce biofilm development on dental surfaces and/or to reduce the adhesion of bacteria to dental surfaces and/or to extend the antibacterial action of antibacterial substances.

The present invention provides an intraoral imaging and illumination apparatus (10) comprising a rear portion (12) and a front portion (14) removably connected to the rear portion (12). The front portion (14) is formed as a light guide (29). The rear portion (12) comprises an imaging device (16) and an illumination device (18). The illumination device (18) is adapted to couple light into the front portion (14) and towards a leading end (30) of the front portion (14) opposite the rear portion (12) so as to illuminate a first object (66). The imaging device (16) is adapted to image the first object (66).

The present invention is directed to a system of devices and a method for preparing a tooth to receive a restoration. The system includes a dental instrument for removal of portions of a tooth in the mouth of a patent and an overlay for guiding the dental instrument during the step of tooth removal. The overlay is designed for temporary installation into the mouth of the patient to guide the dental instrument to remove tooth material. The overlay has one or more sets of guide walls, with a predetermined configuration capable of contacting one or more guide projections of the dental instrument, and a receptacle capable of receiving and attaching to the dental instrument.

A dental bur (10) is disclosed having an elongated shank (11) which extends to a cutting head (12). The shank includes a gripping portion (14), a tapered transition portion (15), and a neck portion (16). The diameter of the neck portion (D1) is generally the same as the diameter of the cutting head (D2). The cutting head includes six helical cutting flutes (20) extending from the neck portion (16) to a tip (18). Each cutting flute has a top cutting edge (21) and a series of generally rectangular shaped cross-cut notches. The rectangular shaped cutting notches are formed by a generally flat floor (25) and two oppositely disposed sidewalls (26). The floor forms a floor cutting edge (28) while the sidewalls form sidewall cutting edges (29). The intersection of the floor cutting edge with the sidewall cutting edges form two interior cutting corners (30).

The tool for treatment of interdental surfaces includes a strip (10) having an abrasive field (12) on at least one of its longitudinal sides (11). The field is situated at a distance (A) from the apical edge (11a) of the longitudinal side, the latter being blank between the apical edge and the field.