Abstract: An apex locator system constructed to enable visualization of an apex location at a vicinity of the mouth of a patient and more specifically on a lip clip, hand file and/or file clip of the apex locator system.

Abstract: A combination includes a dental handpiece and a prophy angle. The dental handpiece includes a nosecone threadably connected to the dental handpiece. The prophy angle includes a proximal body that matingly attaches to the nosecone. A plurality of elongated torque members are formed on each of the prophy angle proximal body and the nosecone. Each of the torque members is a male torque member or a female torque member and each male torque member formed on one of the prophy angle proximal body and the nosecone matingly couples with a female torque member formed on the other of the nosecone and the prophy angle proximal body. The prophy angle, including the plurality of elongated torque members formed on the prophy angle, is formed to also be attachable to a known standard doriot-style nosecone. Other specific features of the handpiece and prophy angle are also disclosed.

Abstract: Various embodiments for cleaning carious regions of a tooth are disclosed herein. For example, a dental apparatus can include a fluid platform having a chamber sized and shaped to retain fluid. The chamber can be configured to be coupled to the tooth over the carious region. A pressure wave generator having a distal end may be configured to be positioned in the chamber. The pressure wave generator may be configured to generate pressure waves in the retained fluid sufficient to clean the carious region.

Abstract: An instrument, article and method are provided for minimizing pain during administration by injection of a liquid, such as, an anesthetic. The instrument has a forward end. A lightpipe mounted freely for vibration projects out of the forward end. The article, a single use tip, is composed of a tip sleeve removably mounted on the forward end of the instrument and a tip member removably mounted on the projecting lightpipe to vibrate a preselected injection site on a human or animal. The tip sleeve and tip member are covered by an elastic overmold that enables the tip member to vibrate freely with respect to the tip sleeve and light from the lightpipe to illuminate the injection site. The overmold of the single use tip is torn during removal of the single use tip from the instrument.

Abstract: A dental handpiece is disclosed which has a head housing, a gear shaft having a gear part with gear teeth and a shaft part extending from the gear part, and a dust control seal sealingly fit on the circumferential surface of the shaft part of the gear shaft. The dust control seal is an annular member, and has a seal body, a first lip projecting radially inwardly from the seal body, and a second lip projecting radially inwardly from the seal body above and spaced apart from the first lip, with a space defined between a contact area between the first lip and the shaft part, and a contact area between the second lip and the shaft part.

Abstract: The invention relates to a medical turbine handpiece, in particular a dental turbine handpiece, having a drive shaft rotatably mounted in the front end region of the handpiece and to which a tool can be connected, as well as a turbine wheel arranged so as to be non-rotatable on the drive shaft and is arranged in a turbine chamber realized in the end region, into which turbine chamber a supply line for a flowing pressure medium for driving the turbine wheel opens out at an inlet opening and from which turbine chamber a removal line extends at an outlet opening, wherein at least one cross connecting channel for the pressure medium is realized in the wall of the turbine chamber, the cross connecting channel connecting the axially remote edge region of the turbine chamber to a region of the turbine chamber that is axially close to the drive shaft.

Abstract: In an electric motor for use in a dental, dental-medical or dental-technical handpiece, having a rotatably mounted rotor and a stator surrounding the rotor, the stator is surrounded by a sheathing having an inner sleeve, on the outside of which there are arranged functionally relevant components of the stator, for example stator winding(s), return plates, and/or contact pins, and an outer sleeve embedding the inner sleeve with the functionally relevant components.

Abstract: A high-speed turbine dental drill handpiece has a drilling needle, a wind wheel axle, a head housing having an annular opening with a two-step profile shape, and a suckback prevention device. The suckback prevention device includes an elastic bowl-shaped axle shroud coupled to an annular skeleton that are buckled in an inner step of the head housing and an annular screw connected to the outer step of the head housing (or retaining of the elastic bowl-shaped axle shroud. An eyelet for the drilling needle is set at the center of the elastic bowl-shaped axle shroud, the diameter of the eyelet being slightly larger than that of the drilling needle.

Abstract: A dental system comprises a dental prophy angle and an adjustable angle adapter. The prophy angle includes a housing and a guard. The adapter is configured to drive the prophy angle and includes a body, a nose, and an outer joint. The nose is configured to receive a portion of a prophy angle. The body is adjustably connected to the nose. The outer joint includes a ball portion connected to the nose, and a ball receiver connected to the body. The nose is rotatable relative to the body into at least a first configuration and a second configuration. The guard engages an outer surface of the ball receiver, and the guard has a greatest outer diameter larger than a greatest outer diameter of the housing.

Abstract: Compositions, particularly for forming dental products, having a hardenable self-supporting structure with sufficient malleability to be subsequently customized into a second shape and then hardened, and methods.

Abstract: A prophylactic system 100 for a dental hand piece 101 of a selected shape and having an outlet 112 for providing a fluid to an operating field is disclosed. A cover 102 has a shape substantially similar to the hand piece 101 for enclosing the dental hand piece 101 and includes an aperture 118 for communicating with the operating field. An s-shaped valve 600 includes a path 605 for coupling the fluid from outlet 118 of the hand piece 101 to the aperture 118 of the cover.

Abstract: A medical handpiece, particularly a dental handpiece, for use with an internally cooled tool, wherein the tool has an axial hollow space into which the cooling fluid is conducted in an essentially radial direction through a bore of the tool shaft, and wherein the bore is arranged between two axially spaced apart sealing members which are arranged in the handpiece head and which seal the handpiece head relative to the tool shaft. The sealing surfaces of the sealing discs extend relative to the tool axis of the tool shaft essentially in a normal, conical or spherical direction.

Abstract: An organosol comprising a high molecular weight (co)polymeric steric stabilizer covalently bonded to an insoluble, high molecular weight thermoplastic (co)polymeric core is described which has the ability to form a three dimensional gel of controlled rigidity. The gel provides improved liquid ink or liquid electrophotographic/electrographic toner compositions by increasing sedimentation stability of the colorant, without compromising print quality or ink transfer performance. The gel is formed by manipulating the solubility parameter difference between the stabilizer and the solvent to achieve optimum performance of the dispersion.

Abstract: A dental handpiece is disclosed which has a housing having a wall, a bur sleeve for receiving and holding a dental tool therein, a bearing for rotatably supporting the bur sleeve, a rotary dust control member fixed on the bur sleeve, and a stationary dust control member forming a gap in cooperation with the rotary dust control member and the wall of the housing for preventing entry of contaminants inside the housing. The stationary dust control member is attached to the bearing.

Abstract: In a device with an elongate housing for examining the gums of a patient, with the housing having a connecting area for connecting a replaceable, movable exploratory tip and with mechanical and/or electronic detection elements provided in the housing for detecting and converting the movements of the exploratory tip. The invention proposes that the detection elements be designed to be liquid-tight and/or liquid-resistant, and surrounded by a potting compound inside the housing.

Abstract: A dental and surgical handpiece with disposable cartridge of the present invention includes a reusable handpiece and a disposable cartridge. The disposable cartridge contains all the major moving parts that provide torque and RPM for high speed dental drilling. The disposable cartridge detachably couples with the head of the reusable handpiece. The handpiece can be heat sterilized after the disposable cartridge is removed. The performance of the handpiece is not reduced by the sterilization since the turbine and bearings are contained in the disposable cartridge.

Abstract: A maintenance-free dental prophylaxis angle includes a one-piece body including a sleeve and a head. The sleeve and head define intersecting bores. A drive assembly, comprising a drive gear and a bushing, is force fitted in the sleeve. A one-piece driven gear is received in the head bore to be driven by the drive assembly. The driven gear includes an upper bur tube, a gear part, and a lower shaft. The gear part of the driven gear rests on an upper face of a boss in the head, the boss forming a thrust bearing for the driven gear. Intersecting bores in the boss form part of a lubricant circulating system. A metal cap is force fitted in the head bore to close the head bore and retain the driven gear in place in the head. A dental tool is connected to the bur tube of the driven gear, and forms a seal with the cap.

Abstract: A dental hose assembly for use with a dental handpiece. The assembly comprises inner tubes, an outer tube enclosing the inner tubes, a connector for connecting the inner tubes to fluid passages in the handpiece, a tubular hose guide enclosing the distal ends of the inner tubes, a tubular joint cover engaging the connector and the distal end portion of the outer tube, and a connector ring sheathing the joint cover and to be connected to the handpiece for preventing the connector from being detached from the handpiece. The connector has a proximal end connected to the inner tubes and a distal end to be connected to the dental handpiece. The hose guide has a frustconical portion proximally tapered and distally flared on its outer surface to end with a projected distal end. The distal end portion of the outer tube is fitted over the hose guide to define an expanded portion. The joint cover has a proximal end thickened radially inwardly with a rounded outer edge.

Abstract: A device is disclosed that dynamically seals the collet of a high-speed surgical or dental drill from the ingress of contaminating substances with which the tool or collet of the drill comes into contact, such as blood, saliva, saline, tissue, bone chips, and tooth particles. The dynamic seal comprises an impeller and a bearing that rotatably supports both the impeller and a surgical tool; furthermore, the seal may be disposed within a burguard that is mounted on the distal end of a surgical drill. The spinning impeller has a disc portion that imparts a centrifugal force to the flow of contaminating substances and thereby pumps the flow entering through the tool opening radially outward through discharge holes in the burguard housing. The dynamic seal further includes an O-ring for sealing against the tool shaft and blocking the contaminating substances from continuing up the tool bore and into the collet of the surgical drill. A backring retains the O-ring in place.

Abstract: A center injection type dental handpiece contains a cutting bar having a hollow axially penetrating the bar, holding means for detachably holding the bar, rotating means for rotating the bar, a water injection nozzle communicating with a cooling water feed source. The water injection nozzle is inserted into the hollow of the bar for injecting a cooling water from tip of the bar. The handpiece further contains a packing for sealing a gap between the outer periphery of the nozzle and the inner periphery of the bar at the proximal end of the bar.

Abstract: An exchangeable cartridge for a dental handpiece includes first dust-proofing members for preventing foreign matter from being intruded into an upper bearing and second dust-proofing members for preventing foreign matter from being intruded into a lower bearing. The first dust-proofing members have an upper rotational partitioning member and an upper fixed partitioning member. The upper rotational partitioning member has a protrusion provided above the upper bearing and protruding radially outwardly. The upper fixed partitioning member has a radially inwardly protruding portion lying adjacent and parallel to the protrusion of the upper rotational partitioning member to define a first interstice leading to the upper bearing. The second dust-proofing members have a lower rotational partitioning member and a lower fixed partitioning member. The lower rotational partitioning member has a protrusion provided below the lower bearing and protruding radially outwardly.

Abstract: An autoclaving collar having a distal end and a proximate end is presented for fastening to the proximate end of a conventional dental handpiece to protect the impeller of the handpiece from the corrosive environment of autoclaving or sterilization. The collar has an opening at its distal end and an axially extending cavity that communicates with the opening and an annular shoulder which is concentric with the longitudinal axis of the collar for captively holding an O-ring member which seals the proximate threaded end of the conventional dental handpiece when the collar having internal mating thread is sufficiently threaded onto the proximate end of the dental handpiece.

Abstract: A maintenance-free dental prophylaxis angle includes a one-piece body including a sleeve and a head. The sleeve and head define intersecting bores. A drive assembly, comprising a drive gear and a bushing, is force fitted in the sleeve. A one-piece driven gear is received in the head bore to be driven by the drive assembly. The driven gear includes an upper bur robe, a gear part, and a lower shaft. The gear part of the driven gear rests on an upper face of a boss in the head, the boss forming a thrust beating for the driven gear. Intersecting bores in the boss form part of a lubricant circulating system. A metal cap is force fitted in the head bore to close the head bore and retain the driven gear in place in the head. A dental tool is connected to the bur tube of the driven gear, and forms a seal with the cap.

Abstract: In a medical or dental treatment instrument, in particular a straight or angled handpiece (1), having a drive shaft (6) for a tool, which drive shaft is mounted in the forward end region of the treatment instrument, in at least one roller bearing (11, 12), rotatable around its middle axis (8), and is drivable for example by a turbine, whereby the roller bearing (11, 12) is blocked or sealed against contaminants with of a blocking ring (31) effective between its outer ring (37) and its inner ring (34). The blocking ring (31) bears with its surface facing the inner ring (34) on the inner ring (34) and is releasibly or non-releasibly attached thereon.

Abstract: The drive assembly for a dental sonic scaler is disconnected from a scaling tip assembly and is then withdrawn from a surrounding tubular handle/sheath. This allows the sheath to be sterilized, after use, while the drive assembly, not needing sterilization, can be easily connected to another sheath, by way of a quick-disconnect joining the components. A tubular seal between the tip assembly and the sheath prevent the drive assembly from being contaminated during use of the scaler.

Abstract: A dental prophylaxis angle includes a body defining a sleeve and a head. A drive assembly is rotatably mounted in the sleeve. A driven gear is rotatably received in the head to be driven by the drive assembly. A cap is mounted in the head to close the head and retain the driven gear in place in the head. A threaded bur tube on the driven gear extends into a stem portion of the cap. The stem portion includes an externally beveled annular knife edge which forms a seal with a dental tool, such as a prophy cup, which is threaded into the bur tube. A protector ring on the cap surrounds the knife edge to prevent damage to the knife edge should the angle be dropped or otherwise contact a hard surface. The protector ring is spaced from the stem sufficiently to permit an elastomeric portion of the dental tool to extend between the stem and the ring.

Abstract: In a straight motorized handpiece (101), in particular for medical purposes, preferably for a medical or dental laboratory, with a clamping device (106) arranged in a sleeve-like casing (111) for the selective clamping of tools (105) which can be inserted from the front into the handpiece (101), whereby the clamping device (106) is arranged on a drive shaft (107), which is rotatably mounted in the casing (111) by means of a rearward and a forward roller bearing (113, 114), whereby for axially retaining the drive shaft (107) a first shoulder (143) is provided on the casing (111) or on attachments thereto, against which the outer ring of one of the roller bearings (113) bears, and there is arranged a releasible arresting shoulder (145) opposite to the first shoulder (143) at an axial spacing, the first shoulder (143) is arranged on the outside of the outer ring of the associated roller bearing (113) and the arresting shoulder (145) is arranged on the outside on the other roller bearing (114), the drive shaft (1

Abstract: A protective system for dentist chill units including a protective element and a sealing substance around the drill to prevent the entrance of undesirable matter such as the HIV (AIDS) virus into the handpiece holding the drill, which may, when the drill is replaced by another drill, infect the next patient, the system including an optional device including at least one valve for preventing undesirable matter such as the HIV virus from remaining in the water system after possible entry through one or more water nozzles in the handpiece, once the water is pumped out and possibly replaced by disinfectant, and then again with cooling water.

Abstract: In a motorized handpiece (101), in particular for medical purposes, preferably for a medical or dental laboratory, with a clamping device (106) arranged in a sleeve-like casing (111) for the selective mounting of tools (105) which may be inserted into the handpiece (101) from the front, whereby for opening and closing the clamping device (106) a moveably mounted actuating part (104a) is provided which is accessible at the circumference of the motorized handpiece (101), whereby the clamping device (106) is arranged on a drive shaft (107), which is mounted by means of a casing (101) rotatable by means of a rear and a forward roller bearing (113, 114), whereby the actuating part (104a) is connected with the clamping device (106) by way of an actuating mechanism (108), and whereby a sealing system (146) is associated with the forward roller bearing (114) on the forward side of the roller bodies thereof, which has at least one sealing disk (146a) which is effective between the inner and the outer ring (114a, 114b)

Abstract: A dental hand piece includes a head to which is secured a burr, and a liquid supply or distribution assembly directs a stream of cooling liquid directly to the burr from exteriorly of the dental hand piece itself. The liquid supply assembly is connected to the head of the hand piece through a block, and the burr is hollow to connect directly to the liquid supply or distribution assembly through the block.

Abstract: A dental handpiece contains a sleeve for rotatably accommodating and securing a dental treatment tool therein, bearings for rotatably holding the sleeve with respect to stationary handpiece casing members, a rotatable rotor fixed to the sleeve for rotating the sleeve under action of a compressed fluid, and stationary convexed and concave protective members for sheathing the bearings exposed to an annular spacing defined by the bearings and the rotatable rotor. The rotatable rotor contains rotatable concave and convexed disc portions. The rotatable concave and convexed disc portions are arranged in proximity to the stationary convexed and concave protective members in a mating relation therewith for defining therebetween at least a first gap and a second gap communicating with the first gap and disposed radially outwardly of the first gap.

Abstract: An extendable latex shield and internal seals are incorporated in a disposable dental hygiene tool for protecting sterility of standard dental handpieces. The flexible nature of the extendable shield allows storage in a first position, permitting the dental professional to easily attach the tool to the handpiece and to unroll the flexible shield to the extended position, thereby protecting the handpiece from splashing of saliva, blood, or other materials during use of the tool in dental procedures. Internal seals in the tool preclude fluids or other material from transfer through the interior of the tool into the dental handpiece. The combination of the present device precludes the contamination of the handpiece, thereby avoiding sterilization procedures and the inherent time loss, inefficiency, and cost associated with such procedures.

Abstract: A cartridge type dental handpiece contains a handpiece main body, a head housing provided at a distal end of the handpiece main body, and a cartridge detachably adapted within the head housing. The cartridge has a cartridge casing and a rotatable sleeve rotatably mounted within the cartridge casing and adapted for detachably holding a dental burr. The dental handpiece further contains a fluid passage defined between an inner surface of the head housing and an outer surface of the cartridge casing when the cartridge is mounted within the head housing, a fluid spraying port formed in a lower surface of the cartridge casing in communication with the fluid passage for spraying the fluid from the fluid passage onto a tooth being treated, and a communication port for supplying the fluid from a fluid supply duct within the handpiece main body into the fluid supply passage.

Abstract: A disposable dental prophy angle designed to be coupled with a conventional dental tool power source, the angle being used in dental prophylaxis. The dental prophy angle is fabricated from synthetic resin material and comprises a housing presenting a head end and a shank end with a passageway extending between said ends, a drive shaft extending along the passageway, a plurality of sealing rings integrally formed as part of the housing and extending inwardly therefrom into sealing engagement with the drive shaft, and a pair of auger flights integrally formed as part of the shaft for propelling buccal matter along the passageway for ejection through the head end.

Abstract: An air motor and accompanying air distributor and motor output drive means are axially stacked within a tubular dental handpiece. A fiber optic bundle extends through a special passage in the thick-wall side of an eccentrically positioned cavity in the motor casing. The bundle also extends axially through the other components in the handpiece and further is directed to a dental tool head mounted on one end of the handpiece. The fiber optic bundle very effectively illuminates a cutting burr or other element mounted on the tool head, a gasket adjacent the motor prevents leakage of air past the metal-to-metal surfaces of the air motor and surrounding housing. The gasket is also provided with a hole through a thick-edge wall for the fiber optic bundle. A further flat resilient seal prevents air passage passed the motor output shaft and the spaces between the bearing races.

Abstract: A device for preventing intrusion of foreign matter into a dental handpiece includes an end cap secured to a bur sleeve for rotation in unison with the bur sleeve. Around the end cap, there are delimited gap sections the one end of which communicates with a forward or lower ball bearing positioned towards a tool inserting opening and the other end of which is opened at the foremost part of the handpiece. A discharge port passing through the main body of the handpiece and communicating with the gap sections is formed at the foremost part of the handpiece. With rotation of the bur sleeve, the end cap is rotated so that the pressure within the gap sections is decreased to suck the foreign matter, such as cut tooth particles or chips, which is expelled to outside through the discharge port under the centrifugal force of the end cap.

Abstract: A medical handpiece, and especially a dental handpiece, including a drivable worktool or implement which is rotatably supported with its shaft at one end of the handpiece and which projects from this handpiece end with its operating end. The implement possesses an elongate blind bore-like passageway which communicates with the outside at the work end of the implement through the intermediary of a discharge opening, and with which there is associated a supply line arranged within the handpiece for the infeed of cooling media to at least one radial through-opening of the implement which stands in communication with the elongate passageway; whereby the at least one radial through-opening is sealed with respect to the interior of the handpiece through the intermediary of a seal which encompassing the shaft of the implement and contacts against a wall portion of the handpiece.

Abstract: A dental appliance has an elongated hollow tube within the interior of which is mounted for rotation an elongated drive shaft. One end of the tube is coupled to a handle as is the drive shaft which is driven from the handle in rotation. A head joined to the other end of the tube defines an interior cavity within which a hub is mounted for rotation about an axis disposed at an angle with respect to the drive shaft. Motion is translated from the drive shaft to the hub. An opening in the head enables the hub to be accessed through the opening. Included in the hub is a barrel section for securing a variety of dental attachments thereto. A seal is created between the opening from the cavity and the hub in order to prevent fluid flow therethrough. Lubricant is introduced within the tube and the drive shaft actuates an augar or the equivalent for propelling the lubricant into the motion translator.

Abstract: This device for preventing the ingress of water into the head of a dental contra-angle comprises a ring seal of cylindrical configuration adapted to be inserted through a hole formed in the bottom wall of the head body for the passage of the dental tool. This ring seal comprises at one end a flange having a diameter greater than the diameter of the passage hole and at its opposite end a bead also of greater diameter than the hole but adapted to be compressed when inserting the ring seal through the hole.

Abstract: A dental tool and handpiece, wherein the tool has a projecting cylindrical, flexible flange extending into a cylindrical recess in the handpiece and sealable thereinto by centrifugal force. Various forms are illustrated. The operation of the flange is independent of the attaching means for the tool, and end forces on the tool are not transmitted through the flange, but rather are transmitted through a driven shaft on which the tool is mounted, thence through a driven gear having a thrust bearing engagement with the closed end of the head.

Abstract: A motorized dental handpiece has a head and a head cap portion which is connectable thereto. The head cap portion includes a head gear shaft, a head gear rotatable with the head gear shaft, a head cap, a flange rotatable with the head gear shaft, and a seal ring positionable between the head cap and the flange. The head gear shaft, head cap, seal ring and flange constitute releasably connected members of a unitary head cap portion assembly which is releasably connectable to the head of the handpiece.

Abstract: A collet of somewhat flexible plastic for holding a dental tool in a dental handpiece, has an inner body which fits within a socket in the burr tube of the handpiece, and at its outer end extends outwardly into a hub and then rearwardly into a cylindrical skirt which fits between the outer surface of the bearing for the burr tube and the inner surface of a counterbore in the handpiece. Centrifugal force caused by rotation of the burr tube flares the skirt outwardly against the counterbore surface to provide a seal therebetween. In a modification the skirt slants outwardly to contact the counterbore surface when the skirt is stationary. A modified skirt tapers from its connection to the hub to the skirt end.In another modification, the collet has a bore in its inner end, with the handpiece end cap, the driven gear and the burr tube having bores aligned with the collet bore so that a burr extractor pin can extend through the bores to push the dental tool out of the collet.

Abstract: An air driven turbine supporting a burr is pivotably mounted at the extremity of an arm, which arm is pivotably attached to the handle of a dental hand piece. Conduits extend through the handle and the arm to the turbine and provide a flow of air to and from the turbine and a flow of fluid directed into proximity of the cutting surfaces of the burr. Sealed moveable junctions at each end of the arm maintain integrity of the air and fluid flows while accommodating articulation of the hand piece.

Abstract: A dental handpiece having a cross head with one end capped and the other end open, a driven gear in the capped end having a thrust bearing against the cap, and a fixed bearing extending from the gear to the open end with a driven shaft rotatably mounted in the bearing; a threaded socket in the driven shaft to receive the complementary attaching means on a dental tool, a cylindrical recess in the open end to receive a flange on the tool and grooves in the driven shaft to restrain travel of abrasive from the open end toward the closed end thereof, the bearing being long enough to give complete bearing support for the rotating mechanism.

Abstract: The assembly includes an electrically insulative support member which overlies electrical contacts on the handpiece and further includes a pair of contact members which press a flexible printed circuit against the electrical contacts to couple a pair of bulbs to the electrical power source. The light source assembly additionally includes means for effectively sealing the contact regions from environmental fluids.

Abstract: A pneumatic laminar motor, for dental purposes, having a sleeve-like housing forming the stator with circular cylindrical inside wall and a rotor inside touching that wall. The rotor has a diameter smaller than the inside wall and its rotary axis is parallel to, but displaced from the axis of the inside wall. The lengthwise slots of the rotor has radially movable lamellas with their outer ends pointing to the inside wall. An air inlet opening from the air supply conduit and an air outlet opening discharge into the space between rotor and inside wall. A freely rotating bearing ring is located between the inside wall and the outer ends of the lamellas and is coaxial with the inside wall. The outer ends of the lamellas contact the bearing ring. Compressed air enters through the air inlet opening into the space between rotor and inside wall and pushes the nearest lamella ahead of it to turn the motor.

Abstract: The dental prophylactic right angle hand piece of the knob type includes conventional driving and driven members, with the driven member including an integral collar and an integral serrated knob to which the dental application or cup is releasably secured for preventing the cup from slipping under pressure. The collar forms an effective seal between the head of the hand piece and the cup to prevent bacteria from entering the interior of the hand piece. With such a construction the hand piece can be operated forwardly or backwardly without the cup slipping or falling out of the hand piece.