Abstract: An abutment for holding a dental prosthesis to a jaw implant, having: an apical section detachably fastening the abutment to the jaw implant, the apical section being structured along a first central axis; a coronal section detachably fastening the dental prosthesis to the abutment, the coronal section being structured along a second central axis, wherein the second central axis extends at an angle to the first central axis; and an indexing element in a shell surface of the coronal section specifying an orientation of a display element that is coupleable to the coronal section for a digital scanning operation, based on an orientation of the first central axis. A display element coupling to an abutment coronal section, and displaying a position and orientation of the abutment for a digital scanning operation, a tooth model system having an abutment and a display element, and a method producing a dental prosthesis.

Abstract: A dental implant including an implant body having a top surface, and at least one non-annular cutaway portion longitudinally extending downwardly from the top surface along one side of the body and outwardly to the periphery, and a method for making the implant. The implant body preferably includes a body portion and a head portion integrally formed with the body portion, the body portion has a periphery and the head portion has a non-circular periphery, and the periphery of the head portion is smaller than the periphery of the body portion.

Abstract: A system and method comprising an anchor assembly including an anchor and a locking element, a tensionable fixation member (e.g., surgical suture, tape, etc.), and a release member, wherein the anchor further comprises a first end, second end and anchor body. The anchor is configured for implantation into bone. One end of a tensionable fixation member is configured for attachment to a tissue to assist with fixation of the soft tissue. Once the anchor has been seated in bone, the second end of the tensionable fixation member is pulled through a “one-way only” passage in the body of the anchor.

Abstract: A dental implant assembly comprises a base member and an abutment member. The base member is adapted for placement into an opening in a jawbone and comprises elongated vertically parallel side walls coupled with opposing curved end walls which together define an eccentrically shaped external surface and an eccentrically shaped internal cavity. The base member also includes an eccentrically shaped curved lip which couples top edge perimeters of the external surface and the internal cavity to one another. The abutment member is adapted for placement into the eccentrically shaped internal cavity of the base member. Responsive to placement of the abutment member in the eccentrically shaped internal cavity of the base member, a trans-gingival emergence profile is formed between the eccentrically shaped curved lip and a region of the lower portion between the eccentrically shaped curved lip and the shoulder.

Abstract: Exemplary embodiments of an orientable dental device are discussed within the dental device includes a ball element that is positionable within a cup within a socket that is fixedly attached to a patient. The ball element includes a post that is orientable over a desired range (laterally and transversely and combination thereof) that allows for the incorporation of an artificial tooth (or teeth) to present a natural appearance.

Abstract: A dental implant evaluation unit is disclosed and described. The dental implant evaluation includes a body portion having threads that mimic the general thread pattern of an actual dental implant, without attempting to copy any of the osseointegrative features of the actual implant. A threaded collar is associated with the body portion, and, in certain embodiments, a safety flange is screwed to the threaded collar. The safety flange prevents the dental implant evaluation unit from infiltrating the sinus of a patient when testing the fit of a maxillary implant. The dental implant evaluation unit can be used by a dentist to evaluate the proper size and fit for an actual dental implant by installing the dental implant evaluation unit, and imaging the same, prior to installing the actual dental implant.

Abstract: A dental veneer is provided herein for supplying identification information. The dental veneer includes circuitry, memory, and an antenna. The circuitry reads and/or writes the identification information to the memory and causes the antenna to transmit the identification information.

Abstract: The present invention provides a trabecular porous tantalum dental implant and a preparation method thereof. The trabecular porous tantalum dental implant provided by the present invention has a cylindrical structure, and sequentially includes a top functional area, a middle functional area and a bottom functional area from top to bottom. The top functional area has a compact structure. The middle functional area has a porous bionic trabecular structure. The bottom functional area has a compact structure. The trabecular porous tantalum dental implant is integrally prepared through an additive manufacturing technology by using pure tantalum or medical tantalum alloy powder as a raw material. The trabecular porous tantalum dental implant provided by the present invention has a high friction force, strength and modulus close to those of human bones, an excellent bone ingrowth effect, high implantation stability and long service life.

Abstract: A dental implant system, comprising: a tooth implant, and a separate abutment that is attachable or attached at the tooth implant by an attachment bolt, wherein the tooth implant is made from a first material with an elasticity modulus between 15 GPa and 75 GPa, wherein the abutment is made from a second material with an elasticity modulus greater than 100 GPa, and wherein the attachment bolt is made from the first material or the second material.

Abstract: The invention relates to an implant (1) comprising a support structure (5) which is prepared for anchoring, following the contours of the bone, in a jaw- and/or cranial bone (2), wherein at least one integrally attached post (7) protrudes from the support structure (5), said post being designed to have a finished denture anchored thereto and the post (7) having a base (9) that is formed out of the support structure (5) and is completed by a distal end region (10) with the interposition of a radially enlarged region (11). The invention also relates to a soft tissue displacement system (19) comprising an implant (1), a manufacturing process for a soft tissue displacement system (19) and a planning process for manufacturing an implant (1).

Abstract: A dental device is described. The dental device includes a surgical template having one or more sites for drilling osteotomies in the maxillary or mandibular jaw and a false teeth set. The surgical template and false teeth set are configured to fit together to form a denture prosthesis that can be implanted in a patient. Also described are a method for creating a surgical dental template, a method for implanting a dental prosthesis, and a method for reducing jaw bone in a patient.

Abstract: Systems are provided for securing tissue to bone. A suture anchor can include an elongate body having a proximal end and a distal end and an external surface with a plurality of longitudinally spaced bone-engaging features formed at least partially circumferentially thereon over at least a portion of a length of the suture anchor. The proximal end can have a lumen extending at least partially into the elongate body and the distal end can have a suture engaging feature proximate thereto. A first series of bone-engaging features can have a dimension that increases from a distal to a proximal end of each bone-engaging feature of the first series of bone-engaging features. A second series of bone-engaging features can have a dimension that decreases from a distal to a proximal end of each bone-engaging feature of the second series of bone-engaging features.

Abstract: A multi-unit abutment aligning a dental implant and a screw-attached prosthesis with copings is disclosed. The multi-unit abutment has a threaded base post for attachment to the implant and a ball portion. A swivel post into the implant with the multi-unit assembly in a linear configuration. The swivel shell is then positioned and fixed at a desired tilt and azimuthal angle. The swivel shell has a mating surface for a coping. The lock screw remains accessible through an aperture in the coping when the prosthesis is positioned on the implant abutments. Different embodiments are disclosed for capturing the swivel shell on the ball. Methods for improving passive alignment of the prosthesis to the implants are described.

Abstract: The present disclosure provides a digital implant system including: detecting an region where a intact first tooth among a plurality of teeth is disposed based on a panorama and a CT device for upper and lower jaws where the plurality of teeth of a user are disposed, and acquiring first oral information of the upper and lower jaws; acquiring first surface information by scanning a user's face through an imaging device; generating an image of a temporary denture based on an auto-bone tooth bone graft material; determining a disposition form of the upper and lower jaws of an implant subassembly; acquiring second oral information on the upper and lower jaws where the implant subassembly is disposed and second surface information by scanning the user's face through the imaging devices; and generating an image of a prosthesis that is coupled to the implant subassembly.

Abstract: A dental implant includes a generally cylindrical body, an interior bore, and a non-rotational feature. The generally cylindrical body has a main-central axis and is formed from cold-worked, high strength, commercially pure titanium having an ultimate tensile strength of at least about 900 MPa. The generally cylindrical body has a proximal portion and an opposing distal portion for anchoring the dental implant in bone of a patient. The interior bore is formed in the generally cylindrical body and has (i) a bore-central axis and (ii) a threaded portion for receiving a screw that is configured to removable hold an abutment in engagement with the dental implant. The non-rotational feature is configured to engage the abutment in a non-rotational fashion.

Abstract: A bone foundation guide system has a bone foundation guide including a body that is contoured to reversibly affix to a bone segment of a dental implant surgical site. The body is further contoured to guide the cutting of a portion of the bone segment from a dental implant surgical site and alternatively support a dental implant surgical guide. The body is further contoured to support a bone foundation guide prosthesis as an alternative to the dental implant surgical guide. The bone foundation guide prosthesis combines with the body to accommodate the bone segment portion as placed through the body prior to the bone segment portion being removed from the dental implant site through the use of the body.

Abstract: A subperiosteal securement kit is provided including a subperiosteal dental implant device and a drilling guide attachable thereto. The subperiosteal dental implant device has a frame engageable with the jawbone of a patient and a Fixation bore sized and shaped to receive therein a bone screw. The drilling guide has an elongated guiding channel sized shaped to receive a drill bit therein and is removably attachable to the frame of the subperiosteal dental implant device, with the guiding channel being in communication with the fixation bore when the drilling guide is attached to the frame of the subperiosteal dental implant device. A method subperiosteal dental implant device is provided to be secured to a jawbone of a patient and being engageable with a drilling guide having a threaded section.

Abstract: A method is provided for producing a dental prosthesis from a blank using a CAD/CAM device, wherein the blank consists partially of base material and partially of tooth material, and a boundary surface between these materials is formed as a wave, the wave crests and wave valleys of which alternate with each other along the outer periphery of the blank. The apex of each wave crest extends substantially radially with respect to the blank. The CAD/CAM device fixes the position of a retention part, which serves to fasten the prosthesis to the alveolar crest of a patient, in particular of an external telescope, of a cover of a bar, or of an abutment in the prosthesis in such a way that it passes through the boundary surface. The retention part is fastened by means of gluing or incorporation by polymerisation.

Abstract: A method may include obtaining a digital preoperative dental model of a patient, designing a guide appliance set on the digital preoperative dental model according to a surgical plan for the patient, and storing the design of the guide appliance set in a computer-aided manufacturing (CAM) compatible file format. Designing the guide appliance set may include designing a base frame configured to engage an oral structure of the patient without obstructing a planned surgical site region of an alveolar ridge, designing an uppermost surface of the base frame to, at least in an area adjacent to the planned surgical site region, terminate below the alveolar ridge when the base frame is engaged with the oral structure, designing at least one attachment that is releasably attachable to the base frame, and designing the at least one attachment to be fully received in a mouth when attached to the base frame.

Abstract: A drill bit for drilling a cavity or a recess into a skull, wherein the cavity or the recess is configured to receive an implantable fixture screw unit of a hearing aid system, is disclosed. The drill bit includes a first part including a drill tip with a first drill diameter, wherein the drill tip comprises a tip angle of between 137 degrees to 143 degrees along a longitudinal axis of the drill bit and wherein the drill tip comprises a back rake angle of between ?1 degree and +1 degree, in particular a back rake angle of substantially 0 degrees, a second part including a plurality of flute blades with a second drill diameter, wherein the second drill diameter is greater that the first drill diameter, and a transition part which is arranged between the first part and the second part and along the longitudinal axis, wherein the transition part includes a body clearance.

Abstract: An anatomical healing abutment is configured to connect to a dental implant. The healing abutment has a body portion which includes at least three reference marks that provide data to orient the connection axis of the abutment with the that of the dental implant so that certain conventional steps, including healing abutment manipulation, multiple scans, and the taking of impressions, can be eliminated, thereby saving time and effort on the part of the practitioner.

Abstract: A dental implant having a substantially cylindrical shape with a longitudinal axis defining a longitudinal direction, including: a coronal section including a coronal end of the implant; a threaded region extending apically from the coronal section to an apical tip of the implant; and an internal blind bore for connection to a secondary part, including: a stabilizing section extending apically from the coronal end; and a drive and indexing section which extends apically from an apical end of the stabilizing section, which includes a plurality of connecting lobes having a concave shape and extending in the longitudinal direction, being interconnected by respective lobe linking areas, including: two convex sections extending in the longitudinal direction and adjacent to a respective connecting lobe; and a concave section extending in the longitudinal direction between the two convex sections. Further, a secondary part and an insertion tool of a configuration matching the dental implant.

Abstract: A dental implant that facilitate insertion and can be used in all bone types. The implant includes a body having a coronal end, and an apical end opposite the coronal end. A tapered region may be adjacent the apical end. On the apical part one or more taps are provided so the tap is cutting when rotating clockwise and counter-clockwise. The implant can have at least one variable profile helical thread that extends along the tapered region. The implant can have also micro-threads below the main threads, a gradual compressing tapered core, a self drilling apical end and a narrow coronal region.

Abstract: Dental implant, comprising an external thread arranged on an outside of the dental implant for fastening the dental implant to a jawbone. Further, the implant comprises an opening extending along a longitudinal axis of the dental implant, in which opening an internal thread for fastening a superstructure to the dental implant is arranged. Still further, the implant comprises an interface for fastening the superstructure to the dental implant, which interface is arranged at a front end of the dental implant. The interface is suitable for direct attachment of a superstructure to the dental implant without the use of an abutment.

Abstract: A dental prosthesis having a guide hole formed therein. The guide hole is configured to guide a drilling for a screw, and configured to receive the screw, holding the prosthesis in place when screwed into the bone of a patient.

Abstract: A dynamic bone anchor includes an anchor member having a tubular body with a first end and a second end, the anchor member defining an anchor axis including a plurality of barb elements, and being made at least partially of a nickel-titanium (Ni—Ti) based shape memory alloy. The dynamic bone anchor also including a core member configured to be inserted from the first end through the second end such that a first portion of the core number extends out from the first end, and a second portion of the core number extends out from the second end. The anchor member and the core member are configured such that when assembled, the first portion of the core member is spaced apart from the anchor member and movable with respect to it, and the second portion of the core member is fixed to and movable together with the anchor member.

Abstract: The present invention relates to a medical device for freeing an implant from the bone of a patient to which the implant adheres to and to an implant for insertion into a bone of a patient, designed such that the implant is more homogenously heatable or coolable in a controlled way. Also provided is a method of removing an implant from a bone of a patient and a computer readable storage medium having recorded thereon a database structure.

Abstract: An attachment member for mating with a dental implant includes a non-rotational structure and a body. The non-rotational structure is configured to mate with a corresponding non-rotational feature of the dental implant. The body extends from the non-rotational structure. The body has (i) an exterior side surface configured to at least partially engage gingival tissue adjacent to the dental implant, (ii) an exterior top surface that is exposed through the gingival tissue, (iii) a screw access bore for receiving a screw that attaches the attachment member to the dental implant in a removable fashion, and (iv) a set of radiopaque information markers that is located internal to the exterior side surface and the exterior top surface. The set of radiopaque information markers indicates information regarding the dental implant that is revealed in response to a scan from a computerized tomography (CT) scanner.

Abstract: Provided are a dental implant with a nano bacteriostatic structure ring at a transgingival part and a machining method thereof. The transgingival part of the dental implant has a three-level micro-nano composite structure, and the three-level micro-nano composite structure endows a surface of the transgingival part of the implant with functions of promoting adhesion and proliferation of a gingival fibroblast and a gingival mesenchymal stem cell and inhibiting adhesion and growth of various oral bacteria. A preparation method thereof comprises: firstly, injecting bioactive, wear-resistant or corrosion-resistant C, N, Ca and P elements into the transgingival part of the dental implant by a plasma injection method; and then, preparing the three-level micro-nano composite structure at a part in which the elements are injected.

Abstract: An abutment screw having a first hardness for use in affixing a dental prosthetic, having a second hardness less than the first hardness, to an abutment that itself is attachable to an implant in the mouth of a patient includes a head and a body. The body includes a smooth shank immediately proximate the head, and a threaded portion with a helical ridge that runs around its body, the helical ridge beginning at a point along the body distal the head portion. The head includes an upper surface, having a drive at a central portion thereof, and an underside surface having a convex radiused curvature extending until it meets the shaft, the convex radiused curvature being configured to conform to a corresponding concave curvature of a receiving portion of the prosthesis.

Abstract: The present invention relates to a dental implant set having a fixture for insertion into a bore hole arranged in bone tissue having first indexing means, a dental component having second indexing means and being adaptable to the fixture in an engaged position where the first and second indexing means mate and in an intermediate position where the dental component and the fixture are in contact with each other but the first and the second indexing means do not mate, and a fixation screw being adapted for fixating the dental component to the fixture. The present invention also relates to a method for attaching a dental component to a dental fixture.

Abstract: A screw-shaped anchoring fixture for anchoring a prosthesis in the skull bone. The anchoring fixture comprises a main body configured to be implanted into the bone and a flange configured to function as a stop to prevent the main body from completely penetrating through the bone. The main body comprises a distal tapered apical portion, a first portion, and a second portion. The inner diameter of the second portion is greater than the inner diameter of the first portion. The method for inserting the anchoring fixture includes providing the anchoring fixture, drilling a hole, and inserting the anchoring fixture into the hole until the flange contacts the skull bone, wherein the hole has a diameter that is greater than the inner diameter of the first portion and less than the outer diameter of the second portion.

Abstract: A method of treating a patient who requires surgical implantation of an orthopedic implant is described. The method includes the steps of: determining the DEXA scan T-score of the patient's native bone at a site of surgical implantation where the implant will be in contact with the patient's native bone; retrieve from among three or more implants of the same type an implant that has a density that is closest to the density of the patient's native bone at the site of surgical implantation based on the DEXA scan T-score of the patient's native bone; and implanting the retrieved implant in the patient to the exclusion of the other two or more implants.

Abstract: A device and a system for forming a releasable connection between a dental implant abutment and prosthetic restoration, and in particular to such a device and system that is configured for use in situations where the inter-occlusal space is very limited, the device having a female connection device having a hollow tubular body featuring an open lumen.

Abstract: The present invention relates to a dental implant (100, 100?, 500) and to a kit for said dental implant. In order to provide dental implants (100, 100?, 500) which meet the general requirements for a successful implantation and use and which can be easily adapted to bone variations and implant offerings, it is proposed according to the invention that the dental implant (100, 100?, 500) comprises a ceramic base body (130, 530), a ceramic abutment (120, 120?, 520), a ceramic tooth structure (110), and/or a connector (1, 1?, 1?, 5) for connecting of base body (130, 530), abutment (120, 120?, 520) and/or tooth structure (110) to each other, and a bushing body (6), which is at least in a final assembly state (E) of the dental implant (100, 100?, 500) received at least partly in the base body (130, 530), in the abutment (120, 120?, 520) and/or in the tooth structure (110) or surrounds the connector (1, 1?, 1?, 5) at least in sections.

Abstract: A bone conduction implant, including a bone fixture including a male screw section configured to screw into a skull and an abutment configured to be rigidly attached to the bone fixture, wherein the abutment includes an exterior surface diameter lying on a first plane normal to a longitudinal axis of the bone conduction implant that is less than or substantially equal to the maximum thread diameter of the male screw section of the bone fixture.

Abstract: A dental implant having an anchoring system consisting of foldable fins actuated by an insertion screw; the dental implant is characterised by the following components: an implant body that includes an implant-abutment connection zone, an externally threaded zone, at least one pair of exit openings and an internally threaded zone; an anchoring having at least one pair of foldable fins and a top opening; an insertion screw having a head with an internal hexagonal socket, a stem and a screw thread; when the insertion screw is screwed into the top opening of the anchoring means, the insertion screw pushes the anchoring down into the implant body and causes the foldable fins to extend outwards through the exit openings.

Abstract: Method for producing a dentist tool formed by an overlay to be used by a dentist in removing tooth structure, said method comprising the steps of: acquiring three-dimensional data relating to a shape of a tooth and at least a part of a neighbouring tooth; processing said three-dimensional data with a computer so as to determine an overlay fitting said tooth and fitting at least said part of said neighbouring tooth; further processing said three-dimensional data with said computer so as to determine a predetermined part of tooth structure to be removed from said tooth so as to prepare said tooth for further treatment; determining at least two guiding edges of which a first and a second guiding edge are spaced apart from each other by a distance d of at least 0.

Abstract: A method for designing a dental prosthesis and a positioning guide for placing the dental prosthesis on implants in the jaw while maintaining proper occlusion relates to designing the dental prosthesis and the positioning guide prior to implant placement.

Abstract: Disclosed herein is a dental implant (1) having a post part (2) which can be placed in a jaw bone and having a structural part (4) associated with said post part, to which structural part a denture piece can be attached, the structural part comprising an integrally molded contact pin (8) which can be placed in an associated shaped recess (10) in the post part (2) with a positive fit, it is to be possible on the one hand to suitably index the implant in a simple and reliable manner, on the other hand a particularly high level of mechanical stability against rotation being ensured, even with an overall height which is kept low.

Abstract: In some implementations, a retainer sleeve may include a body including an at least partially annular configuration defining a retainer axis. The body may include an inner surface configured to rotatably receive an outer surface of a lock. The body may include a plurality of plates circumferentially joined together with respect to the retainer axis, where a first plate of the plurality of plates includes a first leg joined to the first plate extending away from the retainer axis and configured to contact a lock cavity of the lock. The body may include an anti-rotation feature, disposed on the first plate, extending inward from the inner surface toward the retainer axis, the anti-rotation feature including a locking surface configured to contact a lock skirt of the lock, the locking surface disposed at a first angle with respect to a bottom end of the first plate.

Abstract: Bone-secured dental arch veneers and methods for fabricating and utilizing the same. The dental arch veneers include a veneer assembly having one or more tooth veneers and a support structure configured to support the tooth veneer(s). The dental arch veneers also include a coupling structure configured to interconnect the veneer assembly to a bone mount that is anchored along a user's maxilla or mandible. The coupling structure also is configured to permit the veneer assembly to be selectively and repeatedly interconnected with and disconnected from the bone mount. The methods include determining a target region within the user's mouth, obtaining a representation of the target region, manipulating the representation to create a desired arrangement of the user's teeth within the target region, determining anchoring positions proximate the target region for anchoring the bone mount, and forming the dental arch veneer based on the anchoring positions and the desired arrangement.

Abstract: A digital workflow process and associated devices and tools for providing dental restorations and, more particularly, to precise and efficient reconstruction and replacement of teeth using novel digital workflows and improved dental scan bodies, abutments and other dental devices and tools to efficiently achieve a more precise fit and optimal form and function.

Abstract: The invention relates to an abutment for use in a dental implant system, wherein the abutment is provided with a guiding and lock for associating the abutment to a dental implant, the guiding and lock including: a first conically tapered section; a second substantially non-tapered section arranged apically adjacent to the first section, the second section being provided with an anti-rotational means; and a third substantially circular cylindrical section arranged apically adjacent to the second section, such that to provide axial guiding to the abutment upon the insertion thereof into a dental implant. Further, the invention relates to a dental implant formed in a similar manner.

Abstract: An approach is disclosed that involves creating an implant-supported prosthesis that is dynamically guided into position using an image-guided navigation system into position in a patient's mouth without the use of a surgical guide.

Abstract: An implant device configured to be at least partially in contact with bone on implantation has an improved osteoinductive feature to enhance new bone formation. The implant device has one or more bone growth surfaces extending from a structurally solid feature of the implant device. The one or more bone growth surfaces are configured to mimic adult trabecular bone by having trenches, grooves or surface recesses or prominences exhibiting numerous structural elements or walls not perpendicular to the surface that are non-coplanar or arched extending 20 to 500 microns in depth having an increasing inclination from the surface extending inwardly and not parallel to opposing or adjacent walls forming a random or non-random network. The one or more bone growth surfaces configured to mimic trabecular bone have discernable nano features on the structural elements or walls exhibiting nano scale features of less than 200 nano meters within the network.

Abstract: An anatomical healing abutment is configured to connect to a dental implant. The healing abutment has a body portion which includes at least three reference marks that provide data to orient the connection axis of the abutment with the that of the dental implant so that certain conventional steps, including healing abutment manipulation, multiple scans, and the taking of impressions, can be eliminated, thereby saving time and effort on the part of the practitioner.

Abstract: Provided is an implant having a controlled generation rate of reactive oxygen species and a method of controlling generation of reactive oxygen species using the same. The implant having a controlled generation rate of reactive oxygen species according to the present invention includes a body formed of a metallic material and having a groove, a first filling metal filling one region of the groove, and a second filling metal filling the groove on the first filling metal, wherein the second filling metal has an ionization tendency different from that of the first filling metal.

Abstract: The present disclosure relates to an apparatus of attaching a dental component having an angulated screw channel to a dental implant. The present disclosure also relates to a dental component having an angulated screw channel and a metal adapter.

Abstract: A dental superstructure securable to a protruding dental abutment, related assembly and method of design are provided. The dental superstructure is designed to mimick a tooth and is perforated to create a drop-shaped screw conduit for screw insertion and advancement. The screw conduit includes an insertion portion extending substantially conically outwardly from an inlet to enable advancement of an inserted screw along an insertion axis and a spherical angulation portion extending from and communicating with the insertion portion to allow angulation of the screw from the insertion axis to an implant axis. Buccal and/or lingual contours of the screw conduit may be respectively arched outwardly and inwardly from the insertion axis to adapt to screw advancement needs. The dental superstructure may be part of an assembly for a dental implant in combination with an osseointegrable implant including the protruding dental abutment; and a dental abutment screw.