Screw and driver tool

ES 2 551 863 T3

DESCRIPTION

Screw and screwdriver

The present invention relates to a screw and screwdriver combination for fixing dental components to dental implants in the jaw of a patient. More specifically, the invention relates to manipulation of screws in dental components with corresponding screw channels to secure the dental component to the dental implant.

Figure 1 shows an arrangement for a single tooth prosthetic replacement having angled screw channels. The dental implant -110- comprises a channel for the screw -130- that has an internal thread configured to fit with the thread of the screw -160-, such that the screw -160- can be fastened to the implant. The prosthesis -120- is fixed to the dental implant by means of the screw -160-. The prosthesis passes through the gingival tissue to the dental implant -110-. The prosthesis has a screw channel -190- through which the screw -160- is inserted. The channel for the screw -190- has an outlet -180- of the channel for the screw and a seat -140- of the screw at the base of the prosthesis, on which the head -170- of the screw -160- sits when the prosthesis is attached to the implant with the screw. The channel axis for the screw -190- (that is, the line described by the radial center point of the channel at any point) does not follow the channel axis -130-. In fact, the channel for the screw -190- may be straight for the most part but be oriented at a different angle than the channel -130-. Alternatively, the axis of the channel for the screw -190- can be curved or S-shaped. As a result, the axis of the channel for the screw -190- in the outlet -180- of the channel does not coincide with the axis of the channel -130- or with the axis of the seat -140- of the screw.

The problem resulting from this arrangement is how to insert the screw through the angled screw channel and, once the screw has made contact with the dental implant, how to drive the screw to rotate using an inclined screwdriver, in a significant angle with respect to the longitudinal axis of the screw.

What is needed is a way to interconnect the screw and a screwdriver in a way that allows the screw to be manipulated during insertion into the prosthesis and to be driven to rotate from an angle relative to the longitudinal axis of the screw.

US 2010167240 describes a screwdriver for driving a screw to rotate at an angle relative to the axis of the screw. A ball head screwdriver is described, in which the ball shape of the screwdriver head appears to provide a contact surface between the screwdriver and the screw, even when the screwdriver is presented at an angle to the axis of the screwdriver. screw.

Document DE102009015358A discloses a combination of a dental screw and its screwdriver, the screw head having a recess with flanks which are inclined with respect to the longitudinal axis of the screw, the screwdriver head having a polygonal cross section and tapering substantially towards its tip.

According to the invention, there is disclosed a combination of a screw for a dental application (in other words, a dental screw), and a screwdriver for driving the screw to secure a dental component to a dental implant. The screw has a coronal end and an apical end, and comprises a hole extending from the coronal end of the screw along a portion of the screw toward the apical end of the screw, a first number of equidistant recesses arranged circumferentially around the screw. interior surface of the hole, each recess extending one length from the coronal end of the hole toward the apical end of the hole. The length of each recess is inclined with respect to the longitudinal axis of the screw such that the recess is further from the longitudinal axis of the screw at a point parallel to the coronal end of the hole than at a point below the coronal end of the hole. Each pair of adjacent recesses are connected by a contact surface on the interior surface of the hole, each contact surface extending one length from the coronal end of the hole toward the apical end of the screw. Each contact surface is inclined with the screw moving away from the longitudinal axis, such that the surface is further from the longitudinal axis of the screw at a point parallel to the coronal end of the hole than at a point below the coronal end of the hole.

The screwdriver comprises a screwdriver head having an apical and a coronal end, the screwdriver head comprising at least a first and a second part having a polygonal cross-section in the radial plane of the longitudinal axis of the screwdriver, having the first part a substantially rounded cross section in the axial plane of the longitudinal axis of the screwdriver, a second part connected apically with respect to the first part, the second part having a substantially triangular shape tapering towards the apical end of the screwdriver head in the axial plane of the longitudinal axis of the screwdriver.

At least a part of the inner surface of the hole comprises a layer of titanium nitride. The apical end of the hole may be tapered, with the widest point at the apical end of the recesses. In one embodiment, the screw is adapted to secure a dental component to a dental implant. In another embodiment, the screw is (by itself) a dental component directly attachable to a dental implant, in which the

ES 2 551 863 T3 dental component can be selected from the group comprising: a cover screw, a healing abutment, an impression cap, etc.

The head of the screwdriver may comprise a tip portion at the apical end of the head of the screwdriver, having a polygonal section in the radial plane of the longitudinal axis of the screwdriver and a curved apical end. At least a portion of the surface of the screwdriver head may comprise a layer of titanium nitride.

Clamping a dental component to a dental implant comprises the steps of inserting the head of the screwdriver, of the screwdriver described above, into the hole of any of the screws described above, in such a way that the edges of the screwdriver head defined by the polygonal cross section fit inside the screw recesses, apply sufficient force to the screwdriver so that the screwdriver head grips the screw using a driving function, manipulate the screw through a screw channel of the dental component using the driving function until the screw is received in a threaded hole on the dental implant, drive the screw to rotate using the screwdriver, such that the screwdriver head edges defined by the polygonal cross section of the screwdriver head parts smoothly transfer a rotational force to the screw, regardless of the angle of the screwdriver longitudinal axis relative to the screw longitudinal axis.

Aspects of the invention will now be described by way of example with reference to the accompanying drawings. In the drawings:

Figure 1 shows a prosthesis having an angled screw channel and a corresponding screw.

Figures 2A and 2B show the angle of the screwdriver (not shown to scale) with the longitudinal axis of the screw during the process of inserting a screw into the prosthesis of Figure 1.

Figures 3A to 3D show an embodiment of the screw, according to the invention.

Figures 4A to 4C show an embodiment of the screwdriver, according to the invention.

Figures 5A to 5C show the screw in cooperation with the head of the screwdriver.

Figures 6A and 6B show an embodiment of a cover screw, according to the invention.

Specific embodiments of the invention will now be described with reference to the accompanying drawings. However, this invention can be made in many different ways and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are disclosed so that this description will be comprehensive and complete, and will fully convey the scope of the invention to those skilled in the art. The terminology used in the detailed description of the embodiments shown in the accompanying drawings is not intended to limit the invention. In the drawings, like numbers refer to like elements.

Screw

The present invention provides a screw and driver combination for inserting said screw into a dental component having an angled screw channel, and securing the screw in a dental implant, thereby securing the dental component in the implant. dental.

Shown in Figures 3A to 3D is a screw having a screw contact surface, in accordance with the preferred embodiment of the invention. Screw 160 comprises a screw head 310 having a screw contact surface 300. The screw contact surface 300 comprises a hole in the screw head with a polygonal internal shape configured to cooperate with the screwdriver head 400, which is described later in the description. As shown in Figure 3A, the screw contact surface -300- comprises tapering inner walls -320-, a conical section -330-, beveled or rounded edges -340- of the contact surface, and recesses. -350-.

In the preferred embodiment, the screw contact surface 300 comprises six equidistant recesses 350 arranged circumferentially on the inner surface of the screw contact surface. An equivalent screw head with more or less than six recesses is also contemplated. Each recess extends from the top surface of the screw head at a small angle (for example, 2.5^or) towards the inside, with respect to the longitudinal axis of the screw, towards a conical section -330-. Between the recesses are tapering flat surfaces -320-, tapering outward toward the mouth of the screw contact surface. As a consequence, the internal surfaces -350- and -320- delimit a slightly conical internal space, in such a way that the maximum diameter at the mouth of the screw contact surface is greater than the maximum diameter

ES 2 551 863 T3 at the point where the tapering surfaces -320- meet the conical section below. In one embodiment, the tapering surfaces -320- are inclined 2.5^or with respect to the longitudinal axis of the screw.

The conical section -330- comprises the lower part of the contact surface -300- of the screw. At the widest point of the cone, the conical section -330- meets the recesses -350- and with the inner surfaces that taper -320-. The cone shape of section -330- then tapers to a truncated head -360 at the inner end of the screw interface. The cone -330- provides additional support to the edges -310- of the screw head when the screw is pushed hard into the screw seat. While a flat bottom surface (for example, the truncated part -360- having the width of the contact surface) can allow the edges to deform plastically inward when the screw is screwed tightly into the screw seat, the conical shape -330- provides greater support to the edges -310-.

The mouth of the screw contact surface -300- comprises six beveled or rounded edges -360- connecting the upper surface of the screw head -310- and the tapering interior surfaces -320-.

Figure 6A is a side view, in section, and Figure 6B is a perspective view, of an embodiment of a cover screw 160'-, according to the invention. The cover screw 160'- is adapted, in general, to completely cover the upper part (ie, the coronal end) of a dental implant, for example the dental implant -110-.

The cover screw -160'- comprises a screw head -310'-. The screw head -310'- comprises a circumferentially flat apical surface -370'-. The surface -370'- is orthogonal to the longitudinal axis of the cover screw -160'-. The surface -370'- is adapted to act as a stop, and to cover the upper part of the dental implant.

The screw head 310 'further comprises a screw contact surface 300. The contact surface 300 of the screw is of the same type as the contact surface of the screw, of the screw 160 described in connection with Figures 3A to 3D. Therefore, the same screwdriver or tool can be used to manipulate both screw -160- and cover screw -160'-. The description of the contact surface -300- of the screw will not be repeated in this case.

In the apical direction with respect to the surface -370'-, the covering screw -160'- comprises a conical section -380'-, which tapers towards the apical end of the covering screw -160'-. The conical section -380'- is adapted to abut against the corresponding conical section of the dental implant (internal conical section), when the cover screw -160'- is threaded into the implant.

In an apical direction with respect to the conical section -380'-, the covering screw -160'- comprises an externally threaded part -390'- for its coupling with a corresponding internally threaded part of the dental implant, in such a way that the screw coverage -160'- can be insured to the dental implant.

The contact surface -300- of the screw can also be applied to other dental components other than cover screws, such as healing abutments, impression copings, etc.

Screwdriver

According to the preferred embodiment of the invention shown in Figures 4A to 4C, the head -400- of the screwdriver comprises a polygonal shape in the radial plane (that is, the plane normal to the longitudinal axis of the screwdriver) and a ball shape in the axial plane.

In particular, the preferred embodiment of the head -400- of the screwdriver has a polygonal cross section as shown in Figure 4A. In the preferred embodiment, the polygonal cross section has six sides. However, an equivalent screwdriver head with more or less than six sides is contemplated (corresponding to the number of recesses in the screw contact surface). The sides of the polygons form surfaces -410-, which extend between the edges -420-.

In Figure 4B, the screwdriver head is shown in a side perspective. To describe the screwdriver head, it is divided into parts -430-, -440-, -450-, -460- and -470-. The edges -420- of the part of the apical end -470- describe a circular curve in which all the edges -420- meet. The circular curve of the edges in the portion -470- of the apical end delimits a rounded head in the axial plane.

The edges -420- of the part -460- describe a straight line, in such a way that the part -460- comprises the shape of a truncated polygonal pyramid, truncated towards the apical end -470-, in such a way that the surfaces of part -460- meet smoothly with the surfaces of part -470-.

The edges -420- of the part -450- of the apical end describe a circular curve that connects the edges of the part -460- with the part -440-. The circular curve is what gives the part -450- the shape of a truncated ball in the axial plane.

ES 2 551 863 T3

The edges -420- of the part -440- describe a straight line, in such a way that the part -460- comprises the shape of a truncated polygonal pyramid, which narrows away from the apical end -470-, in such a way that the surfaces of part -450- meet smoothly with surfaces of part -430-.

The part -430- is the one where the surfaces -420- meet the cylindrical shaft of the screwdriver.

Cooperation between the screwdriver head and the screw contact surface

As shown in Figures 5A to 5C, the features of the screwdriver head and corresponding screw contact surface are configured to allow the screwdriver head to be inserted into the screw contact surface and for the screw is driven to rotate by the screwdriver at an angle to the longitudinal axis of the screw.

After initial insertion of the screwdriver head into the screw contact surface, the chamfered (or rounded) edges -340- of the screw contact surface mouth guide the tip of the screwdriver head into the screw hole . This simplifies the process of placing the screwdriver head on the screw and requires less precise spatial coordination on the part of the person handling the screwdriver / screw.

The screwdriver head is then rotated until the edges -410- align with the recesses -330-. At this time, the edges -420- will fit into the recesses -350- and the screwdriver head will get a rotational grip with the screw head. The recesses allow the screwdriver head to rotate smoothly at an angle to the longitudinal axis of the screw, without locking collision between the screwdriver head surfaces and the screw contact surface that causes the screwdriver head to be rotationally fixed to the screwdriver head. screw.

As shown in figure 5A, if the head of the screw is inserted into the contact surface of the screw at an angle that coincides with, or approaches the longitudinal axis of the screw, the conical part -460- rests against the internal cone - 330- to provide a comfortable fit and the screwdriver can be operated to turn the screw.

If, as shown in Figures 5B and 5C, the screw head is inserted into the screw contact surface at a considerable angle to the longitudinal axis of the screw (i.e., greater than 5 degrees), the apical end The rounded -470- meets the internal cone -330- at a point above the truncated end -360- of the internal cone. This prevents the screw head from entering the screw contact surface as deeply as when the screw head is inserted into the screw contact surface at an angle close to the longitudinal axis of the screw. At the same time, the rounded edges -410- of the part -450 fit with the recesses -350-. In the preferred embodiment, the angle of the gradient of the internal cone -330- is chosen to ensure that the depth at which the head of the screwdriver enters the head of the screw depends on the angle of the longitudinal axis of the screw with which the head is inserted. screwdriver. By controlling the depth with which the screw head enters the screw contact surface, the rounded edges -410- of the part -450- can be controlled to contact the recesses -350- within an optimal range of the length of recesses -350-, i.e. not too close to the mouth of the screw contact surface for the screwdriver head to slide out of the rotational grip with the screw, and not so close to the internal end of the screw contact surface that the rounded part -450- contacts the internal conical part -330- and introduces additional friction or forces the head of the screw to leave the surface of screw contact. In one embodiment, the optimum contact range for the rounded portion -450 with the recess -350- is between points that span 25% to 75% of the length of the recess. By ensuring that a section of the rounded edges contacts the tapered portion -330- within this range, optimal clearance is achieved between the screw and the driver to allow angle rotation of the screw. Once the head of the screwdriver is moved to rotate, the rounded ratio of the portion -450- in the recesses -350- allows the screw to rotate at an angle to the longitudinal axis of the screwdriver.

The surface -460- of the screwdriver also provides an additional contact surface during the actuation process. For a rounded screwdriver head, each edge of the recess would curve out of the recess after the point where the edge and surface of the recess contact. The straight surface does not curve out of the recess and provides a degree of surface contact to the end of the recess.

In the preferred embodiment of the invention, the slight inclination of the recesses -350- and the surfaces -320- relative to the longitudinal axis of the screw provides a driving function of the screwdriver head. The small angle means that if the screw head is pushed towards the screw contact surface with a certain force, the edges -450- are pushed into the recesses -350- with an increasingly tight fit. At a certain point, the surfaces of the screwdriver head compress against the inner surface of the screw contact surface with such force that the resulting frictional fit allows the screw to be captured by the screwdriver head and driven without any support. for the screw. This is called a driving function and can be vital in simplifying the screw installation process in a dental implant. In the

In a preferred embodiment, the preferred configuration of the screwdriver head and contact surface allows this driving function to exist even when the screwdriver head is inserted at a certain angle relative to the longitudinal axis of the screw. This is particularly advantageous when inserting a screw into an angled screw channel (as shown in Figures 2A and 2B). Furthermore, the configuration of the preferred screwdriver head and contact surface allows the contact position of the rounded portion -450- to be controlled to be within the optimum range, and thus the optimum magnitude of friction to achieve driving function.

In a preferred embodiment of the invention, a coating is applied to one or both surfaces of the screwdriver head 10 or the internal surface of the screw interface, such as titanium nitride, which increases friction between the components. This provides an improved driving function between the screwdriver head and the screw contact surface, and reduces the risk of the screw falling out.

In an alternative embodiment of the invention, the number of recesses in the screw contact surface is greater than 15 out of six. A greater number of recesses provides a smoother action between the cooperating surfaces of the screw contact surface during screw rotation by the screwdriver head.