The present invention pertains generally to dental implants, and more particularly to an expandable dental implant which includes laterally moving anchors for holding the implant in place.
Dental implants are used to replace missing teeth and are well known in the art. The dental implant is usually made of titanium, and is placed in and fuses with the bone of the upper or lower jaw in a process known as “osseointegration”. The implant process is typically divided into two phases. First the implant is inserted into the bone of the jaw. Then after a waiting period of 2-3 months in which osseointegration occurs, the abutment/crown is installed. A problem exists however in that during abutment/crown installation the implant can become loose and rotate. That is, when the screw is removed sometimes the applied rotational force can also unscrew the implant body. Even a small unscrewing means a break of the new bone tissues, and can cause lesions and therefore negate the osseointegration which has taken place.
Expandable dental implants are also known in the art. In one type of expandable dental implant the body of the implant expands by bending. A problem however exists with this technical approach. Dental implants are preferably made from medical grade titanium in order to provide superior bone integration. However, medical grade titanium is brittle and breaks if it is bent. As such, devices which rely on bending are not compatible with medical grade titanium. Additionally, prior art devices have lateral openings which interfere during the screwing of the implant into the bone. The lateral openings (fissures) can catch bone, tissue, and blood and transfer them into the implant. The bone, tissue, and blood can then osteointegrate with the inner parts of the implant and screw and impede or prevent removal. Also, the lateral openings will expose bone tissue to contamination during reopening of the head of the implant (e.g. when taking out the healing screw to insert the stump screw with the crown).
The present invention is directed to an expandable dental implant which provides improved bone anchoring. One or more laterally movable anchors expand by sliding outwardly from the body of the implant and into the bone, and as such serve as an anti-rotational device. The outward movement of the anchors is caused by the downward motion of the healing abutment screw or by the stump abutment screw. The top inside part of the anchor is angled, so as the screw is rotated downward, it abuts the anchor and pushes the anchor outward perpendicular to the motion of the screw. The outwardly expanding anchor provides superior anti-rotation mechanical anchoring to the bone as compared to existing implants.
The anchors can be of different sizes and shapes: for example rectangular, square, elliptical depending the size of the dental implant and the force to be exerted on the bone. The depth of the anchors can be selected to best accommodate the density of the bone: thinner in cases of compact bone, thicker in cases of porous bone. In the case of porous bone or “soft” bone tissue the anchors increased depth offers a immediately greater mechanical seal and anchoring. Furthermore, horizontal compression of the bone tissues made by the anchors increases the local density of the bone itself and can result in faster and increased bone integration. In the case of immediate crown installation (installation of the stump screw abutment immediately after the implant installation): the anchors provide a superior mechanical seal both vertical and longitudinal to the masticatory loads, than that which is offered by simple thread and coils of the current design implants.
The expandable dental implant of the present invention provides better, immediate anchoring to the bone. In the case of the classical technique (for bone tissue integration waiting time of 2-3 months between phase 1 implant installation and phase 2 abutment/crown installation): during the re-opening after the initial period of osseointegration the expandable dental implant avoids the frequent problems due to blocking of the healing abutment for clots and debris, which causes partial loosening or moving the implant in a circular direction. This also avoids the resulting micro-lesions of bone fibers already in the process of osseointegration.
In accordance with an embodiment, an expandable dental implant for implantation in the bone of the jaw of a patient includes a body which has a longitudinal axis. An opening is disposed in the body. An anchor is slidably received by the opening, the anchor being slidable in a direction perpendicular to the longitudinal axis.
In accordance with another embodiment, the expandable dental implant cooperates with a screw. The anchor has an inner part which is beveled, so that when the screw is screwed along the longitudinal axis the screw contacts the inner part of the anchor and urges the anchor outward perpendicular to the longitudinal axis.
In accordance with another embodiment, the expandable dental implant cooperates with a screw, and includes a sealing device for sealing the expandable dental implant. The anchor has an inner part which is beveled, so that when the sealing device is inserted along the longitudinal axis the sealing device contacts the inner part of the anchor and urges the anchor outward perpendicular to the longitudinal axis. The screw is threadably receivable by the body after the sealing device has been inserted.
In accordance with another embodiment, the sealing device is a screw.
In accordance with another embodiment, the body has a first threaded hole for receiving the screw, and a second hole for receiving the sealing device, the first threaded hole for receiving the screw having a larger diameter than the second hole for receiving the sealing device.
In accordance with another embodiment, the expandable dental implant has an unexpanded state in which the anchor does not outwardly project from the body, and an expanded state in which the anchor outwardly projects from the body. The body has external threads, and the anchor has external threads which align with the external threads of the body when the expandable dental implant is in the unexpanded state.
In accordance with another embodiment, when the dental implant is in the expanded state, part of the anchor remains in the body.
In accordance with another embodiment, retaining means are provided for holding the anchor within the opening.
In accordance with another embodiment, the opening and the associated anchor are one of (1) rectangular, (2) square, (3) elliptical, and (4) circular.
In accordance with another embodiment, a plurality of the openings and associated anchors are provided, the plurality of the openings and associated anchors are circumferentially spaced around the body.
In accordance with another embodiment, the circumferential spacing being one of (1) two the openings and associated anchors spaced 180° apart, (2) three the openings and associated anchors spaced 120° apart, and (3) four the openings and associated anchors spaced 90° apart.
In accordance with another embodiment, providing two openings and associated anchors, the two openings and associated anchors being of different shapes.
In accordance with another embodiment, providing two openings and associated anchors, the two openings and associated anchors being of different sizes.
In accordance with another embodiment, a spacing of about 0.002 inches existing between the opening and the anchor.
In accordance with another embodiment, the anchor having a depth which determines how far the anchor will expand into the bone of the jaw.
In accordance with another embodiment, the anchor is not externally threaded; and the body is not externally threaded in the vicinity of the anchor.
In accordance with another embodiment, the expandable dental implant cooperates with a screw, and the patient has a mouth which contains microbes. Sealing means are provided for sealing the expandable dental implant so that the microbes from the patient's mouth cannot pass through the opening and into the bone of the jaw.
In accordance with another embodiment, the screw includes a gasket and the body includes a seat for the gasket. When the screw is screwed into the body, the gasket forms a seal.
Other embodiments, in addition to the embodiments enumerated above, will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the expandable dental implant and method of use.
Referring initially to
Expandable dental implant 20 includes a threaded body 22 which has a longitudinal axis 24. An opening (window) 25 is disposed in body 22. An anchor 26 is slidably received by opening 25. Anchor 26 is slidable in a direction 28 which is perpendicular to longitudinal axis 24. In the embodiment of
In the unexpanded state of
In
In
Referring to
In
Because anchor 26 provides a better immediate grip of the bone 600, the size of the hole into which expandable dental implant 20 is screwed can be larger than that used with standard implants. This reduces the force applied by the manual or power tools needed to screw expandable dental implant 20 into the bone 600. This means:
1. The implant process is atraumatic with lower stress to the bone 600 and tissues during screwing.
2. There is a lower risk of breaking the expandable dental implant 20 components. Sometimes the force applied is over 50 newton metres (nm), and it is known by dentists that the head of implants and/or the connecting tools and screwdriver can break or be damaged.
3. An easier and faster implant insertion process.
In an embodiment, the hole size can be 5% to 10% larger, depending upon the hardness of the bone 600: hard bone 5-10%, medium bone 3-7%, soft bone 0-3%. These numbers are approximate and will vary as a function of specific implant needs.
Referring to
In an embodiment, expandable dental implant 20 including sealing device 80 are disposed in a sterile package. Sealing device 80 is already installed in body 22 of expandable dental implant 20 in a position ready to be screwed down. The procedure is then: (1) unpack dental implant 20 including sealing device 80, (2) screw expandable dental implant 20 into bone 600, (3) screw sealing device 80 down into body 22 of expandable dental implant 20 thereby causing anchors 26 to be pushed out and into bone 600, and (4) screw screw 500 into expandable dental implant 20.
Some of the features of expandable dental implant 20 are listed below: (refer to
1. In expandable dental implant 20 the anchors 26 slide horizontally (i.e. perpendicular to the longitudinal axis 24 of body 22) into the bone 600 under the force of screw 500.
2. Both body 22 and anchors 26 are made of medical grade titanium and are not subjected to any bending force. The force is exerted by screw 500 which pushes against the inner part 27 of anchors 26, thereby causing the anchors 26 to expand outwardly from body 22. The tops 27 of the inner part of the anchors 26 are angled to allow lateral progressive horizontal movement of the anchor 26 itself.
3. In the present implant 20, the dentist can choose between different implant models with 1, 2, 3, 4, or more anchors 26, depending upon the density of the bone 600 and space and location requirements. That is, the dentist has more options and can choose the optimum implant design based upon the parameters of (1) the number of anchors 26, (2) anchor shape, and (3) anchor size (i.e. height H and width W). The diameter and the height of implant 20 can also be chosen to best fit the need of the implant situation.
4. In the present implant 20, the anchors 26 can have different shapes such as rectangular, square, circular, or elliptical depending upon the size of the implant body 22 and the force needed. In an embodiment, the inner section of the anchors 26 is threaded to accept the healing/stump screw 500.
5. In the present implant 20, there are no lateral fissures or openings between anchor 26 and body 22. When screwed into the bone 600 the anchor's thread is perfectly aligned with the implant body 22 thread and therefore does not catch bone residuals nor blood/tissues. By contrast, many prior art implants are open at the bottom (i.e. not sealed). This exposes tissue when healing screw 500 is removed. In an embodiment, the internal cavity of implant body 22 is somewhat sealed because anchors 26 closely fit into an opening 25 in body 22. Additional sealing can be provided by various sealing means/devices.
6. In the present implant 20, when anchors 26 expand into the bone 600, a portion of the anchor remains in body 22. As such, a seal is assured with no exposure of tissues/bone being possible when removing the healing screw 500 and inserting the stump screw 500.
7. In the present implant 20, in cases when a healing screw 500 is not used and the crown is immediately installed after the implant installation, anchors 26 provide a superior mechanical seal, both vertical and longitudinal to the masticatory loads, than is provided by simple coils of the current design implants. In this case bone integration has not yet occurred, and anchors 26 provide an immediate mechanical anchoring which is not provided by traditional implants.
8. In the present implant 20, in the case of porous bone or “soft” bone tissue, the anchors 26 increasing thickness provides a greater mechanical seal and immediate anchoring. Furthermore by horizontally compressing the bone tissues, anchors 26 increase the local density of the bone itself and can promote faster and increased bone integration.
9. In an embodiment, mechanical means are provided to hold anchor 26 in the unexpanded state, so that it will not fall out of body 22 during handling of implant 20 prior to insertion into the bone 600. For example, the surface of anchor 26 could include friction enhancing bumps so that it is friction fit into opening 25. Then it would not become detached during normal handling, but the friction would break under pressure from healing/stump screw 500 when turned by a manual screwdriver or power tool. Another holding means would be to use a bio-compatible adhesive.
10. Because anchor 26 provides a better immediate grip of the bone, the size of the hole into which implant 20 is screwed can be larger that used with standard implants.
11. In an embodiment a sealing device 80 is used to seal expandable dental implant 20 before the insertion of screw 500. The sealing device 80 allows screw 500 to be inserted and removed multiple times without allowing microbes to pass from the patient's mouth through opening 25 and into bone 600.
In terms of use, a method for implanting a dental implant in the bone 600 of the jaw of a patient includes: (refer to
(a) providing an expandable dental implant 20 including;
(b) implanting the expandable dental implant 20 in the bone 600;
(c) providing a screw 500 which is threadably receivable by the body 22; and,
(d) screwing the screw 500 into the body 22 along the longitudinal axis 24 so that the screw 500 contacts the inner part 27 of the anchor 26 and urges the anchor 26 outward perpendicular to the longitudinal axis 24 and into the bone 600.
The method further including:
in (a) a plurality of the expandable dental implants 20 being available, the plurality including implants having different numbers of openings 25, different circumferential spacing of openings 25, different size openings 25, and different shape openings 25; and,
before (b), selecting the implant which is best suited to the specific needs of the patient.
Another method for implanting a dental implant in the bone of the jaw of a patient, includes:
(a) providing an expandable dental implant, the expandable dental implant including;
(c) providing a screw which is threadably receivable by the body;
(b) implanting the expandable dental implant in the bone;
(d) inserting the sealing device into the body along the longitudinal axis so that the sealing device contacts the inner part of the anchor and urges the anchor outward perpendicular to the longitudinal axis and into the bone; and,
(e) after (d), screwing the screw into the body.
The embodiments of the expandable dental implant and method of use described herein are exemplary and numerous modifications, combinations, variations, and rearrangements can be readily envisioned to achieve an equivalent result, all of which are intended to be embraced within the scope of the appended claims. Further, nothing in the above-provided discussions of the expandable dental implant and method should be construed as limiting the invention to a particular embodiment or combination of embodiments. The scope of the invention is defined by the appended claims.
This application claims the filing benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/830,191 filed Jun. 3, 2013, which is hereby incorporated by reference.
Number | Date | Country | |
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61830191 | Jun 2013 | US |