Patent Description:
There are two stages of tooth growth. Teeth erupted in the first stage are baby teeth, which are then shed and replaced with permanent teeth in the second stage. The permanent teeth are harder than the baby teeth and will not grow back if they fall out due to any reason. Therefore, in the event a permanent tooth has a serious defect, such as tooth decay or a tooth breaking, the defective tooth is either repaired locally or extracted entirely. Defective permanent tooth or extraction of permanent tooth not only adversely affects the appearance of teeth, but also causes difficulties in chewing and speaking. Presently, patients having the problem of defective tooth would usually visit a dentist to avoid the condition of tooth dislocation.

Following the constant progress in the dental repair technique, some patients now try to repair their defective tooth using an artificial dental implant. In the process of dental implantation, an alveolar hole is first drilled into the patient's alveolar bone with drill bits and the artificial dental implant is then implanted into the alveolar hole, such that a part of the dental implant is located in the alveolar hole while the remaining part of the dental implant is exposed from the alveolar hole to connect to an artificial crown.

However, in the case of implanting the dental implant into a patient's upper gum that is relatively thin in its thickness, the dentist would usually use a sinus dental implant. Please refer to <FIG> and <FIG>. A conventional sinus dental implant <NUM> includes a main body <NUM>, an external thread <NUM>, and a plurality of spiral cutting flutes <NUM>. The main body <NUM> includes a drilling end <NUM> and a connection end <NUM> located opposite to the drilling end <NUM>. The drilling end <NUM> has a recess 511a formed at a central area thereof and a drilling zone 511b formed around the recess 511a. The external thread <NUM> is formed on an outer peripheral wall surface of the main body <NUM>. More specifically, each of the spiral cutting flutes <NUM> is formed on the external thread <NUM> to extend from the drilling zone 511b toward the connection end <NUM> and is communicable with the recess 511a. As shown, the drilling zone 511b is divided by the spiral cutting flutes <NUM> into a plurality of drilling segments 511b1, which are circumferentially spaced along the recess 511a, and each of the drilling segments 511b1 is horizontal in configuration, such that axially outer surfaces of all the drilling segments 511b1 are located at the same level.

Please refer to <FIG>. Before implanting the conventional sinus dental implant <NUM> into the patient's upper gum <NUM>, the dentist first use drill bits to drill and cut an alveolar hole <NUM> into the upper gum <NUM>. The alveolar hole <NUM> has a profile smaller than the conventional sinus dental implant <NUM>. Then, the dentist implants the conventional sinus dental implant <NUM> into the alveolar hole <NUM>. When the drilling end <NUM> of the conventional sinus dental implant <NUM> is in contact with a bottom of the alveolar hole <NUM>, the drilling segments 511b1 are in surface contact with the alveolar hole bottom. At this point, when the conventional sinus dental implant <NUM> is rotationally driven into the upper gum <NUM>, the drilling segments 511b1 in surface contact with the bottom of the alveolar hole <NUM> and the dentist's accustomed operational manner often cause the drilling end <NUM> to idle in the alveolar hole <NUM> without cutting the same any further, so that the conventional sinus dental implant <NUM> fails to stably and constantly drill the bottom of the alveolar hole <NUM>.

When the conventional sinus dental implant <NUM> is idling in the alveolar hole <NUM>, the dentist surely would apply more force to drive the drilling end <NUM> of the conventional sinus dental implant to drill the bottom of the alveolar hole <NUM>. However, the conventional sinus dental implant <NUM> being driven with excessively applied force would possibly penetrate the upper gum <NUM> to injure a sinus membrane <NUM> located closely above the upper gum <NUM>.

<CIT> discloses a sinus implant that includes a mounting hole axially defined therein, a plurality of positioning threads spirally upwardly extended around the periphery thereof and gradually reducing in width in direction from a bottom side toward an opposing top side thereof, one or multiple spiral grooves extending around the periphery thereof across the positioning threads, and a pushing tip of reduced diameter located at respective top ends of the positioning threads and defining a flat end face and a recess space in the flat end face in communication with each spiral groove.

A primary object of the present invention is to provide an improved sinus dental implant for implanting into an alveolar hole. The improved sinus dental implant has a drilling end that can cut and drill a bottom of the alveolar hole slowly when it is in contact with the bottom, not only preventing the improved sinus dental implant from drilling the bottom of the alveolar hole excessively to result in injured sinus membrane, but also preventing the sinus dental implant from idling in the alveolar hole without moving further and leaving the bottom of the alveolar hole uncut.

To achieve the above and other objects, the sinus dental implant according to the present invention for implanting into a patient's alveolar hole includes a main body, an external thread, and a plurality of spiral cutting flutes.

The main body has two opposite ends defined as a drilling end and a connection end, and an embedment peripheral surface extended from the drilling end toward the connection end. The drilling end has an outer peripheral area formed into a drilling zone capable of contacting with a bottom of the alveolar hole and a sunken central area formed into a recess surrounded by the drilling zone.

The external thread is formed on the embedment peripheral surface of the main body to extend in a first spiral direction for engaging with a side wall surface of the alveolar hole. The spiral cutting flutes are formed on the main body and the external thread to extend from the drilling zone in a second spiral direction, which is opposite to the first spiral direction, such that a cut is formed between every spiral cutting flute and the recess, and the spiral cutting flutes are communicable with the recess via the cuts.

The drilling zone is divided by the spiral cutting flutes into a plurality of drilling segments, that are circumferentially spaced along the recess. Every drilling segment has a lowest portion defined as a lower drilling portion, from the lower drilling portion of the drilling segment rises gradually toward one of the spiral cutting flutes to form an upper drilling portion, and a guide surface is formed between the lower drilling portion and the upper drilling portion while a guide space is also formed between the lower drilling portion and the upper drilling portion to communicate the recess with the spiral cutting flute.

In a preferred embodiment, the lower drilling portion is located adjacent to one of the spiral cutting flutes, while the upper drilling portion is located adjacent to another one of the spiral cutting flutes.

In another preferred embodiment, the main body includes a plurality of notches, the notches are respectively formed on one of the spiral cutting flutes at a position adjacent to the lower drilling portion.

In a further preferred embodiment, the lower drilling portion is located at a middle position of every drilling segment, and the drilling segment further extends upward from the lower drilling portion toward another one of the spiral cutting flutes to form a secondary upper drilling portion that is located opposite to the upper drilling portion, such that a secondary guide surface is formed between the lower drilling portion and the secondary upper drilling portion; and the upper drilling portion and the secondary upper drilling portion are respectively located adjacent to one of the spiral cutting flutes.

In the above three preferred embodiments, the guide surface is a slanting surface slantly extended from the lower drilling portion toward the upper drilling portion, and a gradient ranged between <NUM> and <NUM> degrees, which is smaller than a gradient of the external thread.

Further, the recess is blocked by the drilling zone to be spaced from the external thread, such that all lower drilling portions and all upper drilling portions are located between the recess and the external thread. A height position of the drilling zone relative to the main body is lower than the lowest point of the external thread, preventing the external thread from contacting with the bottom of the alveolar hole. And, every lower drilling portion is extended in a direction from a center of the recess toward an outer periphery of the drilling zone, and the upper drilling portions are extended in a direction tangential to an opening of the recess.

The whole external thread is formed only on a part of the embedment peripheral surface on the main body, such that the part of the main body with the external thread is defined as a first implant body, and other part of the main body without the external thread is defined as a second implant body. The recess is formed on the second implant body.

The spiral cutting flutes respectively include a first cutting flute section and a second cutting flute section. The first cutting flute section is formed only on the external thread, and the second cutting flute section is formed on both of the main body and the external thread. The upper drilling portion, the guide surface and the lower drilling portion on each of the drilling segments are sequentially arranged in the first spiral direction.

Each of the lower drilling portions includes a linear blade edge capable of cutting the bottom of the alveolar hole, and each of the spiral cutting flutes has a radially outmost portion that is formed into a plurality of spirally arranged blade edges capable of cutting the alveolar hole. A shape of The linear blade edges are respectively different from the spirally arranged blade edges.

The sinus dental implant of the present invention is characterized in that the drilling end includes a plurality of drilling segments, each of which has a height decreased gradually from one of the spiral cutting flutes toward another one of the spiral cutting flutes, so that the lower drilling portion and the upper drilling portion of each drilling segment are located at different height positions. When the sinus dental implant is implanted into the alveolar hole to reach the bottom thereof, the lower drilling portions of the sinus dental implant are the first parts of the sinus dental implant that contact with the bottom, making the whole drilling end of the sinus dental implant in line contact with the bottom. Therefore, with the lower drilling portions, the drilling end of the sinus dental implant in contact with the bottom of the alveolar hole can still cut and drill the bottom slowly without cutting the same excessively to result in injured sinus membrane. Further, the sinus dental implant with the above described drilling end enables the lower cutting portions in contact with the bottom of the alveolar hole to keep moving forward and cut the bottom of the alveolar hole instead of idling therein.

The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein.

The present invention will now be described with some preferred embodiments thereof and by referring to the accompanying drawings. For the purpose of easy to understand, elements that are the same in the preferred embodiments are denoted by the same reference numerals.

Please refer to <FIG>. A sinus dental implant <NUM> according to the present invention is configured for implanting into an alveolar hole <NUM> formed on a patient's upper gum <NUM>, so that the sinus dental implant <NUM> can be extended into the patient's sinus area to press against a sinus membrane <NUM> therein. As shown in <FIG>, the alveolar hole <NUM> has an opening <NUM> located at a surface of the upper gum <NUM> and a bottom <NUM> located at another end of the alveolar hole <NUM> opposite to the opening <NUM>. The bottom <NUM> of the alveolar hole <NUM> is located beneath and spaced from the sinus membrane <NUM>. And, the alveolar hole <NUM> has a side wall surface <NUM> defined between the opening <NUM> and the bottom <NUM>.

Please refer to <FIG> and <FIG>. In a first preferred embodiment of the present invention, the sinus dental implant <NUM> mainly includes a main body <NUM>, an external thread <NUM>, and a plurality of spiral cutting flutes <NUM>. The main body <NUM> includes a first implant section <NUM> having a cylindrical configuration and a second implant section <NUM> downward extended and tapered from the first implant section <NUM>. An end of the first implant section <NUM> farther away from the second implant section <NUM> is a connection end <NUM>, to which an artificial crown is connected. An end of the second implant section <NUM> opposite to the connection end <NUM> is a drilling end <NUM> for contacting with the bottom <NUM> of the alveolar hole <NUM>. An outer circumferential surface of the main body <NUM> is defined as an embedment peripheral surface <NUM>, which is in contact with the side wall surface <NUM> of the alveolar hole <NUM>. As shown, a partial area of the embedment peripheral surface <NUM> externally formed around the first implant section <NUM> is defined as a first embedment peripheral surface <NUM>, and the remaining area of the embedment peripheral surface <NUM> externally formed around the second implant section <NUM> is defined as a second embedment peripheral surface <NUM>.

The drilling end <NUM> of the main body <NUM> has a sunken central area that forms a recess <NUM>, and area of the drilling end <NUM> other than the recess <NUM> forms a drilling zone <NUM>. The recess <NUM> has a recess opening 141a that is surrounded by the drilling zone <NUM>; and the drilling zone <NUM> is configured for contacting with the bottom <NUM> of the alveolar hole <NUM>. As shown, a turning area <NUM> is provided on the main body <NUM> between the embedment peripheral surface <NUM> and the drilling zone <NUM>, so that the embedment peripheral surface <NUM> is limited to distribute over the outer circumferential surface of the main body <NUM> only, while the drilling zone <NUM> is located at a bottom surface of the main body <NUM>. That is, being divided by the turning area <NUM>, the embedment peripheral surface <NUM> and the drilling zone <NUM> are distributed over different areas of the main body <NUM>.

Please refer to <FIG> and <FIG>. The external thread <NUM> of the sinus dental implant <NUM> is formed on the embedment peripheral surface <NUM> of the main body <NUM> to extend in a first spiral direction D1, such that the external thread <NUM> is spirally engaged with the side wall surface <NUM> of the alveolar hole <NUM>. As shown in <FIG>, a length of the external thread <NUM> distributed on the first embedment peripheral surface <NUM> surrounding the first implant section <NUM> is a fine thread <NUM>; and other length of the external thread <NUM> distributed on the second embedment peripheral surface <NUM> surrounding the second implant section <NUM> is a coarse thread <NUM>. That is, the fine thread <NUM> is located closer to the connection end <NUM> of the main body <NUM> while the coarse thread <NUM> is located closer to the drilling end <NUM> of the main body <NUM>. The fine thread <NUM> has a pitch smaller than that of the coarse thread <NUM>. In the first preferred embodiment, since the embedment peripheral surface <NUM> and the drilling zone <NUM> are divided by the turning area <NUM> to distribute on different areas of the main body <NUM>, the external thread <NUM> is formed only on the embedment peripheral surface <NUM> without extending to the drilling zone <NUM> of the drilling end <NUM>. Being blocked by the drilling zone <NUM> of the drilling end <NUM>, the recess <NUM> of the main body <NUM> is spaced from the external thread <NUM>. It is noted a height position of the drilling zone <NUM> relative to the whole main body <NUM> is lower than the lowest point of the external thread <NUM>.

As shown in <FIG> and <FIG>, the spiral cutting flutes <NUM> are spirally equally spaced on the embedment peripheral surface <NUM> of the main body <NUM>. Each of the spiral cutting flutes <NUM> is formed on the main body <NUM> and the external thread <NUM> to extend spirally from the drilling end <NUM> of the main body <NUM> in a second spiral direction D2, which is opposite to the first spiral direction D1, such that every spiral cutting flute <NUM> forms a cutting flute inlet <NUM> (see <FIG>) at the drilling zone <NUM> of the drilling end <NUM>. Further, a cut <NUM> located adjacent to the cutting flute inlet <NUM> is formed between each spiral cutting flute <NUM> and the recess <NUM>, so that each of the spiral cutting flutes <NUM> is communicable with the recess <NUM> via the cut <NUM>. In the first preferred embodiment, each of the spiral cutting flutes <NUM> includes a first cutting flute section <NUM> and a second cutting flute section <NUM> located adjacent to the first cutting flute section <NUM>. The first cutting flute section <NUM> is located closer to the connection end <NUM> of the main body <NUM> and is formed only on a part of the coarse thread <NUM> of the external thread <NUM>. The second cutting flute section <NUM> is located closer to the drilling end <NUM> of the main body <NUM> with the cutting flute inlet <NUM> formed at a lower end thereof. The second cutting flute section <NUM> is formed on both of the second implant section <NUM> and the remaining part of the coarse thread <NUM>. That is, the spiral cutting flute <NUM> is not formed on the fine thread <NUM> surrounding the first implant section <NUM>. However, it is understood the arrangement of the spiral cutting flutes <NUM> only on the coarse thread <NUM> without extending to the fine thread <NUM> is only illustrative to facilitate easy description of the present invention. In other embodiments, as shown in <FIG>, the spiral cutting flutes <NUM> may extend through a full length of the coarse thread <NUM> into a part of the fine thread <NUM>. That is, the spiral cutting flutes <NUM> are not formed in the remaining part of the fine thread <NUM>. The radially outmost portion of each spiral cutting flute <NUM> is formed into a plurality of spirally arranged blade edges <NUM> for cutting the side wall surface <NUM> of the alveolar hole <NUM>.

Please refer to <FIG> and <FIG>. The drilling zone <NUM> at the drilling end <NUM> is divided by the cutting flute inlets <NUM> of the spiral cutting flutes <NUM> into a plurality of drilling segments 142a, which are circumferentially spaced along the recess opening 141a, such that each of the cutting flute inlets <NUM> is located between two adjacent drilling segments 142a. As shown, every drilling segment 142a has a height gradually decreasing from one spiral cutting flute <NUM> along a contour of the recess opening 141a toward another adjacent spiral cutting flute <NUM>, such that a guide space 142b is formed at every drilling segment 142a and located adjacent to the recess opening 141a. Portions of the drilling segment 142a at two opposite sides of the guide space 142b are located at different height positions, so that each of the drilling segments 142a includes a lower drilling portion 142c that has a lower height position and an upper drilling portion 142d that has a height position higher than the lower drilling portion 142c. The lower drilling portion 142c is located adjacent to one of the spiral cutting flutes <NUM>, while the upper drilling portion 142d is located adjacent to another spiral cutting flute <NUM>. Every guide space 142b is communicable with the recess <NUM> and the spiral cutting flute <NUM> on the main body <NUM>, and every guide space 142b defines a guide surface 142e between the lower drilling portion 142c and the upper drilling portion 142d. Thus, the upper drilling portion 142d, the guide surface 142e, and the lower drilling portion 142c are sequentially formed on each of the drilling segments 142a in the first spiral direction D1. In the first preferred embodiment, the guide surface 142e has a gradient ranged between <NUM> to <NUM> degrees, which is smaller than a gradient of the external thread <NUM>. Further, each of the lower drilling portions 142c includes a linear blade edge 142c1 capable of cutting the bottom <NUM> of the alveolar hole <NUM>. The linear blade edges 142c1 respectively have a shape different from that of the spirally arranged blade edges <NUM> of the spiral cutting flutes <NUM> and are not connected to the spiral arranged blade edges <NUM>. Further, the lower drilling portions 142c are extended in a direction from a center of the recess <NUM> toward an outer periphery of the drilling zone <NUM>, and the upper drilling portions 142d are extended in a direction tangential to the recess opening 141a.

Please refer to <FIG> and <FIG>. Before implanting the sinus dental implant <NUM> into the upper gum <NUM>, the dentist first uses drill bits to cut and drill a hole into the upper gum <NUM>, so as to form the alveolar hole <NUM> on the upper gum <NUM>. Then, the sinus dental implant <NUM> is rotationally driven into the alveolar hole <NUM>. When the sinus dental implant <NUM> reaches the bottom <NUM> of the alveolar hole <NUM>, the lower drilling portions 142c are the parts of the sinus dental implant <NUM> that first contact with the bottom <NUM> of the alveolar hole <NUM> in line contact, which prevents the external thread <NUM> from contacting with the bottom <NUM>. When the sinus dental implant <NUM> is further rotated to move forward, the linear blade edges 142c1 of the lower drilling portions 142c slowly cut the bottom <NUM> of the alveolar hole <NUM> without causing idling of the sinus dental implant <NUM>; and the slow cutting of the lower drilling portions 142c avoids injuring the sinus membrane <NUM> due to excessive drilling of the bottom <NUM> of the alveolar hole <NUM>. In the first preferred embodiment, in the process of implanting the sinus dental implant <NUM> into the alveolar hole <NUM>, both of the linear blade edges 142c1 of the lower drilling portions 142c and the spiral arranged blade edges <NUM> on the external thread <NUM> cut the upper gum <NUM> to create bone debris <NUM>, which moves along the spiral cutting flutes <NUM> toward the recess <NUM> of the sinus dental implant <NUM>, as shown in <FIG>. When the lower drilling portions 142c drill through an area of the upper gum <NUM> located between the bottom <NUM> of the alveolar hole <NUM> and the sinus membrane <NUM>, the sinus dental implant <NUM> would gradually push against the sinus membrane <NUM>, allowing the bone debris <NUM> to move into a space formed between the sinus dental implant <NUM> and the sinus membrane <NUM>, as shown in <FIG>.

Please refer to <FIG>, in which a sinus dental implant <NUM> according to a second preferred embodiment of the present invention is shown. In the second preferred embodiment, the sinus dental implant <NUM> also includes a main body <NUM>, an external thread <NUM>, and a plurality of spiral cutting flutes <NUM>, which are structurally similar to those in the first preferred embodiment and are not repeatedly described herein. However, the second preferred embodiment is different from the first one in the position of the external thread <NUM> on the main body <NUM>. As shown, in the second preferred embodiment, the fine thread <NUM> of the external thread <NUM> is similarly formed on the first embedment peripheral surface <NUM> around the first implant section <NUM>, while the coarse thread <NUM> of the external thread <NUM> is formed only on a part of the second embedment peripheral surface <NUM> around the second implant section <NUM>, such that the remaining part of the second embedment peripheral surface <NUM> around the second implant section <NUM> does not have the external thread <NUM> formed thereon. In the second preferred embodiment, the part of the main body <NUM> having the external thread <NUM> formed thereon is defined as a first implant body 10a, and the other part of the main body <NUM> having not the external thread <NUM> formed thereon is defined as a second implant body 10b. Wherein, the recess <NUM> is formed on the second implant body 10b.

Please refer to <FIG> and <FIG>, in which a sinus dental implant <NUM> according to a third preferred embodiment of the present invention is shown. The third preferred embodiment is different from the second one in the drilling segments 142a of the drilling end <NUM>. As shown, in the third preferred embodiment, each drilling segment 142a further rises in height from the lower drilling portion 142c along the recess opening 141a in a direction opposite to the guide space 142b until it reaches at the adjacent spiral cutting flute <NUM>, such that a secondary guide space 142f is formed at every drilling segment 142a and located adjacent to the guide space 142b. Portions of the drilling segment 142a at two opposite sides of the secondary guide space 142f are located at different height positions, so that each of the drilling segments 142a includes a secondary upper drilling portion <NUM> having a height position higher than the lower drilling portion 142c. More specifically, the lower drilling portion 142c is located between the upper drilling portion 142d and the secondary upper drilling portion <NUM> of the drilling segment 142a; and the upper drilling portion 142d and the secondary upper drilling portion <NUM> are respectively located adjacent to one of the spiral cutting flutes <NUM>. Each of the secondary guide spaces 142f defines a secondary guide surface <NUM> between the lower drilling portion 142c and the secondary upper drilling portion <NUM>. More specifically, the secondary guide surface <NUM> is a slanting surface slantly extended from the secondary upper drilling portion <NUM> toward the lower drilling portion 142c. Further, the secondary guide surface <NUM> and the guide surface 142e are inclined in two different directions.

Claim 1:
A sinus dental implant (<NUM>) for implanting into an alveolar hole (<NUM>) on a patient's upper gum (<NUM>), comprising:
a main body (<NUM>) having two opposite ends defined as a drilling end (<NUM>) and a connection end (<NUM>), and an embedment peripheral surface (<NUM>) extended from the drilling end (<NUM>) toward the connection end (<NUM>); and the drilling end (<NUM>) having an outer peripheral area formed into a drilling zone (<NUM>) capable of contacting with a bottom (<NUM>) of the alveolar hole (<NUM>) and a sunken central area formed into a recess (<NUM>) surrounded by the drilling zone (<NUM>);
an external thread (<NUM>) being formed on the embedment peripheral surface (<NUM>) of the main body (<NUM>) to extend in a first spiral direction (D1) for engaging with a side wall surface (<NUM>) of the alveolar hole (<NUM>); and
a plurality of spiral cutting flutes (<NUM>) being formed on the main body (<NUM>) and the external thread (<NUM>) to extend from the drilling zone (<NUM>) toward the connection end (<NUM>) in a second spiral direction (D2), which is opposite to the first spiral direction (D1), and a cut (<NUM>) being formed between every spiral cutting flute (<NUM>) and the recess (<NUM>) for communicating the spiral cutting flute (<NUM>) with the recess (<NUM>);
wherein the drilling zone (<NUM>) is divided by the spiral cutting flutes (<NUM>) into a plurality of drilling segments (142a) that are circumferentially spaced along the recess (<NUM>);
the sinus dental implant (<NUM>) being characterized in that every drilling segment (142a) has a lowest portion defined as a lower drilling portion (142c), the drilling segment (142a) rises gradually from the lower drilling portion (142c) of the drilling segment (142a) toward one of the spiral cutting flutes (<NUM>) to form an upper drilling portion (142d), so that a guide surface (142e) is formed between the lower drilling portion (142c) and the upper drilling portion (142d) while a guide space (142b) is also formed between the lower drilling portion (142c) and the upper drilling portion (142d) to communicate with the recess (<NUM>) and the spiral cutting flute (<NUM>).