JP7305283B2 - Implant fixture with tapered thread groove depth - Google Patents

Description

The present invention relates to an implant fixture used in dental implant treatment.

BACKGROUND ART Dental implant treatment is one of dental treatments performed on a site of a missing tooth that has been lost due to caries, periodontal disease, trauma, or the like.

Generally, the main procedure for dental implant treatment is to form a hole in the jawbone with an implant drill that is approximately the same as or slightly smaller than the outer diameter of the dental implant, and then hammer the dental implant into the drilled hole. This is done by screwing in and embedding the dental implant in the desired jawbone position.

After implanting the dental implant, the gingiva is sutured so as not to expose the dental implant to the oral cavity, making it easy to insert the dental implant into and around it and into the jawbone. In the case of an implant fixture with a helical thread formed on its outer surface in order to obtain fixation with the jawbone immediately after implantation, new bone is formed in the gap between the thread groove and the drill hole until fixation is obtained. There is a two-stage procedure in which a healing period is provided and a prosthesis (crown) is attached after the healing period, and a one-stage procedure in which the implanted dental implant is exposed and the gingiva around it is sutured. .

As for the specifications of dental implants, the one-piece type is the easiest to operate and superior in physical strength. In addition, as for the treatment method, the one-stage treatment that completes the entire treatment by attaching the prosthesis to the occlusal part, which is the superstructure, immediately after implanting the dental implant, shortens the total treatment time and days. and can reduce the financial and mental burden on the operator and the patient. However, in cases where the one-piece type and one-step procedure can be applied, the bone quality and bone mass of the jawbone are sufficient, the oral hygiene is good, and the site and dentition where high occlusal pressure is not applied to the treatment site. Since it cannot be performed unless intraoral conditions are met, such as being a patient, the current situation is that the specifications of the dental implant and the treatment method are appropriately selected according to the case.

Implant fixtures used for dental implants include a straight type in which the outer diameter is approximately constant from the tip to the rear end, and a tapered type in which the outer diameter increases from the tip to the rear end. In cases where esthetics are important, such as the anterior teeth, the insertion depth can be fine-tuned according to the positional relationship with the surrounding bone while the implant fixture is embedded. etc., the shape of the implant fixture is appropriately selected according to the case.

Implant fixtures having helical threads formed on their outer surface are widely used in order to facilitate insertion into the jawbone and to obtain fixation with the jawbone immediately after implantation.

In recent years, technological development of dental implants has progressed so that they can be used more easily, and products with improved surface properties, shapes, etc. have been put on the market, but they all have advantages and disadvantages.

Patent Literature 1 discloses an implant fixture in which the root diameter of the thread groove gradually increases from the front end side to the rear end side to be embedded in the jawbone, and the crest diameter is substantially constant. However, there is a problem that the gap between the drill hole and the thread groove is large from the tip side to the mid-abdomen, requiring a long healing period.

Patent Literature 2 discloses a dental implant in which a thread forms a flat surface and has helical grooves on the flat surface and in the root of the thread, respectively. After the healing period has passed, new bone is formed along the grooves to obtain a strong fixation between the implant fixture and the surrounding bone. It became a gap, and the healing period was sometimes long.

JP-A-2005-65760 Japanese Patent No. 05167341

In implant treatment, especially when implant fixtures are implanted into tooth extraction sockets, there are cases where ideal drill holes cannot be obtained. It was hoped that

In order to obtain the above-mentioned high perforability and fixation immediately after implantation, it is necessary to deepen the thread groove, but on the other hand, it is necessary to make the thread groove shallow in order to shorten the healing period. There has been a demand for an implant fixture that can simultaneously solve

The present invention is a dental implant fixture having an implant portion to be implanted in the jawbone,
The implanted part implanted in the jawbone has a truncated cone part and a cylindrical part at the bottom of the truncated cone part, and the truncated cone part and the cylindrical part of the implanted part are the same. articulated on the rotating shaft,
2, 3 or 4 thread grooves having the same lead and pitch and different phases from at least the truncated cone portion to the other end of the cylindrical portion;
At least one first thread groove of the cylindrical portion has a first gradually decreasing depth shape in which the depth gradually decreases from the truncated cone portion side of the cylindrical portion to the other end portion side,
A dental implant fixture characterized in that the depth of another second thread groove of the cylindrical portion is a second gradually decreasing depth shape different from the gradually decreasing depth shape of the thread groove or a constant depth shape that is a constant depth. It is cha.

The present invention is a dental implant fixture having an implant portion to be implanted in the jawbone,
The implanted part implanted in the jawbone has a truncated cone part and a cylindrical part at the bottom of the truncated cone part, and the truncated cone part and the cylindrical part of the implanted part are the same. articulated on the rotating shaft,
2, 3 or 4 thread grooves having the same lead and pitch and different phases from at least the truncated cone portion to the other end of the cylindrical portion;
The cylindrical portion has a first gradually increasing root diameter shape in which the root diameter formed by at least one first thread groove of the cylindrical portion gradually increases from the truncated cone portion side to the multi-end portion side of the cylindrical portion,
A dental implant fixture characterized in that the root diameter of the other second thread groove of the cylindrical portion is a second gradually increasing root diameter shape different from the root diameter shape or a constant root diameter shape that is a constant root diameter shape. It is cha.

It is preferable that the cylindrical portion having the thread grooves has a constant outer shape. All thread grooves in the truncated cone portion preferably have the same depth profile. It is preferable that all the thread grooves on the other end of the cylindrical portion have the same depth shape and the same root diameter shape. At the transition to the frusto-conical shape of the cylinder, all thread grooves preferably have the same thread depth. The first gradually decreasing depth shape and/or the first gradually increasing valley diameter shape of the at least one first thread groove in the cylindrical portion extends to the middle of the cylindrical portion, and the constant depth shape extends from the middle of the cylindrical portion to the other end. And/or it is preferable to have a constant root diameter shape.

The line connecting the bottoms of the first gradually decreasing depth shape or the first gradually increasing root diameter shape of the at least one first thread groove in the cylindrical portion is the axis on the side of the truncated cone portion on the plane including the axis of the cylindrical portion. It is preferable to form a straight line that intersects with . In the cylindrical portion, it is preferable that the depth ratio of the thread grooves at the most different positions is 5:6 to 5:18. Preferably, the leading flank angle of the thread of all thread grooves is 2-20° and the trailing flank angle is 40-60°. It is preferable that the other end of the columnar portion of the implanted portion has a circular groove coaxial with the columnar portion. It is preferable to have a columnar cuff portion coaxial with the columnar portion at the other end of the columnar portion of the implanting portion. Preferably, the dental implant consists of a dental implant fixture and an integral or separate abutment.

It has high perforation at the time of implantation, and while satisfying fixability immediately after implantation, it is possible to shorten the healing period until the gap between the thread grooves is fixed with new bone and the prosthesis is attached.

1 is a side view of a preferred embodiment of the implant fixture of the present invention; FIG. 2 is a cross-sectional view of a plane containing the axis of the cylindrical portion of the implant fixture shown in FIG. 1; FIG. 2 is a partially enlarged cross-sectional view of a plane including the axis of the cylindrical portion of the implant fixture shown in FIG. 1; FIG. FIG. 4 is a partially enlarged cross-sectional view of a plane containing the axis of one cylindrical portion of the preferred embodiment of the implant fixture of the present invention; 1 is a side view of one preferred embodiment of the implant fixture of the present invention; FIG. 1 is a side view of one preferred embodiment of the implant fixture of the present invention; FIG. 1 is a side view of one preferred embodiment of the implant fixture of the present invention; FIG. FIG. 4 is a partial cross-sectional view of a plane containing the axis of one cylindrical portion of a preferred embodiment of the implant fixture of the present invention;

Preferred embodiments are described below. However, the following embodiments are merely examples, and the present invention is not limited to the following embodiments. In addition, other arbitrary components can be provided.

The present invention is a dental implant fixture and can be used with dental implants having implant fixtures. As a first specification of the dental implant, it can be used as a one-piece type in which the implant fixture and the abutment are integrated. The second specification for dental implants consists of two parts, an implant fixture that replaces the root of the tooth and an abutment that replaces the crown abutment, and the abutment is connected to the implant fixture. There is a two piece type that is used. A third type of dental implant is the three-piece type, which consists of three parts, an implant fixture, an abutment, and a screw, and uses the screw to fix the abutment to the implant fixture.
It can be used for any of the 1st to 3rd specification 1 to 3 piece types of dental implants.
A dental implant consisting of an abutment integrated with a dental implant fixture is a one-piece type dental implant of the first specification.
A dental implant consisting of a dental implant fixture and a separate abutment is a 2- or 3-piece type dental implant of the 2nd or 3rd specification.

Applications of the implant fixture of the present invention are not particularly limited. For example, it may be the above-mentioned dental implant used as a substitute for a missing tooth, or a temporary implant used as a fixing base for an orthodontic wire, or any other use. It may be the dental implant used.

In particular, when using a one-piece type dental implant, which is the first specification for a one-stage procedure, the prosthesis of the occlusal part, which is the superstructure, is attached immediately after implantation. The fixture is likely to be subjected to a load due to occlusion, and the implant fixture is a preferred embodiment of the present invention that can be firmly fixed to the jawbone immediately after implantation.
On the other hand, in the case of 2- or 3-piece type dental implants of the second to third specifications for the two-step procedure, it is possible to obtain fixation by the implant fixture and new bone in a short period of time, and the patient is healed. The period can be short and is a preferred aspect of the invention.
The dental implant fixture of the present invention has a diameter (thickness) of 3.0 to 5.0 mm, a length of 7.0 to 17.0 mm, and a thread lead of 0.6 to 2.4 mm. There is a pitch of 0.6 to 1.2 mm.
The diameter (thickness) of the dental implant fixture means the outer diameter of the cylindrical portion, and the length is the length of the implanted portion, which is the portion not including the abutment portion in the one-piece type. In the case of the three-piece type, it means the length of the implanted portion, which is one piece portion including the cylindrical portion and the truncated cone portion.

A dental implant fixture of the present invention is an implant fixture that is used in the oral cavity and has an implant portion that is implanted in the jawbone. The implanting part of the dental implant fixture is the part to be implanted in the jawbone, and preferably has a thread groove. Depending on the surgical technique and application, the implant may be implanted in the jawbone beyond the thread groove of the implanting part, but it is preferable that the implant fixture is implanted in the jawbone up to the end.
The implanted portion is composed of a truncated cone portion and a cylindrical portion. Of the truncated conical upper base and lower base, the wider one is the lower base, and the lower base of the truncated conical part and the bottom side of the cylinder are formed as a continuous integral shape.
It is preferable that the truncated cone portion and the cylindrical portion of the implanted portion are connected on the same rotation axis.
The truncated cone portion of the implant fixture of the present invention preferably has a tapered truncated cone shape, but may have various shapes such as a cylindrical shape and a dome shape.

From the truncated cone portion to the cylindrical portion, it has a thread groove with a lead and a pitch. It is preferable that the portion from the truncated cone portion having the thread groove having the lead and the pitch to the cylindrical portion form the implant portion. Preferably, the implant has a thread groove with lead and pitch extending from the truncated cone portion to the other end of the cylindrical portion. It preferably has threaded grooves with lead and pitch from the top of the frusto-conical portion.
It is preferred that the lead and pitch of each thread groove in the implanted portion be the same, and that the lead and pitch are always the same in any portion. Since the thread grooves have the same lead and pitch, they can be implanted in the jawbone without damaging the jawbone.
Furthermore, it is preferable to have two, three, or four thread grooves with different phases. By using 2, 3 or 4 thread grooves, the lead can be lengthened without widening the thread pitch, and the implanting time can be shortened without impairing the fixation with the jawbone. can.

The depth of the thread groove of the dental implant fixture of the present invention means the axis of the cylindrical portion from the cylindrical surface of the cylindrical portion to the bottom of the thread groove on the plane including the axis of the cylindrical portion of the dental implant fixture. is the straight line distance perpendicular to
Preferably, the depth of the first thread groove of the implant fixture of the present invention has a first tapered depth shape. Gradual decrease means that the groove gradually becomes shallower, and this state is defined as a first gradually decreasing depth shape. The gradually decreasing state in the first gradually decreasing depth shape is a state in which the depth of the first thread groove becomes shallower as the first thread groove progresses from the truncated cone side toward the other end side. It is preferable that the grooves gradually become shallower and that the grooves become shallower at a constant rate.
On the plane including the axis of the cylindrical portion of the dental implant fixture, the line connecting the axis of the cylindrical portion and the bottom of the first gradually decreasing depth shape that becomes shallower at a constant rate intersects the axis of the truncated cone portion. It forms a straight line with an angle of 0.05 to 7°. It is preferably 0.1 to 5°.
This first tapered depth profile need not consist of the entire thread groove, but may be a portion of the thread groove.
At least one first thread groove in the cylindrical portion has a first gradually decreasing depth shape in which the depth gradually decreases from the truncated cone portion side to the other end portion side of the cylindrical portion. The first thread groove extends from the truncated cone portion to the other end of the cylindrical portion, but the portion forming the gradually decreasing first gradually decreasing depth shape is provided at least in the cylindrical portion, and is formed from the middle of the cylindrical portion. However, it is preferable to end in the middle of the cylindrical portion.

It is preferable that the portion forming the gradually decreasing first gradually decreasing depth shape extends from the transition portion of the cylindrical portion on the side of the truncated cone portion toward the other end portion of the cylindrical portion. As a first correspondence of the portion forming the gradually decreasing first gradually decreasing depth shape, it is preferable that it extends to the terminal end of the cylindrical portion of the thread groove in the direction of the other end portion. As for the second correspondence of the portion forming the gradually decreasing first gradually decreasing depth shape, it is preferable that it ends near the middle of the cylindrical portion from the direction of the truncated cone portion, and it is more preferable that it ends at the center of the cylindrical portion. Further, as a third correspondence of the portion forming the gradually decreasing first gradually decreasing depth shape, it is preferable that the portion ends at a position separated by 1.5 mm or more from the other end portion of the cylindrical portion.

The other second thread groove of the cylindrical portion is at least one thread groove other than the first thread groove forming the tapered first tapered depth profile.
The second thread grooves other than the thread grooves forming the gradually decreasing first gradually decreasing depth shape include those forming the second gradually decreasing depth shape or the constant depth shape having a constant depth.
The second gradually decreasing depth shape has the same lead, pitch, and phase as the first gradually decreasing depth shape.

Different portions of the second tapered depth profile and the first tapered tapered depth profile are:
a second gradually decreasing depth shape that gradually decreases in the direction of the truncated cone portion beyond the gradually decreasing range of the first thread groove formed by the gradually decreasing gradually decreasing depth shape;
a second gradually decreasing depth shape that gradually decreases in the direction of the other end beyond the gradually decreasing range of the first thread groove formed by the gradually decreasing first gradually decreasing depth shape;
a second gradually decreasing depth shape that gradually decreases without reaching the gradually decreasing range of the first thread groove formed by the gradually decreasing first gradually decreasing depth shape in the direction of the truncated cone portion;
a second gradually decreasing depth shape that gradually decreases without reaching the gradually decreasing range of the first thread groove formed by the gradually decreasing first gradually decreasing depth shape toward the other end;
On the plane including the axis of the cylindrical portion, the line connecting the bottom of the second gradually decreasing depth shape forms a straight line that intersects the axis of the truncated cone portion, and the line connecting that axis and the bottom of the second gradually decreasing depth shape forms a straight line. Whether the angle and the angle formed by the line connecting the axis and the bottom of the tapered depth profile are different,
On the plane including the axis of the cylindrical portion, the line connecting the valley bottoms of the second gradually decreasing depth shape can be composed of a plurality of straight lines that intersect the axis of the truncated cone portion and straight lines that are parallel to the axis. Preferably, one or more of these are different.
By combining these configurations, it is possible to reduce the gap between the bone hole and the thread groove without impairing the perforation property when implanting the dental implant and the fixation property immediately after implantation, thereby shortening the healing period.

It is preferable that the angle between the axis of the cylindrical portion and the line connecting the valley bottom of the first gradually decreasing depth shape is 0.05 to 7°. The angle between the axis of the cylindrical portion and the line connecting the bottom of the second shape with gradually decreasing depth is preferably 0 to 7°.
The angle formed by the line connecting the valley bottoms of the first gradually decreasing depth shape and the line connecting the bottoms of the second gradually decreasing depth shape is preferably 0.05 to 5°.

The constant depth shape, which is constant depth, is composed of the axis of the cylindrical portion and the bottom of the second thread groove of the second tapered depth shape on the plane containing the axis of the cylindrical portion of the dental implant fixture. It is a shape in which straight lines are parallel.
It is preferable that the other second thread groove of the cylindrical portion has a constant depth shape with a constant depth.

In a dental implant fixture having two thread grooves, there is one first thread groove having a first tapered depth profile that tapers to a cylindrical portion, and one other second thread groove.
In a dental implant fixture having three thread grooves, two first thread grooves having a first gradually decreasing depth profile that gradually decreases in the cylindrical portion and one other second thread groove. is preferred. The gap between the bone hole and the thread groove can be made smaller, and the healing period can be shortened.
In a dental implant fixture having three thread grooves, one first thread groove having a first gradually decreasing depth shape that gradually decreases in the cylindrical portion and two other second thread grooves. is preferred. The drillability of the dental implant fixture is improved.
In a dental implant fixture having four thread grooves, three first thread grooves having a first gradually decreasing depth profile that gradually decreases in the cylindrical portion and one other second thread groove. is preferred. Improving the drillability of the dental implant fixture, and further improving the fixation.
In a dental implant fixture having four thread grooves, two first thread grooves having a first gradually decreasing depth profile that gradually decreases in the cylindrical portion and two other second thread grooves are provided. is preferred. The drillability of the dental implant fixture can be improved, the gap between the bone hole and the thread groove can be reduced, and the healing period can be shortened.
In a dental implant fixture having four thread grooves, one first thread groove having a first gradually decreasing depth profile tapering to the cylindrical portion and three other second thread grooves. is preferred. The drillability of the dental implant fixture can be improved, the gap between the bone hole and the thread groove can be reduced, and the healing period can be shortened.

The root diameter formed by at least one first thread groove of the cylindrical portion is the distance from the bottom of the first thread groove to the axis of the cylindrical portion on a plane including the axis of the cylindrical portion of the dental implant fixture. , means the straight line distance perpendicular to the axis of the cylinder.
Preferably, the first root diameter formed by the first thread grooves of the implant fixture of the present invention has a first gradually increasing root diameter shape. The gradual increase means that the root diameter gradually increases, and this state is referred to as a gradually increasing root diameter shape. The gradually increasing state in the gradually increasing root diameter shape is a state in which the root diameter increases as the thread groove advances from the truncated cone side toward the other end side. The gradual increase in the root diameter is preferably the increase at a constant rate. The first progressive root diameter profile need not consist of the entire thread groove, but may be a portion of the thread groove.
At least one first thread groove in the cylindrical portion has a first gradually increasing root diameter shape in which the first root diameter gradually increases from the truncated cone portion side to the other end portion side of the cylindrical portion. The first thread groove extends from the truncated cone portion to the other end portion of the cylindrical portion, but the portion forming the first gradually increasing root diameter shape is provided at least in the cylindrical portion, and starts from the middle of the cylindrical portion. It may be configured, and preferably ends in the middle of the cylindrical portion. It is preferable that the portion forming the first gradually increasing valley diameter shape extends from the transition portion of the cylindrical portion on the side of the truncated cone portion toward the other end portion of the cylindrical portion. The portion forming the first gradually increasing valley diameter shape that gradually increases preferably ends near the middle of the cylindrical portion from the direction of the truncated cone portion, more preferably ends at the center of the cylindrical portion, and from the other end of the cylindrical portion, It is preferable to end at a position separated by 2 mm or more.

The other second root diameter of the cylindrical portion means a root diameter other than the root diameter forming the gradually increasing first gradually increasing root diameter shape.
The second root diameter other than the first root diameter that forms the gradually increasing root diameter shape includes a second root diameter that forms a second gradually increasing root diameter shape or a constant depth shape that is a constant depth.
The second gradually increasing root diameter shape has the same lead, pitch, and phase as the gradually increasing root diameter shape.

A different part of the second gradually increasing root diameter shape and the gradually increasing first gradually increasing root diameter shape is
a second gradually increasing root diameter shape that gradually increases in the direction of the truncated cone beyond the gradually increasing range of the first root diameter formed by the first gradually increasing root diameter shape, or
a second gradually increasing root diameter shape that gradually increases beyond the range of the first gradually increasing root diameter formed by the first gradually increasing root diameter shape in the multi-end direction;
a second gradually decreasing depth shape that gradually increases without reaching the gradually increasing range of the first root diameter formed by the gradually increasing first gradually increasing root diameter shape in the direction of the truncated cone portion;
or a second gradually decreasing depth shape that gradually increases without reaching the gradually increasing range of the first root diameter formed by the gradually increasing first gradually increasing root diameter shape in the direction of the other end;
On the surface including the axis of the cylindrical portion, the line connecting the bottom of the second gradually increasing root diameter shape forms a straight line that intersects the axis of the truncated cone portion side, and the line that connects the axis and the bottom of the second gradually increasing root diameter shape. Is the angle formed by the line connecting the bottom of the gradually increasing groove diameter on the axis different from the angle formed by
On the plane including the axis of the cylindrical portion, the line connecting the bottoms of the second gradually increasing root diameter shape is preferably composed of a plurality of straight lines that intersect the axis of the truncated cone portion and straight lines that are parallel to the axis.
By combining these configurations, it is possible to reduce the gap between the bone hole and the thread groove without impairing the perforation when implanting the dental implant fixture and the fixation immediately after implantation, which shortens the healing period. can. One or more of these must be different.

A constant root diameter shape with a constant depth is a straight line formed by the axis of the cylindrical portion and the bottom of the thread groove of the second gradually increasing root diameter shape on the plane including the axis of the cylindrical portion of the dental implant fixture. are parallel to each other.
The other second root diameter of the cylindrical portion preferably has a constant root diameter shape.

In a dental implant fixture having two thread grooves, the cylindrical portion has one first root diameter with a gradually increasing root diameter shape and one other second root diameter.
In a dental implant fixture having three thread grooves, it is preferable that the cylindrical portion has two root diameters having a gradually increasing root diameter shape and one other second root diameter. The gap between the bone hole and the thread groove can be made smaller, and the healing period can be shortened.
In a dental implant fixture having three thread grooves, it is preferable that the cylindrical portion has one first root diameter having a gradually increasing root diameter shape and two other second root diameters. . The drillability of the dental implant fixture is improved.
In a dental implant fixture having four thread grooves, it is preferable that the cylindrical portion has three first root diameters having a gradually increasing root diameter shape and one other second root diameter. . Improving the drillability of the dental implant fixture, and further improving the fixation.
In a dental implant fixture having four thread grooves, it is preferable that the cylindrical portion has two first root diameters having a gradually increasing root diameter shape and two other second root diameters. . The drillability of the dental implant fixture can be improved, the gap between the bone hole and the thread groove can be reduced, and the healing period can be shortened.
In a dental implant fixture having four thread grooves, it is preferable that the cylindrical portion has one first root diameter having a gradually increasing root diameter shape and three other second root diameters. . The drillability of the dental implant fixture can be improved, the gap between the bone hole and the thread groove can be reduced, and the healing period can be shortened.
Two, three, or four thread grooves are provided, and at least one of the thread grooves has high drillability to obtain a necessary and sufficient drillability, and at least one of the thread grooves is fixed by new bone. It was found that the fixation required to withstand the occlusal pressure can be obtained if

The outer diameter of the dental implant fixture of the present invention can be tapered to a point or the outer diameter of the implant fixture can be straight. The term “straight” means that the outer diameter is the same as that of the cylindrical portion up to the vicinity of the tip to be embedded in the jawbone, and the tip is preferably hemispherical, chamfered or R-shaped.
It is preferable that the cylindrical portion having the thread grooves has a constant outer shape. The term "constant" means that the straight line connecting the contours is parallel to the axis of the cylindrical portion on the plane including the axis of the cylindrical portion.
The outer diameter of the cylindrical portion of the dental implant fixture of the present invention is preferably a curved surface equidistant in the vertical direction from the axis forming the center of the cylindrical portion. The curved surface is parallel to the axis forming the center of the cylindrical portion. By adopting this configuration, it is possible to finely adjust the embedding depth of the implant fixture during the procedure.
In a plane parallel to the axis of the cylindrical portion of the dental implant fixture of the present invention, it is preferable that the straight lines forming the outer shape of the cylindrical portion are parallel to the axis in any plane.

All thread grooves in the truncated cone portion preferably have the same depth profile. High perforation performance can be obtained by using a shape with high perforation performance and a constant depth.
All thread grooves on the other end of the cylindrical portion preferably have the same depth shape and/or the same root diameter shape, preferably the same depth shape and the same root diameter shape. At the other end, pierceability is not critical, so all thread grooves should be as shallow as possible. By making the thread groove shallower, the fixability immediately after implantation can be improved, and the gap between the bone hole and the thread groove can be made smaller, so that the healing period can be shortened.

Preferably, the first gradually decreasing depth profile and/or the first gradually increasing root diameter profile of the at least one first thread groove in the cylindrical portion extends to the middle of the cylindrical portion. It is preferable that the first thread grooves extending from the middle of the cylindrical portion to the other end have the same depth shape and/or the same root diameter shape.
The root diameter of at least one first thread groove provided in the cylindrical portion forms a first gradually increasing root diameter shape in which the root diameter gradually increases from the truncated cone portion side of the cylindrical portion to the other end portion side. It is preferable to form a constant root diameter shape that does not change from one end to the other end. With this configuration, the fixation property immediately after implantation can be improved, and the gap between the bone hole and the thread groove is reduced, so that the healing period can be shortened.

In the frusto-conical portion, it is preferred that all thread grooves have the same and constant thread depth.
A constant thread depth means that a straight line connecting the outer diameter of the truncated cone and a straight line connecting the root diameter of the thread groove are parallel. With this configuration, when the tip of the implant fixture starts drilling into the bone hole, it contacts the drill hole at multiple points at positions symmetrical with respect to the central axis of the implant fixture, thereby improving the stability and improving the implantation position. The implant angle can be stabilized.

Among the surfaces of the cylindrical portion perpendicular to the axis, among the plurality of thread groove depths, the surface having thread grooves with the most different depths has a depth ratio of 5:6 to 5. :18. The thread groove depth ratio is the ratio of the depth of the shallowest thread groove to the depth of the deepest thread on the same plane perpendicular to the axis of the cylindrical portion. It is preferable that the depth of the deepest thread groove is 6 to 18 when the depth of the shallowest thread groove is 5, which is the position on the axis of the cylindrical portion where the ratio of the depths of the portions is maximized. . Furthermore, it is preferably 7 to 13.
Thread groove depth measurements are taken perpendicular to the axis of the cylindrical portion of the implant fixture.
The thread grooves having the first gradually decreasing depth shape and the thread grooves having the second gradually decreasing depth shape have a depth of either thread groove at the transition portion between the cylindrical portion and the truncated cone portion. They are 0.15-0.4 mm respectively, and 0.15-0.35 mm and 0.1-0.3 mm on the other end side.

Preferably, the leading flank angle of the thread of all thread grooves is 2-20° and the trailing flank angle is 40-60°. More preferably, the leading end flank angle is 2 to 10° and the trailing end flank angle is 45 to 60°. The configuration of this angle is the angle formed with the perpendicular to the axis of the cylindrical portion. The tip side flank angle is the angle formed by the inclination of the thread formed by the adjacent thread grooves toward the truncated cone portion and the perpendicular to the axis of the cylindrical portion. The trailing flank angle is the angle formed by the inclination toward the other end of the cylindrical portion formed by the adjacent thread grooves and the perpendicular to the axis of the cylindrical portion. Both the leading edge flank angle and the trailing edge flank angle are acute angles. The angular difference between the leading end flank angle and the trailing end flank angle is preferably 35 to 55°. Moreover, the sum of the angles of the leading end side flank angle and the trailing end side flank angle is preferably 45 to 70 degrees.

It is preferable that the other end of the columnar portion of the implanted portion has a circular groove coaxial with the columnar portion. The circular grooves are preferably configured so as not to intersect with the thread grooves.
The circular groove is formed on the entire circumference of the cylindrical portion, and it is sufficient if there is one or more grooves, and it is more preferable to form two or three concentric grooves. The circular groove preferably has a depth of 0.03 to 0.1 mm.
After the implant fixture is embedded in the jawbone, the circular grooves can stop bacteria in the oral cavity from entering the gap between the jawbone and the implant fixture, preventing them from entering the thread groove.

It is preferable to have a cuff portion coaxial with the cylindrical portion at the other end of the cylindrical portion of the implant fixture. In that case, said circular groove is preferably located between the cuff portion (8) which penetrates and contacts the gum and the cylindrical portion with the thread groove.
The outer surface of the cuff (8) does not have to be a rough surface as described above, and any known surface properties can be appropriately selected and used. For example, it is preferably a smooth surface or a mirror surface. The shape of the cuff portion (8) is not particularly limited, but it is preferably cylindrical with the same diameter as the cylindrical portion, more preferably reverse tapered at 0.5 to 7°. A reverse tapered shape is a shape that tapers toward the end.
Also, the length of the cuff portion (8) can be selected from the range of 0.1 to 3.0 mm, preferably 0.3 to 1.5 mm.

The dental implant fixture of the present invention shown in the drawings will be described.
FIG. 1 describes a three-piece type implant fixture (1) of the present invention. FIG. 2 shows a cross-sectional view of a plane containing the axis of the cylindrical portion (3) of the implant fixture shown in FIG. FIG. 3 shows a partially enlarged view of the transition of the cylindrical portion (3) of the sectional view shown in FIG. 2 to the truncated conical shape (2).
A structure for connecting an abutment is provided from the other end of the cylindrical portion (3) to the interior of the implant fixture.
The implant fixture (1) in FIG. 1 has an implanting portion to be implanted in the jawbone, and the implanting portion to be implanted in the jawbone has a truncated cone shape (2), a truncated cone portion It consists of a cylindrical portion (3) at the bottom of the cylinder, and two thread grooves (4) with the same lead and pitch but different phases extending from the truncated cone portion to the other end of the cylindrical portion.
The implant fixture in FIG. 1 has a thickness of 4 mm, a length of 11 mm, a lead of 1.2 mm, and a pitch of 0.6 mm. Furthermore, the upper base of the frustoconical portion forms a flat surface.
The first thread groove is shallow from the transition portion of the cylindrical portion to the truncated conical shape toward the other end, and the other second thread groove is configured to transition to the truncated conical shape of the cylindrical portion. The depth of the groove is constant from the portion to the other end of the cylindrical portion.
FIG. 4 is a partially enlarged cross-sectional view of a plane including the axis of the cylindrical portion of one of the preferred embodiments of the implant fixture of the present invention, unlike FIGS. The other second thread groove extends from the transition to the truncated cone of the cylindrical portion to the center of the cylindrical portion. The depth of the groove is constant from the center to the other end of the cylindrical portion.

As shown in FIG. 3, when the cylindrical portion has a constant depth shape where the thread depth is constant from the truncated cone side to the other end of the cylindrical portion, the implant fixture has shallow thread grooves over the entire cylindrical portion. Healing time can be shortened.
More specifically, the depth of one thread groove is continuously tapered from the truncated cone portion side to the other end side of the cylindrical portion to form a first gradually decreasing depth shape, and the trough bottom of the gradually decreasing depth shape is formed. and the axis of the cylindrical portion (100) is 0.4°.
The line connecting the bottoms of the second gradually decreasing depth shape with the depth of the other second thread groove extending from the truncated cone side to the other end side of the cylindrical portion is parallel to the axis of the cylindrical portion. The implant fixture of FIG. 1 can be maintained perforatable by a first tapered-depth profile thread groove to facilitate implantation of the implant fixture, and by a second tapered-depth profile thread groove. , narrowing the gap with the jawbone and shortening the healing period.

In FIG. 4, the depth of one first thread groove forms a first gradually decreasing depth shape in which the depth gradually decreases continuously from the truncated cone portion side of the cylindrical portion to the other end portion side, and the first gradually decreasing depth The first angle (100) between the line joining the roots of the shape and the axis of the cylinder is 0.4°. Another second thread groove depth is greater than the first angle (100) from the truncated cone side of the cylindrical portion to the middle of the cylindrical portion, a line connecting the valley bottom of the second tapered depth shape and the cylindrical portion. A second gradually decreasing depth shape in which the depth of the second thread groove continuously decreases at a second angle (101) with the axis and is constant from the midsection to the other end side is adopted. The angle between the axis of the cylindrical portion and the line connecting the bottom of the second tapered depth profile is 2.4°.

The first thread groove having the first gradually decreasing depth shape forms a deep thread groove on the truncated cone portion side, so that high drillability can be obtained at the time of implantation, and a shallow thread groove on the other end side allows drilling. The gap between the hole and the thread groove is reduced so that fixation by new bone can be obtained in a relatively short healing period.
The second thread groove having the second gradually decreasing depth shape forms a deep thread groove from the truncated cone part to the middle part, and can obtain high drillability at the time of implantation. The thread groove is shallower than the first thread groove in the region up to the end, and fixation with new bone can be obtained in a short healing period in the region from the middle of the cylindrical portion to the other end.

The implant fixture (1) of the present invention has an internal mechanism (5) for supporting a dental prosthesis as shown in FIG. 2, and an external mechanism (5) as shown in FIG. can be adopted.

The implant fixture of the present invention may also have concentric grooves (6) near the other end as shown in FIGS. It has been confirmed that in many cases after dental implants are implanted, bone resorption (regression) of about 1 mm occurs inward from the surface of the jawbone. Bacteria are one of the causes of this bone resorption. is known to enter the boundary with the dental implant from the jawbone surface side and erode the jawbone. It is valid.

The concentric groove (6) is located between the other end (3) and the terminal end of the thread groove (4), and may be formed as a concave or a plurality of minute convexes on the outer circumference of the implant fixture. However, at least one or more grooves may be provided on the outer periphery of the implant fixture.

In order to improve the perforability of the truncated cone portion, it is more effective to have a self-tapping groove (7) near the truncated cone portion (2) (Figs. 6 and 7). In order for the self-tapping groove (7) to function effectively when inserted into a drilled hole, it is preferable that at least the length of the self-tapping groove (7) is equal to or longer than the length of the truncated cone (2).

In addition, in order to accurately embed the implant fixture at a desired angle, when inserting the implant fixture into the drill hole, it is necessary to insert the notch of the thread on the side of the self-tapping groove and the drill hole at multiple places and the implant fixture. The contact is preferably axisymmetric with respect to the central axis of the thread, i.e. the number of self-tapping grooves (7) is preferably a divisor of the number of threads of the thread.

The flank angle of the thread formed by the thread groove (4) can be 30°, which is the same as that of a general thread, but by selecting the optimum flank angle, the drillability can be further improved. When the implant fixture is screwed into a slightly drilled hole at the time of implantation, a reaction force (104) to the force that spreads the surrounding bone is applied to the thread of the implant fixture as shown in FIG. If the component force (107) received by the posterior surface of the screw thread due to the reaction force (104) is greater than the component force (105) received by the apical surface of the screw thread, the implant fixture will receive a downward force from the bone. It becomes easier to receive and spiral. That is, the trailing flank angle (103) of the thread formed by the thread groove should be made larger than the tip flank angle (102). Considering the depth, lead, and pitch of thread grooves that are preferable for implant fixtures, the leading end flank angle (102) is preferably 2 to 20°, and the trailing end flank angle (103) is preferably 40 to 60°. is preferably

Also, the first thread groove and the second thread groove may have different leading end side flank angles (102) and trailing end side flank angles (103), respectively. and second thread grooves preferably have the same leading flank angle (102) and trailing flank angle (103).

The material of the implant fixture (1) is not particularly limited, and can be appropriately selected and used from known materials for implant fixtures. For example, metal materials such as pure titanium and Ti-6Al-4V alloy, and ceramic materials such as alumina and zirconia can be used.

The manufacturing method of the implant fixture (1) is also not particularly limited, and a known manufacturing method used for manufacturing implant fixtures can be appropriately selected. The outer surface of the implant fixture (1) can be produced, for example, by milling. The surface texture produced only by cutting (CAM) using a general precision machining program (CAD) usually has an arithmetic mean surface roughness Ra of about 0.2 μm or a ten-point average roughness Rz of 2.0 μm. and the value of this surface roughness depends only on the machining marks. Such surface properties are unsuitable for osseointegration with the jawbone. Even if Ra or Rz has a large value, it is not suitable for macrophages (proliferation) of cells simply because the height difference of the surface unevenness is large, and it is difficult to obtain early osseointegration.

Therefore, the surface of the implant fixture embedded in the jawbone needs to be moderately rough in order to obtain good osseointegration. Specifically, it is more preferable that Ra is 1.15 to 4.05 μm and Rz is 5.0 to 40 μm.

The surface treatment method for obtaining such a surface is not particularly limited, and a known surface treatment method can be appropriately selected and used. , hydroxyapatite thermal spraying, titanium thermal spraying, or a coating treatment such as calcium phosphate.

FIG. 6 shows an example in which the dental implant fixture of the first embodiment of the internal fitting type is provided with a cuff portion (8). A dental implant fixture can also be similarly provided with a cuff (8).

INDUSTRIAL APPLICABILITY The dental implant of the present invention can be widely applied regardless of the state of the jawbone and the oral environment, and also meets the requirements for dental implants required for both one-stage and two-stage procedures. Although it is possible to treat difficult cases, it is also useful for patients because it can be performed in a short healing period. Therefore, the present invention can be widely used in the field of dental implants.

1 implant fixture 2 truncated cone portion 3 cylindrical portion 4 thread groove 5 mechanical portion for supporting the dental prosthesis 6 concentric groove 7 self-tapping groove 8 cuff portion 100, 101 thread groove inclination angle 102 distal flank angle 103 rear End side flank angle 104 Reaction forces 105, 106 received by the implant fixture Component forces 107, 108 received by the surface on the leading end side of the thread Component forces received by the surface on the trailing end side of the thread

Claims (12)

A dental implant fixture having an implant portion to be implanted in a jawbone,
The implanted part implanted in the jawbone has a truncated cone part and a cylindrical part at the bottom of the truncated cone part, and the truncated cone part and the cylindrical part of the implanted part are the same. articulated on the rotating shaft,
2, 3 or 4 thread grooves having the same lead and pitch and different phases from at least the truncated cone portion to the other end of the cylindrical portion;
At least one first thread groove of the cylindrical portion has a first gradually decreasing depth shape in which the depth gradually decreases from the truncated cone portion side of the cylindrical portion to the other end portion side,
A dental implant fixture characterized in that the depth of the other second thread groove of the cylindrical portion is a second gradually decreasing depth shape different from the gradually decreasing depth shape of the thread groove or a constant depth shape that is a constant depth. Cha. A dental implant fixture having an implant portion to be implanted in a jawbone,
The implanted part implanted in the jawbone has a truncated cone part and a cylindrical part at the bottom of the truncated cone part, and the truncated cone part and the cylindrical part of the implanted part are the same. articulated on the rotating shaft,
2, 3 or 4 thread grooves having the same lead and pitch and different phases from at least the truncated cone portion to the other end of the cylindrical portion;
The cylindrical portion has a first gradually increasing root diameter shape in which the root diameter formed by at least one first thread groove of the cylindrical portion gradually increases from the truncated cone portion side to the multi-end portion side of the cylindrical portion,
A dental implant fixture characterized in that the root diameter of the other second thread groove of the cylindrical portion is a second gradually increasing root diameter shape different from the root diameter shape or a constant root diameter shape that is a constant root diameter shape. Cha. 3. A dental implant fixture according to claim 1 or 2, characterized in that the outer shape of the cylindrical portion having the thread groove is constant. 3. A dental implant fixture according to claim 1 or 2, wherein all thread grooves of said truncated cone have the same depth shape. 3. The dental implant fixture according to claim 1, wherein all the thread grooves on the other end of the cylindrical portion have the same depth shape and the same root diameter shape. 3. Dental implant fixture according to claim 1 or 2, characterized in that all thread grooves have the same thread depth at the transition of the cylindrical portion to the frusto-conical shape. The line connecting the bottoms of the first gradually decreasing depth shape or the first gradually increasing root diameter shape of the at least one first thread groove in the cylindrical portion is the axis on the side of the truncated cone portion on the plane including the axis of the cylindrical portion. 3. A dental implant fixture according to claim 1 or 2, characterized in that it forms a straight line that intersects with . 3. The dental implant fixture according to claim 1, wherein the depth ratio of the thread grooves at the most different positions in the cylindrical portion is 5:6 to 5:18. 3. A dental implant fixture according to claim 1 or 2, wherein the leading flank angle of the threads of all thread grooves is 2-20° and the trailing flank angle is 40-60°. 3. The dental implant fixture according to claim 1, wherein the other end of the cylindrical portion of the implanting portion has a circular groove coaxial with the cylindrical portion. 3. The dental implant fixture according to claim 1, further comprising a columnar cuff portion coaxial with the columnar portion at the other end of the columnar portion of the implanting portion. A dental implant comprising a dental implant fixture according to any one of claims 1 to 11 and an integral or separate abutment.

Images