JPH04150849A - Dental implant - Google Patents

Abstract

PURPOSE:To support an occlusion pressure by a method wherein an upper end of a blade forms a shoulder part with a largest area in a section at the right angle to a direction of projection of an abutment and a part therebelow is formed as tapered part with a thickness thereof reducing gradually so as to let an external circumferential surface of the shoulder section contact a groove internal surface of a surface bone. CONSTITUTION:A shoulder part 4 rectangular viewed in plane having a channel-shaped recess 6 on the top thereof formed at an upper part of a blade 2 integral therewith. A side recess 5 is formed both at right and left ends below the shoulder part 4 and it becomes shallower to be equal to a length of the shoulder part 4 near the lowest part thereof. A plurality of vent holes 7... are made on a plate surface of the blade 2 communicating through the front and the rear thereof. The blade 2 is formed to be a tapered part at an angle alpha so that a lower thickness thereof becomes less gradually from the shoulder part 4 the lower end as viewed in side. As a result, in a section at the right angle to a direction of projection of the abutment 3, the sectional area of the shoulder part 4 is the largest as compared with other parts. This achieves a higher life highly resisting to damage or the like to a bone with higher improvements in strength after burying.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dental implant that is embedded in a patient's jawbone and supports an artificial tooth.

[Prior Art] Dental implants, which are implanted into bone to fix dentures, have been gaining popularity in order to compensate for the loss of masticatory function and aesthetic problems caused by missing natural teeth. These dental implants are made of metal or ceramics, and as shown in Fig. 8, they include a wide blade 2' that is embedded in the bone, and a single or Consisting of a plurality of abutments 3', a small-diameter neck N is formed at the base of the abutment connected to the blade, and a safety stop S whose diameter expands stepwise is formed at the upper end of this neck. It is common for there to be. The one shown in Figure 8 is for the lower jaw, with the abutment on top and the blade on the bottom; however, the one for the upper jaw is the opposite, with the blade on top and the abutment on the bottom. It will be buried so that In conventional dental implants of this type, the entire blade is completely embedded within the alveolar bone sponge, with part of the neck portion touching the surface bone (cortical bone), and the safety stop portion touching the surface during additional implants. It comes into contact with the outer surface of the bone to prevent further invagination.

[Problems to be Solved by the Invention] The conventional dental implant described above has a small-diameter neck portion in contact with the hard surface bone, so even if this neck portion is integrated with the surface bone after implantation, the contact area is small. was small. For this reason, it is difficult to obtain sufficient strength to support the large forces in multiple directions during occlusion, such as vertical force, mesiodistal force, buccolingual force, etc., which may prevent bone regeneration or, in some cases, cause bone destruction. There was a problem with that.

[Means for Solving the Problems] In order to solve the above problems, the present invention employs the following configuration.

That is, the dental implant according to the present invention includes a blade to be embedded in the bone and an abutment for fixing a denture that protrudes upward from the blade, and the upper end of the blade has a cross section perpendicular to the protruding direction of the abutment. The shoulder portion has the largest area, and the portion below the shoulder portion is formed as a tapered portion where the wall thickness below the shoulder portion becomes gradually thinner.

[Operation] By drilling a groove in the patient's bone in advance with the same opening shape as the cross-sectional shape of the shoulder, and embedding the blade until the upper surface of the shoulder matches the upper edge of the groove, the outer peripheral surface of the shoulder Contacts the inner surface of the bone groove and supports occlusal pressure. Since the blade part is formed in a tapered shape such that the thickness of the lower part becomes gradually thinner, further burying is prevented.

[Examples] Examples of the present invention will be specifically described below with reference to the drawings.

FIG. 1 shows an example of this dental implant. This implant 1 includes a wide blade 2 and a plurality of (two in the illustrated example) rod-shaped abutments 3 that protrude upward from the blade.・Consists of -. The upper part of the blade 2 is integrally formed with a shoulder part 4 which is rectangular in plan view and has a gutter-like recess 6 formed on the upper surface, and as shown in FIG. Side recesses 5, 5 are formed in the. This side recess 5 becomes shallower as it goes downward, and is equal to the length of the shoulder portion 4 near the bottom. In addition, the lowest part of the blade 2 is rounded (R, R
' ) has been done. In addition, the plate surface of the blade 2 has a plurality of through holes 7 that pass through the front and back sides. -... is drilled. The through hole 7 is formed in a triangular shape that is wide at the bottom and narrow at the top (on the abutment side). The blade 2 is formed as a tapered portion having an angle α such that the thickness of the blade gradually decreases from the shoulder portion 4 to the lower end portion when viewed from the side. Therefore, in a cross section perpendicular to the protruding direction of the abutment 3, the cross-sectional area of the shoulder portion 4 is the largest compared to other portions.

The abutment 3 integrally protruding from the upper surface of the shoulder portion 4 is formed into a trapezoid that is narrow at the top and wide at the bottom when viewed from the front, and its base portion 3a has the same wall thickness as the shoulder portion 4.

This dental implant 1 is manufactured by electric discharge machining using, for example, a titanium alloy or the like as a material.

Figure 2 shows this dental implant 1 embedded in bone, with the lower part of the blade 2 embedded in the alveolar bone sponge 30 of the mandible, and the upper end line of the shoulder part 4 drilled into the surface bone 31. The height is almost the same as the upper edge of the groove 32,
The outer peripheral surface of the shoulder portion is in close contact with the inner wall surface of the groove 32 over almost the entire surface. In other words, since the cross-sectional area of the shoulder portion 4 is greater than the cross-sectional area of the lower blade, the blade can be inserted into the bone without any problem by drilling a groove with a shape and size that allows the shoulder portion 4 to fit into it. This is possible.

During actual surgery, in order to tightly fit the blade into the burial groove, a blade guide with the same shape is used, which is about 0.2 mm smaller in each direction than the external dimensions of the shoulder part of the implant, and a blade guide that is about 0.2 mm smaller in each direction than the external dimensions of the shoulder part of the implant. Using blade guides of the same shape that are smaller by about 2 mm, first cut a burying groove to fit the smaller blade guide, then enlarge the groove to fit the larger blade guide, and finally cut the actual blade. This involves multiple steps of mating. The blade guide is provided with a stepped portion called a removable stop for engaging a pulling device.

After embedding, the shoulder portion 4 and the surface bone are integrated with each other over time, and the spongy bones on both sides are joined through the through hole 7, forming a passage for nutritional supply and the like. In addition, the upper part of the meat covering the bone gradually covers the upper surface of the shoulder part, but since a groove-shaped recess 6 is formed in this part, the meat gets caught in this part and the implant is properly buried. Ru.

Figure 3 shows an implant for anterior teeth with only one abutment standing upright. Although the shape and dimensions are slightly different from those of the previous embodiment, the same parts are given the same numbers.

FIG. 4 shows a further different example, in which the lower end of the blade is formed in a convex shape when viewed from the front, and the side portions are straight. This implant is used for both upper and lower molars. FIG. 5 shows an implant for the lower jaw, in which the entire blade is formed in a downwardly convex arc shape when viewed from the front, and both sides are straight.

FIG. 6 shows an implant for the upper jaw, and the entire blade is formed in an upwardly convex arc shape in the opposite direction to the implant for the lower jaw. In any of the embodiments, the shoulder portion has a rectangular shape in plan view, and the outer diameter of the shoulder portion is greater than the outer diameter of the other portions. Note that these dental implants can be manufactured from metals such as pure titanium, titanium alloys, and ceramics.

[Effects of the Invention] As is clear from the above description, the dental implant according to the present invention is formed in such a shape that the outer peripheral surface of the shoulder portion is in close contact with the surface bone over almost the entire circumference, and Since it is formed into a wedge-shaped cross-section with a gradually thinning wall, its strength after implantation is greatly improved, resulting in a long lifespan that is less susceptible to bone damage.

[Brief explanation of drawings]

FIGS. 1(a), (b), and (C) show a front view, a top view, and a side view of one embodiment of the present invention; FIGS.
) are front and side views showing the implanted state of the dental implant, Figures 3 (a), (b), (C), and Figure 4 (
a), (b), (C), Figure 5 (a), (b), (C)
1. Figures 6(a), (b), and (C) are front views (a), top views (b), side views (C), right views, and Figures 7(a) and (b) of further different embodiments. is an explanatory diagram of a conventional dental implant.

Claims (1)

[Claims] (1) Comprising a blade embedded in the bone and an abutment for fixing a denture that protrudes upward from the blade,
The upper end portion of the blade is a shoulder portion having the largest area in a cross section perpendicular to the protruding direction of the abutment, and the lower portion thereof is formed as a tapered portion where the wall thickness below becomes gradually thinner. implant.