RU2849245C1 - Drill for preparing operation for installing dental implant (variations) - Google Patents

Abstract

FIELD: dental instruments; surgical instruments.

SUBSTANCE: invention is intended for use in dental implantation. When preparing for dental implant surgery, a drill containing a body with cutting grooves is used. The body contains a coronal part in the form of a truncated cone and an apical part in the form of a cone, or contains a coronal part in the form of a truncated cone, a middle part in the form of a cylinder and an apical part in the form of a cone. The edges of the coronal part of the body and the apical part of the body are made with a concave conical profile, and the cutting grooves are made in the form of a spiral and contain a cutting side made with the possibility of performing osteotomy of bone tissue, and a smooth side designed to perform osteocondensation of bone tissue, the connection between which is achieved by an arc profile. The coronal part of the drill body contains recesses located separately from the cutting grooves and designed to perform osteotomy of bone tissue.

EFFECT: increased stability of the dental implant after its installation and reduced trauma of the installation operation.

1 cl, 8 dwg, 1 tbl, 2 ex

Description

The invention relates to dental and surgical devices, in particular to instruments for implanting dental implants.

A two-section dental implant with self-tapping functionality is known. It is characterized by a tap cutting section with both cutting and chip removal functions, used to increase the bone contact area. To improve the anchoring of the threaded anchor section, the threaded cutting section includes a cutting head, a cutting cone, and a transition groove. The threaded anchor section includes a midsection of the anchor screw thread and is used to connect to an osseointegrated semicircular osseointegrated microthreaded section. This means that the implant has a conical cutting head from its lower end, and the lower end to the middle of the 1/3 length is distributed with multiple cutting edges and is symmetrically distributed along the centerline. The cutting cone of the chip removal groove, the middle part is a quasi-arc transition groove for chip removal and placement, and the upper part is the middle part of the anchor screw thread with deep thread for implant centering and initial fixation. The upper end consists of a semicircular bone connected to a micro-threaded part provided with a micro-thread in the form of a semicircular groove. [CN209770557U, published 12/13/2019].

The disadvantage of the analogue is the lack of elements for creating microperforation in the coronal zone, which impairs osseointegration, as well as uneven distribution of the load on the bone due to a single threaded structure, which together reduces the stability of the implant after its installation, and also increases the trauma of the surgery for its installation.

The closest technical solution is described in a HOLLOW-TIP COMPACTORY TOOL configured to rotate at high speed in both the compression and cutting directions to form a hole in a base material to achieve various effects. The rotating tool includes: a handle that establishes a longitudinal axis of rotation; the handle has a long shaft with an upper end and a lower end; a main body extending axially from the lower end of the shank; a main body having an upper end remote from the shank; and a plurality of grooves arranged around the main body, each groove having a cutting protrusion angle on one side, a cutting surface, and a uniform sealing surface defining a uniform sealing protrusion angle on the other side. Each groove has an axial length and a radial depth, and each groove is formed along one of its lengths having a continuous negative sealing angle, a trailing edge is formed between each pair of adjacent grooves, each of the trailing edges has a working edge along the cutting surface of the groove, and each working edge is substantially not limited by a cavity located in the main body, the cavity extends in the axial direction in the main body and opens through the upper end, and a plurality of projections are located on the upper end of the main body, and the projections are located around the opening of the cavity. [TW202042755A, 01.12.2020].

The disadvantage of the closest technical solution is the inability to create microperforation in the coronal zone, which reduces the stability of the implant installed after drilling the bone tissue.

The technical problem solved by the invention is to eliminate the shortcomings of analogues.

The objective of the claimed invention is to increase the stability of the implant and reduce the trauma of the operation.

The technical result consists in increasing the stability of the implant after its installation and reducing the trauma of the dental implant installation surgery.

The said technical result is achieved in that a drill for preparing an operation for installing a dental implant comprises a body and cutting grooves made on the body, wherein the body is made in the form of a coronal part made in the form of a truncated cone and an apical part made in a conical shape or in the form of a coronal part made in the form of a truncated cone, a middle part made in a cylindrical shape and an apical part made in a conical shape, wherein the edges of the coronal part of the body and the apical part of the body are made with a concave conical profile, and the cutting grooves are made in the form of a spiral and contain a cutting side made with the possibility of performing an osteotomy of bone tissue and a smooth side made with the possibility of performing osteocondensation of bone tissue, the conjugation of which is realized by an arc profile, wherein the coronal part of the drill body contains recesses located separately from the cutting grooves and made with the possibility of performing an osteotomy of bone tissue.

The drill used for preparing a dental implant placement surgery is characterized by the following images:

Fig. 1 shows a side view of the drill according to the first variant;

Fig. 2 shows a projection onto a drill according to the first variant;

Fig. 3 shows a general view of the drill according to the first variant;

Fig. 4 shows a front view of the drill according to the first variant;

Fig. 5 shows a side view of the drill according to the second variant;

Fig. 6 shows a projection onto a drill according to the second variant;

Fig. 7 shows a general view of the drill according to the second variant;

Fig. 8 shows a front view of the drill according to the second variant.

The figures show: 1 – body, 2 – cutting grooves, 3 – coronal part, 4 – apical part, 5 – middle part, 6 – cutting side, 7 – smooth side, 8 – depression.

In this application, increasing the stability of an implant after its installation means ensuring primary stability, i.e., immediate fixation of the implant after installation, ensuring secondary stability, i.e., accelerated and dense bone grafting after implant installation, as well as long-term functional stability due to resistance to fatigue loads, which are achieved through the geometry of the implant, the prevention of implant fractures, and the elimination of stress concentrators.

In this application, reduced trauma refers to a reduction in anatomical trauma by reducing the likelihood of microcracks and macrofractures in bone due to excessive pressure or vibration, as well as thermal damage, where overheating can lead to bone necrosis at temperatures above 47°C. Reduced trauma also refers to a reduction in surgical trauma, due, for example, to a reduction in the number of instruments used, as well as a reduction in biological trauma and clinical consequences due to a reduction in healing time and the risk of peri-implantitis.

According to the invention, a drill for preparing a dental implant placement procedure comprises a body 1 and cutting flutes 2. In the first embodiment, the body 1 of the drill is designed as a coronal portion 3 shaped like a truncated cone and an apical portion 4 shaped like a cone. The truncated cone of the coronal portion 3 ensures gradual penetration of the drill, eliminating jerking and minimizing damage to the cancellous and compact bone in the coronal zone (where the risk of collapse is particularly high). The conical apical portion 4 is self-centering, maintaining a predetermined trajectory, ensuring smooth taper and reducing friction in the deep layers of the bone, thereby reducing the risk of thermal necrosis and perforation of the implant bed wall. The drill's shape also creates a variable-density socket, where the apical cone creates a dense base for primary implant fixation, while the coronal truncated cone forms a funnel, facilitating implant positioning and improving masticatory load distribution. Thus, the proposed drill body shape, combined with its geometric characteristics, provides a comprehensive solution for reducing surgical trauma and increasing implant stability through optimized mechanical load distribution, improved surgical performance, and biomechanical benefits.

In the second embodiment of the drill for preparing dental implant placement, its body comprises a coronal section 3 shaped like a truncated cone, a middle section 5 shaped like a cylindrical section, and an apical section 4 shaped like a cone. The truncated cone of the coronal section 3 ensures gradual drill penetration, eliminating jerking and minimizing damage to the cancellous and compact bone in the coronal region (where the risk of collapse is particularly high). The presence of the middle section 5 and its cylindrical shape ensures the formation of a perfectly smooth cylindrical channel, which is critical for the tight fit of cylindrical implants and for the uniform distribution of masticatory forces. The cylindrical middle section 5 also acts as a guide, preventing drill deviation in cancellous bone and lateral runout when working in dense bone. The conical apical portion 4 is self-centering, maintaining the desired trajectory. This ensures a smooth taper and reduces friction in the deep bone layers, thereby reducing the risk of thermal necrosis and perforation of the implant bed wall. Furthermore, the drill's shape creates a bed with variable density, with the apical cone creating a dense base for primary implant fixation, and the coronal truncated cone forming a funnel, facilitating implant positioning and improving the distribution of masticatory loads. Thus, the proposed drill body shape 1, combined with its geometric characteristics, provides a comprehensive solution for reducing surgical trauma and increasing implant stability through optimized mechanical load distribution, improved surgical performance, and biomechanical advantages.

According to the invention, the edges of coronal portion 3 of body 1 and apical portion 4 of body 1 are designed with a concave conical profile. This means that the projection of coronal portion 3 and apical portion 4 of body 1 is designed with a concave conical profile rather than a straight or convex shape. This means that the lateral surface of apical portion 4 and coronal portion 3 of the drill forms a "cup-shaped" depression along the axis of rotation. The concave shape of these elements reduces friction and heat generation by reducing the contact area with the bone and creates microgaps for coolant circulation. As a result, the temperature in the drilling zone decreases by 15-20°C, which is critical for preventing necrosis. Furthermore, this geometry of these body parts optimizes the distribution of the load during drilling; the concavity creates point pressure zones instead of linear contact, which prevents microcracks in the cortical layer, and increases the accuracy of the bed geometry. This, taken together, significantly reduces the trauma of the implant placement surgery and positively affects the stability of the installed implant due to the controlled temperature during the surgery and the low error in the bed geometry.

According to the invention, cutting flutes 2 are designed in a spiral form and comprise a cutting side 6, capable of performing osteotomy of bone tissue, for example, when the drill is rotated clockwise, and a smooth side 7, capable of performing osteocondensation of bone tissue, for example, when the drill is rotated counterclockwise. Spiral cutting flutes 2 with differentiated sides (cutting and smooth) provide a comprehensive effect on bone tissue, which directly contributes to achieving the claimed technical result. When the drill is rotated clockwise, cutting side 6 effectively performs osteotomy—precisely dissecting bone tissue with minimal trauma. A sharp edge with an optimal sharpening angle ensures a clean, chip-free cut, preserving the bone microstructure. This is especially important in dense bone tissues, where precise, controlled preparation is required. Smooth side 7 of cutting flute 2, activated by counterclockwise rotation, performs the key function of osteocondensation. Its polished surface compacts the walls of the bone bed, creating optimal conditions for the primary stabilization of the implant. This approach is particularly effective in soft, spongy bones, where increased contact zone density is necessary. Furthermore, the arcuate connection between cutting side 6 and smooth side 7 prevents the formation of stress concentrators in the bone tissue. Differentiated bidirectional action allows the surgeon to sequentially perform two critical steps with a single instrument: first, precise shaping of the bed (during primary rotation), then its controlled compaction (during reverse rotation). This eliminates the need to change instruments, reduces surgical time, and reduces the risk of positional errors. Unlike traditional drills with unidirectional cutting flutes 2, the proposed design ensures a more predictable result regardless of the type of bone tissue. The technical effect is enhanced by synergy with other elements of the invention. The concave profile of the facets reduces the contact area with the implant bed walls, reducing friction during reverse rotation. The grooves 8 in the coronal part 3 work in conjunction with the smooth side of the grooves in osteotomy mode, cutting dense, compact bone and preventing overheating, creating uniform compaction across the entire depth of the preparation. This results in a unique combination of minimal procedural trauma and maximum primary implant stability, as confirmed by tests measuring parameters such as the implant stability coefficient and thermal impact.

Moreover, according to the invention, the cutting side 6 and the smooth side 7 of the cutting flute 2 are connected by an arc profile. The arc profile minimizes stress concentration in the transition zone. Unlike sharp angular connections, which can create localized overloads, the rounded radius ensures uniform distribution of mechanical loads across the entire working surface of the drill. This is especially important when changing the direction of rotation of the tool, when the cutting and compacting functions are alternately activated. This design also significantly improves the removal of bone chips. The smooth arc transition creates a continuous trajectory for the chip, preventing it from sticking and jamming in the working zone. During the primary rotation (osteotomy), the chip moves freely along the rounded profile to the spiral cutting flutes 2, and during reverse rotation (osteocondensation), the smooth side 7 effectively compacts the walls of the bed without the risk of contamination by bone particles. Thus, the arc profile of the interface between the cutting side 6 and the smooth side 7 is not simply a design feature, but a technologically sound solution that comprehensively improves the instrument's performance. It ensures gentle bone preparation, a consistently high-quality implant bed, and a predictable result during implant placement, which fully corresponds to the claimed technical result of the invention.

According to the invention, the coronal portion of the drill body contains recesses 8 located separately from the cutting flutes 2 and configured to perform osteotomy of bone tissue in the coronal zone during osteocondensation in the apical portion 4 and middle portion 5 of the drill. Recesses 8 in the coronal portion 3 prevent possible overheating of compact bone in the coronal portion and create additional microperforation of the bone tissue, which significantly improves the conditions for primary implant stabilization. Unlike traditional drills, which form smooth walls of the bed, the proposed design creates a system of microscopic cavities and protrusions of condensed cancellous bone, which increase the contact area between the bone and the implant being installed. This is especially important when working with soft cancellous bone tissue, where conventional preparation methods often do not provide sufficient primary fixation. The location of recesses 8 separately from the main cutting flutes 2 helps maintain the integrity and strength of the drill structure, preventing its possible destruction when working with dense bone structures. This design ensures uniform distribution of mechanical loads across the entire working surface of the instrument, significantly extending its service life and maintaining stable cutting properties throughout its entire service life. Biomechanically, the recesses 8 in the coronal portion 3 create controlled microperforation, which stimulates reparative processes in bone tissue without significantly disrupting its blood supply. This accelerates osseointegration and shortens the implant healing time. The shape and size of the recesses 8 are designed to ensure effective removal of bone chips, preventing their accumulation in the working area and associated tissue overheating. Clinically, this results in a significant improvement in primary implant stability, a reduction in surgical time due to a reduced number of required instruments, and a reduced incidence of postoperative complications associated with bone overheating or inadequate primary implant fixation. Thus, the proposed design of the coronal part of the drill with separate recesses represents a technologically sound solution that comprehensively improves both the osteotomy process and the long-term results of dental implantation.

Implementation examples

First example of implementation

A drill for preparing an operation for installing a dental implant, comprising a body 1 and cutting grooves 2 made on the body 1, wherein the body 1 is made in the form of a coronal part 3 made in the form of a truncated cone and an apical part 4 made in a conical shape, wherein the edges of the coronal part 3 of the body 1 and the apical part 4 of the body 1 are made with a concave conical profile, and the cutting grooves 2 are made in the form of a spiral and contain a cutting side 6 made with the possibility of performing an osteotomy of bone tissue and a smooth side 7 made with the possibility of performing osteocondensation of bone tissue, the conjugation of which is realized by an arc profile, wherein the coronal part 3 of the body 1 of the drill contains recesses 8 located separately from the cutting grooves 2 and made with the possibility of performing an osteotomy of bone tissue.

Second example of implementation

A drill for preparing an operation for installing a dental implant, comprising a body 1 and cutting grooves 2 made on the body 1, wherein the body 1 is made in the form of a coronal part 3 made in the form of a truncated cone, a middle part 5 made in a cylindrical shape and an apical part 4 made in a conical shape, wherein the edges of the coronal part 3 of the body 1 and the apical part 4 of the body 1 are made with a concave conical profile, and the cutting grooves 2 are made in the form of a spiral and contain a cutting side 6 made with the possibility of performing an osteotomy of bone tissue and a smooth side 7 made with the possibility of performing osteocondensation of bone tissue, the conjugation of which is realized by an arc profile, wherein the coronal part 3 of the body 1 of the drill contains recesses 8 located separately from the cutting grooves 2 and made with the possibility of performing an osteotomy of bone tissue.

To confirm the impact of the design of the claimed invention on increasing the stability of the implant after its installation and reducing the trauma of the dental implant installation surgery, a series of experiments were conducted, for which drill samples were manufactured, where:

Sample No. 1 – corresponds to the design of the drill described in the first example of implementation;

Sample No. 2 – corresponds to the design of the drill described in the second example of implementation;

Sample No. 3 – corresponds to the design of the drill described in patent CN209770557U, published on 13.12.2019;

Sample No. 4 – corresponds to the drill design described in patent TW202042755A, 01.12.2020.

Bone model for testing: Bovine rib (D1), decorticalized bovine ilium (D4).

The research was conducted in two stages:

Stage 1. Preparation of the bed:

Implantological physiosipencer (NSK Surgic Pro);

Rotation speed: 800-1200 rpm;

Cooling: physiological solution 25°C;

Depth: 10 mm (for all samples).

Step 2. Measuring parameters:

Bone temperature (IR thermometry);

Primary stability (ISQ, Osstell);

Microscopic analysis of the bed edges;

Micro-CT analysis of the nature of contact between implant and bone (NeoScan N80).

Results:

Thermal effect (max. temperature, °C):

Sample 1: 41.2±0.8 (D1), 38.5±0.6 (D4),

Sample 2: 40.8±0.7 (D1), 38.1±0.5 (D4),

Sample 3: 47.6±1.2 (D1), 43.8±1.0 (D4),

Sample 4: 45.3±1.0 (D1), 42.5±0.9 (D4),

where D1. Dense and homogeneous bone – cortical bone. The ratio of the compact to spongy layer is 2–1; D4. The cortical plate is not defined. Spongy bone is very porous – a thin cortical layer with a very porous spongy substance. The ratio of the compact to spongy layer is 0.5–1.5.

The initial stability (ISQ) is described in Table 1:

Table 1

Density Sample 1 Sample 2 Sample 3 Sample 4 D1 78.2±1.5 79.0±1.3 72.4±2.1 70.8±2.3 D4 68.5±1.8 69.2±1.6 62.7±2.4 60.3±2.7

Quality of bone-implant contact (%):

Samples 1-2: 89-92% uniform contact;

Samples 3-4: 76-81% uneven contact.

Thus, testing revealed that samples 1-2 had 18-23% lower heat generation compared to samples 3-4, 9-12% higher primary stability, and 2.3 times fewer microcracks in the cortical layer. However, in samples 3-4, localized overheating >47°C was observed in 78% of cases (risk of necrosis) and uneven contact density (CV = 24-28%). Thus, samples 1 and 2 significantly outperform samples 3 and 4 in all key parameters, demonstrating a significant increase in the stability of the implant installed after drilling bone tissue, as well as a reduction in surgical trauma when using drills in accordance with the claimed invention.

Claims (1)

A drill for preparing an operation for installing a dental implant, comprising a body with cutting grooves, wherein the body comprises a coronal part made in the form of a truncated cone and an apical part of a conical shape, or comprises a coronal part made in the form of a truncated cone, a middle part of a cylindrical shape and an apical part of a conical shape, wherein the edges of the coronal part of the body and the apical part of the body are made with a concave conical profile, and the cutting grooves are made in the form of a spiral and contain a cutting side made with the possibility of performing an osteotomy of bone tissue, and a smooth side made with the possibility of performing osteocondensation of bone tissue, the conjugation of which is realized by an arc profile, wherein the coronal part of the drill body contains recesses located separately from the cutting grooves and made with the possibility of performing an osteotomy of bone tissue.