A design method for increasing the bonding area and the anti-rotation of an abutment based on geometric parameters

Abstract

This invention relates to the field of dental implant abutment design technology, specifically disclosing a design method for increasing abutment bonding area and anti-rotation performance based on geometric parameters. The method includes: constructing a frustum-shaped abutment model with a central screw channel and defining the abutment's geometric parameters; calculating the theoretical bonding area of ​​an abutment without a axial groove; introducing an axial groove design on the abutment's axial surface to ensure it does not affect the abutment's structural strength; calculating the absolute increase and relative gain rate of bonding area brought about by the axial groove; analyzing the influence of various abutment design variables on the bonding area through a full factorial experimental design; and providing quantitative suggestions for abutment design and axial groove optimization in different clinical scenarios based on the analysis results. This invention establishes a parameterized abutment model, systematically analyzes the influence of abutment geometric parameters on the theoretical bonding area, and introduces an axial groove as an auxiliary retention structure to quantify its bonding area gain effect, thereby improving anti-rotation performance and providing a theoretical basis for clinical abutment selection and personalized design.

Description

Technical Field

[0001] This invention relates to the field of dental implant abutment design technology, specifically to a design method that increases the abutment bonding area and anti-rotation properties based on geometric parameters. Background Technology

[0002] Implant restoration has become a routine treatment for edentulous or missing teeth, and its long-term success rate largely depends on the stable and durable retention between the restoration and the implant. Currently, implant restoration retention methods are mainly divided into two categories: screw retention and adhesive retention, each with its own advantages and disadvantages. Screw retention facilitates the removal and maintenance of the restoration, but carries the risk of screw loosening or breakage, and screw channels may affect the aesthetic appearance of the restoration. Adhesive retention offers better aesthetic continuity, is relatively simple to operate, and distributes stress through the adhesive layer; however, its core challenge lies in obtaining and maintaining sufficient adhesive retention force to prevent restoration detachment.

[0003] The magnitude of adhesive retention force depends primarily on two factors: the adhesive strength of the adhesive itself and the effective bond area between the restoration and the abutment. As the core component of the adhesive interface, the theoretical cementation area (TCA) of the abutment serves as a fundamental parameter for predicting retention force. The geometric design parameters of the abutment, such as diameter, height, and degree of polymerization, directly determine the available bond area. Previous in vitro experiments have shown that increasing the abutment diameter, height, or decreasing the degree of polymerization all contribute to improved retention force, primarily by expanding the effective bond area.

[0004] However, the aforementioned idealized design principles face significant challenges in clinical practice. Patients often have limited target restoration space (TRS): for example, insufficient gingival distance restricts the increase in abutment height; requirements for transgingival contours and soft tissue aesthetics limit the expansion of abutment diameter; and to achieve a common path of insertion or to accommodate tilted implant placement, sometimes a larger axial-wall convergence is necessary. These clinical limitations compress the effective area available for bonding, thereby increasing the risk of restoration retention failure.

[0005] Furthermore, existing adhesive retention methods are significantly inadequate in resisting restoration rotation. Traditional frustum-shaped abutments have smooth axial walls, relying primarily on the chemical adhesive force and limited static friction to resist external forces. However, in the complex biomechanical environment of the oral cavity, restorations (especially single crowns) are subjected to multi-directional lateral forces and rotational torques during chewing. When the abutment diameter is small, the degree of polymerization is high, or the adhesive height is insufficient, the lever arm of the adhesive interface resisting rotation is short and the constraint is weak, making the restoration prone to micro-rotation or gradual rotational loosening. This is a significant mechanism of adhesive restoration failure in clinical practice.

[0006] To address the problem of insufficient retention, clinicians and researchers have drawn on the concept of auxiliary retention forms used in natural tooth preparation, attempting to introduce structures such as axial grooves into implant abutments. These auxiliary structures can theoretically enhance retention by increasing mechanical interlocking and expanding surface area, and can also improve the ability to prevent damage from rotational shear forces.

[0007] Although the importance of abutment geometry and shaft groove for retention is widely recognized, existing technologies still have the following prominent defects and shortcomings:

[0008] The design is based on experience and lacks systematic quantitative guidance: the selection and design of abutments currently rely heavily on the physician's personal experience. There is a lack of a precise, quantitative theoretical model to predict and evaluate how geometric parameters (diameter, height, degree of aggregation) jointly affect the final bonding area.

[0009] The design of auxiliary structures is often ill-conceived, resulting in unclear gain effects: Although it is known that shaft grooves can enhance retention, current technology has not revealed the intrinsic relationship between the specific area gain brought by shaft grooves and the geometric parameters of the abutment itself. For example, for a abutment with a small diameter and low height, what percentage of actual gain does adding shaft grooves actually bring? Is its design limited by space? These questions have no clear answers, leading to the design of shaft grooves being somewhat arbitrary and unable to achieve personalized optimal design.

[0010] Therefore, there is an urgent need in this field for a theoretical method and design guidance system that can systematically quantify the relationship between abutment geometry parameters and bonding area, and accurately evaluate the contribution rate of auxiliary fixation structures (such as axial grooves) in different design scenarios. This will help shift the design of implant abutments from experience-based reliance to precise calculation, providing clinicians with a scientific basis for decision-making when facing complex cases, thereby fundamentally improving the long-term stability and success rate of implant restoration. Summary of the Invention

[0011] The purpose of this invention is to address the aforementioned problems in implant abutment design by providing a design method based on geometric parameters to increase the bonding area and anti-rotation properties of the abutment. By comprehensively analyzing the influence of the abutment geometry and axial groove design on the bonding area and anti-rotation capability, this invention provides a theoretical basis for clinical abutment selection and personalized design under complex clinical constraints, thereby improving the adhesive retention of the prosthesis.

[0012] This invention is achieved through the following technical solution:

[0013] This invention provides a design method for increasing the bonding area and anti-rotation properties of abutments based on geometric parameters, comprising the following steps:

[0014] Step 1: Construct a frustum-shaped base model with a central screw channel and define the geometric parameters of the base;

[0015] Step 2: Calculate the theoretical bonding area of ​​the shaftless trench abutment;

[0016] Step 3: Introduce a shaft groove design on the axial surface of the base to ensure that it does not affect the structural strength of the base;

[0017] Step 4: Calculate the absolute increase in bonding area and relative gain rate brought about by the shaft groove;

[0018] Step 5: Analyze the influence of each design variable of the abutment on the bonding area through a full factorial experimental design;

[0019] Step 6: Based on the analysis results, provide quantitative suggestions for abutment design and shaft groove optimization in different clinical scenarios.

[0020] As a further aspect of the present invention, the geometric parameters of the base in step one include the bottom radius, the crown radius, the height, the degree of convergence, and the radius of the central screw channel.

[0021] As a further aspect of the present invention, the theoretical bonding area of ​​the shaftless groove base in step two specifically includes the lateral area of ​​the frustum and the area of ​​the annular region of the crown after removing the central screw channel.

[0022] As a further aspect of the present invention, step three specifically involves designing several shaft grooves on the axial surface of the base. The shaft grooves are grooves extending along the axial direction of the base, and the shaft grooves are evenly distributed along the circumference of the base to optimize the resistance to rotational torque.

[0023] As a further embodiment of the present invention, the shaft groove is located 1 mm from the root edge of the base, and the minimum distance δ between the bottom of the shaft groove and the wall of the central screw channel should satisfy: δ≥0.5mm.

[0024] As a further aspect of the present invention, in step four, the absolute increment of the bonding area ΔTCA = TCA add -TCAremove TCA add For the additional surface area of ​​the shaft groove, TCA remove This refers to the surface area removed from the base surface when forming the shaft groove.

[0025] As a further aspect of the present invention, in step four, the relative gain rate η = (ΔTCA / TCA) base ) × 100%, where ΔTCA is the absolute increment of the bonded area, and TCA base This represents the theoretical bonding area of ​​the shaftless groove base.

[0026] As a further aspect of the present invention, the additional surface area TCA of the shaft groove add =TCA side +TCA bottom TCA side TCA is the lateral surface area of ​​the shaft groove. bottom The area at the bottom of the shaft groove;

[0027] The surface area TCA removed from the abutment surface during the formation of the shaft groove remove =TCA top +TCA axial TCA top For the top area of ​​the shaft groove, TCA axial The reduced abutment wall area for preparing the abutment groove.

[0028] As a further aspect of the present invention, step five includes selecting the base radius, height, degree of polymerization, and presence or absence of an axial groove as design variables, setting several levels for each variable to conduct a full factorial experiment, and calculating the absolute increase in bonding area and relative gain rate under each combination.

[0029] As a further aspect of the present invention, step five also includes establishing a mathematical model between the theoretical bonding area and each design variable through multiple regression or machine learning methods, and drawing a response surface plot to intuitively display the influence trend and interaction of each variable.

[0030] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0031] 1. This invention establishes a parameterized geometric model of the implantation abutment, systematically analyzes the influence of geometric parameters such as the radius, height, and degree of aggregation of the abutment base on the theoretical bonding area, and introduces an axial groove as an auxiliary fixation structure to quantify its bonding area gain effect, improve anti-rotation capability, and finally provides an optimized design process that can be used for clinical guidance.

[0032] 2. This method can scientifically predict the bonding area and clarify the gain effect of the axial groove under different geometric parameters of the abutment, guiding the rational use of the axial groove auxiliary fixation structure in clinical practice. At the same time, the axial groove design can not only directly increase the surface area, but also form an effective mechanical lock at the bonding interface, significantly enhancing the anti-rotation ability of the restoration, preventing the restoration from rotating and loosening under functional load, and further improving the clinical reliability of the restoration. It is applicable to various implant systems and can assist doctors in optimizing the abutment design in limited restoration space and improving the long-term stability of the restoration. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0034] Figure 1 This is a schematic diagram of the base model in this invention, where (a) is an axonometric view and (b) is a sectional view;

[0035] Figure 2 This is a schematic diagram of the base model with shaft groove in the present invention, wherein (a) is an axonometric view and (b) is a cross-sectional view;

[0036] Figure 3 This is a schematic diagram of the side surface area of ​​the shaft groove in the present invention, wherein (a) is a schematic diagram from the base axle, and (b) is a schematic diagram from the base axle removing the body;

[0037] Figure 4 This is a schematic diagram of the upper and lower areas of the shaft groove in the present invention, wherein (a) is a schematic diagram from the axonometric projection of the base, and (b) is a schematic diagram from the top view of the shaft groove removed from the base;

[0038] Figure 5 This is a schematic diagram of the reduced abutment wall area due to the pre-grooved abutment in the present invention, wherein (a) is a schematic diagram from the abutment abutment and (b) is a schematic diagram from the abutment abutment removal volume.

[0039] Figure 6 This is a fitting diagram of the relationship between the theoretical bonding area and geometric parameters in this invention;

[0040] Figure 7 This is a fitting graph showing the relationship between the absolute increment of the bonding area and the geometric parameters in this invention;

[0041] Figure 8 This is a fitting graph showing the relationship between the relative gain rate of the bonding area and the geometric parameters in this invention;

[0042] Figure 9 This is a flowchart of the design method for increasing the bonding area and anti-rotation properties of the abutment based on geometric parameters in this invention. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0045] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0046] Please refer to Figures 1 to 9 The present application provides a design method for increasing the bonding area and anti-rotation properties of the abutment based on geometric parameters, which specifically includes the following steps:

[0047] Step 1: Establish a parametric abutment geometry model (e.g., Figure 1 (As shown).

[0048] Construct a 3D geometric model of a frustum-shaped abutment with a central screw channel, and define the following geometric parameters: base radius R (located at the implant connection end), coronal radius R... top (Located at the prosthesis connection end), height H (vertical distance from the bottom surface to the coronal side), convergence θ (angle between the axial wall and the vertical direction), and central screw channel radius r. c .

[0049] According to geometric relationships, the perihedral radius R top It can be calculated from the base radius R, height H, and degree of aggregation θ:

[0050] R top =R-Htanθ.

[0051] Meanwhile, a three-dimensional coordinate system is established with the central axis of the base as the Z-axis and the center of the bottom surface as the origin, which facilitates subsequent geometric calculations and parameter analysis.

[0052] Step 2: Calculate the theoretical bonding area (without shaft groove).

[0053] Theoretical bond area of ​​the abutment (TCA) base The area of ​​the crown annular region is composed of the lateral surface area of ​​the frustum and the area of ​​the crown annular region after removing the central screw channel. The calculation formula is as follows: TCA base =π( R + R top ) L +π( R top 2 - r c 2 ); where the length L of the generatrix of the frustum is: L = H / cosθ.

[0054] Step 3: Introduce a shaft groove as an auxiliary retention structure (e.g., Figure 2 (As shown).

[0055] One or more grooves are designed on the axial surface of the base. Each groove is a recess extending along the axial direction of the base. The circumferential distribution of the grooves is planned to optimize resistance to rotational torque. The grooves are evenly distributed circumferentially and are designed to be located 1 mm from the root edge of the base. The radius of the cutting tool used to form the grooves, i.e., the radius of the bur, is r. g To ensure the structural strength of the base, the minimum distance δ between the bottom of the shaft groove and the wall of the central screw channel should meet the following requirement: δ≥0.5mm.

[0056] Bonding area of ​​the axial groove abutment (TCA) groove The actual area is the sum of the theoretical bonding area of ​​the abutment and the newly added area of ​​the shaft groove, minus the original surface area lost by the abutment due to the formation of the shaft groove. The specific expression is:

[0057] ;

[0058] In the formula, TCA base The theoretical bonding area of ​​the shaftless groove abutment, TCA add For the additional surface area of ​​the shaft groove, TCA remove This refers to the surface area removed from the base surface when forming the shaft groove.

[0059] Step 4: Quantize the shaft groove gain effect.

[0060] Based on the constraint of the distance between the deepest part of the shaft groove and the outer wall of the central screw channel (δ=0.5 mm), the distance d between the center axis of the needle and the center axis of the base can be derived. The calculation formula is as follows: This distance d will be used for subsequent calculations of the cross-sectional dimensions of the shaft groove.

[0061] Based on the movement pattern of the needle, the surfaces of the axle groove can be divided into several parts, and the area of ​​each part can be calculated separately:

[0062] 1) Calculation of the side surface area of ​​the shaft groove (e.g.) Figure 3 (As shown)

[0063] Lateral surface area of ​​shaft groove (TCA) side It can be decomposed into two trapezoidal areas (TCA) trapezoid ) and the lateral surface area of ​​a semi-cylinder (TCA) rectangle ) and:

[0064] ;

[0065] The area of ​​the trapezoid is calculated as follows:

[0066] ;

[0067] l top With l bottom Let and represent the lower base of the trapezoid, respectively, and their values ​​can be calculated using trigonometric functions and the Pythagorean theorem:

[0068] ;

[0069] ;

[0070] The radius of the semi-cylinder is the needle radius r. g When unfolded from the side, it becomes a rectangle with a length of H-1 and a width equal to half the circumference of the sewing needle. Its area is calculated as follows:

[0071] ;

[0072] 2) Calculation of the area of ​​the upper and lower parts of the shaft groove (e.g.) Figure 4 (As shown)

[0073] Top area of ​​shaft groove (TCA) top It can be viewed as a combination of semicircles, rectangles, and sector-shaped regions:

[0074] ;

[0075] TCA (Tube Groove Bottom Area) bottom The calculation principle is the same, and the corresponding formula is:

[0076] ;

[0077] 3) Calculation of the reduced abutment wall area due to the preparation of the abutment groove (e.g.) Figure 5 (As shown)

[0078] Since the area of ​​the shaft wall removed during shaft groove preparation is an irregular and complex curved surface, it can be solved using integration. At any height z, the radius R(z) of the abutment is:

[0079] ;

[0080] At this height, the needle intersects with the base to form an arc length s(z), which is calculated using the following formula:

[0081] ;

[0082] The reduction in the area of ​​the abutment shaft wall by preparing a single shaft groove (TCA) axial This can be obtained through integration:

[0083] ;

[0084] Through mathematical derivation, the analytical expression for the above integral can be obtained. (TCA) axial The calculation formula is as follows:

[0085] ;

[0086] Changes in bonded area are evaluated using the absolute increase in bonded area (ΔTCA), calculated using the following formula:

[0087] TCA add =TCA side +TCA bottom ;

[0088] TCA remove =TCA top +TCA axial ;

[0089] ΔTCA=TCA add -TCA remove .

[0090] The change in adhesive area is evaluated by the relative gain ratio (η) of the adhesive area, and the calculation formula is as follows:

[0091] η = (ΔTCA / TCA) base ) × 100%.

[0092] Step 5: Parametric analysis.

[0093] 1) Full factorial experimental design: The base radius R, height H, aggregation degree θ, and presence or absence of an axial groove are selected as design variables. Several levels are set for each variable, and a full factorial experiment is conducted to calculate the results for each combination. TCA and η.

[0094] 2) Response Surface Analysis: Using multiple regression or machine learning methods, a mathematical model is established between the TCA and each design variable, and response surface plots are drawn (e.g., Figures 6-8 As shown in the figure, the influence trends and interactions of each parameter are intuitively displayed.

[0095] Figure 6 This is a set of schematic diagrams showing the trend of the theoretical bond area (TCA) of the abutment as a function of the base radius R, height H, and degree of polymerization θ. The diagrams visually illustrate the correlation between the bond area and R, H, and θ.

[0096] Fitted surface analysis shows that the degree of polymerization has a relatively small impact on the theoretical bond area, and its additive effect on the base radius and height is also small. The base radius has a significant impact on the bond area; a larger base radius results in a larger bond area. Height also enhances the effect of radius, meaning that the greater the abutment height, the more significant the impact of the abutment radius on the bond area. Similarly, abutment height also has a significant impact on the bond area; increasing the height increases the bond area, and the base radius also enhances the height effect.

[0097] Figure 7 and Figure 8 This is a schematic diagram illustrating the relationship between the absolute area increment and relative area gain of the shaft groove and various geometric parameters. It is used to explain the quantitative relationship between the gain effect and each parameter.

[0098] The fitted surface shows that the trend of the absolute area increment is similar to that of the bonded area itself. The degree of polymerization has a relatively small impact, while the base radius and height can significantly affect the absolute area increment, and there is a superposition effect between the two. Figure 7 However, the relative gain exhibits a more complex parameter dependence. The effects of the base radius and height change with their values. When the height and radius are large, the relative gain is less sensitive to changes in these two parameters, while the change in relative gain is more pronounced as the height and radius decrease. Furthermore, the base radius and height moderate the aggregation degree effect. When the height and radius are large, the aggregation degree has little effect on the relative gain, while when the height and radius are small, the aggregation degree has a stronger effect on the relative gain. Unlike the absolute increment, when the base radius increases, the effect of height on the relative gain decreases, and when the height increases, the effect of base radius on the relative gain decreases. Figure 8 ).

[0099] Step Six: Provide Design Guidance

[0100] Based on the analysis results, quantitative suggestions are provided for abutment design and shaft groove optimization in different clinical scenarios.

[0101] This application establishes a parametric model for calculating the bonding area of ​​implant abutments, systematically quantifies the influence of geometric parameters and axial groove design on the bonding area, and proposes an axial groove optimization design method based on geometric parameters. This method is applicable to the design and evaluation of abutments for various implant systems, including implant crown restorations and screw hole veneer restorations, both for anterior and posterior teeth. However, this design scheme can also be used in other cases where auxiliary retention features are required based on the specific restoration condition. Auxiliary retention features, including but not limited to axial groove retention features, are set on the abutment surface. These axial groove retention features are located on the buccal / lingual or mesiodistal surfaces, and their circumferential arrangement aims to provide optimal anti-rotational constraints. They are symmetrical and parallel to each other, aligned with the direction of the insertion path, and the minimum distance between the deepest part of the axial groove and the wall of the central screw channel is at least 0.5 mm. Of course, the axial groove morphology can also be replaced with other auxiliary retention structures (such as grooves, textures, etc.). The model can be extended to analyze complex structures such as multi-axial grooves and asymmetric abutments.

[0102] Specifically, the following examples are optimized designs for low-height abutments with limited gingival distance, suitable for clinical scenarios where the vertical height of the restoration space in the posterior tooth region is limited (e.g., about 3-4 mm).

[0103] The geometric parameters of the base designed in this embodiment are: height H is approximately 3.0 mm, and bottom radius R is approximately 2.5 mm. To achieve maximum retention within the limited height, a relatively small cohesion θ of approximately 3° is adopted. Based on this, a shaft groove is added to the axial surface of the base. The depth of the shaft groove is designed to ensure that the mechanical strength of the base body is not compromised, and to ensure that the bottom of the shaft groove maintains a minimum distance δ of not less than 0.5 mm from the wall of the central screw channel.

[0104] Calculations using the parametric model of this application show that, compared to traditional abutments of the same geometric dimensions but without an axial groove design, the design of this embodiment can achieve a significant increase of approximately 7%-8% in theoretical bonding area. This solution effectively solves the clinical problem of insufficient retention force in low abutments, and provides a reliable enhancement method, especially for cases where adhesive retention is necessary and the gingival distance is insufficient.

[0105] Specifically, the following embodiments are for retention enhancement design of small-diameter abutments in the aesthetic zone, which are suitable for scenarios with high aesthetic requirements and small implant platform diameter, such as the maxillary anterior tooth region.

[0106] Due to the aesthetic constraints on the gingival contour, the abutment diameter needs to be strictly controlled. In this embodiment, the abutment base radius R is designed to be approximately 2.0 mm (corresponding to a diameter of approximately 4.0 mm), and the height H is designed to be approximately 5.0 mm to meet the basic bonding height requirements. The degree of convergence θ can be slightly larger, approximately 5°, to facilitate placement of the restoration and create a good aesthetic transition. To address the issue of insufficient inherent retention caused by the small diameter and high degree of convergence, this embodiment features three shallow but sufficiently axially extended axial grooves evenly distributed circumferentially on the abutment axial surface. This increases the bonding area while also enhancing the ability to prevent damage from rotational shear forces.

[0107] Computational analysis shows that this "multi-shallow-groove" design can increase the total bonding area of ​​the abutment by approximately 6%-7% while ensuring the wall thickness in the weak areas of the abutment and avoiding stress concentration. Furthermore, the three axial grooves form evenly distributed resistance points in the circumferential direction, resulting in a balanced and significant improvement in the restoration's resistance to rotation (rotational torque) in all directions. This is particularly suitable for anterior teeth susceptible to lateral forces, effectively preventing restoration torsion. This design balances aesthetic and retention requirements and is suitable for single-crown restorations in anterior teeth.

[0108] Specifically, the following embodiments are designed to maximize the retention efficiency of large abutments, and are suitable for scenarios where there is ample space in the posterior tooth restoration area, allowing the use of large abutments, with the aim of pursuing the ultimate long-term retention stability.

[0109] This embodiment employs an optimal combination of geometric parameters: a large base radius R (approximately 3.0 mm), a sufficient height H (approximately 5.0 mm), and a very small degree of cohesion θ (approximately 1°), thereby maximizing the initial bonding area. Based on this superior geometry, two axial grooves are designed in this embodiment to further enhance the retention safety margin.

[0110] According to the quantitative evaluation of this model, under such ideal parameters, the axial groove design can bring a relative gain of more than 10% in bonding area, with an absolute increase of more than 10 mm². This means that even under long-term exposure to large occlusal forces or slight degradation of adhesive performance over time, the restoration can still maintain extremely high retention, greatly reducing the risk of restoration loosening, and is particularly suitable for molar areas where long-term stability is extremely important.

[0111] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A design method for increasing the bonding area and anti-rotation properties of abutments based on geometric parameters, characterized in that, Includes the following steps: Step 1: Construct a frustum-shaped base model with a central screw channel and define the geometric parameters of the base; Step 2: Calculate the theoretical bonding area of ​​the shaftless trench abutment; Step 3: Introduce a shaft groove design on the axial surface of the base to ensure that it does not affect the structural strength of the base; Step 4: Calculate the absolute increase in bonding area and relative gain rate brought about by the shaft groove; Step 5: Analyze the influence of each design variable of the abutment on the bonding area through a full factorial experimental design; Step 6: Based on the analysis results, provide quantitative suggestions for abutment design and shaft groove optimization in different clinical scenarios; The shaft groove is located 1 mm from the root edge of the base, and the minimum distance δ between the bottom of the shaft groove and the wall of the central screw channel should satisfy: δ≥0.5 mm; In step four, the absolute increase in bonding area ΔTCA = TCA add -TCA remove TCA add For the additional surface area of ​​the shaft groove, TCA remove This refers to the surface area removed from the base surface when forming the shaft groove; In step four, the relative gain rate η = (ΔTCA / TCA) base ) × 100%, where ΔTCA is the absolute increase in adhesive area, and TCA base This represents the theoretical bonding area of ​​the shaftless trench abutment. Step five includes selecting the base radius, height, degree of polymerization, and presence or absence of shaft groove as design variables. Several levels are set for each variable to conduct a full factorial experiment, and the absolute increase in bonding area and relative gain rate under each combination are calculated.

2. The design method for increasing the bonding area and anti-rotation properties of the abutment based on geometric parameters according to claim 1, characterized in that, The geometric parameters of the base in step one include the bottom radius, the crown radius, the height, the degree of convergence, and the radius of the central screw channel.

3. The design method for increasing the bonding area and anti-rotation properties of the abutment based on geometric parameters according to claim 1, characterized in that, The theoretical bonding area of ​​the shaftless groove abutment in step two specifically includes the lateral area of ​​the frustum and the area of ​​the annular region of the crown after removing the central screw channel.

4. The design method for increasing the bonding area and anti-rotation properties of the abutment based on geometric parameters according to claim 1, characterized in that, Step three specifically involves designing several shaft grooves on the axial surface of the base. The shaft grooves are grooves extending along the axial direction of the base, and the shaft grooves are evenly distributed along the circumference of the base to optimize the resistance to rotational torque.

5. The design method for increasing the bonding area and anti-rotation properties of the abutment based on geometric parameters according to claim 1, characterized in that, The increased surface area TCA of the shaft groove add =TCA side +TCA bottom TCA side TCA is the lateral surface area of ​​the shaft groove. bottom The area at the bottom of the shaft groove; The surface area TCA removed from the abutment surface during the formation of the shaft groove remove =TCA top +TCA axial TCA top For the top area of ​​the shaft groove, TCA axial The reduced abutment wall area for preparing the abutment groove.

6. The design method for increasing the bonding area and anti-rotation properties of the abutment based on geometric parameters according to claim 1, characterized in that, Step five also includes establishing a mathematical model between the theoretical bonding area and each design variable through multiple regression or machine learning methods, and drawing response surface plots to intuitively show the influence trend and interaction of each variable.

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