JPS5918649B2 - Bonding durability tester for dental veneers - Google Patents

Description

Detailed Description of the Invention The present invention relates to a bonding durability tester for dental veneers, which applies pressure to porcelain (porcelain), synthetic resin, etc. that has been built up and fired on a metal base in dental metal bond, etc. The present invention provides and discloses a testing machine characterized by applying pressure with a pressurizing body or relatively sliding pressure repeatedly multiple times with bodies in constant contact with each other.

In fact, in the dental field, there are so-called porcelain veneers that are made of fired and coated porcelain, and because these porcelain veneers can express the same color and light selection as natural teeth, they especially look like front teeth to people. It is used in many places.

The so-called porcelain work is completed by carefully performing various complicated manufacturing conditions and multi-step processes, but after it is placed in the patient's mouth, damage or breakage can occur in a relatively short period of time. The cause is completely unknown, and we cannot guarantee long-term durability, so we rely on the skill and intuition of skilled technicians. As illustrated in FIG. 9, the porcelain front crown has a porcelain 2 bond to a metal bond 1 of a metal crown cast using a nickel-chromium alloy or the like.
It is made by building up and firing multiple layers of Porcelain 2, but it is important for the product to ensure that the coating strength of Porcelain 2 is sufficient and that it will not peel or chip during use. It is also the point that determines whether it is good or bad.

This requires testing the seizure strength of porcelain, and this has also been published in the academic publications shown in Table 1.

As a conventional test method, Fig. 5 shows the main parts of an apparatus for testing the tensile strength of porcelain.
, after firing between the four end faces, the alloy bodies 4, 4 are pulled left and right as shown by the arrows to test the tensile strength of the porcelain 2, or as shown in Fig. After firing 2, the shear strength of Boselen 2 is examined by applying a load to the alloy bodies 4 as shown by the arrows, or
As shown in the figure, the tubular body of porcelain 2 is placed on a fixed base 8 in which an opening 7 is formed in the rod-shaped body 6, and the protruding lower end of the rod-shaped body 6 is pulled downward by a tensioning machine (not shown). In order to test the pull-out shear strength of the coated surface of the cylindrical body, and furthermore to test the bending strength as shown in Fig. 8, the porcelain 2 was built up on the fulcrums 9, 9, and the fired plate-like body was A method has been practiced in which the alloy plate 4 is positioned in the shape of a simple beam and pressed with a presser 10 from above the center.

An example of the results of a porcelain seizure strength experiment using these methods is shown in Table 2 below. The pullout shear test in Table 2 corresponds to the test method shown in FIG. 5, and the circular pure shear test corresponds to the test method shown in FIG. 4, respectively.

As seen from this table, the strength shows completely different values depending on the test method. These test methods use research specimens to study the seizure mechanism and seizure strength, so there is little correlation with the seizure strength of the clinical veneer itself, and they require extremely expensive Because testing equipment is used, testing can only be conducted at specific institutions. In addition to the above-mentioned test method, in order to investigate the thermal characteristics during the manufacturing process of the veneer, the porcelain veneer was heated to, for example, 100°C.
By repeating the process of heating the porcelain to 0°C, cooling it to 0°C, and then heating it again to 100°C several times, we can observe the presence or absence of cracks caused by thermal shock in the porcelain itself, and indirectly measure the seizure strength of the porcelain. In other countries, research is being carried out. However, the test method described above not only causes the measurement data to vary as described above, but also applies a one-time external force to the porcelain and examines the characteristics due to changes in thermal stress, so it is difficult to predict the lifespan of the clinical veneer crown itself. This is a test method that has little relation to durability and performance, and is a test method of pressurization or sliding pressure that is adapted to the actual usage of porcelain veneers, such as wearing it in the patient's mouth and performing repeated occlusions. Currently, this is not being implemented.

In addition, there is no established test method that can scientifically and objectively evaluate the durability and strength of dental veneers, and it is not only impossible to evaluate the manufacturing skills of the technicians who made the veneers; It is also difficult to control the quality of veneers. This is a situation that could even cause great damage to the patient. The present invention solves the above-mentioned problems with porcelain veneers and has developed an effective testing machine suitable for actual use. The present invention provides a bonding durability tester for dental veneers, which is characterized by repeatedly applying pressure or sliding pressure to the porcelain by keeping a pressurizing body in constant contact with the porcelain. That is, the present invention applies repeated pressure or sliding pressure to one or more layers of porcelain (clinical actual material) that is built up and baked on a metal base in dental metal bonding, etc., to evaluate its durability and strength. For the purpose of testing the seizure strength with a metal substrate, a test machine configured to repeatedly apply pressure or sliding pressure by keeping the pressurizing body in constant contact with the porcelain and repeatedly applying pressure multiple times. This is what I did.

Therefore, there are naturally various modes of implementation of the testing machine, including the one shown in the drawings as an example, including manual type, automatic type, vertical pressure type against porcelain, horizontal or This includes diagonal pressurization types and the like. Alternatively, by inserting various measurement elements that can measure the load repeatedly applied to the supporting and fixed side of the test object, it is possible to record the measurement history of the load applied during the test of the test object. It also includes those that can make necessary changes in the magnitude of the load that is repeatedly applied during the test according to a preset program. Hereinafter, the present invention will be explained in detail based on the embodiments shown in FIGS. 1 to 3.

In FIG. 1, a pressurizing body 15 at the tip of a pressurizing rod 14 that swings about a fulcrum 13 is placed on a mount crown 12 mounted on a sample stage 11. A spring 17 is stretched between the part and the tip of the crank arm of the crank mechanism 16, and the crank mechanism 16 is driven to keep the pressurizing body 15 in constant contact with the muzzle crown 12 to apply pressure repeatedly, and the number of repetitions is cumulatively counted. Measure with instrument 25.

In FIG. 2, the pressurizing body 15 at the lower end of the pressurizing rod 16, which is vertically arranged and guided so as to be slidable up and down, is placed on the muzzle crown 12, and the rotational force of the pressurizing rod 18 and the motor 19 is A spring 21 is interposed between the transmission rod 20 and the transmission rod 20 which is guided in the vertical direction, and the motor 19 is driven to keep the pressurizing body 15 in constant contact with the muzzle crown 12 to apply pressure repeatedly, and the number of repetitions is accumulated. Measure with a counter 25.

In FIG. 3, the muzzle crown 12 is mounted horizontally on the sample stage 11 on the elastic support 24, and the pressurizing body 15 at the tip of the pressurizing rod 22 arranged horizontally and guided in the front-rear direction is A transmission rod 23 that is brought into contact with the muzzle crown 12 and transmits the rotational force of the motor 19 is connected to the base end of the pressurizing rod 22, and the motor 19 is driven to bring the pressurizing body 15 into constant contact with the muzzle crown 12. and pressurize repeatedly,
The number of repetitions is measured by an integration counter 25.

In addition to the three embodiments described above, various mechanisms for applying pressure to the veneer crown 12 are conceivable.

Further, the shape of the pressurizing surface of the pressurizing body 15 can be changed according to the veneer crown 12, and an acute-angled shape is preferable in order to approximate the actual occlusal state, especially when testing sliding occlusion. Incidentally, in the above description, only an example is described in which the pressurizing body 15 is kept in constant contact with the veneer crown 12 and pressure is repeatedly applied.
In these embodiments, the sample stage 11 on which the veneer 12 is mounted is displaced in conjunction with the pressurization of the pressurizing body 15 to the veneer 12, and the pressurizing body 15 is moved relative to the veneer 12. Slide and pressurize.

The displacement of the sample stage 11 may be minute, and is actuated by a mechanical mechanism, pneumatic pressure, or hydraulic pressure based on the pressure applied by the pressurizing body 15, and is repeated in the same manner as pressurization to achieve sliding pressure. Furthermore, the following methods can be considered for organizing the data obtained using this test method. In other words, the data obtained by varying the amount of pressure and the amount of slippage and cumulatively measuring the number of repetitions until the veneer breaks under each condition is expressed as a curve. Data for determining durability performance can be obtained from the shape of the curve between the magnitude of pressure and the number of repetitions (which can also be expressed as a unit of time), and these results can also lead to the standardization of manufacturing conditions, load conditions, etc. It will be opened. As described above, the present invention is a method for applying pressure or sliding pressure using a pressurizing body repeatedly to a porcelain that has been built up and fired on a metal base such as a dental metal bond multiple times. This is a joint durability tester for crowns, and instead of the conventional testing method for porcelain, it is now possible to test porcelain by repeatedly applying pressure or sliding pressure, and it is possible to test the joint durability of porcelain after repeated use. It is now possible to conduct strength assurance tests to determine the long-term durability of the product in the form of a clinically actual product.

In addition, the present invention makes it possible to establish a test method that can scientifically and objectively evaluate the durability and strength of dental veneers. It also becomes possible to control the quality of the crown, and it becomes possible to provide dental treatment to patients with peace of mind.

[Brief explanation of the drawing]

Figures 1, 2, and 3 are front views of each embodiment of the dental veneer bonding durability tester according to the present invention, and Figure 4 is for organizing and examining the test results in accordance with this test method. Characteristic diagram of 5th
The figure is an explanatory diagram of the main parts of a conventional device for testing the tensile strength of porcelain, Figure 6 is an explanatory diagram of the main parts of a device that also tests shear strength, and Figure 7 is a diagram of the main parts of a device that also tests the pullout shear strength. FIG. 8 is an explanatory view of the main part of a device for testing bending strength, and FIG. 9 is a cross-sectional view of a porcelain veneer crown. 1... Metal base, 2... Porcelain,
15... Pressure body.

Claims (1)

[Scope of Claims] 1. Bonding of dental veneers, characterized in that a pressure body is constantly brought into contact with porcelain, etc., which is built up and fired on a metal base in dental metal bond, etc., to repeatedly apply pressure. Durability tester. 2. In dental metal bond, etc., the porcelain, etc. that has been built up and fired on a metal base is repeatedly pressurized with a pressurizing body in constant contact with the pressurizing body, and the veneer crown is attached by displacing the pressurizing body or in conjunction with the pressurizing body. 1. A bonding durability tester for dental veneers, characterized in that the pressurizing body is made to slide relatively on a pressurized surface such as porcelain by displacing a sample stand.