THE RELATED ART

Invention in general relates to a chewing simulator conducting in vitro wearing and fatigue tests on tooth implants and composite restorative materials made from polymer, ceramic and similar materials.

Invention particularly relates to a chewing simulator capable to conduct two- body abrasive wearing, three-body abrasive wearing and thermal fatigue on tooth implants and composite restorative materials.

BACKGROUND OF THE RELATED ART

Today tooth implants and tooth materials such as composite restorative materials are exposed to mechanical fatigue in clinic tests during development of them. The purpose is to foresee the behaviours of developed implants or restorative materials caused by loads they are exposed to in the mouth, and thus to develop such material.

Test devices providing such mechanical fatigue in the related art actually fail to simulate the in-mouth tribological properties.

In order to simulate long-time stay of implants or restorative materials placed in human mouth in dentistry in laboratory environment, persistency of all parameters occurring on living tissue are important. Test results must be repeatable so as to fulfil the criteria stating 8 different wearing test methods which are specified under ISO standards and can be applied to tooth materials. When tribological properties in the mouth are considered, in addition to mechanical resistance, thermal fatigue should also be taken into account. Hot or cold liquids and solid food (tea, coffee, cola, meals etc.) consumed in daily life expose teeth, tooth implants and tooth materials such as restorative materials in the mouth to thermal fatigue.

A German application numbered DE102012105923 in the related art discloses a device measuring wear of a sample put on chewing simulator. It discloses a wear measuring device measuring amount of abrasion on a sample surface in the simulator modelled with chewing actions, and a load measurement device measuring load on the sample. Even if said chewing simulator offers an opportunity of testing close to reality by modelling chewing actions, it does not provide a realistic test simulator because it fails to meet other tribological properties in mouth and thermal fatigues.

Patent application numbered KR200101 1 1910 in the related art discloses a tooth abrasion simulator. Said patent document discloses conversion of rotation force from engine into linear motion and providing rotary motion by cam part thereafter. It discloses abrasion of teeth fixed to cam part with rotary movement. Although said tooth abrasion simulator performs chewing action by means of sliding and cam parts in its embodiment, it does not comprise components providing other tribological effects in mouth and thermal fatigues. In conclusion, developments have been made in chewing simulators and, therefore, new embodiments eliminating the above disadvantages and offering solutions to existing systems are needed.

PURPOSE OF THE INVENTION The present invention relates to a chewing simulator meeting the needs mentioned above, eliminating all disadvantages and providing some additional advantages.

Main purpose of the invention is to develop a chewing simulator conducting wearing, mechanic and thermal fatigue tests on tooth implants and composite restorative materials made from polymer, ceramic and similar materials.

Another purpose of the invention is to develop a chewing simulator controlled by computer to provide all parameters specified before testing at sensitivity specified under ISO standards and provide persistency.

A further purpose of the invention is to develop a chewing simulator comprising fluid cell providing contact of tooth implants and composite restorative materials with liquid in order to provide testing at tribological properties in mouth.

Another purpose of the invention is to disclose an embodiment providing liquid input and output to liquid cell in order to provide thermal fatigue.

In order to achieve all advantages mentioned above and to be understood better with the details given below, the invention is a chewing and thermal fatigue simulator having in its embodiment abrasive and thermal fatigue on tooth implants and composite restorative materials comprising

- at least an AC engine running the system by initial rotating driving,

- at least a reducer to recover drops that might occur in torque from said AC engine,

- at least a crank converting rotating motion from said reducer into linear motion,

- at least an arm transferring linear motion received from said crank downward, - at least a load carrying apparatus driven by motion from said arm and providing application of load onto sample,

- at least a ball tip apparatus connected to said load carrying apparatus and providing application of load onto sample,

- at least a step engine providing axial horizontal motion for providing convenient abrasion environment,

- at least a control unit controlling said step engine and AC engine, and

-at least a sample holder located under said ball tip apparatus and keeping sample fixed during testing and comprising,

- at least a liquid chamber located in a manner surrounding said sample holder and with top left open for access of said tip apparatus to the sample to be tested in said sample holder and allowing putting liquids of various temperatures therein,

- at least a liquid inlet providing liquid entrance into said liquid chamber to provide thermal fatigue,

- at least a liquid outlet to provide evacuation of particulates to be generated during testing and liquid from liquid chamber and connected to said liquid chamber.

The structural and characteristic features and all advantages of the invention will be understood better in the figures given below and the detailed description by reference to the figures. Therefore, the assessment should be made based on the figures and the detailed descriptions.

BRIEF DESCRIPTION OF FIGURES

In order to make the embodiment and additional members being subject of the present invention as well as the advantages clearer for better understanding, it should be assessed with reference to the following described figures.

Figure 1 is isometric view of chewing simulator of the invention. Figure 2 is front view of chewing simulator of the invention. Figure 3 is side view of chewing simulator of the invention.

Figure 4 is top view of chewing simulator of the invention.

REFERENCE NUMBERS

1. AC Engine

2. Reducer

3. Control unit

4. Arm

5. Primary Spindle

6. Load carrying apparatus

7. Ball tip apparatus

8. Liquid chamber

9. Step engine

10. Liquid inlet

1 1. Liquid outlet

12. Sample holder

13. Crank

14. Table

15. Lower stand

16. Mid-stand

17. Upper stand

18. Secondary spindle

19. Connection hose

DETAILED DESCRIPTION OF THE INVENTION

Repeatability of test results is inevitable criterion for fulfilment of said effective test method criteria. Otherwise, it is always needed to repeat the test with standard material or reference for wearing tests, which will not only increase time needed for tests but also reduce test reliability. Having computer control of this invention provides sensitivity and persistency of all test parameters set out prior to testing until end of test according to ISO standards.

In this detailed description, the preferred embodiments of the chewing simulator being subject of the invention have been described in a manner not forming any restrictive effect and only for purpose of better understanding of the matter.

Figure 1 shows an isometric view of chewing simulator. Figure 2, Figure 3 and figure 4 shows respectively front, side and top views of chewing simulator. Wearing, mechanical and thermal fatigue tests on tooth implants and composite restorative materials are conducted by means of components placed on lower stand (15). An AC engine (1 ) is fixed onto a table (14) located on the lower stand (15). Torque loss from rotating forces from AC engine (1 ) are recovered by a reducer (2) connected thereto. Speed of rotating motion transmitted from reducer (2) to the crank (13) is provided by control unit (3).

Rotating force from the crank (13) moves mid stand (16) up and down by means of two arms (4) located on the upper stand (17). Mid-stand (16) moves by sliding on two secondary spindles (18) fixed to upper stand (17) and lower stand (15) and extending through said mid-stand by motion from said arms (4). Also, upper stand (17) and lower stand (15) are fixed by help of four primary spindles (5) parallel to each other.

Load carrying apparatus (6) located in upper part of mid-stand (16) comprises load to be applied and ball tip apparatus (7) providing contact to sample. Ball tip apparatus (7) can apply the load received from load carrying apparatus (6) whereto connected to the sample placed in sample holder (12) section on same vertical level. Capability to adjust contact distance of ball tip apparatus (7) by half stroke sample (range of 0.1 - 9 mm) allows adjustment of waiting time. At one full stroke, mid-stand (16) moves upward and takes load carrying apparatus (6) and completes motion.

Creation of axial horizontal movement to provide eligible wearing setting is provided by step engine (9). Said step engine (9) can move said sample holder (12) on horizontal plane. The motion provided for occurrence of wearing in the same area on the sample to be tested all the times must be very sensitive. The sensitivity can be provided through step controller by the step engine (9). Parameters such as positioning control (step length) of step engine (9) to be integrated to test device, speed and working time is controlled by step engine driver card provided in control unit (3). In other words, control unit (3) controls both the AC engine (1 ) and the step engine (9).

Sample holder (12) where samples to be tested are placed is located inside liquid chamber (8). Upper part of said liquid chamber (8) is open for applying force onto sample by said ball tip apparatus. In addition, said liquid chamber (8) is placed to surround said sample holder (12) so that both mechanical and thermal wearing can occur. Upon start of device operation, load carrying apparatus (6) starts moving and load is started to be applied onto the sample by the ball tip apparatus (7). Liquid chamber (8) comprises at least one liquid inlet (10) so that working conditions are not influenced by particulates leaving from sample surface as a result of wearing and that thermal fatigue effects can be tested.

Liquid flowing provided from said liquid inlet (10) can be provided by help of hot or cold liquids, However, the liquid is hot water in a preferred embodiment of the invention. Use of other liquids is also possible in order to provide in- mouth tribological properties. Liquid chamber (8) also stores water in its chamber in thermal fatigue tests. The liquid chamber (8) comprises at least a liquid outlet (1 1 ) in order to keep temperature of water under control and evacuate the particulates generating during testing,

In a preferred embodiment of the invention, said liquid inlet (10) and liquid outlet (1 1 ) can be located not on liquid chamber (8) but a separate area. In such case, liquid flowing can be provided by means of a connection hose (19) and a pump.

After placement in the sample holder (12) apparatus chewing speed and other test parameters of the sample to be tested, can be adjusted from control unit (3) connected to computer. In a preferred embodiment of the invention, said reducer (2) has worm gear rotation feature.

In a preferred embodiment of invention, said control unit (3) is PLC based so that system is not influenced by electronic noise that might occur during testing.