DE29619974U1 - Test device for determining the risk of caries - Google Patents

Description

Applicant: m & m Dental-Medizin GmbH
Representative: Dr. Schoenen
15.11.1996

Utility model application

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Test device for determining the risk of caries

The invention relates to a test device for taking samples to determine the risk of caries in a human or animal subject, with a sterilely packaged elongated carrier that has a sterile absorbent material, in particular dry medical cotton wool, on one end. In particular, the absorbent material consists of cotton.

To prevent caries, regular check-ups at the dentist are necessary. In general, a six-monthly check-up is recommended. However, this recommendation is often not followed because the medical layperson (patient) does not know his or her personal risk of caries and often mistakenly believes that this risk is low for him or her.

One way for laypeople to obtain information about their personal caries risk in a simple, quick, convenient and inexpensive way is described in WO 96/18902 A1. To carry out the test, the test subject inserts a carrier with an absorbent material into their mouth. The absorbent material, which consists in particular of dry medical cotton wool, is coated with a coating that stimulates the metabolism of the microorganisms in the oral cavity. As a result, the pH value drops. After the coating dissolves, the saliva or at least part of the saliva is absorbed by the absorbent material. To determine the caries risk, the test subject briefly rolls the moist absorbent material back and forth on a test strip until the strip changes color. By comparing the color with

Applicant: m & m Dental-Medizin GmbH

A color scale next to the test strip shows the pH value and thus the risk of caries, which is particularly high at a low pH value.

Although the known test device allows a general statement about the risk of caries, information about the type and number of microorganisms in the oral cavity and thus about the specific causes of the risk of caries would be desirable, since the individual types of microorganisms have a different function in the development of caries.

In many cases, the exact diagnosis and the selection of the right therapeutic agents depend on identifying the pathogens and determining the drugs that are effective against them. Today, medical science aims to use a drug that is particularly effective against the pathogen in question, as this causes the least amount of stress for the patient and best ensures the success of the treatment. The increasing development of resistance in bacteria, especially against the broad-spectrum antibiotics that are frequently used, makes this measure necessary in many cases.

Since most dental practices are not equipped for bacteriological tests and are not allowed to carry out the tests for hygiene reasons, bacteriological tests should be carried out in special laboratories. The quality of the bacteriological tests is decisively influenced by the quality of the material that is made available to the laboratory for testing. In addition to errors in taking samples, the transport of the test material in particular has proven to be a significant weak point. Unless the transport times are very short, the pathogens must therefore be protected against drying out and oxidation damage by a suitable transport medium. Drying out is usually prevented by immersion in water.

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embed in a suitable semi-solid agar medium and the oxidation damage is achieved by a nitrogen or carbon dioxide-containing protective gas, so that the pathogens are still fully usable after 6 to 12 months when stored at normal temperatures between 6 and 20 ⁰ C 5 .

Saliva tests and aids for taking saliva for analysis purposes have been known for a long time. One such method is described, for example, in DE 36 32 303 A1. Here, an elastic, absorbent, inert body is chewed by the test subject and then placed in a centrifuge tube with a perforated bottom.

However, like many other known procedures, the procedure is only carried out in the dentist's office. It must be ensured that no other germs, apart from the microorganisms of the oral cavity, reach the elastic body.

EP 0 418 739 A1 describes a device for taking saliva from the oral cavity. The device consists of an absorbent material, a pad, which is clamped into a groove in a plastic stick. To take the saliva, the stick is grasped and the pad attached to it is inserted into the oral cavity. After the pad has absorbed a sufficient amount of saliva, it can be stored in a container until the test is carried out.

The container consists of a centrifuge tube into which an inner tube is inserted. In order to insert the pad into the container without contamination with foreign germs, an additional aid is required, which consists of a small plate with an opening for the plastic stick. After removing the container cap and inserting the pad into the inner

Applicant: &tgr;&eegr; & m Dental-Medizin GmbH

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tube of the container, the plate with its opening is placed over the opposite end of the plastic rod until the plate rests on the edge of the opening of the container. When the plastic rod is withdrawn from the container, the pad is held back by the plate and thus removed from the rod. A liquid is then added that prevents the analysis result from being falsified even if the sample is stored for a long time, and the cap is placed on the container.

This relatively complicated procedure is not suitable for use by a layperson without the assistance of a dentist, especially since when the pad is placed in the container it must always be ensured that there is no contamination with foreign germs.

There is another, particularly important reason why this well-known method is less suitable for determining the risk of caries. A saliva sample taken during a dental examination has two major disadvantages. The relatively high level of saliva production during the course of a day, which is around 20 ml per hour, leads to a relatively low concentration of microorganisms in the oral cavity due to the antibacterial activity of saliva and the relatively high amount of saliva compared to when sleeping at night, when only 20 ml of saliva is produced in total over a 7-hour period. Although the growth rate of dental plaque is reduced at night, it can be concluded from this data that the destructive effect of cariogenic microorganisms is particularly pronounced during sleeping at night and that their concentration in the oral cavity is highest immediately after sleeping at night. 35

To determine the risk of caries, it is therefore not the saliva taken during the day that is important, but rather the saliva taken immediately after the subject has had a night’s rest.

Applicant: m & m Dental-Medizin GmbH 21-8a

taken saliva is interesting. It would therefore be advantageous if the test subject took his saliva without the help of a dentist and preserved the microorganisms contained therein himself until the sample is microbiologically analyzed. The known methods for collecting and analyzing saliva do not meet these requirements.

The known methods and test devices either require the assistance of a medical professional, as some methods are too cumbersome and complicated for a layperson and are therefore only suitable for analyzing saliva taken in a doctor's office. As already explained, however, a precise analysis of the saliva taken immediately after the test subject has had a night's rest is particularly desirable. The other known methods and test devices only indicate the presence of certain microorganisms or their metabolic products in general terms, but do not provide any information about the number of different microorganisms.

Further test methods and test devices for saliva are known from WO 92/16842 A1 and WO 95/02822 A1. However, here the saliva is not taken immediately after the subject has had a night's rest and the test devices do not have a transport medium to store the saliva for a longer period of time until it is analyzed.

The test device known from WO 95/27205 A1 has a test stick with a predetermined breaking point so that the handle can be removed after the saliva has been taken.

Finally, WO 95/02996 Al and WO 95/30484 Al describe further systems for collecting saliva samples. However, these are relatively complicated and expensive systems, which also do not contain a transport medium to transport the saliva sample to

Applicant: m & m Dental-Medizin GmbH _ .. ..

to preserve it for later analysis. The absorbent material used here also has no specific, predetermined absorption capacity for saliva.

The invention is therefore based on the object of developing a simple and cost-effective way to determine the risk of dental caries and its causes significantly more accurately.

This object is achieved according to the invention in the test device mentioned at the outset by a resealable container which contains a sterile transport medium and is suitable for receiving the carrier with the absorbent material, wherein the other end of the carrier is designed as a handle part which is located outside the container after the container containing the carrier and the absorbent material has been closed.

A few hours after taking the sample, the test subject can hand over the transport medium with the absorbent material used to his dentist, who will either analyse the sample himself or send it to a laboratory. The transport medium enables an analysis of the type and number of microorganisms in the oral cavity of the test subject, without the number of microorganisms and the relative frequency of the different types changing during the period, which is usually several hours, between taking the sample early in the morning and the microbiological determination. It is expressly emphasised that the transport medium mentioned is not a nutrient medium, because a significant change in the number of germs, which is typical for nutrient media, must not occur.

In the test method according to the invention it is possible to determine the type and concentration of microorganisms in the oral cavity without the test result being distorted by the presence of fresh saliva. In the current state of

Applicant: m & m Dental-Medizin GmbH

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With modern technology, however, such an examination can only be carried out if the dentist takes plaque from the space between the teeth and has it examined. In addition to the more complex step of taking the sample, the known method has the disadvantage that the microbiological conditions are only examined at a specific point in the mouth. In contrast, the method according to the invention enables these conditions to be recorded in the entire mouth, without any disruption caused by fresh saliva flow.

The analysis can be carried out using known microbiological methods. A microbiological laboratory determines the type and/or number of microorganisms on/in the absorbent material and the caries risk is determined using the results obtained.

The contamination of the saliva contained in the absorbent material with foreign germs during sampling is prevented by the carrier mentioned, as the medical layperson is not tempted to touch the absorbent material with his hands. To remove the absorbent material from his mouth, the test subject will instead grasp the carrier by its handle, which cannot come into contact with the transport medium. Important for convenient and quick introduction of the sample from the oral cavity into the transport medium is the suitability of the resealable container to also accommodate the carrier. In contrast to the state of the art, sterile aids for stripping the absorbent material from the carrier are not required according to the invention. In this way, contamination of the sample between removal from the oral cavity and introduction into the transport medium is avoided, even when the sample is taken by an untrained layperson, without any special additional measures being necessary.

Applicant: m & m Dental-Medizin GmbH

An exact, reproducible statement about the concentration of the different types of microorganisms in the oral cavity is achieved by the fact that the absorbent material has a certain, predetermined absorption capacity for saliva, which is in particular 0.8 to 1.2 ml of saliva with an absorption period of about 2 minutes.

In a particularly preferred embodiment of the invention, the handle part of the carrier is designed as a closure cap for the resealable container. To introduce the sample into the transport medium, it is therefore only necessary for the test subject to open the container for the transport medium and insert the carrier with the absorbent material into this container. Since he only touches the closure cap and thus avoids contact with the absorbent material and the other parts of the carrier, a high level of security against contamination of the sample with foreign germs is ensured.

Because the carrier with the sterile absorbent material must also be sterilely packaged until use, it is preferred if the carrier with the absorbent material is packaged in a second container, this container being tightly closed by the aforementioned closure cap.

In a further embodiment of the invention, the test subject, who may be a layperson with varying degrees of skill and training, is relieved of the need to touch the parts of the carrier that come into contact with the transport medium or the inside of the container with his hands, even if he handles it very clumsily. For this purpose, the closure cap protrudes from the container opening when the container is closed.

A sufficient surface for the fingers of the subject to remove and replace the closure is

Applicant: m & m Dental-Medizin;Gjfli>H .1 .&Idigr; ."*..

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if the closure cap protrudes at least 5 mm from the container opening.

The proposed design of the closure cap attached to the carrier ensures that only the part that is on the outside when the container is closed is contaminated with foreign germs. The entire absorbent material and all parts of the carrier and the closure cap that are inside the container with the transport medium do not come into contact with foreign germs during the transfer from the oral cavity into the transport medium, without the test subject having to be particularly skilled or in an assistive position during this process.

Known gel-like or liquid compositions suitable for this purpose can be used as transport media. The transport medium for microorganisms is preferably intended and suitable for gram-negative, gram-positive and anaerobic bacteria.

In particular, the transport medium contains, in addition to water, 0.2 to 1 wt.% agar,

0.1 to 0.3 wt.% meat extract,
0.01 to 0.1 wt.% sodium chloride,

0.01 to 0.05 wt.% potassium chloride,

0.01 to 0.05 wt% calcium chloride, 0.01 to 0.05 wt% magnesium chloride, 0.05 to 0.2 wt% sodium thioglucolate and 0.2 to 1 wt% sodium glycerol phosphate.

The mixture preferably has a pH of 7.3 ± 0.1 at 25 ⁰ C.

Depending on the intended purpose, a redox indicator such as methylene blue or resazurin can be added to the mixture, which indicates through its color whether the transport medium contains oxygen.

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If only certain pathogens are to be examined, the addition of selectively acting antimicrobial additives such as vancomycin, kanamycin, nystatin or trimethoprim can prevent the growth of pathogens of no interest, which may be introduced as contamination by incorrect sampling.

Preferably, the carrier is coated with a mass that is soluble in saliva and stimulates the metabolism of the microorganisms, in particular a sugar-like substance or other carbohydrates, and optionally also with a sugar substitute, whereby the mass is chosen so that it does not influence the flow of saliva. In particular, a starch content is advantageous because it does not stimulate the flow of saliva. The addition results in a weak supply of nutrients, which obviously promotes the persistence of the pathogens, but without initiating growth and thus proliferation.

Preferably, the mass is designed as a coating for the absorbent material, whereby the coating completely encloses the absorbent material. The absorbent material only absorbs the saliva and the microorganisms present in the oral cavity when part of the coating or even the entire coating has already dissolved and a certain waiting time has elapsed during which the microorganisms have reacted to the ingredients of the mass in the desired manner.
30

In order to make it easier for the test subject to observe the waiting time required for the reaction of the microorganisms, it is further suggested that the composition and quantity of the mass have been chosen in such a way that when the mass has completely dissolved in the saliva, the minimum time required to trigger the reaction of the microorganisms has elapsed. If the test subject therefore determines that the mass has completely dissolved,

Applicant: m & m Dental-Medi&zgr;in GmbH 21-8a *· ;♦·. .

the carrier is removed and placed into the container with the transport medium.

It is further proposed that the composition and amount of the mass have been chosen such that it dissolves in the oral cavity over a period of 1 to 10 minutes, preferably 2 to 5 minutes.

It is also advantageous if the layer (coating) consists of a mass that essentially consists of the ingredient that stimulates the metabolism of the microorganisms and fat as a binding agent. Such a coating can be applied to the absorbent material in a particularly economical manner in the mass production of the test device.

Alternatively, it is proposed that the mass consist of 17 to 45 wt.% glucose,
8 to 45% by weight gelatin,

0 to 70% by weight preservative, 2 to 10% by weight sucrose and
0.2 to 0.3 wt.% starch
consists.

Preferably, the mass is designed as a coating for the absorbent material with a thickness of 0.1 to 0.5 mm, in particular from 0.1 to 0.2 mm. In this design, it is ensured that after the complete dissolution of the coating, a waiting time of 2 to 5 minutes has been observed.

The consumer's acceptance of the test device is improved if the mass also contains flavorings. Examples include the flavors of lemon, lime, peppermint and eucalyptus.

In the following, an embodiment of the invention is explained in more detail with reference to a drawing which shows a sterile

Applicant: m & m Dental-Medizin GmbH

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packaged carrier with the absorbent material in the resealable container with a gel-like transport medium in longitudinal section.

A wooden test stick, the carrier 1, has a cotton ball 2, the absorbent material, at one end, the upper end in the figure. The medical cotton is covered with a neutral, pleasant-tasting mass 4 that does not promote saliva secretion. 10

After the saliva has been taken, the test stick is placed in a glass tube 5. A closure cap 6 with two ring-shaped sealing lips 7 arranged one behind the other and molded onto an inner sleeve 3 is connected to the end of the test stick 1 that is opposite the cotton ball 2. The closure cap 6 protrudes about 10 mm beyond the opening 8 of the glass tube 5 in order to form a comfortable gripping surface. The profiling of the outside of the gripping surface in the longitudinal direction, which is indicated by a few lines 9, makes it easier to remove and insert this closure cap 6 connected to the test stick 1, so that it is not necessary or advisable for the user to touch the stick 1 or the absorbent mass 2 with his hands or another object. 25

The resealable container 5 provided in the test device also contains a gel-like transport medium 10. The container 5 is secured air- and liquid-tight with the closure cap 6.
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The transport medium is composed as follows: 5 g agar,

2 g meat extract,
0.5 g NaCl,
0.2 g KCl,
0.1 g _CaCl2 ,
_0.1MgCl2
1.0 g sodium thioglucolate,

Applicant: m & m Dental-Medizin GmbH

10 g sodium glycerol phosphate and water to 1000 g.

The pH value of this gel-like transport medium is 7.3 at 25 ⁰ C.

Claims (15)

1. Test device for taking samples to determine the risk of caries in a human or animal subject, particularly suitable for carrying out the method according to one of the preceding claims, with a sterilely packaged elongated carrier (1) having at one end a sterile absorbent material (2), in particular dry medical cotton wool, characterized by a resealable container (5) which contains a sterile transport medium (10) and is suitable for receiving the carrier (1) with the absorbent material (2), the other end of the carrier being designed as a handle part which is located outside the container after the container (5) containing the carrier and the absorbent material has been closed. 2. Test device according to the preceding claim, characterized in that the absorbent material (2) has a certain, predetermined absorption capacity for saliva, which is in particular 0.8 to 1.2 ml of saliva with an absorption period of about 2 minutes. 3. Test device according to one of the preceding claims, characterized in that the handle part of the carrier (1) is designed as a closure cap (6) for the resealable container (5). 4. Test device according to the preceding claim, characterized in Applicant: m & m Dental-Medizin GmbH ** 2i-8a ·: :.. that the carrier (1) with the absorbent material (2) is packed in a second container, this container being tightly closed by the closure cap (6).
5 5. Test device according to claim 3 or 4, characterized in that the closure cap (6) protrudes from the container opening when the container (5) is closed. 10 6. Test device according to the preceding claim, characterized in that the closure cap (6) protrudes at least 5 mm from the container opening.
15 7. Test device according to one of the preceding claims, characterized in that the transport medium contains, in addition to water, 0.2 to 1 wt.% agar, Contains 0.1 to 0.3% by weight meat extract, 0.01 to 0.1% by weight sodium chloride, 0.01 to 0.05 % by weight potassium chloride, 0.01 to 0.05% by weight calcium chloride, 0.01 to 0.05% by weight magnesium chloride, 0.05 to 0.2% by weight sodium thioglucolate and 0.2 to 1% by weight sodium glycerol phosphate. 8. Test device according to one of the preceding claims, characterized in that the carrier (1) is coated with a mass (4) which is soluble in saliva and stimulates the metabolism of the microorganisms, in particular a sugar-like substance or other carbohydrates, and optionally additionally with a sugar substitute, wherein the Applicant: m & m Dental-Medizin GmbH 21-8a ·: :I! Mass (4) is selected so that it does not influence the flow of saliva. 9. Test device according to claim 8,
characterized in that the mass (4) is designed as a covering for the absorbent material (2), wherein the covering (4) completely encloses the absorbent material (2). 10. Test device according to claim 8 or 9, characterized in that the composition and amount of the mass (4) have been selected such that when the mass is completely dissolved by the saliva, the minimum time for triggering the reaction of the microorganisms has elapsed. 11. Test device according to the preceding claim, characterized in that the composition and amount of the mass (4) have been selected such that it dissolves in the oral cavity during a period of 1 to 10 minutes, preferably 2 to 5 minutes. 12. Test device according to one of claims 8 to 11, characterized in that the layer (4) consists of a mass which is essentially composed of the ingredient which stimulates the metabolism of the microorganisms and fat as a binding agent. 13. Test device according to claim 11, characterized in that the mass consists of 17 to 45 wt.% glucose,
8 to 45% by weight gelatin,
0 to 70% by weight preservative, 2 to 10% by weight sucrose and Applicant: m & m Dental-Medi&zgr;in GmbH 0.2 to 0.3 wt.% starch
consists. 14. Test device according to one of claims 9 to 13, characterized in that the mass is designed as a coating for the absorbent material with a thickness of 0.1 to 0.5 mm, in particular 0.1 to 0.2 mm. 15. Test device according to one of claims 8 to 14, characterized in that the mass (4) additionally contains flavorings.