JP2005257604A - Simple method and tool for determining caries risk - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for determining a caries risk of a subject quickly, simply and inexpensively. <P>SOLUTION: In the method, a period of time required to bring a prescribed volume of saliva to pass through a filter member is examined under a constant pressure, and fiterability of the saliva is evaluated, and the caries risk of the subject is determined from the fiterability. The more the saliva has mutans streptococcus number, sedimentary amount (mainly dental plaque) and viscosity value, the more the subject has caries risk. These factors act on the saliva so as to lower the filterability. Accordingly, if the saliva has a high caries risk, the filterability becomes worse. Therefore, the determination is carried out simply and quickly by evaluating the fiterability, without the need for a special system. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a caries risk determination method and a caries risk determination tool.

  In recent years, attempts have been made to determine caries risk in the oral cavity of humans and prevent caries. The risk of caries is determined by measuring the number of mutans streptococci in the saliva, the number of Lactobacillus bacteria, saliva properties such as saliva secretion, saliva viscosity and saliva buffering capacity, the amount of plaque adhering, the number of meals and the use of fluoride. This is performed by examining each inspection item such as a custom (see Non-Patent Document 1, for example). Among the above items, the number of mutans streptococci is said to be closely related to the caries risk, and measurement of the number of mutans streptococci is important for the determination of caries risk.

  The following methods have been developed as methods for examining the above items. The number of mutans streptococci and the number of Lactobacillus are measured by a culture method using a selective medium. For example, in the measurement of the number of mutans streptococci, a solid medium such as S. salivarius or bacitracin is used as a selective medium. ing. The saliva secretion amount is measured by collecting saliva secreted in a certain time in a measuring cup or the like. The saliva buffering capacity is measured by a method in which the pH after mixing a certain amount of acid and a certain amount of saliva is examined, and the color change of the pH indicator is examined. Lifestyles such as saliva viscosity, amount of plaque adhesion, number of meals and use of fluoride are carried out by visual inspection of dentists and patient interviews. In addition, when the amount of saliva secretion is small, it is said that the viscosity of the saliva tends to be high and the buffer capacity tends to be low.

  At some dental clinics, all of the above examination items have been examined, and attempts have been made to prevent dental caries by reducing the total caries risk in the patient's oral cavity to a certain level or less. (For example, refer nonpatent literature 1).

  A method for simply and inexpensively examining a plurality of physical properties of saliva has been proposed. In this method, the amount of saliva, viscosity, dryness and wetness of the oral mucosa can be measured by measuring the degree of saliva penetration into the support (see, for example, Patent Document 1).

Clinical Carriology, Takashi Kumagai, Ishiyaku Shuppan Co., Ltd. 1996 77 pages Japanese Patent Laid-Open No. 2000-329763

  However, the method of inspecting all of the above-mentioned inspection items requires a long time for the inspection, and is performed in combination with various inspection kits and devices, so that the dentist and patient are burdened with time and cost. Had a big problem. For example, in the culture method used for measuring the number of mutans streptococci, the culture requires a long time (about 2 days) and an expensive incubator. In addition, in the method of measuring saliva viscosity with a viscometer or measuring the amount of saliva precipitation (plaque) with the wet weight of the centrifuged precipitate, the apparatus is expensive and the measurement operation is complicated, so it is a busy dental practice. It was difficult to carry out at the clinic in the clinic. Therefore, a method that can easily and inexpensively determine the caries risk is desired.

  In the method for inspecting a plurality of physical properties of saliva in a simple and inexpensive manner, the amount of saliva, the viscosity, the dryness of the oral mucosa, and the wetness can be measured by measuring the saliva penetration to the support. However, this method does not take into account the number of mutans streptococci in saliva and the number of precipitates (mainly plaque), and there has been a demand for the development of a more accurate method for determining caries risk.

  From the above, a caries risk determination method that can easily and inexpensively determine caries risk has been desired. In particular, saliva properties such as the number of mutans streptococci in saliva, the amount of sediment (mainly plaque) in saliva, and the viscosity of saliva are considered to be closely related to the occurrence and progression of caries. A method that can easily and inexpensively determine the properties of saliva has been desired.

  The present inventors have continued intensive studies in view of the above problems. As a result, it was found that the filterability when saliva was filtered correlates with the number of mutans streptococci in saliva, the amount of sediment (mainly plaque) in saliva, and the viscosity of saliva. That is, the present inventors have found that the caries risk can be determined by an extremely simple method of examining the filterability when saliva is filtered, and have completed the present invention.

  That is, the present invention is a simple determination method for caries risk by evaluating the filterability of saliva. Another aspect of the invention is a caries risk determination tool comprising a filtering device in which a saliva supply chamber and a saliva discharge port communicate with each other via a filter medium and provided with a pressurizing means upstream of the saliva supply chamber.

  According to the caries risk determination method of the present invention, the number of mutans streptococci in saliva, the amount of sediment in saliva and the viscosity of saliva can be evaluated quickly, simply and inexpensively. Thereby, a subject's caries risk can be determined quickly, simply, and inexpensively.

  The caries risk determination method of the present invention is carried out by evaluating the filterability of saliva.

  The method for collecting the saliva used in the present invention is not particularly limited, and conventionally known methods for collecting stimulated saliva and unstimulated saliva can be used. In the method of chewing paraffin and gum for a certain period of time and discharging and collecting the secreted stimulated saliva into the container, the plaque on the tooth surface is peeled off and collected in the saliva by chewing the paraffin and gum. When examining the filterability of saliva, it is possible to determine caries risk considering the amount of plaque on the tooth surface. Further, in this method, since saliva is chewed for a certain period of time, the saliva is well agitated, and uniform saliva can be collected. For these reasons, a method of discharging and collecting stimulated saliva that has been chewed and secreted with paraffin or gum for a certain period of time is preferable because the risk of caries can be determined more accurately.

  In the present invention, the collected saliva is filtered with a filter medium, and the filterability at that time is examined. In the present invention, the filterability is an index representing the ease of saliva filtration. Examples of such filterability include time required for filtering a predetermined amount of saliva (filtering time), the amount of saliva that can be filtered per unit filter medium, or the filtration pressure when saliva is filtered. High filterability means that filtration is easy. At this time, the filtration time is short, the filterable amount is large, and the filtration pressure is low. Low filterability means that filtration is difficult. At this time, the filtration time is long, the filterable amount is small, and the filtration pressure is high.

  The saliva filtration time can be examined, for example, by measuring a time required when a predetermined amount (area or volume) of a filter medium is used and a predetermined amount of saliva is filtered under a predetermined filtration pressure. For example, when saliva is filtered using a predetermined amount of filter medium, the filterable amount can be checked by measuring the amount of saliva filtered until the filtration pressure reaches a predetermined value or the filter medium is clogged. . The filtration pressure can be examined, for example, by measuring the load or force applied to the pressurizing means when the saliva is filtered using a predetermined amount of filter medium, or by measuring the pressure during pressurization.

  In the present invention, the caries risk is determined by evaluating the filterability. That is, the greater the number of mutans streptococci, the greater the amount of sediment, and the higher the viscosity of saliva (at the same time, the buffering capacity tends to be lower), the lower the saliva filterability and thus the higher the risk of caries Therefore, the overall caries risk can be determined at a time only by evaluating the filterability.

  For example, in the method of measuring only the number of mutans streptococci, for example, there are many precipitates, and even if the viscosity of saliva is high, if the number of mutans streptococci is small, it is determined that the caries risk is small, According to the present invention, there are almost no such problems, and the determination method is excellent.

  The first factor that affects the filterability evaluated in the present invention is the number of mutans streptococci. The occurrence and progression of dental caries is considered to be closely related to oral mutans streptococci, which are caries attack factors, and the greater the number of mutans streptococci, the higher the caries risk.

  Here, mutans streptococci are Streptococcus mutans (Streptococcus mutans, serotype c, e, f), Streptococcus sobrinus (Streptococcus sobrinus, serotype d, g), Streptococcus crisetus (Streptococcus critus cc serotype). ), Streptococcus rattus (Serotype b), Streptococcus ferus (Streptococcus ferus, serotype c), Streptococcus macacae, serotype c h, Streptococcus serotype c , Serology, genetics It has been classified into seven different kinds of mold. Streptococcus mutans and Streptococcus sobrinus are mainly present in the human oral cavity. These bacteria adhere to the tooth surface via cell surface proteins such as Pac protein and produce sticky / insoluble glucan to form cariogenic plaque (plaque). The decalcification of teeth progresses due to the acid produced by various bacteria such as mutans streptococci in cariogenic plaques, and caries occurs and progresses. That is, mutans streptococci act as a caries attack factor. Further, when the number of mutans streptococci in the oral cavity is high, cariogenic plaque (plaque) is likely to be formed.

  The second and third factors that affect the filterability evaluated in the present invention are the deposits in saliva and the viscosity of saliva.

  The action of saliva, a protective factor against caries, is to neutralize mutans streptococci adhering to the tooth surface (washing action) and acids produced by various bacteria in cariogenic plaque (plaque) Action (buffer action).

  When saliva has a high viscosity, the fluidity of saliva in the oral cavity is low, and the cleaning and buffering actions described above are difficult to reach the tooth surface. When the amount of cariogenic plaque (plaque) on the tooth surface is large and the number of mutans streptococci is high, the plaque is blocked and the buffering action is difficult to reach the tooth surface. Since it is produced, it falls into a vicious circle in which the viscosity of saliva becomes higher and higher. That is, the greater the amount of precipitates in saliva such as dental plaque, and the higher the saliva viscosity, the higher the caries risk. In addition, it is thought that the reduction | decrease of the washing | cleaning effect | action and buffering effect by the viscosity of saliva reflecting the low saliva secretion amount and the low saliva buffering ability.

  As mentioned above, the greater the number of mutans streptococci, the greater the number of insoluble precipitates, and the higher the viscosity of saliva, the higher the risk of caries.Furthermore, these factors tend to decrease the filterability. Works. That is, if the number of mutans streptococci in saliva, the amount of precipitate (mainly plaque), and the viscosity of saliva are high, it can be said that the risk of dental caries in the oral cavity is high. On the contrary, if the number of mutans streptococci in saliva, the amount of precipitate (mainly plaque), and the viscosity of saliva are low, it can be said that the risk of dental caries in the oral cavity is low. In such a case, the filterability of saliva increases, and therefore the caries risk can be determined by evaluating the filterability of saliva.

  In the present invention, the shape and amount (area and volume) of the filter medium to be used are not particularly limited, and may be appropriately selected according to the amount of saliva to be used so that the filterability can be easily measured. The amount of saliva to be used is preferably 0.05 ml or more from the viewpoint of measuring the filterability with good reproducibility, and preferably 10 ml or less from the viewpoint of measuring the filterability in a short time using the minimum necessary filter medium. Since the secretion rate of stimulated saliva is usually 0.04 to 6 ml / min and there are some subjects who are difficult to collect saliva including infants, the amount of saliva used is so that the same measurement method can be applied to many subjects. 0.25 to 2 ml is particularly preferred.

  The pore diameter of the filter medium used in the present invention may be appropriately selected so that the filterability can be easily measured according to the saliva used, the material of the filter medium, and the amount of the filter medium. If the pore size of the filter medium is too small, depending on the amount of saliva and filter medium used, the filtration time will be too long, the filterable amount will be too small, the filtration pressure will be too high, or the measurement itself will be clogged. It can be difficult. On the other hand, when the pore diameter of the filter medium is too large, the filtration time may be too short, the filterable amount may be too large, or the filtration pressure may be too low, making it difficult to measure filterability. Since the filterability can be measured under an appropriate filtration time, filterable amount, or filtration pressure, the pore diameter of the filter medium is preferably 0.6 to 4 μm, particularly preferably 0.8 to 2 μm.

  The pore diameter of the filter medium is a value defined by the minimum particle diameter that can be retained by the filter medium when a test solution containing particles having a known particle diameter is naturally filtered with the filter medium. Such particles with known particle sizes include gelatinous precipitates such as metal hydroxides and precipitated silica, crystalline precipitates such as ammonium phosphomolybdate, calcium oxalate, lead sulfate and barium sulfate, red blood cells and platelets. Examples include blood cells such as Escherichia coli, bacteria such as E. coli, microorganisms such as yeast, various colloids, pollen, spores, tobacco smoke, and the like. The ability to hold the filter medium means that the filter medium holds 98% or more of particles having a known particle size contained in the test solution.

  In the present invention, as the material of the filter medium, any filter medium made of a conventionally known material can be used without limitation as long as it is a material capable of filtering saliva. Examples of the material of the filter medium include glass fibers; plastics such as polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polysulfone, polycarbonate, polyethylene, polypropylene, and polyamide; cellulose, nitrocellulose, acetylcellulose, and the like. The celluloses etc. of this can be illustrated.

  As the filter medium used in the present invention, a conventionally known membrane filter or depth filter made of the above materials can be used. As such a membrane filter, a porous film filter made of the above celluloses or plastics can be used. Examples of the depth filter include cellulose fiber filter paper, silica fiber filter paper, and glass fiber filter paper. Further, an aggregate produced by packing glass fiber filter paper, fine pieces of filter paper, particles of activated carbon or the like into a cartridge or by laminating a plurality of filter media can also be used as the filter media of the present invention.

  When a membrane filter is used, filtration becomes difficult when the surface layer of the filter medium becomes clogged, whereas when a depth filter or the above aggregate is used, filtration is performed using the entire volume of the filter medium. Therefore, when a filter medium having the same pore diameter is used, the amount of saliva that can be filtered per unit area tends to increase when a depth filter or the above-described aggregate is used. In order not to increase the area of the filter medium to be used more than necessary, it is preferable to use a depth filter or the above-mentioned aggregate. It is preferable to use a depth filter because it is easy to make a filtration device. Especially when glass fiber filter paper is used, the amount of saliva that can be filtered per unit area tends to be high for the same pore size. Therefore, it is particularly suitable.

  The filterability evaluation method in the caries risk determination method of the present invention is not particularly limited. However, the saliva supply chamber and the saliva outlet are provided in that they are extremely simple and quick and do not require a large device. It is preferable to use a caries risk determination tool that is communicated via a filter medium and includes a filtration device provided with a pressurizing means upstream of the saliva supply chamber.

  The filtration device will be described below with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of a filtration device used in the present invention.

  The filtration device includes a saliva supply main chamber 1 and a saliva outlet 2. The filter medium 3 is stored in a filter medium storage section 4, and the saliva supply main chamber 1 is connected to the filter medium storage section 4 by a connection section 5. Therefore, the saliva supply main chamber 1 and the saliva outlet 2 are connected to each other via the filter medium 3. This apparatus is a semi-enclosed system with no other openings other than the saliva discharge port 2 and a connection port to pressurizing means provided upstream of the saliva supply chamber 1 described later.

  In the present invention, the saliva supply chamber refers to all of the voids provided upstream from the filter medium in which a certain amount of saliva is stored. Therefore, a small space 6 for temporarily storing the saliva flowing into the filter medium accommodating portion is provided in the upper portion of the filter medium 3 in the filter medium accommodating portion 4, and this small space 6 is also saliva in the present invention. Part of the supply room. If necessary, the volume of all the saliva supplying the small space 6 can be stored, and a member corresponding to the saliva supply main chamber 1 may not be provided.

  Upstream of the saliva supply chamber 1 is provided with a pressurizing means comprising a syringe 9 composed of a syringe outer cylinder 7 and a plunger 8. As the pressurizing means, any conventionally known pressurizing means can be used without limitation as long as it has a function of pressurizing the inside of the apparatus. As such a pressurizing means, various manual instruments such as a syringe, a dropper, and a rubber ball, and various apparatuses such as a pressurizing pump and a cylinder can be used. The method of using the above various manual instruments as the pressurizing means is preferable because the operation is simple.

  A negative pressure means can be installed in the saliva outlet 2 so that the inside of the filtering device can be in a negative pressure state with respect to the outside of the device. As such negative pressure means, various manual instruments such as a syringe, a dropper, and a rubber ball, and various devices such as a vacuum pump and an aspirator can be used. Compared with the method using negative pressure means, pressure filtration is preferable because it enables more efficient filtration.

  The shape and material of the filter medium storage portion 4 are not particularly limited, and the shape may be appropriately selected according to the shape of the filter medium 3. For the purpose of preventing deformation and breakage of the filter medium 3 during pressurization, a plate-like structure having various pattern structures such as radial, grid, and dot on the upper or lower surface of the filter medium 3; Porous material; Fiber material such as glass fiber or polypropylene nonwoven fabric may be interposed. Further, a filter aid such as activated carbon or filter paper powder can be added to the upper surface of the filter medium 3 for the purpose of controlling filterability so that it can be measured in an appropriate measurement range, or a glass filter, polypropylene nonwoven fabric, etc. It is also possible to install a prefilter.

  FIG. 2 is a side view showing another embodiment of the filtration device used in the present invention. In this filter device, almost no space is formed above and below the filter medium 3 in the filter medium storage section 4, and the tip of the syringe 9 as a pressurizing means can be directly attached to and detached from the upper surface of the filter medium storage section 4. The saliva supply chamber is formed in the inner space of the syringe outer cylinder 7. Such an apparatus is preferable because of its simple structure.

  Of course, the shape of the filtration device is not limited to FIGS.

  The caries risk determination method of the present invention when the tool having the structure shown in FIG. 1 is used is as follows. That is, first, saliva is supplied to the saliva supply chamber 1. This supply operation is appropriately performed by removing a connection portion with the syringe 9 from the saliva supply main chamber 1 and then supplying a predetermined amount of saliva to the saliva supply main chamber 1 using an instrument such as a pipette. Good. Next, the saliva is flowed down to the filtration membrane 3 and subjected to pressure filtration using a pressurizing means such as natural filtration or pressurizing the inside of the apparatus by pressing the plunger 8 in the syringe 9. The caries risk can be easily determined by measuring the filterability of saliva during filtration. 2 is the same as the above except that the plunger 8 in the syringe 9 is removed from the outer cylinder 7.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by a following example.

Example 1 [Measurement of salivary filterability and determination of caries risk]
(1) [Measurement of the number of mutans streptococci in saliva by collecting saliva and culturing]
Eight different subjects were chewed with the gum for 5 minutes, and the secreted saliva was discharged into a sterile container.

  0.5 ml of the obtained saliva is collected, subjected to ultrasonic treatment at 40 W for 10 seconds, and then appropriately diluted, and 50 μl is solid as Mits Salivarius bacitracin (hereinafter sometimes referred to as “MSB”). It added on the culture medium and it culture | cultivated for 48 hours under 37 degreeC and anaerobic conditions. The number of colonies generated on the MSB solid medium was counted, and the number of mutans streptococci was calculated as number / ml from the dilution rate of saliva.

  In addition, 0.5 ml of the obtained saliva was collected to obtain 10,000 r. p. m, centrifuged for 2 minutes, the supernatant was removed, the saliva-derived precipitate (mainly plaque component) was collected, and its wet weight was measured.

  Moreover, the sterilization container which collect | recovered saliva was shaken, and the viscosity of saliva was visually determined in three steps, smooth, normal, and sticky.

(2) [Measurement of filterability using a filtration device]
A glass fiber filter paper GA-100 (Toyo Filter Paper Co., Ltd., retained particle diameter: 1.0 μm) is used as a filter medium, and a syringe filter 10 having an effective filtration area of 1.1 cm ² (the diameter of an effective filtration surface of the filter medium is 1.2 cm) is used. A prototype was prepared and a syringe 9 (Terumo, 2.5 ml) was set to produce a filtration device having the structure of FIG.

  Pull out the plunger 8 from the filtration device, add 0.5 ml of saliva collected in Example 1 (1) into the syringe outer cylinder 7, attach the plunger 8, and then push down the plunger 8 under a predetermined finger pressure. The saliva was filtered by pressurizing the inside of the syringe 9 (about 2 atm). The filtration time required to filter the entire 0.5 ml saliva was measured.

(3) [Determination of caries risk]
The eight subjects of Example 1 (1), mutans streptococci concentration is less than 1 × 10 ⁵ cells / ml in saliva, 1 × 10 ⁵ cells / ml or more in less than 5 × 10 ⁵ cells / ml, 5 * 10 ⁵ / ml or more, less than 1 * 10 ⁶ / ml, 1 × 10 ⁶ / ml or more, classified into 4 levels, scored 0, 1, 2, 3 respectively (SM score) .

  The eight subjects of Example 1 (1) are classified into three stages such that the wet weight of the precipitate derived from saliva is less than 20 mg / 0.5 ml, less than 30 mg / 0.5 ml, and 30 mg / 0.5 ml or more, Each was scored 0, 1, 2 (precipitation score).

  The eight subjects of Example 1 (1) were scored as 0, 1 and 2 respectively for the viscosity of saliva, smooth, normal and sticky (viscosity score).

  The caries risk score for each subject was calculated as the sum of the mutans streptococcal score, saliva precipitation score, and saliva viscosity score.

  The measurement result of the filtration time obtained in Example 1 (2), the number of mutans streptococci in saliva obtained in Example 1 (1), the wet weight of the precipitate in saliva, and the viscosity of saliva. Compared. The results are shown in Table 1.

  The measurement result of the filtration time obtained in Example 1 (2) was compared with the caries risk score obtained in Example 1 (3). The results are shown in Table 2.

  As shown in Table 2, the saliva filtration time measurement result correlated well with the caries risk score. By using the caries risk determination method of the present invention, the number of mutans streptococci in saliva, the amount of precipitate in saliva, and the caries risk reflecting saliva viscosity can be quickly determined (the time required for saliva filtration is (Within 30 seconds), it was easy and inexpensive.

This figure is the said schematic of one aspect | mode of the filtration apparatus used for this invention. This figure is the said schematic of one aspect | mode of the filtration apparatus used for this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Saliva supply main room 2 ... Saliva discharge port 3 ... Filter medium 4 ... Filter medium storage part 5 ... Connection part 6 ... Small space 7 ... Syringe outer cylinder 8 ... Plunger 9 ... Syringe 10 ... Syringe filter

Claims (4)

  A simple determination method of caries risk by evaluating the filterability of saliva.   2. The simple determination method of caries risk according to claim 1, wherein the filterability is evaluated by permeability of a filter medium having a pore diameter of 0.8 to 2 [mu] m.   3. The simple determination method for caries risk according to claim 1, wherein the filterability is evaluated with a filter medium made of glass fiber filter paper. The simple determination method for caries risk according to claim 1, wherein the saliva supply chamber and the saliva discharge port are in communication with each other through a filter medium, and the saliva supply chamber and the saliva discharge port include a filtering device including a pressurizing means upstream of the saliva supply chamber. Used caries risk assessment tool.

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