Method for measuring rate of bad breath generation

Abstract

To provide a method and an instrument for measuring a foul breath generation rate capable of measuring the foul breath generation ability of a subject, and a method for screening a foul breath inhibitor capable of efficiently suppressing the foul breath of the subject.SOLUTION: An oral malodor formation rate measuring method for calculating the maximum formation rate of VSCs by rinsing the oral cavity with a cysteine and / or methionine solution and measuring the concentration of VSCs in the oral cavity gas; an oral malodor formation rate measuring instrument provided with a means for collecting the oral cavity gas after rinsing the oral cavity with the aforementioned solution, a means for detecting the concentration of VSCs in the oral cavity gas, and a means for calculating the oral cavity VSC formation rate from the VSC concentration and the collection time; and an oral malodor formation rate measuring method for calculating the maximum formation rate of VSCs (1) by rinsing the oral cavity with the aforementioned solution and measuring the concentration of VSCs in the oral cavity gas. The method for screening the halitosis inhibitor comprises rinsing the inside of the oral cavity with an aqueous solution containing a candidate substance, rinsing the inside of the oral cavity with the solution, measuring the VSC concentration in the gas in the oral cavity, calculating the maximum VSC production rate 2 and evaluating the candidate substance.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for measuring the rate of bad breath production, a bad breath measuring device, and a method for screening bad breath suppressants using these. [Background technology]

[0002] Bad breath is produced by microorganisms in the oral cavity from proteins and amino acids contained in food residue, blood, and other bodily fluids. It is said that hundreds of billions of bacteria live in the oral cavity, and anyone who has substances that cause bad breath in their mouth will inevitably have bad breath. For this reason, a wide variety of products to combat bad breath have been released on the market.

[0003] It is well known that the main causative agents of bad breath (accounting for approximately 90% of bad breath) are volatile sulfur-containing compounds (VSCs) hydrogen sulfide and methyl mercaptan (CHSH), which are produced by the decay of sulfur-containing proteins in the oral cavity (Non-Patent Document 1). These compounds are produced from amino acids by amino acid lyases present in oral bacteria, etc., with hydrogen sulfide (HS) being produced from the sulfur-containing amino acid cysteine ​​and methyl mercaptan being produced from the sulfur-containing amino acid methionine. Methods for measuring these compounds include a method for quantifying VSCs in oral gas by gas chromatography, such as with OralChroma, a device that analyzes the components of gases contained in bad breath to identify the cause (Non-Patent Document 1), and a method in which bacteria contained in saliva are cultured and the concentration of sulfur-containing compounds produced in the culture medium is measured by gas chromatography or a sensory test (Non-Patent Document 2).

[0004] In dental clinics and other medical institutions, bad breath is commonly measured by using a VSC meter to measure the VSCs in the gas in the mouth of a subject more than one hour after eating or brushing their teeth.

[0005] However, the concentration of VSCs produced by the enzymatic reaction of amino acid lyases increases rapidly when the corresponding amino acid concentration is high, but does not increase as the amino acid becomes depleted. Therefore, with conventional halitosis measurement methods, VSC production plateaus, and comparisons of measured VSC concentrations between subjects do not accurately reflect the subject's true VSC production ability. Furthermore, VSCs are not produced when the oral cavity is thoroughly cleaned of proteins and amino acids. However, when sulfur-containing proteins and sulfur-containing amino acids are supplied to the oral cavity through diet or oral bleeding or inflammation, VSCs are produced by oral bacteria. Therefore, the measurement of halitosis depends on multiple factors, including the number of oral bacteria, oral cleanliness, and the presence or absence of inflammation or bleeding.

[0006] As such, the strength of bad breath (VSC concentration) at the time of measurement is largely dependent on the degree of oral cleanliness. If the sulfur-containing proteins, sulfur-containing amino acids, etc. that form the basis of VSCs are removed before measurement, VSCs will not be produced and bad breath will not be detected. When VSC raw materials are present in the oral cavity in everyday life, VSCs will be produced by oral bacteria, etc., and will cause bad breath. Therefore, in order to fundamentally suppress bad breath, it is essential to kill or inhibit the growth of oral bacteria.

[0007] Furthermore, a wide variety of bacteria and fungi live in the oral cavity, forming a flora. The oral flora varies from subject to subject, and the number and species of bacteria also differ from person to person. Microorganisms that do not have the amino acid lyase activity mentioned above exist, and whether they have flora that easily produces VSCs or flora that does not easily produce VSCs varies greatly from person to person. As such, the occurrence of bad breath is a complex combination of factors such as the number of bacteria in the oral cavity, the bacterial flora contained in the oral flora, and the presence or absence of inflammation or bleeding, but currently there is no clear indicator for measuring the ability to produce bad breath. [Prior art documents] [Non-patent literature]

[0008] [Non-Patent Document 1] 0ral Surg, Vol, 45+No, 4. P.560~567(1978) [Non-patent document 2] Arch, Orl Biol, Vol, 9+P.39~45(1984) Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present invention is to provide a method and device for measuring the rate at which bad breath is produced, which are capable of measuring a subject's ability to produce bad breath. Another object of the present invention is to provide a method for screening for an anti-halitosis agent that can efficiently suppress the bad breath of a subject. [Means for solving the problem]

[0010] The inventors believed that if it were possible to quantify the number of oral bacteria and the ability to produce bad breath, which is dependent on the bacterial flora, that each individual has in their mouth, it would be extremely useful in developing products to combat oral environment problems, and as a result of extensive research, they discovered that it was possible to measure the initial rate of VSC production in the oral cavity. They then developed a method for measuring the potential bad breath-producing ability by measuring this initial rate of VSC production, as well as a new measuring device that can easily carry out this measurement. They then developed a method for using this method to screen for breath fresheners that can efficiently suppress the bad breath of a subject, and completed the present invention.

[0011] That is, the gist of the present invention is [1] Rinse the oral cavity with a cysteine ​​and / or methionine solution having a concentration of 5 to 50 mM, Next, a method for measuring the rate at which bad breath is generated, characterized in that gas in the oral cavity is collected multiple times over a predetermined period of time, the concentration of volatile sulfur compounds (VSCs) in the gas is measured, and the maximum rate at which VSCs are generated is calculated. [2] A means for collecting oral gas after rinsing the oral cavity with a cysteine ​​and / or methionine solution having a concentration of 5 to 50 mM; a means for detecting a concentration of volatile sulfur compounds (VSCs) in the oral gas; a means for calculating an oral VSC production rate from the time when the oral gas was collected and the VSC concentration; a bad breath production rate measuring device comprising: [3] A first step of rinsing the oral cavity with a cysteine ​​and / or methionine solution having a concentration of 5 to 50 mM, then collecting gas from the oral cavity multiple times at predetermined intervals, measuring the concentration of volatile sulfur compounds (VSCs) in the gas, and calculating the maximum VSC production rate 1; A second step of rinsing the oral cavity with an aqueous solution containing the candidate substance, rinsing the oral cavity with a cysteine ​​and / or methionine solution having a concentration of 5 to 50 mM after a predetermined time has elapsed, and then collecting gas from the oral cavity multiple times over a predetermined period of time to measure the concentration of volatile sulfur compounds (VSCs) in the gas and calculate the maximum VSC production rate 2; comparing the maximum production rate 1 with the maximum production rate 2, and evaluating the candidate substance as a bad breath suppressant if the maximum production rate 2 is lower; How to screen breath fresheners Regarding. [Effects of the Invention]

[0012] The method for measuring the rate of bad breath production of the present invention makes it possible to measure the bad breath production ability of a subject. Furthermore, by using the bad breath production rate measuring device of the present invention, the bad breath production ability of a subject can be easily measured. Furthermore, the screening method of the present invention makes it possible to easily find out an ingredient that suppresses bad breath and is effective for a subject. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a graph showing the results of the hydrogen sulfide production rate (ppb / min) obtained by plotting the hydrogen sulfide concentration over time obtained in Example 1. The table on the right side of the figure shows the slope of the production rate (ppb / min) for each cysteine ​​concentration. [Figure 2]1 is a graph showing the results of the hydrogen sulfide production rate (ppb / min) plotted against the methyl mercaptan concentration over time obtained in Example 1. The table on the right side of the figure shows the slope of the production rate (ppb / min) for each methionine concentration. [Figure 3] 1 is a graph showing the results of intraoral methyl mercaptan concentration obtained in Example 2. [Figure 4] 1 is a graph showing the results of the slope of the rate of methyl mercaptan production in the oral cavity obtained in Example 2. [Figure 5] 1 is a graph showing the results of the methyl mercaptan production rate for subject E obtained in Example 3 when using commercially available mouthwash A. In the figure, the table on the right shows the slope (ppb / min) of the maximum production rate 1 (before) before rinsing and the maximum production rate 2 (after) after rinsing. [Figure 6] 1 is a graph showing the results of the methyl mercaptan production rate when commercially available mouthwash X was used for subject E obtained in Example 3. In the figure, the table on the right shows the slope (ppb / min) of the maximum production rate 1 (before) before rinsing and the maximum production rate 2 (after) after rinsing. [Figure 7] 1 is a graph showing the results of the methyl mercaptan production rate for subject E obtained in Example 3 when using commercially available mouthwash Y. In the figure, the table on the right shows the slope (ppb / min) of the maximum production rate 1 (before) before rinsing and the maximum production rate 2 (after) after rinsing. [Figure 8] 8 is a graph summarizing the results for commercially available mouthwashes A, X, and Y shown in FIGS. 5 to 7. DETAILED DESCRIPTION OF THE INVENTION

[0014] The present invention will be described in detail below.

[0015] (Method for measuring the rate of bad breath production) The method for measuring the bad breath production rate of the present invention (hereinafter also referred to as the measurement method of the present invention) is as follows: Rinse the oral cavity with a cysteine ​​and / or methionine solution having a concentration of 5 to 50 mM, Next, gas in the oral cavity is collected multiple times over a predetermined period of time, the concentration of volatile sulfur compounds (VSCs) in the gas is measured, and the maximum generation rate of VSCs is calculated.

[0016] As described above, rinsing the oral cavity with a cysteine ​​and / or methionine solution of a predetermined concentration aims to provide sulfur-containing amino acids, which cause VSCs, to the oral cavity. The types and abundance of oral bacteria, fungi, and other microorganisms that are responsible for bad breath (hereinafter referred to as halitosis microorganisms) vary from subject to subject, and even within the same individual, the amount of bad breath produced in the oral cavity can vary depending on whether or not the subject brushes their teeth or gargles, and the type and amount of food and drink eaten immediately before the halitosis test. In contrast, when the oral cavity is rinsed with a cysteine ​​and / or methionine solution of a predetermined concentration as in the present invention, a sufficient amount of sulfur-containing amino acids is provided to allow the halitosis microorganisms to produce maximum halitosis, making it possible to measure the maximum amount of halitosis produced in the oral cavity of the subject.

[0017] From the viewpoint of safety, the cysteine ​​and / or methionine solution may be prepared by dissolving a predetermined concentration of cysteine ​​and / or methionine in drinkable water. The type of water is not particularly limited. The cysteine ​​and / or methionine solution may also contain optional ingredients such as sodium chloride. The content of the optional components is not particularly limited, but may be, for example, 1% by weight or less.

[0018] From the viewpoint of enabling accurate measurements, it is preferable to rinse the oral cavity with warm water (for example, around 37°C) before putting the cysteine / methionine solution into the oral cavity. By rinsing the oral cavity before measurement, substances that cause bad breath are washed away in advance, and then a sufficient amount of cysteine / methionine, which are the raw materials for VSCs, is supplied to the oral cavity to produce VSCs. By measuring the rate at which VSCs are produced, it is possible to quantify and compare the differences in the ability to produce bad breath that depend on oral bacteria / flora.

[0019] The cysteine / methionine solution may also be warmed (for example, to about 37°C).

[0020] The time for rinsing the mouth with the cysteine ​​and / or methionine solution is not particularly limited, but may be 5 seconds to 1 minute, from the viewpoint of allowing cysteine ​​and / or methionine to sufficiently contact with the bad breath microorganisms present in the oral cavity and measuring the initial rate immediately after the start of the reaction.

[0021] After rinsing as described above, the cysteine ​​and / or methionine solution is spit out of the mouth.

[0022] Furthermore, at the time point of 0 minutes of the reaction time, gas from the oral cavity immediately before rinsing the oral cavity with the cysteine / methionine solution may be collected and analyzed.

[0023] Alternatively, immediately after rinsing the oral cavity with the methionine / cysteine ​​solution and expectorating it, a predetermined amount of air (for example, 30 ml) may be injected into the oral cavity to ensure that the amount of air in the oral cavity is consistent among subjects.

[0024] Next, gas in the oral cavity is collected multiple times over a predetermined period of time, the concentration of volatile sulfur compounds (VSCs) in the gas is measured, and the maximum generation rate of VSCs is calculated.

[0025] In the present invention, "multiple times within a predetermined period of time" means three or more periods of time. For example, three or more time points can be mentioned, such as immediately after the cysteine ​​and / or methionine solution is spat out of the mouth (0 min), and 1 and 2 min later. The time interval may be one minute or more, but from the viewpoint of calculating the initial maximum production rate, the time interval is preferably in the range of 10 seconds to 1 minute. The intervals between each time point may be constant or may vary. The number of time points is not particularly limited, as long as it is three or more.

[0026] Until intraoral gas is collected, it is only necessary to prevent intraoral gas from moving outside the oral cavity and extraoral gas from moving into the oral cavity.

[0027] A known halitosis measuring device may be used as a method for collecting gas from the oral cavity and measuring the VSC concentration in the gas. The halitosis measuring device is not particularly limited, but may be a general gas chromatograph, etc. For example, "OralChroma CHM-2" (manufactured by NISSHA) or the like may be used.

[0028] The method for sampling gas in the oral cavity is not particularly limited, and any appropriate method may be used depending on the type of the halitosis measuring device. For example, when using "OralChroma CHM-2" (manufactured by NISSHA), a method of collecting gas from the oral cavity using a syringe can be mentioned.

[0029] When using the halitosis measuring device, the VSC concentration may be measured in accordance with the instruction manual of the halitosis measuring device. The VSC to be measured is hydrogen sulfide (H2S) when cysteine ​​is used, and methyl mercaptan (CH3SH) when methionine is used.

[0030] To calculate the maximum VSC production rate, the VSC concentration at each time point is plotted, and the maximum value of the slope calculated by connecting the plotted points can be used as the VSC production rate (initial VSC production rate). Specifically, the plot is made on a spreadsheet software, an approximation formula is calculated using a function attached to the spreadsheet software, and the magnitude of the slope of this approximation formula can be taken as the VSC generation rate.

[0031] The VSC production rate obtained by the measurement method of the present invention is the maximum VSC production rate of oral halitosis microorganisms. Compared with conventional oral halitosis tests conducted at dental clinics, in which the results are unstable depending on the cleanliness of the oral cavity on the day of the test, the previous meal, etc., the VSC production rate can be used as a new index for evaluating oral halitosis because it can more accurately measure the subject's potential ability to produce bad breath.

[0032] (Halitosis production rate measuring device) The bad breath production rate measuring device of the present invention (hereinafter also referred to as the device of the present invention) is A means for collecting oral gas after rinsing the oral cavity with a cysteine ​​and / or methionine solution having a concentration of 5 to 50 mM; a means for detecting a concentration of volatile sulfur compounds (VSCs) in the oral gas; a means for calculating an oral VSC production rate from the time when the oral gas was collected and the VSC concentration; Equipped with.

[0033] By providing the above-described configuration, the measurement method of the present invention can be carried out efficiently. The device of the present invention will be described below, but explanations of configurations that overlap with the measurement method of the present invention will be omitted.

[0034] In the device of the present invention, the cysteine ​​and / or methionine solution having a concentration of 5 to 50 mM may be any solution that is used in the measurement method of the present invention.

[0035] In the device of the present invention, examples of means for collecting oral gas after the subject has rinsed the oral cavity (hereinafter also referred to as collection means) include a syringe and a collection tube.

[0036] In the device of the present invention, a known halitosis measuring device may be used as the means for detecting the VSC concentration in oral gas (hereinafter also referred to as the detection means). Examples of the halitosis measuring device include "OralChroma CHM-2" (manufactured by Nissha) and "Halimeter PLUS" (manufactured by Interscan), but there is no particular limitation. A gas chromatograph, which is a common analytical device, can also be used.

[0037] In the device of the present invention, the means (hereinafter also referred to as the calculation means) for calculating the oral VSC production rate from the time the oral gas was collected and the VSC concentration may be, for example, a calculator that is electrically connected to the detection means so as to be able to communicate with the detection means and that can calculate the VSC production rate based on the results of the detection means. The calculator is not particularly limited, but may be, for example, a computer equipped with software specifically for calculation.

[0038] Examples of embodiments using the device of the present invention include: After the subject rinses the oral cavity with a cysteine ​​and / or methionine solution having a concentration of 5 to 50 mM for a predetermined period of time, a sampling means provided in the device of the present invention is inserted into the oral cavity to sample gas in the oral cavity at predetermined multiple time points; The obtained oral gas is introduced into a detection means, and the VSC concentration in the detected oral gas is measured; Data on the time of sampling and the VSC concentration at that time are sent to a computer, which is a calculation means electrically connected to the detection means, to calculate the VSC production rate.

[0039] The device of the present invention can automatically collect oral gas, detect VSC concentrations, and calculate the VSC production rate, making it possible to easily measure a subject's ability to produce bad breath.

[0040] (Method for screening breath fresheners) The method for screening an oral odor suppressant of the present invention (hereinafter also referred to as the screening method of the present invention) comprises: A first step of rinsing the oral cavity with a cysteine ​​and / or methionine solution having a concentration of 5 to 50 mM, then collecting gas from the oral cavity multiple times over a predetermined period of time, measuring the concentration of volatile sulfur compounds (VSCs) in the gas, and calculating the maximum VSC production rate 1; A second step of rinsing the oral cavity with an aqueous solution containing the candidate substance, rinsing the oral cavity with a cysteine ​​and / or methionine solution having a concentration of 5 to 50 mM after a predetermined time has elapsed, and then collecting gas from the oral cavity multiple times over a predetermined period of time to measure the concentration of volatile sulfur compounds (VSCs) in the gas and calculate the maximum VSC production rate 2; This method involves comparing the maximum production rate 1 with the maximum production rate 2, and evaluating the candidate substance as a bad breath suppressant if the maximum production rate 2 is lower.

[0041] In conventional dental clinics, although various medications effective in suppressing bad breath are known, the judgement of whether they are suitable for the subject has to depend on the dentist's experience, and in some cases, it takes a great deal of effort on the part of both the dentist and the subject to find an appropriate bad breath suppressant, and in some cases, an appropriate bad breath suppressant cannot be found. In contrast, the screening method of the present invention is carried out for each individual subject with a different oral cavity environment, making it possible to efficiently screen for an effective halitosis suppressant for that subject.

[0042] The screening method of the present invention will be explained below, but explanation of the components that overlap with the measurement method of the present invention will be omitted.

[0043] In the first step of the screening method of the present invention, for example, depending on the state of the halitosis microorganisms present in the oral cavity, if the concentrations of cysteine ​​and methionine in the cysteine ​​and / or methionine solution are low, the calculated production rate may be low. Therefore, the maximum production rate calculated when the concentration of cysteine ​​and methionine in the solution is in the range of 5 to 50 mM is defined as maximum production rate 1.

[0044] In the first step, the cysteine ​​and / or methionine solution having a concentration of 5 to 50 mM, the method of rinsing the oral cavity with the solution after a predetermined time has elapsed, the method of collecting gas from the oral cavity multiple times over a predetermined period of time, and the method of measuring the VSC concentration in the gas may be the same as those in the measurement method of the present invention.

[0045] In the second step of the screening method of the present invention, the oral cavity is rinsed with an aqueous solution containing a candidate substance, and after a predetermined time has passed, the oral cavity is rinsed with a 5 to 50 mM cysteine ​​and / or methionine solution. Then, gas in the oral cavity is collected multiple times over a predetermined period of time, the concentration of volatile sulfur compounds (VSCs) in the gas is measured, and the maximum VSC production rate 2 is calculated. In this way, by rinsing the oral cavity in advance with an aqueous solution containing the candidate substance, performing the measurement method of the present invention and calculating the maximum production rate 2, the effect of the candidate substance on bad breath production can be confirmed. That is, when the maximum production rate 1 is compared with the maximum production rate 2, if the maximum production rate 2 is lower, the candidate substance exhibits a halitosis suppressing effect on the subject, and can therefore be evaluated as a halitosis suppressant.

[0046] Furthermore, by examining multiple candidate substances, it is possible to screen for the most effective halitosis suppressant. For example, by checking the degree of decrease in maximum production rate 2 relative to maximum production rate 1 for multiple candidate substances, the effectiveness of each halitosis suppressant can be determined.

[0047] Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples. [Example]

[0048] Example 1: Measurement Method: Optimization of Sulfur-Containing Amino Acid Concentration (Hydrogen sulfide generation) Cysteine ​​hydrochloride was dissolved in drinking water to prepare solutions containing 5 mM, 10 mM, 25 mM, and 50 mM cysteine. Next, subject A (55-year-old male) held 10 mL of each concentration of cysteine ​​solution, which had been incubated at 37°C for 5 minutes, in his mouth, circulated it around his mouth for 5 seconds, and spat it out. After exhaling the air from his mouth, 30 mL of air was injected into his mouth. While maintaining a state of no gas flowing in or out of the mouth, the gas in his mouth was sampled with a syringe after 1, 2, and 3 minutes. The syringes used for sampling were kept capped to prevent gas leakage until measurement. Next, the gas collected in the syringe was injected into an oral odor measuring device, "OralChroma CHM-2" (manufactured by NISSHA), and the hydrogen sulfide concentration was measured. The hydrogen sulfide concentration in the oral cavity at each collection time was calculated.

[0049] (Methyl mercaptan formation) Methionine was dissolved in drinking water to prepare solutions containing 5 mM, 10 mM, 25 mM, and 50 mM methionine. Next, subject A held 10 mL of each concentration of methionine solution, which had been incubated at 37°C for 5 minutes, in his mouth, circulated it around his mouth for 5 seconds, and then spat it out. After exhaling the air from his mouth, 30 mL of air was injected into his mouth. While maintaining a state of no gas flow in or out of the mouth, the gas in his mouth was sampled with a syringe 1, 2, and 3 minutes later. The syringes used for sampling were kept capped to prevent gas leakage until measurement. Next, the gas collected in the syringe was injected into the OralChroma CHM-2, the methyl mercaptan concentration was measured, and the methyl mercaptan concentration in the oral cavity at each collection time was calculated. The initial value of the oral methyl mercaptan concentration was determined by injecting 30 ml of air into the oral cavity before the methionine solution was added, collecting the gas in the oral cavity 30 seconds later, and measuring the methyl mercaptan concentration using an OralChroma CHM-2.

[0050] (Measurement of bad breath generation rate) The obtained hydrogen sulfide and methyl mercaptan concentrations over time were plotted, and the hydrogen sulfide and methyl mercaptan production rates (ppb / min) were calculated. The results are shown in Figures 1 and 2. The table on the right in Figure 1 shows the slope of the production rate (ppb / min) for each cysteine ​​concentration. The table on the right in Figure 2 shows the slope of the production rate (ppb / min) for each methionine concentration.

[0051] The production of hydrogen sulfide (Fig. 1) and methyl mercaptan (Fig. 2) was similar at cysteine ​​and methionine concentrations of 25 mM and 50 mM, respectively. Cysteine ​​and methionine concentrations above 25 mM were shown to be optimal. In subsequent measurements, a 25 mM solution was used.

[0052] Example 2: Measurement of the effect of commercially available mouthwash on the rate of inhibiting bad breath formation The effectiveness of commercially available mouthwash A in suppressing the rate at which bad breath is produced was verified. Subjects B (50-year-old male), C (56-year-old male), and D (27-year-old female) rinsed their mouths with 37°C water, then 30 ml of air was injected into their mouths. After 30 seconds, the gas in their mouths was collected and the methyl mercaptan concentration (at time 0) was measured using the OralChroma CHM-2. Next, 10 ml of 25 mM methionine-containing solution was placed in the mouth, circulated for 5 seconds, and then spat out. After exhaling, 30 ml of air was injected into the mouth. After 1 minute (time point 1) and 2 minutes (time point 2), the gas in the mouth was sampled with a syringe while maintaining a state of no gas in or out of the mouth. The gas collected in the syringe was injected into the OralChroma CHM-2, the methyl mercaptan concentration was measured, and the methyl mercaptan concentration (ppb) in the gas phase in the oral cavity at each collection time was calculated (first and second time points). The measured methyl mercaptan concentration (ppb) was plotted against the sampling time to calculate the methyl mercaptan production rate (ppb / min) (maximum production rate 1).

[0053] After that, the mouth was rinsed with 20 ml of commercially available mouthwash A for 30 seconds, and then 30 minutes later the mouth was rinsed with 37°C water. 30 ml of air was then injected into the mouth, and the gas in the mouth was collected 30 seconds later, and the methyl mercaptan concentration was measured using the OralChroma CHM-2 (time point 0). Next, in the same manner as in the measurement of maximum production rate 1, the methyl mercaptan concentrations (ppb) measured at the first and second time points were plotted for each sampling time to calculate the methyl mercaptan production rate (ppb / min) (maximum production rate 2). Figure 3 shows the results of the methyl mercaptan concentration in the oral cavity, and Figure 4 shows the results of the slope of the methyl mercaptan production rate in the oral cavity. In Figure 3, "before" indicates the oral methyl mercaptan concentration (ppb) for subjects B, C, and D at time 0, and "after" indicates the oral methyl mercaptan concentration (ppb) for subjects B, C, and D at time 2. In FIG. 4, "before" indicates the slope of maximum production speed 1, and "after" indicates the slope of maximum production speed 2.

[0054] The results of the methyl mercaptan concentration in the oral cavity shown in Figure 3 show that, similar to the results of halitosis tests commonly conducted at dental clinics, commercially available mouthwash A had a halitosis-reducing effect on subject B, but had no halitosis-reducing effect on subjects C and D. On the other hand, the results of the methyl mercaptan production rate shown in Figure 4 show that commercially available mouthwash A has a bad breath reduction effect for subjects B, C, and D, as the maximum production rate 2 was lower than the maximum production rate 1. In particular, for subject B, the reduction rate of maximum production rate 2 was the largest, indicating that it is a suitable bad breath reducer that can actually feel the bad breath reduction effect. Therefore, it is clear that the measurement method of the present invention makes it possible to screen for an effective breath odor reducing agent for each subject.

[0055] Example 3 For subject E (male, 55 years old), commercial mouthwash X and commercial mouthwash Y were used in addition to commercial mouthwash A. Oral gas was collected at time 0, time 1, and time 2 in the same manner as in Example 2, and the methyl mercaptan concentration and methyl mercaptan production rate were measured. The obtained production rate results are shown in Figures 5 to 7. In Figures 5 to 7, "before" indicates maximum generation rate 1, and "after" indicates maximum generation rate 2. In addition, the tables on the right in Figures 5, 6, and 7 show the slope (ppb / min) of maximum generation rate 1 (before) before rinsing and maximum generation rate 2 (after) after rinsing.

[0056] Next, to evaluate the effectiveness of commercially available mouthwashes A, X, and Y as bad breath suppressants, the slopes of the obtained maximum production rates 1 and 2 are summarized in Figure 8. In FIG. 8, "before" indicates the slope of maximum production speed 1, and "after" indicates the slope of maximum production speed 2. From the results shown in Figure 8, it can be seen that the rate of methyl mercaptan production when treated with commercial mouthwash X is lower than when treated with commercial mouthwashes A and Y, and therefore commercial mouthwash X is the most effective in reducing the bad breath of subject E, and therefore is the most suitable agent for suppressing bad breath.

[0057] The results of Examples 1 to 3 show that by using the measurement method of the present invention, it is possible to measure the potential bad breath-producing ability of an individual subject, which could not be confirmed by conventional measurements of VSC concentrations in oral gas. As a specific embodiment of the measurement method of the present invention, for example, a patient rinses with a cysteine ​​and / or methionine solution having a concentration of 5 to 50 mM at a dental clinic, and then the VSC concentration in the gas in the patient's mouth is measured using an oral odor measuring device already installed at the dental clinic, and the maximum generation rate may be calculated from the concentration result using a calculator or the like. Three types of syringes and an instruction manual describing the method and time for collecting oral gas may be provided to each subject who wishes to take the measurement. The syringes collected by the subject at three specified time points may then be mailed to an examiner at another location, who may then use a breath odor measuring device and a calculator owned by the examiner to measure the VSC concentration in the oral gas in the syringes, calculate the maximum generation rate, and provide feedback of the results to the subject.

Claims

1. Rinse the oral cavity with a cysteine ​​and / or methionine solution having a concentration of 5 to 50 mM, Next, the method for measuring the rate at which bad breath is produced is characterized by collecting gas from the oral cavity multiple times over a predetermined period of time, measuring the concentration of volatile sulfur compounds (VSCs) in the gas, and calculating the maximum rate at which VSCs are produced.

2. A means for collecting oral gas after rinsing the oral cavity with a cysteine ​​and / or methionine solution having a concentration of 5 to 50 mM; a means for detecting a concentration of volatile sulfur compounds (VSCs) in the oral gas; a means for calculating an oral VSC production rate from the time when the oral gas was collected and the VSC concentration; A bad breath production rate measuring device equipped with the above.

3. A first step of rinsing the oral cavity with a cysteine ​​and / or methionine solution having a concentration of 5 to 50 mM, then collecting gas from the oral cavity multiple times at predetermined intervals, measuring the concentration of volatile sulfur compounds (VSCs) in the gas, and calculating the maximum VSC production rate 1; a second step of rinsing the oral cavity with an aqueous solution containing the candidate substance, rinsing the oral cavity with a 5 to 50 mM cysteine ​​and / or methionine solution after a predetermined time has elapsed, collecting gas from the oral cavity multiple times over a predetermined period of time, measuring the concentration of volatile sulfur compounds (VSCs) in the gas, and calculating the maximum VSC production rate 2; the maximum production rate 1 is compared with the maximum production rate 2, and if the maximum production rate 2 is lower, the candidate substance is evaluated as a bad breath suppressant; A method for screening breath fresheners.

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