How to measure oral health

Abstract

To provide a method of measuring the oral hygiene status.SOLUTION: A method is provided for measuring the oral hygiene status of a subject who provided a blood sample using a value obtained by dividing a reflection value of the oxidized HDL level in the blood sample by a reflection value of the HDL level in the blood sample as an indicator.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to methods for measuring oral hygiene, etc. [Background technology]

[0002] Maintaining good oral hygiene is important for preventing dental caries and periodontal disease. Methods for checking oral hygiene include checking the amount of plaque and tartar on the teeth and the resulting gingival bleeding, but currently, these methods are mainly performed by undergoing oral examinations by dentists, etc., and there is a need for a simple method for checking oral hygiene.

[0003] In addition, the rate of dental examinations included in health checkups is low, making the development of a simple method for checking oral hygiene status a challenge. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6779776 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present disclosure is to provide a method for measuring oral hygiene conditions such as the presence or absence of tartar and bleeding gums, etc. Another object of the present disclosure is to provide a method for measuring oral hygiene conditions such as the presence or absence of tartar and bleeding gums, etc., without a dental checkup. [Means for solving the problem]

[0006] The inventors discovered that when there is tartar or gingival bleeding, the value reflecting the amount of oxidized HDL in a blood sample divided by the value reflecting the amount of HDL in a blood sample is higher than when there is no tartar or gingival bleeding, and have made further improvements.

[0007] The present disclosure includes, for example, the subject matter described in the following sections: Section 1. A method for measuring the oral hygiene status of a subject from whom a blood sample was taken, using as an index a value reflecting the amount of oxidized HDL in a blood sample divided by a value reflecting the amount of HDL in the blood sample. Section 2. Item 2. The method according to item 1, wherein the oral hygiene condition is a tartar buildup condition or a gingival bleeding condition. Section 3. (A) measuring a value reflecting the amount of oxidized HDL in a blood sample; and (B) measuring a value reflective of HDL content in a blood sample; The method according to item 1 or 2, comprising: Section 4. The measurement of the reflected value of the oxidized HDL amount (1) The method is carried out by a method including a step of mixing a blood sample with a solution containing a transition metal compound and an acidic buffer solution, The method according to item 3. Section 5. The measurement of the reflected value of the oxidized HDL amount moreover, (2) The method is carried out by a method including a step of measuring the free radicals produced in the step (1), The method according to item 4. Section 6. Item 4. The method according to Item 3, wherein the measurement of the reflection value of HDL amount is carried out by a direct HDL method. Section 7. Item 7. The method according to any one of Items 1 to 6, wherein the reflection value of the oxidized HDL amount is a change in absorbance per unit time. Section 8. Item 8. The method according to any one of Items 1 to 7, wherein the value reflecting the HDL amount is a concentration. Effect of the Invention

[0008] A method for measuring oral hygiene such as the presence or absence of tartar and bleeding gums is provided. Also provided is a method for measuring oral hygiene such as the presence or absence of tartar and bleeding gums without a dental checkup. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing tooth numbers and names. [Diagram 2] The graph shows plots of the value reflecting the amount of oxidized HDL in blood samples of each subject divided by the value reflecting the amount of HDL in blood samples (oxHDL / HDL) in the groups with and without CI. [Diagram 3] The graph shows plots of the value reflecting the amount of oxidized HDL in blood samples divided by the value reflecting the amount of HDL in blood samples (oxHDL / HDL) in the groups with and without BOP. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Each embodiment included in the present disclosure will be described in further detail below. The present disclosure encompasses a method for measuring the oral hygiene status of a subject. In this specification, the method may be referred to as the "measurement method of the present disclosure."

[0011] The measurement method of the present disclosure uses as an index a value reflecting the amount of oxidized HDL in a blood sample collected from a subject divided by a value reflecting the amount of HDL in the blood sample. The measurement method of the present disclosure may include measuring a value reflecting the amount of oxidized HDL in a blood sample collected from a subject, or may include measuring a value reflecting the amount of HDL in the blood sample.

[0012] The subject may be a human or a non-human mammal. The human may be, for example, a healthy individual, a human suffering from periodontal disease (a periodontal disease patient), or a human suspected of suffering from periodontal disease. Examples of the subject include a human with HbA1c of less than 5.6%, a human with fasting blood glucose of less than 110 mg / dL, a human with a BMI of less than 30, or a human with two or more of these characteristics. The non-human mammal is not particularly limited, and examples thereof include mammals kept as pets, livestock, laboratory animals, etc. Examples thereof include dogs, cats, monkeys, cows, horses, sheep, goats, pigs, rabbits, mice, rats, camels, llamas, etc.

[0013] The blood sample is not particularly limited as long as it is a sample derived from blood collected from a subject, and may be, for example, whole blood or a blood separation product (e.g., serum, plasma, etc.). The method and conditions for storing the blood sample collected from the subject are not particularly limited, and may be carried out according to a conventional method.

[0014] The method for collecting a blood sample from a subject is not particularly limited and may be performed according to a conventional method. When serum or plasma is used as a blood sample, it is preferable to use a vacuum blood collection tube containing a serum or plasma separator from the viewpoints of ease of handling, prevention of infection, etc. The collected blood sample may be used as is, or may be freeze-dried or otherwise stored and then the freeze-dried product may be dissolved in a suitable solvent as described below and then used. The collected blood sample may be frozen and stored as is, or may be frozen and stored after being dissolved in a suitable solvent as described below and then thawed when ready for use.

[0015] The value reflecting the amount of oxidized HDL refers to a value reflecting the amount of oxidized HDL contained in a blood sample, and examples thereof include the weight (mass) and concentration of oxidized HDL. Alternatively, for example, a measured value reflecting the amount of oxidized HDL contained in a blood sample may be used, and examples of such values ​​include absorbance and fluorescence intensity. The measured value may be a value measured using a measurement auxiliary reagent. Examples of such measurement auxiliary reagents include fluorescent dyes, oxidized HDL-specific recognition molecules (e.g., antibodies or fragments thereof), and combinations of two or more of these.

[0016] The method for measuring the reflected value of the amount of oxidized HDL in a blood sample is not particularly limited, and can be performed according to a conventional method. For example, a method for measuring oxidized HDL (malondialdehyde-modified HDL) using an ELISA method, a method for measuring the nitration or chlorination of Apo-A1, a protein constituting HDL, using a mass spectrometer, and a method including (1) a step of mixing a blood sample with a solution containing a transition metal compound and an acidic buffer solution, as described in Japanese Patent No. 6779776 (Patent Document 1), are included. Among them, it is preferable to measure by a method including (1) a step of mixing a blood sample with a solution containing a transition metal compound and an acidic buffer solution. In this specification, this step may be referred to as "step (1)". Furthermore, it is more preferable to measure by a method including (2) a step of measuring the free radicals produced by the step (1). In this specification, this step may be referred to as "step (2)".

[0017] The method for measuring the reflective value of the amount of oxidized HDL in a blood sample may include a step of separating HDL from the blood sample. In the present specification, this step may be referred to as "step (0)". The HDL separated in step (0) can be used as the blood sample in step (1). The method for separating HDL from a blood sample is not particularly limited, and can be performed according to a conventional method. For example, the dextran sulfate method using dextran sulfate and magnesium ions can be mentioned.

[0018] The transition metal compound is not particularly limited as long as it can be ionized in the mixed solution to become a metal ion and can react with hydroxyperoxide (R-OOH) to generate a free radical, and examples thereof include copper (II) compounds, iron (II) compounds (divalent iron compounds), and iron (III) compounds (trivalent iron compounds). Among these, iron compounds such as iron (II) compounds and iron (III) compounds are preferred. Examples of iron compounds include ammonium iron (II) sulfate hexahydrate and iron (III) chloride hexahydrate. By using a transition metal compound in step (1), advantageous effects such as 1) the presence of a sufficient amount of transition metal ions that react with hydroxyperoxide makes it possible to measure oxidized HDL with a small amount of blood sample and 2) the measurement of oxidized HDL can be achieved without being affected by the amount of iron contained in blood are achieved.

[0019] In addition, the reflected value of the amount of oxidized HDL is larger in a solution containing a divalent iron compound than in a solution containing a trivalent iron compound. In other words, a measurement method using a divalent iron compound can measure oxidized HDL with higher sensitivity than a trivalent iron compound. Therefore, among the above-mentioned iron compounds, a divalent iron compound is particularly preferred.

[0020] The concentration of the transition metal compound in the mixed solution is not particularly limited, and can be, for example, about 0.1 to 150 μM, preferably 1 to 100 μM.

[0021] The acidic buffer solution is not particularly limited as long as it has an acidic pH and a buffering effect, and any known buffer solution can be used, such as an acetate buffer solution.

[0022] The pH of the acidic buffer solution is not particularly limited as long as it is acidic, and is preferably about 2 to 6.9, more preferably about 3 to 6.5, and even more preferably 4.5 to 6. When a color development method is used as a method for measuring free radicals in step (2) described below, the pH of the acidic buffer solution is particularly preferably about 3 to 6.9.

[0023] The concentration of the acidic buffer solution is not particularly limited and is, for example, 0.005 to 0.5M, preferably 0.01 to 0.2M.

[0024] The reaction temperature in step (1) is not particularly limited and can be, for example, about 20 to 40°C.

[0025] As described above, in step (1), hydroperoxides (R-OOH) in oxidized HDL contained in a blood sample react with transition metal ions to generate peroxy radicals (R-OO · ) and alkoxy radicals (RO · By measuring the free radicals produced in step (1), oxidized HDL can be measured.

[0026] Therefore, it is preferable that the method for measuring a value reflecting the amount of oxidized HDL further comprises the step (2) of measuring the free radicals produced in the above step (1).

[0027] The method for measuring free radicals is not particularly limited, and any known method can be used, such as a color development method, a chemiluminescence method, or an electron spin resonance (ESR) method.

[0028] The color-developing method uses a substance that reacts with free radicals to produce color (a color-developing substance), and measures the absorbance of the colored substance using a spectrophotometer or the like.

[0029] The color-forming substance is not particularly limited as long as it is a compound that reacts with a free radical or an alkoxy radical to develop color, and any known compound can be used. For example, a compound represented by the following general formula (1) or a salt thereof can be used.

[0030] [ka]

[0031] In the above general formula (1), each R is the same or different and represents a hydrogen atom, a halogen atom, methyl, or ethyl. In particular, it is preferable that at least two of each R are methyl or ethyl, and it is more preferable that R substituting the same nitrogen atom are both methyl or ethyl.

[0032] As the compound represented by the general formula (1), N,N-dimethyl-p-phenylenediamine (DMPD) and N,N-diethyl-p-phenylenediamine (DPD) are preferred.

[0033] Examples of the salt of the compound represented by the general formula (1) include sulfates, oxalates, and diacetates.

[0034] The compound represented by formula (1) or a salt thereof used in the reaction step may be used alone or in combination of two or more.

[0035] In addition, the compound represented by the general formula (1) can be used by dissolving it in a solvent as necessary. The solvent is not particularly limited, and examples thereof include pure water, a buffer solution, and dimethyl sulfoxide (DMSO). The concentration of the solution is not particularly limited, and can be, for example, about 0.1 to 50 mM, and preferably about 1 to 20 mM.

[0036] The method for measuring the absorbance of the colored substance is not particularly limited, and can be performed by a conventional method. For example, since a radical cation that exhibits a reddish purple color is generated by the reaction of a free radical with a color-forming substance, the radical cation can be measured by measuring the absorbance using a known device. The wavelength for measuring the absorbance can be, for example, 460 to 570 nm, preferably 500 to 560 nm.

[0037] In addition, when measuring absorbance, it is preferable to measure the time course of absorbance between the start time and the end time of measurement in order to measure quantitatively. For example, the rate of increase in absorbance (change in absorbance per unit time) may be measured with the start point being 3 minutes after the start of the reaction between the free radical and the color-developing substance and the end point being 6 minutes after the start of the reaction.

[0038] The chemiluminescence method uses a substance (luminescent substance) that reacts with free radicals to emit light, and measures the light emitted when the excited substance returns to its ground state using a luminescence spectrometer or similar device.

[0039] The luminescent substance is not particularly limited as long as it is a compound that reacts with free radicals to emit light, and known compounds can be used, such as luminol, Dansyl-TEMPO, lucigenin, 2-methyl-6-p-methoxyphenylethynylimidazopyrazinone (MPEC), hydroxyphenyl fluorescein (HPF), aminophenyl fluorescein (APF), and Cypridina luciferin derivative (MCLA).

[0040] The method for measuring the light emitted by the luminescent substance is not particularly limited, and can be appropriately determined depending on the type of the luminescent substance used, etc.

[0041] The electron spin resonance method (ESR method) is a spectroscopic analysis that observes the transition between levels that occurs when an unpaired electron is placed in a magnetic field. The electron spin resonance method is not particularly limited and can be performed using a known method and device, and may be either a direct method in which free radicals are directly measured or an indirect method in which a spin trapping agent is reacted with a free radical. When an indirect method is adopted, the spin trapping agent is not particularly limited and a known spin trapping agent can be used. Examples of the spin trapping agent include nitrone-based spin trapping agents such as 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), 2,5,5-triethyl-1-pyrroline-N-oxide (M3PO), 3,3,5,5-tetramethyl-1-pyrroline-N-oxide (TMPO), and N-tert-α-phenylnitrone (PBN); and nitroso-based spin trapping agents such as 2-methyl-2-nitrosopropane (MNP) and nitrosodurene (ND).

[0042] The value reflecting the amount of HDL refers to a value reflecting the amount of HDL contained in a blood sample, and examples thereof include the weight (mass) and concentration of HDL. Alternatively, for example, a measured value reflecting the amount of HDL contained in a blood sample may be used, and examples of such values ​​include absorbance and fluorescence intensity. The measured value may be a value measured using a measurement auxiliary reagent. Examples of such measurement auxiliary reagents include fluorescent dyes, HDL-specific recognition molecules (e.g., antibodies or fragments thereof), and combinations of two or more of these.

[0043] The method for measuring the HDL concentration of a blood sample is not particularly limited, and can be performed according to a conventional method. For example, the HDL direct method, the HPLC method, the precipitation method, etc. can be mentioned. The HDL direct method is a method for calculating the HDL concentration by measuring the colored matter generated by reacting free HDL cholesterol with cholesterol esterase and cholesterol oxidase in the presence of a dye, for example, at a wavelength of 560 nm. Among them, the HDL direct method is preferred.

[0044] The value obtained by dividing the reflected value of the oxidized HDL amount in a blood sample by the reflected value of the HDL amount in a blood sample may be calculated from the reflected value measured using the same blood sample, or may be calculated from the reflected value measured using a different blood sample taken from the same subject.

[0045] Both reflected values ​​may be based on the same measurement method or different measurement methods. For example, the reflected value of the amount of oxidized HDL may be calculated as the rate of increase in absorbance (change in absorbance per unit time) (mOD / min) with the starting point being 3 minutes after the start of the reaction between the free radical and the chromogenic substance and the ending point being 6 minutes after the start of the reaction, and the reflected value of the amount of HDL may be calculated as the concentration (mg / dL).

[0046] As shown in the examples below, when the value obtained by dividing the oxidized HDL amount of blood sample by the value obtained by dividing the HDL amount of blood sample is high, it is possible that plaque is present or the amount is large, or that gingival bleeding is present or the amount is large, and the oral hygiene state is considered to be poor. Therefore, according to the measurement method of the present disclosure, the value obtained by dividing the oxidized HDL amount of blood sample by the value obtained by dividing the HDL amount of blood sample can be used as an index to measure the oral hygiene state of the subject from whom the blood sample was taken.

[0047] Oral hygiene conditions include, for example, tartar adhesion (presence or absence of tartar adhesion, amount of adhesion, degree of adhesion, etc.), gingival bleeding (presence or absence of bleeding, amount of bleeding, degree of bleeding, etc.) etc. One common method for examining oral hygiene conditions is to measure dental plaque (amount of plaque), but while this method reflects the oral hygiene condition on that day, tartar adhesion and gingival bleeding are considered to reflect the cumulative results of oral hygiene conditions up to the present.

[0048] According to the measurement method of the present disclosure, for example, when the value reflecting the amount of oxidized HDL in a blood sample taken from a subject divided by the value reflecting the amount of HDL in the blood sample is equal to or greater than a standard value, it is possible to predict (determine) that oral hygiene may be poor, compared to when the value is less than the standard value.

[0049] The reference value to be compared with the value obtained by dividing the reflected value of the amount of oxidized HDL in the blood sample collected from the subject by the reflected value of the amount of HDL in the blood sample can be, for example, about 0.5, 0.6, or 0.7 (mOD / min) / (mg / dL) when the reflected value of the amount of oxidized HDL in the blood sample is calculated as the rate of increase in absorbance (change in absorbance per unit time) (mOD / min) and the reflected value of the amount of HDL in the blood sample (direct method) as a concentration (mg / dL) with the starting point being 3 minutes after the start of the reaction between the free radical and the color-forming substance and the end point being 6 minutes after the start of the reaction. For screening purposes, it is preferable to set the reference value to about 0.5 (mOD / min) / (mg / dL). For example, the reference value can be set so that the false negative rate (1-(sensitivity)) is low in terms of screening potential oral hygiene poor individuals. In addition, depending on the method for measuring oxidized HDL and HDL levels, standard values ​​can be set based on the sensitivity, specificity, false positive rate, false negative rate, likelihood ratio, etc., in accordance with the purpose of the test, following the concept of general testing.

[0050] In addition, the reference value to be compared with the value obtained by dividing the value reflected by the amount of oxidized HDL in a blood sample collected from a subject by the value reflected by the amount of HDL in the blood sample can be, for example, the value obtained by dividing the value reflected by the amount of oxidized HDL in a blood sample collected from a subject with normal oral hygiene, more specifically, a subject without tartar and without gingival bleeding, by the value reflected by the amount of HDL in the blood sample. This value may be standardized based on previously obtained data.

[0051] In addition, the standard value to be compared with the value obtained by dividing the value reflecting the oxidized HDL amount in a blood sample collected from a subject by the value reflecting the HDL amount in the blood sample can be, for example, the average, median, 25th percentile, 75th percentile, or mode of the value obtained by dividing the value reflecting the oxidized HDL amount in a blood sample in a group consisting of multiple subjects by the value reflecting the HDL amount in the blood sample.

[0052] In addition, according to the measurement method of the present disclosure, it is also possible to measure the change in oral hygiene state over time of the same subject.For example, if the value reflecting the amount of oxidized HDL in the blood sample collected from the subject divided by the value reflecting the amount of HDL in the blood sample increases over time, it can be predicted (determined) that the oral hygiene state may have deteriorated.For example, if the value reflecting the amount of oxidized HDL in the blood sample collected from the subject divided by the value reflecting the amount of HDL in the blood sample decreases over time, it can be predicted (determined) that the oral hygiene state may have improved.

[0053] According to the present disclosure, by using the value reflecting the amount of oxidized HDL in a blood sample divided by the value reflecting the amount of HDL in a blood sample as an index, oral hygiene status can be measured, for example, based on the results of blood tests in a health checkup, even when a dental professional is not present or a dental checkup has not been conducted.

[0054] The present disclosure also encompasses a method for assisting in assessing the oral hygiene status of a subject, which may be referred to herein as the "assisted method of the present disclosure."

[0055] The assisting method of the present disclosure uses as an index a value obtained by dividing the reflection value of the oxidized HDL amount of a blood sample collected from a subject by the reflection value of the HDL amount of the blood sample. The assisting method of the present disclosure may include measuring the reflection value of the oxidized HDL amount of a blood sample collected from a subject, or may include measuring the reflection value of the HDL amount of a blood sample.

[0056] The above-mentioned description of the "measurement method of the present disclosure" can be used to refer to the values ​​reflecting the oxidized HDL amount in the blood sample collected from the subject and the values ​​reflecting the HDL amount in the blood sample.

[0057] The assisting method of the present disclosure can assist in assessing a subject's oral hygiene status.

[0058] In addition, in this specification, the term "comprising" includes "consisting essentially of" and "consisting of." In addition, the present disclosure includes all of the constituent elements described in this specification in any combination.

[0059] In addition, the various characteristics (properties, structures, functions, etc.) described in each embodiment of the present disclosure above may be combined in any way to specify the subject matter included in the present disclosure. In other words, the present disclosure includes all subject matter consisting of all combinations of each combinable characteristic described in this specification. EXAMPLES

[0060] The contents of the present disclosure will be specifically explained using the following test examples. However, the present disclosure is in no way limited to these. In the following, unless otherwise specified, the experiments were performed under atmospheric pressure and room temperature conditions.

[0061] subject The study involved 159 men (mean age 52.0 years, standard deviation 6.4), excluding those with HbA1c of 5.6% or higher, fasting blood glucose of 110 mg / dL or higher, or BMI of 30 or higher. In addition, oral indices were measured for six representative teeth per person (Figure 1). The representative teeth were the upper right 6, the upper right 1, the upper left 6, the lower right 6, the lower left 1, and the lower left 6. However, if tooth 6 was missing, tooth 7 was measured.

[0062] Test Example 1 Calculation of the value reflecting the amount of oxidized HDL in a blood sample divided by the value reflecting the amount of HDL in a blood sample (oxHDL / HDL) (1) Preparation of blood samples Blood was collected from the subject's vein using a vacuum blood collection tube, left at room temperature for 1 hour, and then centrifuged under general serum separation conditions to obtain the supernatant (serum) as a blood sample, which was then stored at -80°C.

[0063] (2) Measurement of oxidized HDL (oxHDL) A mixture of 0.1M acetate buffer (pH 4.8) and 100μM ammonium iron(II) sulfate hexahydrate was added to each well of the microplate and kept at 37℃. Next, N,N-diethyl-p-phenylenediamine sulfate solution (solvent: DMSO) was added to each well, and then the serum obtained in (1) above was added. The absorbance at a wavelength of 505nm was measured using a microplate reader (manufactured by Bio-Rad) set at 37℃. The absorbance was measured by setting the instrument to Kinetics, measuring 48 times (8 minutes in total) every 10 seconds, and calculating the absorbance change per unit time (unit: mOD / min) from each value 3 minutes to 6 minutes after the start of the measurement.

[0064] (3) Measurement of HDL mass HDL was measured by the direct method using serum (unit: mg / dL).

[0065] (4) Calculation method of the value reflecting the amount of oxidized HDL in a blood sample divided by the value reflecting the amount of HDL in a blood sample (oxHDL / HDL) The oxHDL / HDL (unit: (mOD / min) / (mg / dL)) was calculated by dividing the value reflecting the amount of oxidized HDL (mOD / min) calculated in (2) above by the value reflecting the amount of HDL (mg / dL) calculated in (3) above.

[0066] The subjects' oxHDL was 30.6 mOD / min on average, with a standard deviation of 4.7, and the oxHDL / HDL was 0.54 (mOD / min) / (mg / dL) on average, with a standard deviation of 0.16.

[0067] Test Example 2 Measurement of CI (Culculus Index) CI is an index showing the degree of calculus deposition. CI was measured for six representative teeth according to the following criteria. <Standards> 0: No deposition observed 1: Supra-gingival calculus present 2: Subgingival calculus present For the CIs of the six representative teeth, if the maximum CI value was 0, it was judged as "no CI," and if the maximum CI value was 1 or greater, it was judged as "with CI."

[0068] Test Example 3: Measurement of BOP (bleeding on probing) BOP is an evaluation index for the presence or absence of bleeding that occurs after probing (examination of periodontal pockets using a probe). BOP was measured for six representative teeth. If any one of the six representative teeth bleeds, it is considered "BOP present," and if none of the six teeth bleeds, it is considered "BOP absent."

[0069] The subjects were classified into a group with or without CI, and the oxHDL / HDL in each group was plotted, as shown in Figure 2. In Figure 2, the tips of the whiskers extending upward from the columns indicate the interquartile range multiplied by 1.5 and added to the 75th percentile value, the top of the columns indicates the 75th percentile value, the horizontal line in the columns indicates the 50th percentile value (median), the bottom of the columns indicates the 25th percentile value, and the tips of the whiskers extending downward from the columns indicate the interquartile range multiplied by 1.5 and subtracted from the 25th percentile value.

[0070] As shown in Figure 2, the oxHDL / HDL ratio in the CI group was significantly higher than that in the non-CI group. This suggests that when oxHDL / HDL is high, there is a possibility that tartar adhesion is present or the amount is large. In other words, it is suggested that the degree (presence or absence) of tartar adhesion can be measured by oxHDL / HDL. Note that this data was the result of an analysis conducted on only male subjects, but similar results were obtained when the analysis was conducted including female subjects.

[0071] The subjects were classified into a group with or without BOP, and the oxHDL / HDL in each group was plotted, as shown in Figure 3. In Figure 3, the tips of the whiskers extending upward from the columns indicate the interquartile range multiplied by 1.5 and added to the 75th percentile value, the top of the columns indicates the 75th percentile value, the horizontal line in the columns indicates the 50th percentile value (median), the bottom of the columns indicates the 25th percentile value, and the tips of the whiskers extending downward from the columns indicate the interquartile range multiplied by 1.5 and subtracted from the 25th percentile value.

[0072] As shown in Figure 3, the oxHDL / HDL ratio in the BOP group was significantly higher than that in the non-BOP group. This suggests that when oxHDL / HDL is high, there is a possibility that gingival bleeding occurs or is of a large amount. In other words, it was found that the degree (presence or absence) of gingival bleeding can be measured by oxHDL / HDL. Note that this data was the result of an analysis conducted on men only, but similar results were obtained when the analysis was conducted on women as well.

[0073] These findings suggest that a high oxHDL / HDL ratio may indicate poor oral hygiene, suggesting that oral hygiene can be measured using oxHDL / HDL.

Claims

1. A method for measuring an oral hygiene state of a subject from whom a blood sample was taken, comprising: dividing a value reflecting an amount of oxidized HDL in a blood sample by a value reflecting an amount of HDL in the blood sample as an index; The method, wherein the oral health condition is a bleeding gum condition.

2. A method for measuring an oral hygiene condition of a subject from whom a blood sample was taken, using as an index a value reflecting the amount of oxidized HDL in a blood sample divided by a value reflecting the amount of HDL in the blood sample, comprising: The method wherein the oral hygiene condition is a tartar condition.

3. (A) measuring a value reflecting the amount of oxidized HDL in a blood sample; and (B) measuring a value reflective of the HDL content of the blood sample; The method of claim 1 or 2, comprising:

4. The measurement of the reflection value of the amount of oxidized HDL (1) The method is carried out by a method including a step of mixing a blood sample with a solution containing a transition metal compound and an acidic buffer solution, The method according to claim 3.

5. The measurement of the reflection value of the amount of oxidized HDL moreover, (2) The method is carried out by a method including a step of measuring the free radicals produced in the step (1). The method according to claim 4.

6. The method according to claim 3, wherein the measurement of the reflection of the HDL amount is carried out by a direct HDL method.

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