JP7635066B2 - How to measure oral health - Google Patents

Description

The present disclosure relates to a method for measuring oral hygiene status, etc.

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

In addition, the adoption rate of dental examinations in health checkups is low, making the development of a simple method for checking oral hygiene status a challenge.

Patent No. 6779776

The objective of the present disclosure is to provide a method for measuring oral hygiene, such as the presence or absence of tartar or bleeding gums. Another objective is to provide a method for measuring oral hygiene, such as the presence or absence of tartar or bleeding gums, without a dental checkup.

The inventors discovered that when there is dental calculus 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 the blood sample is higher than when there is no dental calculus or gingival bleeding, and have made further improvements.

The present disclosure includes, for example, the subject matter described in the following sections:
Item 1.
A method for measuring the oral hygiene state 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.
Item 2.
Item 2. The method according to item 1, wherein the oral hygiene condition is a dental tartar buildup condition or a gingival bleeding condition.
Item 3.
(A) measuring a value reflective of the amount of oxidized HDL in a blood sample; and (B) measuring a value reflective of the amount of HDL in a blood sample.
3. The method according to claim 1 or 2, comprising:
Item 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,
Item 3. The method according to item 3.
Item 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).
Item 5. The method according to item 4.
Item 6.
Item 4. The method according to Item 3, wherein the measurement of the reflection value of the HDL amount is carried out by a direct HDL method.
Item 7.
Item 7. The method according to any one of Items 1 to 6, wherein the reflection value of the amount of oxidized HDL is a change in absorbance per unit time.
Item 8.
Item 8. The method according to any one of Items 1 to 7, wherein the reflection value of the HDL amount is a concentration.

A method for measuring oral hygiene, such as the presence or absence of tartar or bleeding gums, is provided. Also provided is a method for measuring oral hygiene, such as the presence or absence of tartar or bleeding gums, without the need for a dental checkup.

FIG. 1 is a diagram showing tooth numbers and names. 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 the blood samples (oxHDL/HDL) in the groups with and without CI. The results are plotted as a value reflecting the amount of oxidized HDL in blood samples divided by a value reflecting the amount of HDL in blood samples (oxHDL/HDL) for each subject in the groups with and without BOP.

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."

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.

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.

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 standard methods.

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.
In addition, 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. In addition, 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.

The value reflecting the amount of oxidized HDL refers to a value reflecting the amount of oxidized HDL contained in the blood sample, such as the weight (mass) or concentration of oxidized HDL. Alternatively, for example, a measured value reflecting the amount of oxidized HDL contained in the blood sample may be used, such as absorbance or fluorescence intensity. The measured value may be a value measured using a measurement auxiliary reagent. Examples of the measurement auxiliary reagent include a fluorescent dye, an oxidized HDL-specific recognition molecule (e.g., an antibody or a fragment thereof), or a combination of two or more of these.

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 that constitutes 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 Publication No. 6779776 (Patent Document 1), are included. Among these, it is preferable to perform the measurement 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 perform the measurement 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)".

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

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 produce 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 is possible without being affected by the amount of iron contained in the blood are achieved.

The reflected value of oxidized HDL is greater 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 iron compounds mentioned above, a divalent iron compound is particularly preferred.

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.

There are no particular limitations on the acidic buffer solution, so long as it has an acidic pH and a buffering effect, and any known buffer solution can be used. For example, an acetate buffer solution can be used.

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. In addition, when a color development method is used as a method for measuring free radicals in step (2) described below, it is particularly preferable that the pH of the acidic buffer solution is about 3 to 6.9.

The concentration of the acidic buffer is not particularly limited, but is, for example, 0.005 to 0.5 M, preferably 0.01 to 0.2 M.

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

As described above, in step (1), hydroperoxides (R-OOH) in oxidized HDL contained in the blood sample react with transition metal ions to produce free radicals such as peroxy radicals (R-OO ^. ) and alkoxy radicals (R-O ^. ). By measuring the free radicals produced in step (1), oxidized HDL can be measured.

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

The method for measuring free radicals is not particularly limited, and any known method can be used. Examples include the color development method, the chemiluminescence method, and the electron spin resonance method (ESR method).

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 similar device.

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 produce a 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.

In the above general formula (1), each R may be 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 the Rs substituting the same nitrogen atom are both methyl or ethyl.

Preferred compounds represented by general formula (1) are N,N-dimethyl-p-phenylenediamine (DMPD) and N,N-diethyl-p-phenylenediamine (DPD).

Salts of the compound represented by general formula (1) include, for example, sulfates, oxalates, and diacetates.

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

The compound represented by general formula (1) can also be dissolved in a solvent as needed. Examples of the solvent include, but are not limited to, 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.

The method for measuring the absorbance of the colored substance is not particularly limited and can be performed by a conventional method. For example, radical cations that exhibit a reddish purple color are generated by the reaction of free radicals with a color-forming substance, and the radical cations 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.

When measuring absorbance, it is preferable to measure the time course of absorbance between the start and end of the measurement in order to measure quantitatively. For example, the rate of increase in absorbance (change in absorbance per unit time) may be measured starting from 3 minutes after the start of the reaction between the free radicals and the color-forming substance and ending from 6 minutes after the start of the reaction.

The chemiluminescence method uses a substance (a 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.

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. Examples include luminol, dansyl-TEMPO, lucigenin, 2-methyl-6-p-methoxyphenylethylimidazopyrazine (MPEC), hydroxyphenyl fluorescein (HPF), aminophenyl fluorescein (APF), and Cypridina luciferin derivative (MCLA).

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 luminescent substance used, etc.

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 (M ₃ PO), 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).

The value reflecting the amount of HDL refers to a value reflecting the amount of HDL contained in the blood sample, such as the weight (mass) or concentration of HDL. It may also be a measured value reflecting the amount of HDL contained in the blood sample, such as absorbance or fluorescence intensity. The measured value may be a value measured using a measurement auxiliary reagent. Examples of the measurement auxiliary reagent include a fluorescent dye, an HDL-specific recognition molecule (e.g., an antibody or a fragment thereof), or a combination of two or more of these.

The method for measuring the HDL concentration of a blood sample is not particularly limited, and can be performed according to a conventional method. Examples include the HDL direct method, the HPLC method, and the precipitation method. The HDL direct method is a method in which free HDL cholesterol is reacted with cholesterol esterase and cholesterol oxidase in the presence of a dye to produce a colored substance, which is measured at a wavelength of, for example, 560 nm to calculate the HDL concentration. Among these, the HDL direct method is preferred.

The value obtained by dividing the reflected value of the oxidized HDL amount of a blood sample by the reflected value of the HDL amount of 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.

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 radicals and the color-forming substance, and the end 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).

As shown in the examples below, when the value reflected by the amount of oxidized HDL in a blood sample divided by the value reflected by the amount of HDL in a blood sample is high, there is a possibility that there is tartar adhesion or a large amount of tartar adhesion, or there is gingival bleeding or a large amount of tartar adhesion, and oral hygiene is considered to be poor. Therefore, according to the measurement method disclosed herein, the value reflected by the amount of oxidized HDL in a blood sample divided by the value reflected by the amount of HDL in a blood sample can be used as an index to measure the oral hygiene of the subject from whom the blood sample was taken.

Oral hygiene status includes, for example, tartar adhesion status (presence or absence of tartar adhesion, amount of adhesion, degree of adhesion, etc.), gingival bleeding status (presence or absence of bleeding, amount of bleeding, degree of bleeding, etc.). One common method for checking oral hygiene status is to measure dental plaque (amount of plaque), but while this method reflects the oral hygiene status on that day, tartar adhesion status and gingival bleeding status are thought to reflect the cumulative results of oral hygiene status up to the present.

According to the measurement method disclosed herein, 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 reference value, it is possible to predict (determine) that the oral hygiene condition is likely to be poor, compared to when the value is less than the reference value.

The reference value for comparing the value obtained by dividing the reflected value of the oxidized HDL amount of the blood sample taken from the subject by the reflected value of the HDL amount of 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 oxidized HDL amount is calculated as the rate of increase in absorbance (change in absorbance per unit time) (mOD/min) and the reflected value of the HDL amount (direct method) of the blood sample 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 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 for potential individuals with poor oral hygiene. In addition, depending on the method of measuring oxidized HDL and HDL amounts, the reference value can be set in accordance with the purpose of the test, taking into account the sensitivity, specificity, false positive rate, false negative rate, likelihood ratio, etc., following the general concept of testing.

The reference value for comparing 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 can be, for example, the value reflecting the amount of oxidized HDL in a blood sample taken from a subject with normal oral hygiene, more specifically, a subject without tartar and without gingival bleeding, divided by the value reflecting the amount of HDL in the blood sample. This value may be standardized from previously obtained data.

The reference value for comparing 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 can be, for example, the average, median, 25th percentile, 75th percentile, or mode of the value reflecting the amount of oxidized HDL in a blood sample divided by the value reflecting the amount of HDL in the blood sample in a group of multiple subjects.

Furthermore, according to the measurement method disclosed herein, it is also possible to measure changes in oral hygiene over time in the same subject. For example, if the value reflecting the amount of oxidized HDL in a blood sample taken from the subject divided by the value reflecting the amount of HDL in the blood sample increases over time, it is possible to predict (determine) that the oral hygiene condition may have deteriorated. For example, if the value reflecting the amount of oxidized HDL in a blood sample taken from the subject divided by the value reflecting the amount of HDL in the blood sample decreases over time, it is possible to predict (determine) that the oral hygiene condition may have improved.

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, it is possible to measure oral hygiene status based on the results of blood tests in health checkups, for example, even when a dental professional is not present or a dental checkup has not been conducted.

The present disclosure also encompasses a method for assisting in assessing the oral hygiene status of a subject. In this specification, the method may be referred to as the "assisted method of the present disclosure."

The assistance 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 assistance 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.

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

The assistance method disclosed herein can assist in assessing the oral hygiene status of a subject.

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.

Furthermore, the various characteristics (properties, structures, functions, etc.) described for each embodiment of the present disclosure above may be combined in any way to identify the subject matter encompassed by the present disclosure. In other words, the present disclosure encompasses all subject matter consisting of any combination of the combinable characteristics described in this specification.

The contents of this disclosure will be specifically explained using the following test examples. However, this 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.

The subjects were 159 men (mean age 52.0 years, standard deviation 6.4), excluding those with HbA1c of 5.6% or more, fasting blood glucose of 110 mg/dL or more, or BMI of 30 or more.
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.

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 vein of the subject using a vacuum blood collection tube, and then left at room temperature for 1 hour. Then, the blood was centrifuged under general serum separation conditions to obtain the supernatant (serum) as a blood sample, which was then stored at −80° C.

(2) Measurement of the reflectance value of oxidized HDL amount (oxHDL) A mixture of 0.1 M acetate buffer (pH 4.8) and 100 μM ammonium iron (II) sulfate hexahydrate was added to each well of the microplate and kept at 37° C. 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 505 nm was measured using a microplate reader (manufactured by Bio-Rad) set at 37° C. The absorbance was measured by setting it to Kinetics, measuring a total of 48 times (for a total of 8 minutes) every 10 seconds, and calculating the absorbance change per unit time (unit: mOD/min) from each value 3 minutes after the start of measurement to 6 minutes after the start of measurement.

(3) Measurement of the reflection value of HDL amount Using serum, HDL was measured by the direct HDL method (unit: mg/dL).

(4) Method for calculating the value (oxHDL/HDL) obtained by dividing the value reflecting the amount of oxidized HDL in the blood sample by the value reflecting the amount of HDL in the blood sample The value reflecting the amount of oxidized HDL (mOD/min) calculated in (2) above was divided by the value reflecting the amount of HDL (mg/dL) calculated in (3) above to calculate oxHDL/HDL (unit: (mOD/min)/(mg/dL)).

The subjects' oxHDL averaged 30.6 mOD/min with a standard deviation of 4.7, and oxHDL/HDL averaged 0.54 (mOD/min)/(mg/dL) with a standard deviation of 0.16.

Test Example 2 Measurement of CI (Culculus Index) CI is an index showing the degree of tartar 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 Regarding the CI of the six representative teeth, if the maximum CI value was 0, it was recorded as "no CI," and if the maximum CI value was 1 or greater, it was recorded as "CI present."

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

The subjects were classified into groups with and 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.

As shown in Figure 2, it was confirmed that the oxHDL/HDL of the group with CI was significantly higher than that of the group without CI. 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 is the result of an analysis conducted on male subjects only, but similar results were obtained when the analysis was conducted including female subjects.

The subjects were classified into groups with and 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.

As shown in Figure 3, it was confirmed that the oxHDL/HDL of the group with BOP was significantly higher than that of the group without BOP. This suggests that when oxHDL/HDL is high, there is a possibility that gingival bleeding will occur or the amount of bleeding will be large. 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 is the result of an analysis conducted on men only, but similar results were obtained when the analysis was conducted including women.

These findings suggest that a high oxHDL/HDL ratio may indicate poor oral hygiene. In other words, it is possible to measure oral hygiene using oxHDL/HDL.

Claims (6)

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 . 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 hygiene condition is a tartar condition . (A) measuring a value reflective of the amount of oxidized HDL in a blood sample; and (B) measuring a value reflective of the amount of HDL in a blood sample.
The method of claim 1 or 2, comprising: 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. 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. The method according to claim 3, wherein the measurement of the reflection value of HDL amount is performed by a direct HDL method.

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