CN115791328A

CN115791328A - Whitening effect evaluation method and evaluation structure of blue light whitening toothpaste

Info

Publication number: CN115791328A
Application number: CN202211523012.3A
Authority: CN
Inventors: 刘莉; 张环; 邓全富; 王伯初; 郝石磊; 董海德; 唐伟月; 王雄英; 肖博文; 邓嵘
Original assignee: Chongqing Dencare Corp; Chongqing University
Current assignee: Chongqing Dencare Corp; Chongqing University
Priority date: 2022-11-30
Filing date: 2022-11-30
Publication date: 2023-03-14

Abstract

The invention relates to the technical field of toothpaste efficacy evaluation, in particular to a whitening effect evaluation method of blue light whitening toothpaste. The method uses the hydroxyapatite sheet to prepare the tooth staining model, then uses the toothpaste to be tested to brush teeth and clean the stained hydroxyapatite sheet, dissolves the cleaned hydroxyapatite sheet in acid, and then stains the filter paper, so that the pigment in the hydroxyapatite sheet is fully transferred to a liquid phase firstly, and then transferred to the filter paper for solid phase analysis. And finally, a W value capable of effectively representing the whitening effect is obtained by calculating the change value of the L value before and after tooth brushing cleaning. By adopting the technical scheme, the technical problem that the prior art lacks a stable and reliable efficacy evaluation method for the blue light whitening toothpaste is solved, and the W value shows a small deviation value when the blue light whitening toothpaste is repeatedly measured for many times, so that the technical scheme can be used as a standardized whitening effect evaluation method for the blue light whitening toothpaste, accurately evaluates the performance of the toothpaste and has an ideal application prospect.

Description

Whitening effect evaluation method and evaluation structure of blue light whitening toothpaste

Technical Field

The invention relates to the technical field of toothpaste efficacy evaluation, in particular to a whitening effect evaluation method and an evaluation structure of blue light whitening toothpaste.

Background

With the improvement of living standard, people pay more attention to their facial appearance and the degree of whitening teeth is also receiving more attention from consumers. In recent years, with the development of medical technology, the application of chemical bleaching and covering whitening is common, and the two modes need to be carried out in a professional oral clinic or beauty hospital; in addition, a common tooth whitening mode is achieved by daily use of whitening toothpaste, common whitening principles of the toothpaste include physical whitening and chemical whitening, recently, some manufacturers apply a cold light whitening technology used in oral diagnosis to oral products or oral instruments, and daily household blue light whitening product experience is brought to consumers.

The cold light whitening is a chemical bleaching technology based on a photocatalytic reaction, and the method uses 480-520nm wavelength high-intensity blue light to irradiate a reagent which takes hydrogen peroxide or carbamide peroxide as a main component to generate an oxidation-reduction reaction, and removes pigments attached to the surface and the deep layer of teeth through dentin tubules, thereby achieving the whitening effect. Patent CN 111759751A discloses that a toothpaste product uses polydopamine to wrap and modify the surface of titanium dioxide nanoparticles, so that electrons are excited by the polydopamine under the condition of visible light and blue light to generate active oxygen with strong oxidizing property, and thus, pigments are decomposed by redox reaction to achieve the effect of whitening teeth.

At present, relevant patents and literature reports are reported for the development of blue light whitening toothpaste, but the research on the whitening effect evaluation method of blue light whitening toothpaste is still immature, a systematic and complete whitening effect evaluation method of blue light whitening toothpaste is not provided, although a small amount of patent documents mention simple methods, deep thinking is not provided from the principle of blue light whitening, comprehensive factors are not considered in scheme design, the influence of environmental factors is large, and the problems of authenticity, accuracy and repeatability of results are caused. For example, in patent CN 111759751A, when testing the whitening effect of blue light whitening toothpaste, a toothbrush is adopted to pick up the solution, the blue light of the LED is turned on, and the teeth are brushed for three minutes, and the whitening effect is evaluated by color level comparison. The design of the blue light whitening assessment method is simple and rough, and important test conditions such as blue light intensity, tooth brushing strength and tooth chromaticity assessment precision are not accurately controlled, so that the accurate whitening effect of the blue light whitening toothpaste cannot be accurately and quantitatively assessed, and therefore a systematic and simple whitening effect assessment method of the blue light whitening toothpaste is urgently needed, an accurate direction is provided for the development of products, and products with stable whitening effect are brought to consumers.

Disclosure of Invention

The invention aims to provide a whitening effect evaluation method of blue light whitening toothpaste, and solves the technical problem that a stable and reliable efficacy evaluation method aiming at the blue light whitening toothpaste is lacked in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme:

whitening effect evaluation of blue light whitening toothpasteThe estimation method is characterized in that the whitening effect of the blue light whitening toothpaste is represented by a W value, and the W value is obtained by the following formula: w = (Δ L) _T -ΔL ₀ Average value)/(Δ L ₀ Mean value of- Δ L _H Average) × 100;

wherein, Δ L _T The method comprises the following steps:

s1-1, dyeing the hydroxyapatite sheet to obtain hydroxyapatite sheet I, measuring the value L, and recording the value L _{Before T} ；

S1-2, under the irradiation of blue light, soaking a hydroxyapatite sheet I in toothpaste liquid to be detected, and brushing two surfaces of the hydroxyapatite sheet I respectively by using a toothbrush to obtain a hydroxyapatite sheet II;

s1-3: dissolving the hydroxyapatite tablet II by using hydrochloric acid to obtain a dissolved solution I; the filter paper is dyed with the dissolving solution I to obtain filter paper I, and the value L is measured and recorded as L _{After T} ；L _{T front} And L _{After T} The difference is Δ L _T ；

ΔL ₀ The method comprises the following steps:

s2-1: dyeing the hydroxyapatite sheet to obtain hydroxyapatite sheet I, measuring the value L, and recording the value L _{Before 0} ；

S2-2: under the irradiation of blue light, brushing two surfaces of the hydroxyapatite sheet I in water by using a toothbrush respectively to obtain a hydroxyapatite sheet III;

s2-3: dissolving the hydroxyapatite sheet III by using hydrochloric acid to obtain a dissolved solution II; the filter paper is dyed by using the dissolving solution II to obtain filter paper II, and the value L is measured and recorded as L _{After 0} ；L _{Before 0} And L _{After 0} The difference is Δ L ₀ (ii) a After multiple measurements, the average value is taken to obtain the delta L ₀ Average value;

ΔL _H the method comprises the following steps:

s3-1: detecting the L value of the hydroxyapatite sheet and recording as L _{H front} ；

S3-2: under the irradiation of blue light, brushing two surfaces of a hydroxyapatite sheet in water by using a toothbrush respectively to obtain a hydroxyapatite sheet IV;

s3-3: hydrochloric acid is used for dissolving the hydroxyapatite sheet IV,obtaining a dissolving solution III; the filter paper is dyed with the dissolving solution III to obtain filter paper III, and the value L is measured and recorded as L _{After H} ；L _{H front} And L _{After H} Is Δ L _H (ii) a After a plurality of measurements, the average value is taken to obtain the delta L _H Average value.

The principle and the advantages of the scheme are as follows:

in the technical scheme, the hydroxyapatite sheet is used for replacing the conventional experimental model bovine teeth in the prior art so as to reduce the in-batch errors of the sample measurement results. The technical scheme not only washes and measures the dyed hydroxyapatite sheet with toothpaste slurry, but also washes and measures the dyed hydroxyapatite sheet with clear water, and brushes and measures the dyed hydroxyapatite sheet with toothpaste slurry. After the above-mentioned detection process, Δ L is obtained _T 、ΔL ₀ Mean sum Δ L _H Average value, and then according to the formula W = (Δ L) _T -ΔL ₀ Average value)/(Δ L ₀ Mean value of- Δ L _H Mean value) × 100 to obtain W value, which is used for evaluating whitening effect of toothpaste. By adopting the detection method of the technical scheme, more accurate detection results can be obtained, the measurement error is greatly reduced, and the whitening effect of the blue light whitening toothpaste is more accurately evaluated.

According to the technical scheme, the estimation of the product on the tooth whitening effect is obtained by establishing a simple and effective evaluation method, and the effect presentation of the product after the product is on the market is ensured. The whitening effect evaluation method of the blue light whitening toothpaste is beneficial to the systematic research of blue light whitening products, and how to design the light intensity and wavelength of blue light in the optimal state when different whitening agent components are accurately determined, so that the direction is pointed out for the research and development of products.

Further, in S1-1, S2-1 and S3-1, the hydroxyapatite sheet is obtained by sintering an initial hydroxyapatite sheet at 750-850 ℃ for 3-5 hours. The hydroxyapatite sheet is sintered at proper temperature and time, so that the stability and parallelism of the test can be improved, and the cleaning capability of toothpaste or other oral care products can be more accurately reflected.

Further, in S1-1 and S2-1, a dyeing liquid used for the dyeing treatment is prepared by the following method: dissolving 16-18g of instant coffee, 16-18g of black tea powder, 0.4-0.5g of ferric chloride and 12-14g of gastric mucin in 1000mL of tryptone soybean broth to obtain the product. The staining solution suitable for the hydroxyapatite sheet can be prepared by adopting the formula, the hydroxyapatite sheet can be stably stained, and staining substances can be removed by tooth brushing under blue light treatment, so that the blue light whitening effect of the toothpaste can be accurately measured.

Further, in S1-1 and S2-1, the time of dyeing treatment is 15 to 20 days, L _{Before T} And L _{Before 0} The numerical ranges of (A) and (B) are all 20-40. The dyeing time ensures that the hydroxyapatite sheets are fully and uniformly dyed for subsequent experiments. L is _{T front} And L _{Before 0} The numerical range of (A) is 20-40, which can ensure the dyeing condition consistency of each hydroxyapatite sheet, ensure the parallelism of the experiment and reduce the experiment error.

Further, in S1-2, S2-2 and S3-2, the surface pressure of the brush head of the toothbrush to the object to be brushed is 140-160g. The weight for applying surface pressure is added at the brush head of the tooth brushing machine in the prior art, so that the surface pressure of the brush head to a brushed object is ensured to be 140-160g (the sum of the weight and the weight of a toothbrush fixing rod), the surface pressure is moderate, the normal tooth brushing force of a human body is close to, and the proper cleaning force to the hydroxyapatite sheet is ensured.

Further, in S1-2, S2-2 and S3-2, the distance from the blue light source to the object to be brushed is 5-10cm, and the wavelength of the blue light source is 480-520nm.

Further, in S1-2, S2-2 and S3-2, the number of times of brushing the toothbrush is 600-1000 times per face. The brushing times ensure that the brush head properly removes the dyeing substances on the hydroxyapatite sheet, ensure the difference between different test groups to be obvious and ensure the precision of the measurement range of the experiment.

Further, in S1-3, S2-3 and S3-3, the concentration of hydrochloric acid dissolved is 1.5 to 3.0mol/L. The hydrochloric acid with the concentration can ensure that the hydroxyapatite sheet is fully dissolved, and the dyeing substance is fully released for subsequent detection.

Further, in S1-3, S2-3 and S3-3, the dyeing time of the filter paper is 30-60min; the filter paper is plant fiber filter paper. The filter paper is plant fiber filter paper with dense gaps, and the high permeability and uniformity of the filter paper are utilized to rapidly and uniformly disperse the pigment, so that the liquid phase analysis is converted into the solid phase analysis.

Further, in S1-3, S2-3 or S3-3, the L value is detected after drying filter paper I, filter paper II or filter paper III. The drying process can eliminate the influence of moisture on the detection.

The technical scheme also provides a whitening effect evaluation structure of the blue light whitening toothpaste, which comprises a tooth brushing unit and a blue light source unit; the tooth brushing unit comprises a toothbrush fixing rod and a connecting rod, and the connecting rod comprises a horizontal part; the toothbrush fixing rod comprises a brush head fixing part for fixing a brush head and a rod part for being in sliding connection with the horizontal part, and a weight bearing ring is arranged above the rod part; the blue light source unit comprises light source mounting frames positioned at two sides of the toothbrush fixing rod; the connecting rod is used for driving the toothbrush fixing rod and the light source mounting rack to horizontally reciprocate; the light source mounting bracket includes a light source fixing head and a threaded rod that is threadedly connected with the horizontal part and is used for vertical movement.

The toothbrush fixing rod is provided with matched weights for adjusting the pressure of the toothbrush head. The blue light source is installed on the light source mounting bracket, and the light source mounting bracket includes the threaded rod, can adjust the light source height. The height of the light source can be accurately controlled through an external laser range finder, and the intensity of blue light can be quantitatively adjusted. The light source mounting bracket all is connected with the connecting rod with the toothbrush dead lever, can make the blue light follow the toothbrush motion like this, along with the path irradiation of toothbrush, has ensured the uniformity of every tooth sample blue light irradiation range.

Drawings

Fig. 1 is a schematic view of the overall structure of the blue whitening test platform in example 1 (the connection details of the toothbrush fixing rod and the light source mounting rack and the connecting rod are not shown);

fig. 2 is an exploded view of fig. 1.

Fig. 3 is a front view of a toothbrush fixing rod.

Fig. 4 is a right side view of the portion a of fig. 3 (with the brush head attached).

Fig. 5 is a front view of the threaded rod of the light source mounting bracket.

Detailed Description

The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto. Unless otherwise specified, the technical means used in the following examples are conventional means well known to those skilled in the art; the experimental methods used are all conventional methods; the materials, reagents and the like used are all commercially available.

Reference numerals in the drawings of the specification include: the toothbrush comprises a chute 1, a connecting rod 2, a tooth brushing unit host machine 3, a nut 4, a sample box 5, an experimental sample bottom plate 6, a toothbrush fixing rod 7, a light source mounting rack 8, a rod part 9, a brush head fixing part 10, a fixing bolt 11, a fixing cylinder 12, a weight bearing ring 13, an annular weight 14, a bristle fixing plate 15, bristles 16, an inner side bulge 17 and a threaded rod 18.

In this embodiment, a plurality of types of blue light whitening toothpaste and negative toothpaste were used as test products to evaluate the whitening effect of the blue light whitening toothpaste on teeth.

A method for evaluating whitening efficacy of blue light whitening toothpaste comprises the following steps:

step 1: the hydroxyapatite sheet used in the scheme is a circular thin sheet with the diameter of 10mm multiplied by the thickness of 5 mm. The hydroxyapatite tablet is a conventional substance used for replacing real teeth to evaluate the effect of oral cleaning products or related medicaments in the prior art, and the main component of the hydroxyapatite tablet is Ca ₁₀ (PO ₄ ) ₆ (OH) ₂ . In the embodiment of the scheme, the hydroxyapatite sheet is prepared in a laboratory (after the preparation method is attached), the self-made hydroxyapatite sheet is sintered for 4 hours (optional range is 3-5 hours) at high temperature of 800 ℃ (optional range is 750 ℃ -850 ℃), the treated hydroxyapatite sheet is loaded on a dyeing machine (the dyeing machine has applied utility model patent: CN 209269958U), and the configuration of the dyeing liquid comprises: 17.00g of instant coffee (optional range 16-18 g), 17.00g of black tea powder (optional range 16-18 g), 0.45g of ferric chloride (optional range 0.4-0.5 g), 13.00g of gastric mucin (optional range 12-14 g) dissolved in 1000mL of tryptone soy broth (TSB medium conventional in the art). After 15 days (can)Selecting a dyeing time range: 15-20 days), forming a film or a coating with thick coloring on the surface of the hydroxyapatite sheet, taking the dyed hydroxyapatite sheet down from a dyeing machine, washing with water, drying in the air for ten minutes, detecting the dyed surface with a color difference instrument, selecting the hydroxyapatite sheet with the L value of 20-40, and refrigerating for later use; the L values of all the dyed hydroxyapatite sheets were measured by a color difference meter (Konika Meinenda CM-700 d) and grouped.

The preparation process of the hydroxyapatite tablet comprises the following steps:

(1) Preparing a premixed solution containing 35wt% (optional range 20-50 wt%) of a freezing template agent dimethyl sulfoxide, an organic monomer hydroxyethyl acrylate monomer and a cross-linking agent N-hydroxymethyl acrylamide in deionized water, wherein the dimethyl sulfoxide accounts for 45wt% (optional range 20-50 wt%) of the total mass of the organic matter, and the weight ratio of the hydroxyethyl acrylate monomer to the N-hydroxymethyl acrylamide is 1.

(2) Adding the premixed liquid obtained in the step (1) into commercially available micron-sized hydroxyapatite powder, preparing hydroxyapatite slurry with the volume of 20vol% (the volume of the hydroxyapatite powder accounts for the volume of the premixed liquid, and the optional range is 10-30 vol%), and performing ball milling for 36h (the optional range is 24-72 h) to ensure that the viscosity of the hydroxyapatite slurry is less than 1 Pa.s.

(3) Adding 25mL of initiator hydrogen peroxide (the dosage ratio of the initiator to the hydroxyapatite slurry can be kept at 10-40mL 100mL) into 100mL of hydroxyapatite slurry at 45 ℃, stirring uniformly, and then injecting the slurry into a circular mold with the diameter of 10mm multiplied by the thickness of 5 mm.

(4) Directionally freezing for 120min (optional range of 100-140 min) in a low-temperature environment of-50 ℃ (optional range of-55 to 45 ℃) to generate a frozen wet blank, then heating the frozen wet blank at a heating rate of 0.2 ℃/min (optional range of 0.1 to 0.5 ℃/min) under the condition of absolute pressure of 5Pa (optional range of 2 to 7 Pa) until the temperature of the blank is-40 ℃ (optional range of-40 to-35 ℃), then carrying out constant-temperature vacuum sublimation treatment for 4h (optional range of 3 to 5 h) on the blank subjected to heating treatment to obtain a sublimed blank, heating the sublimed blank at a heating rate of 0.2 ℃/min (optional range of 0.1 to 0.5 ℃/min) under the condition of absolute pressure of 5Pa (optional range of 2 to 7 Pa) until the temperature of the sublimed blank is 25 ℃ (optional range of 20 to 30 ℃), and then carrying out constant-temperature vacuum drying treatment for 6h (optional range of 5 to 7 h) on the blank subjected to heating treatment to obtain a dried hydroxyapatite blank (namely, a hydroxyapatite sheet which is not sintered in the scheme.

(5) And (3) putting the dried porous hydroxyapatite blank into a sintering furnace, and sintering at 800 ℃ (optional range of 750 ℃ -850 ℃) for 4h (optional range of 3-5 h) to obtain a sintered hydroxyapatite sheet (namely the hydroxyapatite sheet subjected to sintering treatment for tooth brushing test).

In the examples which follow, hydroxyapatite sheets were obtained following the best preparation described above. Besides, the hydroxyapatite sheet can be prepared according to the optional range, the whitening effect of the toothpaste can be tested according to the test mode of the embodiment 1, the obtained W value is small in standard deviation in the group, the relative standard deviation is small, the discrete type of test data is good, the precision of the method is high, and the method is similar to the embodiment 1.

Step 2: and mounting the dyed hydroxyapatite sheet on a tooth sample base plate of a blue light whitening test platform. Blue light test platform of whitening reforms transform on prior art's tooth machine unit's basis, has mainly increased the blue light source unit to the function of shining the blue light when realizing brushing teeth the test.

Referring to fig. 1 and 2, a blue light whitening test platform is schematically illustrated, wherein a prior art tooth brushing machine set comprises a tooth brushing machine set main body 3. A sample box 5 is fixed above the main machine 3 of the tooth brushing machine set through screws, and an experimental sample bottom plate 6 (which can be used for fixing hydroxyapatite sheets for testing) for fixing hydroxyapatite samples is fixedly arranged at the bottom of the sample box 5. The height of the kit is 200mm, the designed height is higher than that of a common kit, so that the arrangement height of the blue light source is lower than the internal height of the kit, the irradiation range of the blue light source of each group is kept consistent, and the influence of other groups of light sources on the experiment of the group is avoided. The main machine 3 of the tooth brushing machine set is the same as a conventional tooth brushing machine, and is provided with a driving device and a control board with a counter. Two sliding holes 1 (guide rails) are respectively arranged on the front side and the rear side of the main machine 3 of the tooth brushing machine set, and a sliding block is connected in the sliding holes 1 in a sliding manner. The slider is fixed with the connecting rod 2 of the type of falling U, and every connecting rod 2 includes vertical portion (two) and the horizontal part of integrated into one piece, and the slider in the slide opening 1 passes through the screw and fixes with the vertical portion that corresponds. When the main machine 3 of the tooth brushing machine set operates, the machine set drives the sliding block to drive the connecting rod 2 to move left and right, and the tooth brushing process is simulated. The experiment sample bottom plate 6 is provided with three circular through holes with the diameter of about 10mm and the thickness of 5mm, three samples can be loaded at the same time each time for parallel test samples, the efficiency of the instrument is improved, the size of the through holes is consistent with the size of the hydroxyapatite sample, the hydroxyapatite sample is clamped into the through holes, and therefore the experiment sample bottom plate 6 just fixes the hydroxyapatite sheet.

Except the toothbrush unit host 3, the blue light whitening test platform also comprises a toothbrush unit and a blue light source unit. As shown in fig. 1 and 2, the tooth brushing unit includes a toothbrush fixing rod 7, and the blue light source unit includes a light source mounting bracket 8. In fig. 1 and 2, only the positional relationship between the toothbrush fixing rod 7 and the light source mounting bracket 8 and the connection rod 2 and the sample box 5 is shown, and the details of the arrangement of the toothbrush fixing rod 7 and the light source mounting bracket 8 on the connection rod 2 are not shown, and the details are shown later.

As shown in fig. 3 and 4, the toothbrush fixing rod 7 includes a head fixing portion 10 at a lower side and shaft portions 9 at an upper side, and two shaft portions 9 are fixed above each head fixing portion 10 by screws. Two fixing bolts 11 are connected to the brush head fixing portion 10 through threads, and an inner side protrusion 17 is integrally formed on the inner side of the lower portion of the brush head fixing portion 10. The specific manner of fixing the brush head to the brush head fixing portion 10 is as follows: the conventional brush head comprises two parts of a bristle fixing plate 15 and bristles 16, wherein the bristle fixing plate 15 is slightly wider than the bristles 16 in a rectangular array, so that the bristle fixing plate 15 can be abutted against the inner protrusions 17 on two sides below, and then two fixing bolts 11 are screwed downwards to abut against the bristle fixing plate 15 tightly, so that the brush head is fixed on the brush head fixing part 10. The gripping means not only secures the brush head, but also ensures that the bristles 16 can be pressed vertically against the surface of the test specimen. The upper end of the rod part 9 is penetrated with a fixed cylinder 12 and is connected in a sliding way. The fixed cylinder 12 is inserted and fixed in the horizontal portion of the tie bar 2 by bonding. A weight receiving ring 13 is fixedly bonded to the part of the rod part 9 above the fixed cylinder 12, and a ring-shaped weight 14 can be placed above the weight receiving ring 13 to increase the pressure during tooth brushing. In actual operation, the specific process is as follows: the brush head is first secured to the brush head fixture 10 and a pressure acquisition plate, conventional in the art, is positioned beneath the bristles 16 and connected to a computer for pressure data acquisition. Depending on the computer reading, an appropriate number of ring-like weights 14 are placed on demand above the weight receiving ring 13 until the computer reading is that of the desired brushing pressure (e.g., 150 g). The pressure acquisition plate is then removed and a hydroxyapatite sheet to be tested is placed beneath the bristles 16. This scheme can directly guarantee the best pressure between brush head and the experimental sample through weight quality, omits the step that the pressure was corrected (when the test was brushed first and is taken place to change, will carry out the pressure again and correct).

As shown in fig. 1, 2 and 5, the light source mounting brackets 8 are provided on both sides of the toothbrush fixing bar 7, and two light sources are provided for each test sample to ensure sufficient irradiation of the sample. The light source mounting rack 8 comprises a light source fixing head and a threaded rod 18, the light source fixing head is fixed on the threaded rod 18 through screws, and the light source is fixed below the light source fixing head through screws. A nut 4 is screwed on the upper side of the threaded rod 18, and the nut 4 is inserted and fixed in the horizontal part of the connecting rod 2. The threaded rod 18 is rotated to realize the ascending and descending of the light source fixing head, so that the height of the light source from the sample is adjusted, the specific height value is measured by a conventional laser range finder in the prior art, and the external laser range finder is independent of a blue light whitening test platform.

In the test process, the brush heads are flat-head toothbrushes of Jiajieshi, the surface pressure of each brush head to the enamel block is 150g (optional range is 140-160 g), the height of the blue light source is adjusted to be 5cm (optional distance is 5-10 cm), the wavelength is adjusted to be 480 (optional wavelength is 480-520 nm), and the intensity of the blue light source is determined to be a fixed value. The dyed hydroxyapatite sheet is treated 1 time on each side (i.e. the surface of the hydroxyapatite sheet is brushed by a brush head), and each time is 800 times (600-1000 times of operation can be carried out). In actual operation, the height of the blue light and the tooth brushing times can be adjusted according to the requirements of products to be tested, and in the technical scheme, the height of the blue light source is 5cm, and the tooth brushing times are 800 times each time for example, and subsequent experimental research is carried out to test the feasibility and the effect of the method. The preparation method of the test toothpaste liquid comprises the following steps: weigh 1 part toothpaste and 3 parts water into a 50mL centrifuge tube, mix for 15min with a vortex mixer to fully disperse and dissolve the toothpaste. For testing, the hydroxyapatite tablets were soaked in toothpaste liquid and the teeth brushed as described above. When the water is used for brushing teeth, the toothpaste liquid is replaced by the same amount of water.

And step 3: putting the tested hydroxyapatite tablets into a centrifuge tube, adding 50g of 2mol/L hydrochloric acid, oscillating to completely dissolve the hydroxyapatite tablets, then putting filter paper into the solution, soaking for 30min, finally taking out the filter paper, and drying for later use.

And 4, step 4: measuring the L values of all the filter papers processed in the step 3 by using a color difference meter, recording the L value difference value of the hydroxyapatite sheet and the processed filter paper, and processing data according to a W formula: preferably, to ensure the accuracy of the detection result Δ L ₀ And Δ L _H The average of multiple measurements was used. Δ L _T Using the value of a single measurement

W＝(ΔL _T -ΔL ₀ Average value)/(Δ L ₀ Mean value of- Δ L _H Mean value) × 100 formula (1)

ΔL ₀ The method for obtaining (control group of dyed hydroxyapatite tablets) was as follows:

the L value (required to be in the range of 20-40) of the dyed hydroxyapatite sheet is measured and is recorded as L _{Before 0} (ii) a Putting the dyed hydroxyapatite sheet into a blue light whitening test platform, carrying out tooth brushing operation on the dyed hydroxyapatite sheet by using clear water according to the mode of the step 2, and simultaneously applying blue light irradiation according to the mode of the step 2 to obtain a hydroxyapatite sheet A; performing the operation according to the step 3 on the hydroxyapatite sheet A to obtain dyed filter paper A, and testing the L value of the dyed filter paper A and recording the L value as L _{After 0} (ii) a Calculating Δ L ₀ The formula is as follows: Δ L ₀ ＝L _{After 0} -L _{Before 0} After a plurality of measurements, the mean value Δ L is taken ₀ Mean value of。

ΔL _T The acquisition method of (1) was as follows (experimental group):

the dyed hydroxyapatite sheet is tested for L value (20-40 is required) which is recorded as L _{Before T} (ii) a Putting the dyed hydroxyapatite sheet into a blue light whitening test platform, carrying out tooth brushing operation on the dyed hydroxyapatite sheet by using toothpaste to be tested according to the mode of the step 2, and simultaneously applying blue light irradiation according to the mode of the step 2 to obtain a hydroxyapatite sheet B; and (3) operating the hydroxyapatite sheet B according to the step (3), obtaining dyed filter paper B, and testing the L value of the dyed filter paper B and recording the L value as L _{After T} (ii) a Calculating Δ L _T The formula is as follows: Δ L _T ＝L _{After T} -L _{Before T} 。

ΔL _H The method for obtaining the hydroxyapatite chips is as follows (a control group of undyed hydroxyapatite chips):

the hydroxyapatite sheet (undyed) was tested for L value, which was noted as L _{H front} (ii) a Putting the hydroxyapatite sheet into a blue light whitening test platform, carrying out tooth brushing operation on the hydroxyapatite sheet by using water according to the mode of the step 2, and simultaneously applying blue light irradiation according to the mode of the step 2 to obtain a hydroxyapatite sheet C; and (4) operating the hydroxyapatite sheet C according to the step (3) to obtain dyed filter paper C, and testing the L value of the dyed filter paper C and recording the L value as L _{After H} (ii) a Calculating Δ L _H The formula is as follows: Δ L _H ＝L _{After H} -L _{H front} After several measurements, the mean value Δ L is taken _H Average value.

In the scheme, the higher the W value is, the better the whitening effect of the blue light whitening toothpaste is. Due to the complex dietary environment of consumers, in order to obtain the dyeing liquid closer to the living habits of the consumers, the experiment adopts the dyeing liquid prepared from a plurality of dyeing sources, the dyeing liquid has great influence on the experiment results, and the customized whitening efficacy W value is used for evaluating the experiment results of different times without using the Delta L value (Delta L) _H ) A direct comparison was made.

And 5: and calculating the W value of each experimental sample, evaluating the whitening effect of the product, analyzing the data by adopting span software, comparing by using t test, and evaluating the whitening effect of the product.

The blue light whitening toothpaste 1, the blue light whitening toothpaste 2 and the negative toothpaste were used for testing according to the above method, the three types of toothpaste were self-made toothpaste, the formula of the toothpaste is shown in table 1 below, and the obtained measurement results of Δ L value and W value are shown in tables 2 to 6.

Table 1: formula of blue light whitening toothpaste 1, blue light whitening toothpaste 2 and negative toothpaste

The preparation method of the toothpaste comprises the following steps:

negative toothpaste:

(1) Firstly, glycerol and sorbitol are added into a preparation container, then sodium carboxymethyl cellulose is added, and the mixture is quickly stirred and homogenized.

(2) Sequentially adding saccharin sodium, water, sodium lauroyl sarcosinate and sodium benzoate, and uniformly stirring.

(3) Adding hydrated silica by vacuumizing, and stirring for homogenizing.

(4) Finally, adding essence, stirring, homogenizing and degassing to obtain the toothpaste.

Blue light whitening toothpaste 1: the preparation method of the group is that hydrogen peroxide is added after the step of adding saccharin sodium in the preparation method of the negative toothpaste.

Blue light whitening toothpaste 2: the preparation method of the group is that carbamide peroxide is added after the step of adding saccharin sodium in the preparation method of the negative toothpaste.

Table 2: control raw data of unstained hydroxyapatite sheet (group A: unstained hydroxyapatite sheet as cleaning object and tooth brushing with water)

Table 3: control group raw data of dyed hydroxyapatite sheet (group B: dyed hydroxyapatite sheet as cleaning object and tooth brushing with Water)

Table 4: raw data of the first experimental group and W value calculation results (C group: dyed hydroxyapatite sheet as a cleaning object and tooth brushing with negative toothpaste)

Table 5: the second experimental group raw data and the W value calculation results (group D: dyed hydroxyapatite sheet as a cleaning object and brushing teeth with blue light whitening toothpaste 1)

Table 6: third experimental group raw data and W value calculation results (E group: dyed hydroxyapatite sheet as cleaning object and tooth brushing with blue light whitening toothpaste 2)

Statistical analysis was performed on the above raw data, and the results are shown in tables 7 to 10.

Table 7: in-group analysis of L values before assay

Table 8: in-line analysis of L values after test

Table 9: intra-and inter-group analysis of W values after test

Table 10: after-test multiple comparisons of W values with Bonferroni

As can be seen from the data analysis results in Table 7, the pre-test L values had an intraclass standard deviation SD of 2 or less and a relative standard deviation RSD of 3 or less. Therefore, the uniformity of the dyeing degree of the hydroxyapatite sheet is better, and the error of the subsequent experiment is reduced.

As can be seen from the data analysis results in Table 8, the intra-group standard deviation SD of the L values after the test is less than or equal to 2, and the relative standard deviation RSD is less than or equal to 2. From this, it is clear that the dispersion of the test data is good and the precision of the method is high.

As can be seen from the data analysis results in Table 9, the W values after the test had an intraclass standard deviation SD of 9 or less and a relative standard deviation RSD of 7 or less. From this, it is clear that the dispersion of the test data is good and the precision of the method is high.

The data analysis results in table 10 show that after the experimental sample test, the W values of the blue light whitening toothpaste 1 treatment group and the blue light whitening toothpaste 2 treatment group are significantly different from the W values of the negative toothpaste treatment group; there was no significant statistical difference in W values between the blue whitening toothpaste 1 treatment group and the blue whitening toothpaste 2 treatment group. It can be concluded that both blue light whitening toothpaste 1 and blue light whitening toothpaste 2 have good whitening effects.

Example 2

This example is substantially the same as example 1 except that the test cleaning object was replaced with a bovine tooth sample from a hydroxyapatite sheet (stained or unstained). The bovine tooth sample is self-made, and the preparation method comprises the following steps: cutting the middle incisor of the cattle into 80-100mm by a cutting machine ² The height of the model is 10mm (five surfaces except the labial surface can be polished by a water mill), the polished tooth sample is put into a polytetrafluoroethylene mould to wrap the other surfaces except the labial surface, the size of each small hole of the mould is 13mm multiplied by 14mm, and the self-solidified denture powder is poured into the mould after being debugged and naturally solidified. After setting, the tooth specimen was taken out, and the burred surface and the exposed enamel surface were slightly polished with a water mill (when polishing the enamel surface, care was taken to observe that the resin and stained portions of the enamel surface were polished smooth while avoiding exposure of dentin), so that the final size was 13mm × 14mm in size and 10mm in height.

Since the bovine tooth sample is difficult to decompose with hydrochloric acid, step 3 in example 1 is no longer applicable, and the tooth-brushed bovine tooth is directly subjected to an L value test by using a color difference meter and calculated according to the W' formula:

W’＝(ΔL _T ’-ΔL ₀ ' average value)/(Δ L ₀ ' average value-. DELTA.L _H ' average value) × 100 formula (2)

ΔL ₀ ' the method of obtaining was as follows (control group of stained bovine tooth samples):

testing the L value (required to be in the range of 20-40) of the stained bovine tooth sample, and recording the L value as L _{Before 0} '; placing the dyed bovine tooth sample into a blue light whitening test platform, using clear water to brush teeth of the dyed bovine tooth sample according to the mode of the step 2, andsimultaneously applying blue light irradiation in the mode of the step 2 to obtain a cleaned bovine tooth sample A; the cleaned bovine tooth sample A is tested for the value L which is recorded as L _{After 0} '; calculating Δ L ₀ ', the formula is: Δ L ₀ ’＝L _{After 0} ’-L _{Before 0} ', taking the average value DeltaL after multiple measurements ₀ ' average value.

ΔL _T The acquisition method of (a) was as follows (experimental group):

testing the L value (required to be in the range of 20-40) of the stained bovine tooth sample, and recording the L value as L _{Before T} '; placing the dyed bovine tooth sample into a blue light whitening test platform, carrying out tooth brushing operation on the dyed bovine tooth sample by toothpaste to be tested according to the mode of the step 2, and simultaneously applying blue light irradiation according to the mode of the step 2 to obtain a cleaned bovine tooth sample B; the cleaned bovine tooth sample B is tested for the value L which is recorded as L _{After T} '; calculating Δ L _T ', the formula is: Δ L _T ’＝L _{After T} ’-L _{Before T} ’。

ΔL _H The method of obtaining (control group of unstained bovine tooth sample) was as follows:

testing the L value (required to be in the range of 20-40) of the stained bovine tooth sample, and recording the L value as L _{H front} '; placing the hydroxyapatite sheet into a blue light whitening test platform, performing tooth brushing operation on the dyed bovine tooth sample by using water according to the mode in the step 2, and applying blue light irradiation according to the mode in the step 2 to obtain a cleaned bovine tooth sample C; the cleaned bovine tooth sample C is tested for the value L which is recorded as L _{After H} '; calculating Δ L _H ', the formula is: Δ L _H ’＝L _{After H} ’-L _{H front} ', taking the average value DeltaL after multiple measurements _H ' average value.

The results of the Δ L 'and W' values obtained by performing the test using the blue light whitening toothpaste 1, the blue light whitening toothpaste 2, and the negative toothpaste according to the above method are shown in tables 11 to 15.

Table 11: control group raw data of unstained bovine tooth sample (group A: unstained colored bovine tooth sample as cleaning object and water brushing teeth used)

Table 12: control group raw data of stained bovine dental samples (group B: stained bovine dental samples as cleaning objects and water brushing teeth used)

Table 13: first experimental group raw data and W value calculation results (group C: stained colored bovine tooth sample as cleaning object and brushing teeth using negative toothpaste)

Table 14: second experimental group raw data and W value calculation results (group D: stained colored bovine tooth sample as cleaning object and brushing teeth with blue light whitening toothpaste 1)

Table 15: third experimental group raw data and W value calculation results (group E: stained colored bovine tooth sample as cleaning object and brushing teeth with blue light whitening toothpaste 2)

Statistical analysis was performed on the above raw data, and the results are shown in tables 16 to 21.

Table 16: in-line analysis of the Pre-test L values

Table 17: in-line analysis of L values after test

Table 18: after test Δ L _T ' Intra-and inter-group analysis of value groups

Table 19: analysis of W' values within groups after test

Table 20: after test Δ L _T ' values Bonferroni multiple comparisons

Table 21: multiple comparisons of W' values after the test, bonferroni

As can be seen from the results of the data analysis in Table 16, the pre-test L values had an intra-group standard deviation SD of 4 or less and a relative standard deviation RSD of 10 or less. From this, it was found that the staining degree of the bovine tooth sample was less uniform.

As can be seen from the results of the data analysis in Table 17, the intra-group standard deviation SD of the L values after the test was not more than 5 and the relative standard deviation RSD was not more than 10. This indicates that the dispersion of the test data is poor and the precision of the method is poor.

As can be seen from the data analysis results in Table 18, the in-group standard deviation SD of the Δ L values after the test was not more than 4 and the relative standard deviation RSD was not more than 24. This indicates that the dispersion of the test data is poor and the precision of the method is poor.

As is clear from the data analysis results in Table 19, the W values after the test had an intraclass standard deviation SD of not more than 110 and a relative standard deviation RSD of not more than 85. This indicates that the discrete type of test data is very poor and the precision of the method is very poor.

The data analysis results in table 20 show that after the experimental sample test, the Δ L of the blue light whitening toothpaste 1 treatment group, the blue light whitening toothpaste 2 treatment group and the negative toothpaste treatment group are respectively _T ' there are significant statistical differences in values; delta L of blue light whitening toothpaste 1 treatment group and blue light whitening toothpaste 2 treatment group _T ' there were no significant statistical differences in the values. It can be concluded that both blue light whitening toothpaste 1 and blue light whitening toothpaste 2 have a better whitening effect.

As can be seen from the data analysis results in table 21, after the experimental sample test, the W' values of the blue light whitening toothpaste 1 treatment group and the blue light whitening toothpaste 2 treatment group are significantly different from those of the negative toothpaste treatment group; there was no significant statistical difference in W' values between the blue whitening toothpaste 1 treatment group and the blue whitening toothpaste 2 treatment group. It can be concluded that both blue light whitening toothpaste 1 and blue light whitening toothpaste 2 have good whitening effects.

Example 3

This embodiment is basically the same as embodiment 1, except that step 3 is not performed, and the specific flow is as follows:

steps 1 and 2 are the same as Steps 1 and 2 of example 1, and step 4 is the same as step 5 of example 1.

And step 3: and (3) detecting the L value of the cleaned hydroxyapatite sheet, wherein the cleaned hydroxyapatite sheet is the hydroxyapatite sheet subjected to tooth brushing operation according to the mode of the step (2), and the cleaned hydroxyapatite sheet is obtained. Data was processed according to the formula W':

W”＝(ΔL _T ”-ΔL ₀ "average value)/(Δ L ₀ "mean value-. DELTA.L _H "average value) × 100 formula (3)

ΔL ₀ "the method for obtaining the hydroxyapatite tablets was as follows (control group of dyed hydroxyapatite tablets):

the dyed hydroxyapatite sheet is tested for L value (20-40 is required) which is recorded as L _{Before 0} "; putting the dyed hydroxyapatite sheet into a blue light whitening test platform, carrying out tooth brushing operation on the dyed hydroxyapatite sheet by using clear water according to the mode of the step 2, simultaneously applying blue light irradiation according to the mode of the step 2 to obtain a hydroxyapatite sheet A, measuring the value L, and recording the value L as the value L _{After 0} "; calculating Δ L ₀ ", the formula is: Δ L ₀ ”＝L _{After 0} ”-L _{Before 0} ", after a number of measurements, take the average value Δ L ₀ "average value.

ΔL _T "the acquisition method was as follows (experimental group):

the L value (required to be in the range of 20-40) of the dyed hydroxyapatite sheet is measured and is recorded as L _{Before T} "; putting the dyed hydroxyapatite sheet into a blue light whitening test platform, carrying out tooth brushing operation on the dyed hydroxyapatite sheet by using toothpaste to be tested according to the mode of the step 2, simultaneously applying blue light irradiation according to the mode of the step 2 to obtain a hydroxyapatite sheet B, measuring the value L, and marking as L _{After T} "; calculating Δ L _T ", the formula is: Δ L _T ”＝L _{After T} ”-L _{Before T} ". After a plurality of measurements, the mean value Δ L is taken _T "average value.

ΔL _H "the method of obtaining the hydroxyapatite was as follows (control group of unstained hydroxyapatite tablets):

the hydroxyapatite (unstained) plates were tested for L value, noted L _{H front} "; putting the hydroxyapatite sheet into a blue light whitening test platform, brushing teeth on the hydroxyapatite sheet by using water according to the mode of the step 2, applying blue light irradiation according to the mode of the step 2 to obtain a hydroxyapatite sheet C, measuring the value L, and recording the value L as the value L _{After H} "; calculating Δ L _H The formula is as follows: Δ L _H ”＝L _{After H} ”-L _{H front} ", after a number of measurements, take the average value Δ L _H "average value.

Blue light whitening toothpaste 1, blue light whitening toothpaste 2 and negative toothpaste were tested according to the method of example 1, and 20 samples were tested for each of groups a-E. Pre-experiment L values (L) for groups A-E _{H front} "or L _{Before T} "or L _{Before 0} ") and post-test L values (L) for groups A-E _{After H} "or L _{After T} "or L _{After 0} ") to determine intra-group data bias:

value of L before experiment (L) _{H front} "or L _{Before T} "or L _{Before 0} ", samples were selected that stained uniformly, and the L value was between 20 and 40 to ensure parallelism of the experiment, as follows): group A (L) _{H front} ") RSD (relative standard deviation) =1.07, group B (L) _{Before 0} ") RSD =2.10, group C (L) _{T front} ") RSD =2.73, group D (L) _{Before T} ") RSD =1.72, group E (L) _{Before T} ”)RSD＝2.82；

Post-test L value (L) _{After H} "or L _{After T} "or L _{After 0} "): group A (L) _{After H} ") RSD =3.29, group B (L) _{After 0} ") RSD =4.45, group C (L) _{After T} ") RSD =3.77, group D (L) _{After T} ") RSD =4.62, group E (L) _{After T} ”)RSD＝3.56。

The average W "values of the negative toothpaste (group C), blue light whitening toothpaste 1 (group D), and blue light whitening toothpaste 2 (group E) were calculated to be 107.38, 214.93, and 224.01, respectively. W "value data relative standard deviation: RSD =15.77 for group C, RSD =14.65 for group D, and RSD =9.31 for group E

In this example, the hydroxyapatite sheet after the tooth brushing treatment was not dissolved in hydrochloric acid, and the L value was directly measured on the hydroxyapatite sheet after the tooth brushing treatment. After the operation is reduced, the measured parameter W 'reflecting the whitening capability of the toothpaste is larger, and the relative standard deviation of the average W' in each group is larger, which indicates that the experimental method has poor parallelism and accuracy, and is not suitable for being used as a standard method for evaluating the whitening effect of the toothpaste.

Example 4

This example is basically the same as example 1, except that the cleaning object is selected, and the cleaning object used in this example is a hydroxyapatite sheet that is not sintered.

Blue light whitening toothpaste 1, blue light whitening toothpaste 2 and negative toothpaste were tested according to the method of example 1, and 20 samples were tested for each of groups a-E.

Pre-experiment L values (L) for groups A-E _{H front} Or L _{T front} Or L _{Before 0} ) Analysis was performed for post-experimental L values (L) for groups A-E _{After H} Or L _{After T} Or L _{After 0} ) Analysis was performed to determine intra-group data bias:

value of L before experiment (L) _{H front} Or L _{Before T} Or L _{Before 0} ): group A (L) _{H front} ) RSD (relative standard deviation) =1.23, group B (L) _{Before 0} ) RSD =2.43, group C (L) _{T front} ) RSD =2.46, group D (L) _{T front} ) RSD =2.47, group E (L) _{Before T} )RSD＝2.97；

Post-test L value (L) _{After H} Or L _{After T} Or L _{After 0} ): group A (L) _{After H} ) RSD =5.07, group B (L) _{After 0} ) RSD =6.35, group C (L) _{After T} ) RSD =13.65, group D (L) _{After T} ) RSD =17.54, group E (L) _{After T} )RSD＝16.07。

The average W values of the negative toothpaste (group C), the blue light whitening toothpaste 1 (group D) and the blue light whitening toothpaste 2 (group E) are respectively 81.16, 116.09 and 121.98 through calculation; w value data relative standard deviation: RSD group C =50.46, RSD group D =50.35, RSD group E =46.94.

The experimental result shows that the calcining treatment step of the cleaning object is very critical to ensure the stability of the experimental method, and if the hydroxyapatite sheet is not calcined, the test result (W value) is smaller and the deviation of the data in the group is larger.

Example 5

This example is basically the same as example 1, except that the cleaning object is selected, and the cleaning object used in this example is a hydroxyapatite sheet sintered at a high temperature of 500 ℃ for 6 hours.

Pre-test L values (L) for groups A-E _{H front} Or L _{Before T} Or L _{Before 0} ) Analysis was performed for the post-test L values (L) of groups A-E _{After H} Or L _{After T} Or L _{After 0} ) Analysis was performed to determine intra-group data bias:

value of L before experiment (L) _{H front} Or L _{T front} Or L _{Before 0} ): group A (L) _{H front} ) RSD (relative standard deviation) =1.72, group B (L) _{Before 0} ) RSD =2.79, group C (L) _{T front} ) RSD =2.80, group D (L) _{T front} ) RSD =2.71, group E (L) _{Before T} )RSD＝2.55；

Post-test L value (L) _{After H} Or L _{After T} Or L _{After 0} ): group A (L) _{After H} ) RSD =4.25, group B (L) _{After 0} ) RSD =5.01, group C (L) _{After T} ) RSD =10.43, group D (L) _{After T} ) RSD =14.47904, group E (L) _{After T} )RSD＝13.81。

The average W values of the negative toothpaste (group C), the blue light whitening toothpaste 1 (group D) and the blue light whitening toothpaste 2 (group E) are respectively 79.12, 148.97 and 150.67 through calculation; w value data relative standard deviation: RSD group C =42.41, RSD group D =37.15, RSD group E =36.16.

The experimental result shows that the calcining treatment step of the clean object is very critical to ensure the stability of the experimental method, and if the calcining temperature of the hydroxyapatite sheet is too low, the test result (W value) is smaller and the deviation of the data in the group is larger.

Example 6

This example is basically the same as example 1, except that the cleaning object is selected, and the cleaning object used in this example is a hydroxyapatite sheet sintered at a high temperature of 1000 ℃ for 4 hours.

Value of L before experiment (L) _{H front} Or L _{Before T} Or L _{Before 0} ): group A (L) _{H front} ) RSD (relative standard deviation) =2.51, group B (L) _{Before 0} ) RSD =2.57, group C (L) _{T front} ) RSD =2.73, group D (L) _{Before T} ) RSD =2.55, group E (L) _{Before T} )RSD＝2.72；

Post-test L value (L) _{After H} Or L _{After T} Or L _{After 0} ): group A (L) _{After H} ) RSD =3.53, group B (L) _{After 0} ) RSD =4.23, group C (L) _{After T} ) RSD =6.86, group D (L) _{After T} ) RSD =4.88, group E (L) _{After T} )RSD＝4.14。

The average W values of the negative toothpaste (group C), the blue light whitening toothpaste 1 (group D) and the blue light whitening toothpaste 2 (group E) are respectively 97.18, 188.44 and 188.28 through calculation; w value data relative standard deviation: RSD group C =22.93, RSD group D =11.09, RSD group E =8.65.

The experimental result shows that the calcining treatment step of the cleaning object is very critical to ensure the stability of the experimental method, and if the calcining temperature of the hydroxyapatite sheet is too high, the test result (W value) is larger and the deviation of the data in the group is larger.

Example 7:

in this example, 80 pieces of each of the experimental samples used in example 1, example 2, example 4, example 5 and example 6 were selected, stained by the staining method of example 1, and then the L values of the samples were measured to compare the magnitude of the variation in the L values after staining between the samples.

L value after dyeing: example 1 (L) RSD (relative standard deviation) =2.82, example 2 (L) RSD =8.46, example 4 (L) RSD =8.56, example 5 (L) RSD =6.28, example 6 (L) RSD =6.64;

the experimental results show that the hydroxyapatite sheets after special treatment have better dyeing uniformity (example 1), and the temperature and time of calcination treatment affect the dyeing uniformity of the hydroxyapatite sheets (examples 4-6), resulting in larger data difference between the dyed sample groups. Using bovine teeth as the test object, the staining uniformity was poor and the relative deviation of the L value of the sample was large (example 2).

Summary and analysis of the experimental results of the above examples:

example 1 the whitening effect of a blue light whitening toothpaste on teeth was evaluated using the method of this patent. Example 2 was verified using experimental conditions more commonly used in current whitening methods. Examples 3-6 are various attempts by the inventors before determining the mode of operation of example 1. Now, comparative analysis is performed on the differences of specific data in the examples, which are as follows:

(1) In example 1, the "hydroxyapatite sheet sintered at a high temperature of 800 ℃ for 4 hours" was used as an experimental sample and subjected to the dyeing treatment, and the data analysis in table 7 revealed that the L value data after the staining of the hydroxyapatite sheet (before the tooth brushing treatment) had a small relative standard deviation. In example 2, the staining treatment was performed using bovine teeth as an experimental sample, and the data analysis in table 16 shows that the L value data after staining bovine teeth (before the brushing treatment) was relatively high in standard deviation. Example 4 using unsintered hydroxyapatite plates for staining, the relative standard deviation of the L value data after staining (before brushing) was large. Comparison of the RSD data of the same groups revealed that the pre-test L values (L) of groups A, B, C, D and E in example 1 _{H front} Or L _{Before T} Or L _{Before 0} ) The RSD data are lower than those of examples 2 and 4, and it is clear that the uniformity of the staining degree of the hydroxyapatite sheets subjected to the special treatment is better.

(2) In example 1, the "hydroxyapatite sheet sintered at 800 ℃ for 4 hours" was used as an experimental sample and was dyed, and the data analysis in table 8 shows that the L value data of the treated filter paper has a small relative standard deviation. In example 4, the filter paper was dyed using a hydroxyapatite sheet without sintering, and the relative standard deviation of the L value data of the treated filter paper was large. Comparison of the RSD data of the same groups revealed that the experimental L values (L) of groups A, B, C, D and E in example 1 _{After H} Or L _{After T} Or L _{After 0} ) RSD data was lower than that of example 4, and thus, it can be seen that exampleThe RSD value in 4 is higher than that in the embodiment 1, the influence of the test data is larger, the structural stability of the hydroxyapatite sheet after special treatment is high, and the influence on the form of the hydroxyapatite sheet after external force treatment such as tooth brushing is smaller. The methods of treating the hydroxyapatite sheets of examples 5 and 6 were not optimized, resulting in a post-experimental L value (L) _{After H} Or L _{After T} Or L _{After 0} ) RSD data is large.

(3) Example 1 used "step 3: putting the tested hydroxyapatite tablets into a centrifuge tube, adding 50g of hydrochloric acid of 2mol/L, oscillating to completely dissolve the hydroxyapatite tablets, then putting filter paper into the solution, soaking for 30min, finally taking out the filter paper, and drying for later use, wherein the data analysis in the table 8 shows that the relative standard deviation of the L value data of the treated filter paper is small. In example 2, the L value after the conventional direct test of the bovine tooth test was used, and the data analysis in Table 17 shows that the L value data after the bovine tooth brush test had a large relative standard deviation. In example 3, the L value after the hydroxyapatite sheet test was directly tested was used, and the relative standard deviation of the L value data after the brushing test was large. Comparing the RSD data of the same group, the RSD data of the groups A, B, C, D and E in the embodiment 1 is lower than that of the

embodiments

2 and 3, so that the fact that all the pigments can be transferred into the liquid solution by completely dissolving the hydroxyapatite sheet through the treatment of the special step 3 in the patent can be known, and meanwhile, the filter paper is adopted for transferring the pigments, so that the discrete type of the test data is better, and the precision of the method is higher.

(4) In the embodiment 1, the whitening degree is calculated by adopting a W value formula, the influence of experimental samples and experimental processes on the chromaticity is considered in the formula, the whitening value obtained by the formula is closer to the real test value of the blue light whitening toothpaste, and the W value data has lower relative standard deviation through the data analysis of the table 9. Example 2 delta L before and after the more common test was used to express whiteness without considering the influence of experimental samples and experimental processes on chromaticity, and it can be seen from the data analysis in table 18 that delta L _T ' value data is relatively high with respect to standard deviation. Comparison of the RSD data of the same groups shows that the data of groups C, D and E in example 1 are all lower than those in example 2, so that the experimental samples and experiments are considered after the treatment of the patent methodThe influence of the test process on the chromaticity also ensures that the test data has better discrete type and the method has higher precision.

(5) In example 2, whiteness was calculated using the W 'value, and the data analysis in table 11 shows that the W' value data has a high relative standard deviation. By comparing with the values in table 9, the relative standard deviation of the W' value under the experimental conditions of example 2 is very high, which shows that the experimental method of example 1 (including using hydroxyapatite sheet instead of bovine teeth) greatly improves the discrete form of the experimental data, and the precision of the method is obviously improved.

The foregoing is merely an example of the present invention and common general knowledge in the art of designing and/or characterizing particular aspects and/or features is not described in any greater detail herein. It should be noted that, for those skilled in the art, without departing from the technical solution of the present invention, several variations and modifications can be made, and these should also be considered as the protection scope of the present invention, which will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.

Claims

1. A whitening effect evaluation method of blue light whitening toothpaste is characterized by comprising the following steps: the whitening effect of the blue light whitening toothpaste is characterized by a W value, wherein the W value is obtained by the following formula: w = (Δ L) _T -ΔL ₀ Average value)/(Δ L ₀ Mean value of- Δ L _H Average) × 100;

wherein, Δ L _T The method comprises the following steps:

s1-1, dyeing the hydroxyapatite sheet to obtain a hydroxyapatite sheet I, measuring the value L, and recording the value L as the value L _{T front} ；

s1-3: dissolving the hydroxyapatite tablet II by using hydrochloric acid to obtain a solution I; the filter paper is dyed by using the dissolving solution I,a filter paper I was obtained and the value of L was measured and recorded as L _{After T} ；L _{Before T} And L _{After T} The difference is Δ L _T ；

ΔL ₀ The method comprises the following steps:

s2-1: dyeing the hydroxyapatite sheet to obtain hydroxyapatite sheet I, measuring the value L, and recording as L _{Before 0} ；

s2-3: dissolving the hydroxyapatite sheet III by using hydrochloric acid to obtain a dissolved solution II; the filter paper is dyed by using the dissolving solution II to obtain filter paper II, and the value L is measured and recorded as L _{After 0} ；L _{Before 0} And L _{After 0} The difference is Δ L ₀ (ii) a After a plurality of measurements, the average value is taken to obtain the delta L ₀ Average value;

ΔL _H the method comprises the following steps:

s3-1: detecting the L value of the hydroxyapatite sheet and marking as L _{H front} ；

s3-3: dissolving the hydroxyapatite sheet IV by using hydrochloric acid to obtain a dissolved solution III; the filter paper III was stained with the dissolving solution III to obtain a filter paper III, and the value L was measured and recorded as L _{After H} ；L _{H front} And L _{After H} Is Δ L _H (ii) a After a plurality of measurements, the average value is taken to obtain the delta L _H Average value.

2. The whitening effect evaluation method of blue light whitening toothpaste according to claim 1, wherein: in S1-1, S2-1 and S3-1, the hydroxyapatite sheet is obtained by sintering an initial hydroxyapatite sheet at 750-850 ℃ for 3-5 h.

3. The whitening effect evaluation method of the blue light whitening toothpaste according to claim 1, wherein: in S1-1 and S2-1, the dyeing liquid used for the dyeing treatment was prepared as follows: dissolving 16-18g instant coffee, 16-18g black tea powder, 0.4-0.5g ferric chloride and 12-14g gastric mucin in 1000mL tryptone soybean broth.

4. The whitening effect evaluation method of the blue light whitening toothpaste according to claim 3, wherein: in S1-1 and S2-1, the dyeing treatment time is 15-20 days, L _{Before T} And L _{Before 0} The numerical ranges of (A) and (B) are all 20-40.

5. The whitening effect evaluation method of blue light whitening toothpaste according to claim 1, wherein: in S1-2, S2-2 and S3-2, the surface pressure of the toothbrush head to the object to be brushed is 140-160g.

6. The whitening effect evaluation method of the blue light whitening toothpaste according to claim 5, wherein: in S1-2, S2-2 and S3-2, the distance between the blue light source and the object to be brushed is 5-10cm, and the wavelength of the blue light source is 480-520nm.

7. The whitening effect evaluation method of the blue light whitening toothpaste according to claim 6, wherein: in S1-2, S2-2 and S3-2, the number of times the toothbrush is brushed is 600-1000 times per face.

8. The whitening effect evaluation method of blue light whitening toothpaste according to claim 1, wherein: in S1-3, S2-3 and S3-3, the concentration of hydrochloric acid dissolved is 1.5-3.0mol/L.

9. The whitening effect evaluation method of blue light whitening toothpaste according to claim 8, wherein: in S1-3, S2-3 and S3-3, the dyeing time of the filter paper is 30-60min; the filter paper is plant fiber filter paper; and drying the filter paper I, the filter paper II or the filter paper III, and then detecting the L value.

10. A whitening effect evaluation structure of blue light whitening toothpaste is characterized by comprising a tooth brushing unit and a blue light source unit; the tooth brushing unit comprises a toothbrush fixing rod and a connecting rod, and the connecting rod comprises a horizontal part; the toothbrush fixing rod comprises a brush head fixing part for fixing the brush head and a rod part for being in sliding connection with the horizontal part, and a weight bearing ring is arranged above the rod part; the blue light source unit comprises light source mounting frames positioned at two sides of the toothbrush fixing rod; the connecting rod is used for driving the toothbrush fixing rod and the light source mounting rack to horizontally reciprocate; the light source mounting bracket includes a light source fixing head and a threaded rod that is threadedly connected with the horizontal part and is used for vertical movement.