WO2018162214A1

WO2018162214A1 - Tooth assessment system

Info

Publication number: WO2018162214A1
Application number: PCT/EP2018/054027
Authority: WO
Inventors: Alexander Thomas Ashcroft; Adam John Limer; Robert Mckeown; Gareth Jon OWENS
Original assignee: Unilever Plc; Unilever N.V.; Conopco, Inc., D/B/A Unilever
Priority date: 2017-03-09
Filing date: 2018-02-19
Publication date: 2018-09-13
Also published as: DE202018101337U1; FR3063629A3; CN209574941U; FR3063629B3

Abstract

An assessment tool for assessing properties of the tooth surface, which comprises a magnified 3D skin of the tooth surface on a backing material, wherein the 3D skin has a thickness of from 50 to 1000 microns.

Description

TOOTH ASSESSMENT SYSTEM

Field of Invention

The present invention relates to an assessment tool for assessing properties of the surface of teeth, a method of using the assessment tool to assess properties of the tooth surface and a method of making the assessment tool.

Background and Prior Art

Methods of measuring properties of surfaces are described in the following prior art. US 2003/0234650 discloses a comparator for surface finishes for the evaluation of SPI surface finishes with the turbine steam path. An embodiment comprises a small particle impingement comparator comprising a plurality of sample cells arranged side-by-side in ascending order of roughness from 1190 micro-inches to 6950 micro-inches. WO2014/170065 discloses an oral care composition effective to impart improved surface properties to teeth and an assessment device packaged with the composition. The device including a graduated scale corresponding to a spectrum of surface roughness.

A method of demonstrating a tooth treatment by production of a magnified 3D model is described in WO2016/071182.

Despite the prior art there remains a need for improved methods and devices that provide accurate yet simple means for assessing the state of the teeth. We have now found that by implementing a 3D skin, with a thickness of 50 to 1000 microns, into a device for the assessment of teeth, a surprisingly advantageous device is enabled. For example, several representations of an individual's teeth may be included on a single 3D skin, such as before, during and after treatment. In this way, it is possible to demonstrate any surface improvement, such as enamel repair. It also becomes possible to recommend a suitable product according to an individual's need. This enables accurate assessment of the tooth surface to several aspects, such as level of damage, type of damage and deposition of matter of the surface. The assessment achieved is more extensive and complete than other known assessments.

Definition of the Invention

A first aspect of the invention provides an assessment tool for assessing properties of the tooth surface, which comprises a magnified 3D skin of the tooth surface on a backing material, wherein the backing material has a 2D image of the 3D skin superimposed onto it and the 3D skin has a thickness of from 50 to 1000 microns.

A second aspect of the invention provides method of providing an assessment tool according to any preceding claim, comprising the steps of:

(i) collecting imaging data for at least one tooth surface,

(ii) converting the imaging data collected at step (i) into a format to create magnified skins from a 3D printer,

(iii) producing a magnified 3D skin of the tooth surface from a 3D printer using the data from step

(iv) producing a 2D image of the 3D skin and applying to a backing material

(v) superimposing the 3D skin onto the 2D image to provide a composite image that contains both visual and textural information.

A third aspect of the invention provides a method of assessing properties of tooth, comprising the steps of:

i) obtaining an assessment tool comprising a 3D skin of the first aspect

ii) analysing the 3D skin using visual analysis, tactile analysis or a combination thereof, and iii) comparing the results of step (ii) to properties of the teeth.

The tooth surface comprises enamel and dentine. The properties of the teeth of step may include aspects of the tooth surface such as damage, erosion and pitting, gloss, shine and tubile blocking

The method of the invention may optionally comprise the further step of applying a treatment or assault to the teeth and the analysis repeating steps. Skins of the tooth in different states, for example before and after application of a composition may be included on a single skin. The device preferably further comprises a scale. The scale may indicate the level of one or more properties of the tooth surface, preferably properties related to teeth damage or repair, for example, roughening due to erosion by dietary acids or the blocking of dentine tubules due to mineral deposition from a toothpaste. A comparison of the aspects shown on the skin to the scale may be carried out in step (iii) of the method of assessing properties of teeth.

The backing material

The backing material may be any suitable substrate, preferably selected from plastic, paper and card. The backing material is preferably flexible.

Preferably, a colour is applied to the substrate to highlight the areas of interest. The colours can be varied according to the surface height. This is useful in showing up areas of interest such as the topography of the tooth surface such as the depth of holes and degree of roughness due to erosive wear; also deposits on the surface. It is preferable if the colour is added by taking a 2D image of the 3D skin and using the 2D image to apply colour.

The 3D skin

The 3D skin used in the present invention is different from a rigid conventional model. In the field of 3D rendering, a virtual model is used to create the skin. In the context of the present invention, the 3D skin and the backing make the final model of the tooth. The 3D skin is applied to a suitable backing surface, which results in an end product that is much more flexible in terms of use than a fully printed model and therefore has many more uses than 3D models typical of the prior art. Unlike a final model, this 3D model (excluding any backing) is thin and flexible with a thickness of from 50 to 1000 microns, preferably from 75 to 750 microns most preferably from 100 to 350 microns.

This gives a device with real tooth surface properties (pitting, roughness, tubule blocking) which is not simulated or mimicked. It may be printed directly onto a backing, for example a side of a bottle or packaging, for example to illustrate the effect of the product in the tube on teeth.

A preferred 3D skin has a sticky back such that it may be peeled from a backing material and stuck onto a carrier surface. The 3D skin is preferably printed onto the backing material by digital printing with UV inks for colouring. Texture is preferably built up of layers of varnish.

A suitable process of making the skin is as follows:- - Data is collected, including X, Y and Z co-ordinates.

The data is then manipulated to produce the skin using CAD software. A suitable file format is *.STL

The STL file is then manipulated using the following steps in order to facilitate the printing process.

- The file is converted into PDF format, which is a graphic printable file.

The PDF is imported into printer specific software, for example, RIP software.

Layers are built up as an in-silico mask, based on the Z data oriented at the X, Y coordinates.

From this mask, a "flat" colour background is printed (the 2d image of the model).

- Onto this colour background is printed varnish in layers -each layer being cured with a U.V. light source.

The layers are built up until the maximum height is reached and a 3D model is now represented. The image

The data used in generating the skin is captured by using a 3D optical profiler, such as a Sensofar S neox, or laser profilometer.

The topographic surface of the tooth is converted into a format suitable for a 3D printer, preferably it is exported in a digital file as spatial coordinates (X, Y, Z) of each point which describes the topographic (3D) surface. Preferably, this is completed using a profilometer. An example of a suitable profilometer is the Sensofar S neox profilometer that can produce a 3d skin of the surface to be studied. The profilometer software, for example sensoSCAN v5, can export a file ".dat" that is a list of all the X, Y, Z coordinates of each point.

Preferably, the magnified 3D skin for use in the skin has a magnification of from 100 to 50,000, preferably 10,000 times.

It is preferable if the conversion of the imaging data iv) comprises a magnification process. The magnification is preferably achieved by change of resolution, units and/or rescale of coordinate axis, producing a new digital file with the new spatial coordinates. A preferred way of magnifying the data points is using Matlab. In this preferred method, the ".dat" file is imported in Matlab as a matrix and a set of Matlab scripts are used to manipulate the matrix and change the resolution/scale. It is highly preferred if the matrix is exported into a new ASCII file ".XYZ" as a list of all the X, Y, Z coordinates of each point.

The imaging data is converted into an image suitable for a 3D printer. Preferably, the file is imported in a 3D-CAD software and the 3D surface is applied onto a face of a parallelogram to obtain a 3D object. The resulting 3D image is exported to a digital file compatible with the 3D-printer device software. The XYZ file is preferably imported into a software conversion package, for example the "Rhino" software package, which can convert it into a 3d file and export as a .STL file.

The 3D image is printed to form a skin. This can be achieved by using a modem 3D printer, such as a Flatbed proofing press available from The Logan Press. Primer Ink with UV varnishes are commercially available and may be used with appropriate inkjet printers.

In a preferred embodiment, the images are converted into 3D image (.stl) files and 2D optical images (.png) of the 3d images are also captured. The 2D and 3D images are combined to produce a textured image on paper, where the 3D data is used to create the texture on top of the printed image file. In embodiments that demonstrate tubule blocking images, the negative image of the 3D file is used so that the main feature (the dark holes where the tubules are) is recessed into a raised area where the solid dentine is. For most other examples, any features are printed as texture in the image.

The resulting image as described in the description above may be printed the onto a toothpaste tube, carton or brochure (card or plastic), etc

Analysing the 3D skin

Properties that may be seen in the 3D skin are external topographical aspects of the tooth surface, for example damage, erosion, cracks, tubule blocking and pitting. The extent to which these are present at the initial imaging stage (i) depends on the age and condition of the teeth at the beginning of the method.

Different oral care compositions can affect the surface of the teeth. Consumer perceivable effects are any changes, perceived by the consumer, as a result of the treatment with the oral care composition, these can be perceived by properties such as rough feel, smoothness, pitting, tubule blocking and friction, by rubbing the finger on the surface of a 3D skin produced before and after treatment, The use of a 2D image places further emphasis on visual cues as well as 3D cues. It is possible to recommend a suitable product according to an individual's need, that targets the properties of the tooth.

The method of the invention may be used in an educational tool, in communication with press, media or trade, at point of sale, in professional environments such as dentists, and in commercial material, advertisement material and promotional material.

The assessment tool

The assessment tool may be the form of packaging, promotional or educational leaflet or an adhesive carrier, preferably a, a sticky label, a card, a leaflet or a tube. For example, the assessment tool may be a package comprising the product of the first aspect on an outer surface of the package, or it may be a leaflet carrying the product of the second aspect of the invention in the form of a sticky label.

The assessment tool preferably comprises written instructions and/or comparative scales for analysis. It may further include a tooth characterization process and/or recommendation of products. Comparative scales, for example, relating erosive roughness on the 3D skin to level of erosive damage, or relating tubule blocking on the 3d skin to reduced levels of tooth

hypersensitivity, and correlations to suitable products are preferred features. In a preferred embodiment, the assessment tool is a leaflet, preferably comprising folding leaves.

Such a leaflet brings to life the teeth in the context of treatments and enables the individual to analyse their own teeth and see how they are affected by the factors that are most relevant to them. The leaflet comprises a 3D skin that preferably shows, for example, damaged enamel/dentine, healthy enamel/dentine and treated dentine/enamel, on the same skin. The skin may also or alternatively show deposition of materials from products (eg to demonstrate tubule blocking) and/or the effects of environmental factors such as dietary acid.

It is possible to illustrate exactly how a treatment or assault is affecting the surface of the tooth from a visual and tactile perspective - the skin enables the user to see and feel a true representation of teeth. Figures

Figure 1 is a perspective 2D view of a device of the invention comprising a 3D skin (1 ) with a printed tooth surface (2). A is a representation of native enamel, B a representation of polished enamel, C a representation of eroded enamel and D a representation of repaired enamel

Figure 2 is a perspective 2D view of a device comprising a 3D skin. A shows damaged dentine and S shows dentine that has been treated.

Claims

An assessment tool for assessing properties of the tooth surface, which comprises a magnified 3D skin of the tooth surface on a backing material, wherein the backing material has a 2D image of the 3D skin superimposed onto it and the 3D skin has a thickness of from 50 to 1000 microns.

An assessment tool as claimed in claim 1 that further comprises a scale.

An assessment tool as claimed in any preceding claim wherein the backing material is flexible.

An assessment tool as claimed in any preceding claim, wherein the 3D skin has a sticky surface.

An assessment tool according to any preceding claim in which the tooth surface to be assessed is enamel.

An assessment tool according to any one of claims 1 to 5 in which the tooth surface is dentine.

A method of providing an assessment tool according to any preceding claim, comprising the steps of:

(i) collecting imaging data for at least one tooth surface,

(iii) producing a magnified 3D skin of the tooth surface from a 3D printer using the data from step (ii),

(iv) producing a 2D image of the 3D skin and applying to a backing material

A method as claimed in claim 9, wherein steps (iii) and (iv) are combined into one step.

A method of assessing properties of the tooth surface, comprising the steps of: i) obtaining an assessment tool comprising an image as claimed in any of claims 8 to 9, ii) analysing the image using visual analysis, tactile analysis or a combination thereof, and

iii) comparing the results of step (ii) to properties of the tooth.

A method of any one of claims 8 to 10 comprising the further step of applying a non- therapeutic treatment or assault to the tooth surface and repeating the assessment method.