WO2024028323A1

WO2024028323A1 - Shade guide device, particularly a translucent one, for the dental direct composite restoration of anterior teeth

Info

Publication number: WO2024028323A1
Application number: PCT/EP2023/071290
Authority: WO
Inventors: Gaetano PAOLONE; Nicola Scotti; Enrico Felice GHERLONE; Andrea BOVE; Paolo CAPPARE'
Original assignee: Ospedale San Raffaele S.R.L.
Priority date: 2022-08-03
Filing date: 2023-08-01
Publication date: 2024-02-08

Abstract

Shade guide device (60) for dental restoration, comprising a core (31) of opaque composite corresponding to a dentine of a dental anatomy, the core (31) being moulded and shaped with portions with differentiated thickness (A, B, C) imitating mamelons of anterior tooth, and further comprising a buccal layer (40) of translucent enamel applied on the core (31) and forming an additional thickness on at least one buccal side of the shade guide device (60) at the portions with differentiated thickness (A, B, C). A shade guide kit. A manufacturing method of a shade guide device.

Description

Title: Shade guide device, particularly a translucent one, for the dental direct composite restoration of anterior teeth

DESCRIPTION

Technical field

The present invention relates to a shade guide device for dental restoration, particularly for dental direct composite restoration of anterior teeth. The present invention also refers to a shade guide kit for dental restoration, comprising a plurality of shade guide devices and intended to assist the doctor in selecting the shade of the materials which is more suited to the dental restoration for the specific patient. Moreover, the present invention refers to a manufacturing method of a shade guide device for dental restoration.

The present invention finds a particular application in the dental field, for dental composite reconstruction and restoration.

Prior art

The teeth white colour, in the various shades which depend on genetics, is due to the combination of two tissue layers, the external one and the internal one: the enamel and the dentine. The enamel is a material composed of calcium minerals, is semi-transparent and very glossy, the dentine can vary from off white to yellow and grey, but it does not extend up to the edges of the teeth.

The success of a dental aesthetic restoration intervention depends on several aspects; in particular the selection of the colour of reconstruction materials plays a fundamental role for the aesthetic outcome, but other aspects are very important like the external and internal anatomy of the specific tooth, which is peculiar to the patient. The best results are achieved by suitably modelling the material, and by suitably selecting opaque and translucent shades. It is known to provide shade guides, used for assessing the teeth colour and for selecting the shade of the composite to be used to restore the tooth.

Document US4618325A refers to a transparent hollow mould provided for forming a custom dental shade guide. The mould is provided with an opening into which the dentist inserts raw filling material selected from the material which is to be used on the patient. The mould is equipped with a handle and after the hardening of the raw material it forms a dental shade guide.

Document US2012056343A1 refers to a moulding device for moulding a dental shade guide, which comprises a moulding plate having a moulding portion of the shade guide and a groove which holds a handle. A dental composite resin paste is filled in the moulding portion of the shade guide.

Document US5261815A refers to a system for matching the shades of an artificial tooth with the shades of a natural tooth, employing a singlesided master shade guide and a plurality of paired sample teeth.

Document WO8808285A1 refers to a casting mould of a dental shade guide, for the preparation of samples of tooth restoration material. The mould is shaped like a human tooth and is adapted to receive an amount of photocurable composite.

Document Paolone G, Orsini G, Manauta J, Devoto W, Putignano A. “Composite shade guides and color matching” Int J Esthet Dent. 2014 Summer;9(2): 164-82. PMID: 24765625 refers to a review of composite shade guides available on the market and proposes to produce self-made standardized “tooth-shaped” shade guide specimens, wherein small changes in composite enamel thickness may determine huge differences in esthetic outcomes.

Document US6174168B1 refers to a prosthetic tooth having an enamel layer which has a zone of substantially constant thickness; this tooth is molded using a dental tooth mold part prepared by imaging a dental pattern of a prosthetic tooth shade layer and / or shader mold part outer surface, and forming the dental pattern in a mold by program directed milling. A prosthetic incisor tooth includes a tooth body having two generally symmetrical curved grooves between three curved ridges on the labial face of the body at the incisal end of the body; the grooves are deepest at the incisal end.

Document Schlichting LH, Magne P. “Double-milled CAD-CAM composite resin restorations: A proof-of-concept approach to producing histoanatomic bilaminar restorations” J Prosthet Dent. 2020 Jul; 124(l):5-9. doi: 10.1016/j.prosdent.2019.09.006. Epub 2019 Nov 21 refers to bilaminar semi-indirect composite resin computer-aided design and computer-aided manufacturing (CAD-CAM) restorations creating a histoanatomic dentin base which can then be freehand-layered with an enamel-like composite resin.

Document Hassel AJ, Kreuter A, Rammelsberg P. “Fabrication of an individual set of composite resin anterior teeth duplicated from a preserved stone cast: a clinical report” J Prosthet Dent. 2008 Nov; 100(5):333-7. doi: 10. 1016/S0022-3913(08)00135-2. PMID: 18992565 refers to a technique for fabrication of an individual set of composite resin teeth for an edentulous patient, wherein a diagnostic cast is duplicated with a silicone matrix.

Document EPl 121908A1 refers to an artificial front tooth consisting of a main body and a neck leading smoothly into one another; the front tooth has a vestibular surface and a mesially-distally pointing tooth equator.

Unfortunately, known systems are not fully effective in reproducing opaque and translucent areas which are specific to incisal edges, in shade guides.

Moreover, known systems are not fully effective in assisting the doctor in selecting the appropriate translucent and opaque composites for the specific tooth of the specific patient. Summary of the invention

A general object of the present invention is to overcome drawbacks of the prior art.

A particular object of the present invention is to provide a shade guide which allows opaque and translucent areas to be accurately reproduced, imitating at best in particular the incisal edges.

A further particular object of the present invention is to effectively assist the doctor in selecting the appropriate translucent and opaque composites for the specific tooth of the specific patient.

A further particular object of the present invention is to accurately reproduce the dental structure in shade guides, to obtain an aesthetically realistic reproduction of the tooth which will be reconstructed.

These and other objects are achieved by a shade guide device for dental restoration according to the features of the attached claims, which form an integral part of the present description.

An idea underlying the present invention is to provide an overlapping of a translucent shade material over an opaque shade material, simulating the interaction of the enamel/ dentine shades. The dentinal opaque shade material is shaped according to a standardized internal anatomy with mamelons, over which a second translucent shade material is overlapped.

The invention provides a shade guide device for dental restoration, comprising a core of opaque composite corresponding to a dentine of a dental anatomy. The core is moulded and shaped with portions with differentiated thickness imitating mamelons of anterior tooth. The shade guide device comprises a buccal layer of translucent enamel applied on the core, forming an additional thickness on at least one buccal side of the shade guide device at the portions with differentiated thickness of the core. Advantageously, the invention allows to visualize the interaction between the translucent and opaque shades of the materials associated with the dentine and enamel in the shade guide device, and moreover to show the internal anatomy characterized by internal mamelons and translucent areas which are typical of the anterior teeth, also in the shade guide device.

Advantageously, the use of a mould for forming the core of the tooth allows a more realistic rendering of the dental anatomy to be obtained, particularly starting from a standardized 3D model preferably obtained by an incisor tooth anatomy.

Advantageously, the shade guide device of the invention allows the aspect of an incisal third of anterior teeth to be more accurately reproduced with any composite combination.

Advantageously, the shade guide device of the invention allows mamelons, translucency, opacity of the anterior teeth of a patient to be reproduced.

With the shade guide device of the invention, it becomes possible for a doctor to test and effectively reproduce the shades and translucency of the mamelons and of the incisal third of the anterior teeth, prior to a dental restoration intervention.

In some embodiments, a palatal layer of translucent enamel applied on the shade guide device is further provided, forming a second additional thickness on at least one palatal side.

Advantageously, the reproduction accuracy of mamelons, translucency, opacity of the anterior teeth of a patient is thereby increased.

The present invention also refers to a relevant shade guide kit for dental restoration, comprising a plurality of shade guide devices.

The present invention also refers to a manufacturing method of a shade guide device for dental restoration. The manufacturing method provides moulding a core of opaque composite corresponding to a dentine of a dental anatomy, the core being shaped with portions with differentiated thickness which imitate mamelons of anterior tooth. The manufacturing method provides applying a buccal layer of translucent enamel on the core, forming an additional thickness on at least one buccal side of the shade guide device at the portions with differentiated thickness.

The manufacturing method is generally adapted to manufacture a shade guide device for dental restoration according to the present invention.

Further features and advantages will be more apparent from the following detailed description of preferred non-limiting embodiments of the present invention, and from the dependent claims which outline preferred and particularly advantageous embodiments of the invention.

Brief description of the drawings

The invention is illustrated with reference to the following figures, given by way of non-limiting examples, in which:

Figure 1 illustrates a standardized CAD 3D model through which a core of a shade guide device according to an embodiment of the present invention is shaped.

Figure 2 illustrates a geometry for a mould of a core of a shade guide device according to an embodiment of the present invention.

Figures 3A, 3B, 3C, 3D exemplify the process of forming an opaque composite and a palatal layer of translucent enamel in a mould corresponding to Figure 2.

Figures 4A and 4B exemplify the process of forming a buccal layer of translucent enamel applied to a core of a shade guide device according to an embodiment of the present invention.

Figure 5 reproduces a picture of a core of a shade guide device according to an embodiment of the present invention.

Figure 6 reproduces a picture of a shade guide device according to an embodiment of the present invention, including the core of Figure 5, a buccal layer of translucent enamel and a palatal layer of translucent enamel.

Figures 7A and 7B exemplify the application of a shade guide device according to embodiments of the present invention, used for the selection of suitable shades of materials with respect to a denture of a specific patient.

In the different figures, analogous elements will be identified with analogous reference numbers.

Detailed description

A preferred, and in any case non-limiting, embodiment of shade guide device according to the present invention will be described also illustrating an exemplary manufacturing method (or process) thereof. The structural features which will be described with reference to the shade guide device itself will be also clearly apparent from the manufacturing method.

The shade guide device is intended to create a custom translucency shade guide for the selection of the composites, so that the doctor can select the translucency rather than just the shade.

The shade guide device provides a natural- shaped dentinal core, which also comprises the incisal edge, which models the dentinal shape with opaque composite and in which a layer of composite translucent enamel is applied.

As it will be further described, the shade guide device comprises a core of opaque composite corresponding to a dentine of a dental anatomy. The core is moulded and shaped with portions with differentiated thickness imitating mamelons of an anterior tooth.

In the context of the present invention, “anterior teeth” means in particular the central and lateral incisors, being both upper and lower, of human denture.

The shade guide device further comprises a buccal layer of translucent enamel applied on the core. The buccal layer of translucent enamel forms in particular an additional thickness on at least one buccal side of the shade guide device, at the portions with differentiated thickness, creating a translucency effect particularly corresponding to the dental anatomy.

Figure 1 illustrates a standardized CAD 3D model 10 by means of which a core of a shade guide device is shaped, as it will be further described.

The 3D model 10 reproduces a right maxillary central incisor, and a section 11 thereof which is cut horizontally at a distance of 5 mm from the incisal edge is taken into consideration. The section 11 represents the tooth region where the translucent and opaque parts are more evident.

The section 11 which will be used to shape a mould is extracted from this cut 3D model 10.

In particular, the core of the shade guide device is shaped starting from the standardized CAD 3D model.

Figure 2 illustrates a geometry 20 for a mould of a core of a shade guide device.

To create the geometry 20 a CAD 3D modeling software, for example Fusion 360 of Autodesk, is used.

A master model of the core is then formed, preferably being printed using a 3D printer. Afterwards said master model is polished to remove the imperfections encountered during the printing procedure. In order to create the mould, the master model is placed with the palatal part on a double-sided adhesive tape. A light dental impression material, for example Elite HD+ light body normal set of Zhermack is then applied on the surface of the master model. Afterwards a putty, for example Elite HD+ putty soft normal set of Zhermack is applied to the master model. Excesses of impression material are removed and expects that the impression material itself solidifies constituting the mould. Once the mould is created, the composite is applied thereto to obtain dentinal and incisal portions of the shade guide device.

As it can be appreciated by considering the geometry 20, the shade guide device comprises three portions with differentiated thickness connected to each other, in order to imitate three mamelons of incisor tooth.

Figures 3A, 3B, 3C, 3D exemplify the process of forming an opaque composite 31 and a palatal layer 32 of translucent enamel in a mould 30 corresponding to the geometry 20.

The dentinal opaque composite 31 is introduced into the mould 30 from the palatal portion, in the direction indicated by the arrow in Figure 3A.

The mould 30 allows the dentinal and incisal portion of the core of the dental shade guide device to be formed. There are 0.5 mm of palatal layer 32 of translucent enamel for a first translucent shade. The buccal layer of translucent enamel is instead applied after the removal of the modelled part 31 and 32.

The opaque dentine composite 31 is layered with small increments, making sure not to leave any gap between it and the mould faces, for example using the condenser tip of a Posterior RESTOREITDIN tool of HuFriedy. Each increment of opaque composite 31 is cured, for example with Vaio Cordless of Ultradent for 20 seconds using the Standard Power mode (1000 mW/cm²). First, the central dentinal core 31 is layered, with the mamelons thereof, making sure to leave enough space for the palatal layer 32 of translucent enamel.

Afterwards an opaque dentine composite 33 is applied in the incisal portion to reproduce the incisal edge, making sure not to overflow and to join the central dentinal core only on the sides of the core of the dental guide device.

Then a thin layer of translucent enamel composite 32 is applied and gently pressed to ensure not to leave any gap. Excesses are then removed. The specimen of the dental scale device 31, 32, 33 is gently pulled out from the mould 30 and further cured from the anterior and lateral sides.

As already hinted, the opaque composite 31 and 33 is formed in a mould 30, being introduced from a direction corresponding to a palatal portion of the shade guide device to provide the core 31, and the incisal edge element 33 which will be further described. A palatal layer 32 of translucent enamel is applied to the core 31 , forming a second additional thickness on at least one palatal side of the shade guide device. In particular, the palatal layer 32 of translucent enamel is applied to the core 31 before a removal of the opaque composite from the mould 30. Preferably, the shaped mould 30 is made of silicone, particularly of impression additive silicone.

Figures 4A and 4B exemplify the process of forming a buccal layer 40 of translucent enamel applied to a core 31 of a shade guide device. As can be seen, in this example the palatal layer 32 of translucent enamel is not represented, which is optional and present in a preferred embodiment.

The covering material for the buccal layer 40 of translucent enamel (and, preferably, also for the palatal layer 32 of translucent enamel) is more translucent/ transparent, being preferably a composite material, which is typically used in dental restoration, which does not require a countermould.

In the front view of Figure 4A three mamelons A, B, C can be appreciated, corresponding to the geometry 20 of the 3D model. The mamelon A is in contact with the incisal edge, while the mamelon B and the mamelon C are at a distance of 0.5 mm and 0.8 mm therefrom, respectively.

As can be seen in Figure 4B, the cross sections of each mamelon A, B and C show different thicknesses of the buccal layer 40 of translucent enamel due to the different slope angles of the mamelons A, B, and C.

Once the dentinal stump is picked up, the buccal layer 40 of translucent enamel can be standardized in its thickness, for example using Calibra RESTOREITDIN of HuFriedy.

Possible excesses of buccal layer 40 of translucent enamel on the incisal edge and on the proximal sides can be removed with medium-grained abrasive discs, for example 3M Sof-Lex of 3M, making sure not to reduce the original shape of the mamelons A, B, and C and of the incisal edge 33. It is possible, but not mandatory, to insert small amounts of additional characterizing translucent-effect enamel between the incisal edge 33 and the mamelons A, B, C, to reproduce high-translucency areas.

Preferably, the final buccal layer 40 of translucent enamel is layered, for example with an Anterior RESTOREITDIN tool of HuFriedy while the possible excesses are removed with Calibra TNCALIBRA of HuFriedy. The specimen of shade guide device is finally cured for 40 seconds. The incisal edge is then characterized using a medium-grained abrasive disc, for example 3M Sof-Lex of 3M. Afterwards, the specimen of shade guide device is finished and polished preferably using a contra-angle handpiece trimming mill, a silicone rubber tip, a natural bristle brush impregnated with a high lustre polishing paste, for example Opal L No. 520-0001 of Renfert GmbH.

It is worth noting that, preferably but not limitedly, the buccal layer 40 of translucent enamel is applied to the core 31 after a removal of the opaque composite 31, 33 from the mould 30.

The present invention thus provides a shade guide device for dental restoration comprising a core 31 of opaque composite corresponding to a dentine of a dental anatomy. The core 31 is moulded in a mould 30 and shaped with portions with differentiated thickness imitating mamelons A, B, C of an anterior tooth. The dental guide device comprises a buccal layer 40 of translucent enamel applied on the core 31 forming an additional thickness on at least one buccal side of the shade guide device, at the portions with differentiated thickness A, B, C.

Preferably, the portions with differentiated thickness A, B, C, have slopes which are different from each other, constituting areas of the buccal layer 40 of translucent enamel forming the additional thickness which is variable along the shade guide device, as shown in Figure 4B.

Preferably, the shade guide device comprises an incisal edge element 33 of moulded opaque composite, only laterally connected to the core 31. The buccal layer 40 of translucent enamel fills a gap between the core 31 and the incisal edge element 33. Preferably, the incisal edge element 33 defines a gap with variable distance from the core 31.

Preferably, the additional thickness of the buccal layer 40 of translucent enamel is standardized by calibrated shaping, preferably having a thickness comprised between 0.3 mm and 0.7 mm at a distance of 2.5 mm. from an incisal edge of the shade guide device, as shown in Figure 4B. Optionally, the buccal layer 40 of translucent enamel can comprise one enamel or more enamels with different translucency.

Figure 5 reproduces a picture of a core 31 and of an incisal edge element 33, corresponding to a semi-finished shade guide device, while Figure 6 reproduces a picture of a shade guide device 60 including the core 31 (in translucency), the incisal edge element 33 (in translucency), a buccal layer 40 of translucent enamel (applied as a covering) and a palatal layer 32 of translucent enamel (which is optional, in this case rear and not visible).

In a preferred embodiment, the shade guide device 60 is associated with a gripping element 61, such as a micro-brush using a small amount of adhesive and composite applied on the superior-posterior side of the shade guide device 60. An operator is thereby able to hold the shade guide device 60 by grasping the gripping element 61. In a preferred embodiment, the size (height) of the shade guide device is about 5-8 mm from the incisal edge.

Figures 7A and 7B exemplify the application of two different shade guide devices, in shades which are different from each other, used for the selection of suitable shades of materials with respect to a denture of a specific patient.

The different shade guide devices are manufactured in different shades, for example using two different composite systems for making various combinations of samples: Mosaic universal of Ultradent and Clearfil Majesty ES-2 Premium of Kuraray.

The different shade guide devices can be included in one or more kits for dental restoration. With this kit, each dentist can assess the effect of different shades and rapidly foresee the final result of the restoration.

In this respect, a shade guide kit for dental restoration is provided, comprising a plurality of shade guide devices, comprising in turn respective pluralities of materials in different shades, for the opaque composite of the core 31 and for at least the buccal layer 40 of translucent enamel.

Industrial applicability

Shade guide devices according to the present invention are useful for the clinician or doctor to obtain better aesthetic results, when dealing with direct restorations of anterior teeth, especially when teeth show marked areas of translucency.

The shade guide device according to the invention accurately reproduces the dentinal mamelons and the incisal edge, focusing on the translucent areas of the incisal third. The present invention allows the clinicians and doctors to be provided with a custom shade guide which has a real dentinal core with standardized mamelons and translucent area. Moreover, the shade guide device according to the invention is useful for the clinician or doctor who is interested in the restoration of other teeth, for example canines, premolars, or molars. The translucent area provided in the custom shade guide according to the present invention is in fact useful for assessing the better aesthetic result also in other types of teeth, although devoid of mamelons. The clinician or the doctor are in fact able to assess at best the effect of the available materials even when used for the reconstruction of these different types of teeth, besides incisors.

Considering the above-mentioned description, the person skilled in the art will be allowed to devise further modifications and variants, in order to meet contingent and specific requirements.

For example, the manufacturing method of the device may be adapted and refined in its details, to achieve the manufacture of a shade guide device using at best the composite materials which are actually available in the specific case.

The here-described embodiments are therefore to be considered as illustrative and non-limiting examples of the invention.

Claims

1. Shade guide device (60) for dental restoration, comprising a core (31) of opaque composite corresponding to a dentine of a dental anatomy, said core (31) being moulded and shaped with portions with differentiated thickness (A, B, C) imitating mamelons of anterior tooth, and further comprising a buccal layer (40) of translucent enamel applied on said core (31) and forming an additional thickness on at least one buccal side of said shade guide device (60) at said portions with differentiated thickness (A, B, C).

2. Shade guide device according to claim 1, comprising three of said portions with differentiated thickness (A, B, C) being connected to each other in order to imitate three mamelons of incisor tooth.

3. Shade guide device according to claim 1 or 2, wherein said portions with differentiated thickness (A, B, C) have slopes which are different from each other, constituting areas of said buccal layer (40) of translucent enamel forming said additional thickness which is variable along said shade guide device (60).

4. Shade guide device according to any one of claims 1 to 3, further comprising a palatal layer (32) of translucent enamel forming a second additional thickness on at least one palatal side of said shade guide device (60).

5. Shade guide device according to any one of claims 1 to 4, further comprising an incisal edge element (33) of moulded opaque composite, only laterally connected to said core (31), wherein said buccal layer (40) of translucent enamel fills a gap between said core (31) and said incisal edge element (33).

6. Shade guide device according to claim 5, wherein said incisal edge element (33) defines said gap with variable distance from said core (31).

7. Shade guide device according to any one of claims 1 to 6, wherein said additional thickness of said buccal layer (40) of translucent enamel is standardized by calibrated shaping, in value, preferably having a thickness comprised between 0.3 mm and 0.7 mm at a distance of 2.5 mm from an incisal edge of said shade guide device (60) .

8. Shade guide device according to any one of claims 1 to 7, wherein said buccal layer (40) of translucent enamel comprises one enamel or more enamels with different translucency, said buccal layer (40) of translucent enamel being preferably polished.

9. Shade guide kit for dental restoration, comprising a plurality of shade guide devices (60) according to any one of claims 1 to 8, said plurality of shade guide devices (60) comprising respective pluralities of materials in different shades, for said opaque composite of said core (31) and for at least said buccal layer (40) of translucent enamel.

10. Manufacturing method of a shade guide device (60) for dental restoration, said manufacturing method comprising:

- moulding a core (31) of opaque composite corresponding to a dentine of a dental anatomy, said core (31) being shaped with portions with differentiated thickness (A, B, C) imitating mamelons of anterior tooth;

- applying a buccal layer (40) of translucent enamel on said core (31), forming an additional thickness on at least one buccal side of said shade guide device (60) at said portions with differentiated thickness (A, B, C).

11. Manufacturing method according to claim 10, wherein said core (31) is shaped starting from a standardized CAD 3D model (20), preferably obtained by an anatomy of incisor tooth (10, 11).

12. Manufacturing method according to claim 10 or 11, wherein said opaque composite is formed in a mould (30), being introduced from a direction corresponding to a palatal portion of said shade guide device (60) to provide said core (31).

13. Manufacturing method according to claim 12, wherein said buccal layer (40) of translucent enamel is applied to said core (31) after a removal of said opaque composite from said mould (30).

14. Manufacturing method according to claim 12 or 13, further comprising a palatal layer (32) of translucent enamel forming a second additional thickness on at least one palatal side of said shade guide device (60), said palatal layer (32) of translucent enamel being applied to said core (31) before a removal of said opaque composite from said mould (30).

15. Manufacturing method according to any one of claims 10 to 14, adapted to manufacture a shade guide device (60) for dental restoration according to any one of claims 1 to 8.