Patent Application
20250134628
The present disclosure concerns a computer implemented method for producing a serious of different dental appliances.
The disclosure further concerns a dental appliance to be worn on teeth for intra-oral delivery of one or more agents to a patient, which may be obtained by applying said computer implemented method. The dental appliance comprises a solid core, which may be preferably made of a thermoplastic material that can be thermoformed. In particular, the appliance may be fabricated by forming the core into a patient-specific shape.
The disclosure further concerns a series of such appliances, process details for fabricating a dental appliance and a method for reloading (i.e., re-equipping) such an appliance with a releasable agent, for example a flavor, a drug, or an antimicrobial agent.
It is well-known that releasable agents such as antimicrobial agents can be loaded by diffusion processes into porous superficial layers of a dental appliance. When the user is wearing such an appliance in his mouth, the agent may be released from the appliance to provide protection against inflammation of the teeth and gums. Loading such agents into a dental appliance can also be beneficial for keeping the appliance hygienically clean, i.e., free from dangerous pathogens.
Starting out from this background, the invention aims at providing dental appliances and associated methods that can provide substantial benefits for the end-user. In particular, it is an object of the invention to provide means that allow personalized delivery of an agent to a patient's mouth that is tailored to the specific needs of that patient.
In accordance with the present invention, a dental appliance is provided having one or more of the features disclosed herein, which achieves the afore-mentioned objectives. In particular, the invention proposes a dental appliance as introduced at the beginning, which, in addition, is characterized in that, within a region of interest, the core features a multitude of micro-reservoirs, which are (or more precisely have been) formed in the core.
Preferably, the micro-reservoirs may be formed in an outer surface of the core.
Each of the micro-reservoirs may have sub-mm dimensions, in particular a diameter below 1 mm or preferably below 0.2 mm. This approach is highly beneficial for accurate control of the release rate within the defined region of interest (ROI) of the dental appliance, because the micro-reservoirs can be loaded with a releasable agent. This may be achieved by letting the agent diffuse from a source (e.g., a reload liquid containing the agent) into the micro-reservoirs.
In addition, the proposed approach—for example through variation of the spatial density (number of micro-reservoirs/cm2) and/or depth and/or diameter of each micro-reservoir—allows application/delivery of a localized (i.e., only within the ROI) and patient-specific dosage of at least one releasable agent to a ROI within the mouth of a patient. When the patient is wearing the appliance, the ROI is defined by the location of the micro-reservoirs on the appliance, for example at a particular tooth that has undergone surgery and is thus susceptible to a possible inflammation.
As mentioned, the proposed micro-reservoirs can be loaded with a defined amount of releasable agent prior to use of the dental appliance in the mouth of a patient. Moreover, the rate at which the micro-reservoirs release the agent in the mouth to a patient, which will define the dosage delivered to the patient, can be accurately controlled by controlling the geometry of the micro-reservoirs during the fabrication of the dental appliance. A precise dosage of the agent can thus be delivered to the ROI over prolonged time of several hours (during which the patient is wearing the dental appliance on his teeth).
The dosage to be delivered to an individual patient can be readily and comfortably controlled by controlling the geometric parameters of the micro-reservoirs formed in the core, in particular the diameter and/or depth of each micro-reservoir (and thereby its volume).
In addition, the choice of a possible filling material (filling up the micro-reservoirs) and the use of a diffusion barrier can be used to fine-tune the release rate of the agent, when the dental appliance is worn in the mouth, as will be detailed below.
Using a high number of micro-reservoirs also has great advantages, in particular when the dental appliance is thermoformed after the micro-reservoirs have been formed in the core, because in this particular case, the risk of affecting the mechanical stability of the core (which would be the case when using only two or three larger reservoirs) will be minimized. The definition of the reservoirs with microscopic dimensions thus helps to maintain the mechanical stability of the core during thermoforming of the dental appliance.
The appliance itself may be designed (in particular as a dental splint) such that the core forms a plurality of cavities (at least two) shaped to receive teeth of a mouth of a patient (patient-specific design). The micro-reservoirs may be generally designed such that they can receive (in particular through a diffusion barrier) and store one or more agents and later release the one or more agents to the patient, more precisely to the ROI of the mouth that is adjacent to said ROI of the appliance, in which the micro-reservoirs are located.
More details of possible embodiments of such a dental appliance will now be presented:
For example, each micro-reservoir may be formed by an air pocket of sub-mm size, for example with a diameter of at least 10 μm, preferably of at least 50 μm, in particular of at least 100 μm.
Importantly, each air pocket may have been actively formed at a pre-defined location using a separate fabrication step. In other words, an air pocket in the meaning of the invention is not simply a pore within a porous material but a geometrically well-defined and intentionally created reservoir at a particular location. This reservoir/pocket may take up an agent, store it and later release it to the patient.
The active control of the geometry of the air pocket by applying a separate fabrication step (e.g. laser processing, 3D-printing, hot embossing, micro-machining, molding or other additive or subtractive processes) is crucial for obtaining precise control of the geometry and thereby control of the amount of agent and resulting release rate that can be obtained with each micro-reservoir. This control is particularly important for enabling personalization of the micro-reservoirs for the specific needs of a patient, as will be explained in greater detail below.
Alternatively, each micro-reservoir may be filled, at least partly, with a filling material that is capable of absorbing and releasing an agent, such as a flavor molecule, an antimicrobial or a drug. In the final appliance (directly before use), the filling material may be loaded with such an agent.
The filling material may preferably fill up the respective micro-reservoir completely. Using this approach, the filling material can be firmly linked to the micro-reservoir, in particular when the micro-reservoir increases in diameter with increasing depth (e.g., in the shape of a pear).
According to another embodiment, the micro-reservoirs may be covered by a cap layer. Preferably the cap layer can comprise or preferably be made up entirely of cellulose acetate butyrate (CAB). The cap layer may cover an area of the core that stretches over a distance that is at least ten times an average distance between two of the micro-reservoirs which are adjacent to each other. Preferably, the cap layer can be a layer of uniform thickness.
The cap layer may have a thickness of less than 50 μm, preferably of less than 25 μm. Such a design of the appliance allows to maintain a high wearing comfort for the user, because the overall dental appliance can remain thin and flexible.
According to one particular embodiment, the cap layer can be made up by the filling material. In this case, the cap layer may form an outer surface of the dental appliance. In addition, the cap layer may be such that the agent can be loaded into a surface area that is defined/covered by the outer cap layer. In this embodiment, the filling material may thus form a uniform outer cap layer that connects the micro-reservoirs with each other and fills them.
The solid core of the appliance can be made from Polyethylenterephthalat (PET), preferably from glycol modified Polyethylenterephthalat (PETG). In this case, a suitable filling material is a cellulose-based filling material. Preferably the filling material may comprise cellulose acetate butyrate (CAB). This material system allows accurate control of the release rate of a number of particularly small-sized agents.
As already mentioned, the micro-reservoirs may be formed as micro-cavities and may be micro-sized, i.e. with diameters below 1 mm. For example, the micro-reservoirs can have the shape of a dead hole with a bottom of each micro-reservoir being formed by the material of the core.
The multitude of micro-reservoirs may comprise, for example, a number of at least 20, at least 50 or even at least 100 micro-reservoirs. A typical spatial density of the micro-reservoirs may be in the range [1-100] micro-reservoirs/cm2. Moreover, the micro-reservoirs may be arranged within the ROI in a regular or irregular pattern.
The depth t of each micro-reservoir may also be of sub-mm size, preferably in the range of t=[50-800] μm.
As mentioned, the multitude of micro-reservoirs may be located within a particular region of interest (ROI) of the dental appliance, i.e., they do not need to be spread over the full outer surface of the core. This approach allows concentrated and controlled release of the agent within the ROI, e.g. at a tooth location, where the user wearing the dental appliance has obtained an implant that is susceptible for inflammation. In such a case, the dental appliance can provide a tailor-made protection against inflammation by releasing a drug or an antimicrobial into the ROI, where it is needed.
The micro-reservoirs can each have a diameter of less than 0.5 mm, preferably of less than 0.2 mm. Most preferably their depth can be at least 5%, preferably at least 25%, of a thickness of the core.
Furthermore, it is beneficial for achieving a prolonged time of delivery of the agent if the depth of each micro-reservoir is larger than 0.05 mm, preferably larger than 0.2 mm or even larger than 0.5 mm. In other words, the micro-reservoirs may each offer an aspect ratio AR=depth/diameter of AR≥0.2, preferably of AR≥0.5, such that the depth of each micro-reservoir amounts to at least 20%, preferably at least 50%, of the diameter of the respective micro-reservoir.
According to one embodiment, the micro-reservoirs may have been patterned into the core after forming the core (but possibly before thermoforming the core into its final shape). This may be done preferably using an ablative process, most preferably an ablative laser-process, which removes the material of the core at the location of each micro-reservoir.
Alternatively, the micro-reservoirs may be implemented also with non-ablative processes, for example by hot embossing the micro-reservoirs into the core, for example after forming the core as a foil.
In all of these variants, the mentioned filling material (if employed) can be filled into the micro-reservoirs after formation of the micro-reservoirs, for example by using a blade process or roll-to-roll-process or a lamination technique. Finally, the desired final dental appliance shape may then be obtained by thermoforming the core (in particular in the shape of a core foil) with filled micro-cavities using conventional techniques.
The invention may also be implemented by forming the micro-reservoirs together with the core in a single fabrication step. This may be done, in particular, using: (i) an additive manufacturing technique such as 3D-printing, in particular such that the micro-reservoirs are embedded in the core; or (ii) a forming technique such as hot embossing, in particular wherein the core features multiple layers of different materials; or (iii) the micro-reservoirs may have been formed in a separate outer, in particular 3D-printed, layer of the core that is formed on a solid inner layer of the core.
According to another embodiment, the cap layer, which may be an outer layer of the appliance, is different from the filling material. In this case, the cap layer may cover (and thus close) each of the micro-reservoirs, in particular in such a way that the agent can be loaded and released from the filling material located in the micro-reservoirs only through the cap layer. This approach can thus provide accurate control of the release rate of the agent through the choice of material and choice of thickness of the cap layer.
In more detail, the cap layer may offer a diffusion rate with respect to an agent (to be delivered to the patient and) that is embedded into the filling material that is at least 50% lower than the corresponding diffusion rate of the filling material. In this case, the cap layer may effectively form a diffusion barrier that limits the release rate of each of the micro-reservoirs.
For example, if the diffusion rate of the cap layer is 50% lower than that of the filling material, this can result in a release rate of the micro-reservoir that is reduced by roughly 50% as compared to the case of using no diffusion barrier/no cap layer. As a result, the useable period of time in which the appliance delivers a minimum dosage of the agent may be prolonged from 4 to 6 hours, as an example, thus providing prolonged protection for the patient.
In this variant, the release rate of each micro-reservoir can thus be accurately controlled by choice and dimensioning (in particular regarding the thickness) of the cap layer.
The embedding of the agent into the filling material located in the micro-cavities can be achieved by soaking the dental appliance in a reload-liquid containing the agent at a defined concentration. The agent may thus diffuse into the filling material over time. Afterwards, when the dental appliance is worn on the teeth of a user, the agent may be released from the micro-reservoirs over a prolonged time at a relatively moderate release rate, since the cap layer inhibits the diffusion of the agent out of each of the micro-reservoirs.
According to a preferred embodiment, the cap layer may be formed as a diffusion barrier from a cellulose-based thermoplastic material, preferably comprising cellulose acetate butyrate (CAB). This material should offer short length of its molecular chains to achieve the desired low diffusion rate.
According to another embodiment, the cap layer may be different from the filling material, and it may cover each of the micro-reservoirs. Furthermore, for each micro-reservoir, a corresponding release hole, preferably with a diameter of less than 20 μm, may be formed in the cap layer. The agent can then be release from the reservoir through the release hole, which offers a well-defined cross-sectional area for this transfer. In such an embodiment, the cap layer can be even impermeable to the agent that is embedded into the filling material. Through the release holes, the agent can be released from the filling material located in the respective micro-reservoir at a defined and lowered release rate, as compared to a direct release from the reservoir.
The agent may have been embedded into the filling material prior to covering the micro-reservoirs with the outer cap layer. However, a preferred approach is to load the agent into the filling material after completing fabrication of the dental appliance. In the latter case, the agent can be transferred through the cap layer and/or through the release hole (if employed) into the respective micro-reservoir.
One particular advantageous embodiment suggests that a cross-sectional area of the release hole is smaller than a micro-release-opening that is defined by the micro-reservoir (its outermost opening to the outside world). To achieve a low release rate and thus the ability to release the agent from the micro-reservoir over a prolonged period of time, it is of advantage if the cross-sectional area of the release hole is less than 5 times, preferably less than 10 times, the cross-sectional area of the micro-release-opening.
In detail, each micro-reservoir may thus offer a micro-release-opening of defined dimensions located in the outer surface of the core. Preferably the micro-release-openings may be of same cross-sectional area. In this case, each micro-reservoir can produce the same release-rate of the agent in an oral cavity when fully loaded (saturated) with the agent.
The release rate may be measured for example as the amount of agent (in mg) that is released from one of the micro-reservoirs within a defined period of time (in minutes/hours), in a defined ambient (in particular at a defined humidity).
According to a preferred embodiment, all of the micro-reservoirs may show a constant depth and/or volume. In this case, each micro-reservoir can be loaded with a same maximum amount of a releasable agent and/or each micro-reservoir can thus offer the same amount of maximum release dosage of the agent.
The release dosage may be measured for example as the amount of agent (in mg) that can be loaded into and released from one of the micro-reservoirs within a limited period of time, e.g., 12 hours. Preferably, all micro-reservoirs may show identical dimensions, and may be filled with the same filling material. In this case, they will offer the same amount of releasable agent when fully loaded with a commonly used agent.
According to another embodiment, the filling material may be a thermoplastic material that can be thermoformed together with the core to form the final dental appliance.
In addition, or alternatively, the filling material may also be a porous material featuring microscopic, sub-micrometer-sized, voids.
To ease fabrication of the appliance by thermoforming, one particular embodiment suggests that a melting temperature of the filling material is lower than a glass transition temperature of the material used for the core. Moreover, said melting temperature may be equal or lower than the melting temperature of the cap layer (if employed). Such a material choice will result in enough mobility of the molecular chains of both core and filling material such that efficient thermal interlocking can be achieved through thermal fusion (sometimes referred to as “thermal welding”). This has the advantage, that the core can be thermally fused with the filling material during thermoforming of the dental appliance, which results in excellent anchoring of the filling material within the core.
For meeting the objectives mentioned at the beginning, the invention also proposes a series of dental appliances (each intended for intra-oral delivery of one or more agents to a patient). Each of the appliances of that series may have features as described before, and each appliance may have a multitude of micro-reservoirs formed in the core of the respective dental appliance. The series is characterized in that the dental appliances of the series are all made from common materials and share a common solid core. For example, the dental appliances may employ the same type of micro-reservoirs fabricated in the same way. In addition, the dental appliances differ from each other in at least one geometrical design parameter of the individual micro-reservoirs. Such a design parameter, which may characterize each one of the micro-reservoirs and/or the arrangement of the micro-reservoirs in the core, may be a spatial density and/or a depth, in particular an average depth, and/or a respective volume of the micro-reservoirs.
By arranging the micro-reservoirs in a certain spatial density (measure as number of micro-reservoirs/cm2), it is possible to define a maximum areal release rate in (mg/cm2)/hour, that can be delivered in/to the ROI.
In addition, said geometrical design parameter of the individual micro-reservoir employed in the respective appliance of the series may define the respective total amount of releasable agent (measured in mg over a period of 6 hours for example) either per micro-reservoir or for all micro-reservoirs of the appliance and/or it may define the maximum initial release rate of an agent (in mg/hour) that can be delivered by the appliance as soon as it is fully loaded/saturated with an agent.
It is also possible to alter other design parameters such as the diameter of the respective release hole employed with a micro-reservoir (in case a cap layer is used) and/or the thickness and/or material of the cap layer (if employed).
All of these approaches allow tailoring of the amount of agent and its release rate to the needs of a specific patient. The series can thus comprise a number of different appliances, each designed/tailored for a patient-specific application case. This approach can be supported by a computer-implemented-method according to the invention, which will now be described in more detail.
For enabling rapid delivery of a dental appliance that is personalized to the specific (in particular medical) needs of a patient, the invention proposes a computer-implemented method for producing (i.e. fabricating) a series of different dental appliances, which may have features as just explained. This method comprises the following steps:
The simplest way of fine-tuning the release rate of a particular appliance can be to alter the spatial density and/or number of micro-reservoirs per appliance within the series of appliances. Further possible design parameters that define the micro-reservoir arrangement may be: diameter and/or depth of each micro-reservoir; volume of each reservoir; spatial density of the reservoirs; diameter of release hole (if employed); choice of material and thickness of cap layer (if employed); etc. The design parameter characterizing one of the m different micro-reservoir-arrangements can also be a set of different design parameters (for example: location and size of the arrangement; number of micro-reservoirs, volume of each reservoir; density of the reservoirs within the arrangement; etc.).
As a result, each of the m different dental appliances of that series can meet the respective specified release parameter (as documented in the digital data set).
Another way to meet desired release parameters is to tailor the concentration of the respective agent (that is later to be released from the dental appliance when placed in the mouth of the patient) as contained in a reload-liquid (sometimes described as a “care solution”). Such a reload-liquid may be used to initially load an agent into the dental appliance and/or to replenish/re-load the agent into the dental appliance. Therefore (in addition or as an alternative to calculating m different design parameters for defining a set of m different micro-reservoir-arrangements in step 2), the method introduced above may be designed such that in step 2 of the method, at least one ingredient parameter for a reload-liquid is calculated. This calculation may be done, for example, for a given set of design parameters specifying the arrangement of micro-reservoirs of the dental appliance to be used with said reload-liquid. When using this dental appliance featuring well-defined micro-reservoirs with a reload-liquid fulfilling said at least one ingredient parameter, the desired release rate may be achieved. In other words, the method can thus deliver patient specific ingredient parameters. As a result, for each patient, a corresponding customized reload-liquid may be synthesized/mixed according to said at least one ingredient parameter calculated with the computer-implemented method. The customized reload-liquid obtained with the method and a corresponding dental appliance may then be sent to a patient as a product package to be used together. If the dosage is to be adjusted over some time, one or two or even more customized reload-liquids, each with customized concentration of the respective agent, may be produced according to said method (and later sent to the customer) to be used with the same type of dental appliance.
In this method, a computer may be employed to process large data sets and to automatically calculate and deliver the necessary design parameters for defining the micro-reservoirs of each appliance of the series and/or for calculating and delivering the necessary ingredient parameters. The design parameters can also be used as digital input to be delivered to a machine (e.g. a laser device) that forms the micro-reservoirs in the respective cores, for example by ablation. Likewise, the ingredient parameter may be fed to a machine capable of delivering a customized reload-liquid with well-defined concentration of the agent. Such a machine may be an automated liquid mixing device.
It is also possible to fabricate the micro-reservoirs by thermoforming or other forming processes, by ablative processes or by additive manufacturing techniques such as 3D-printing, as has been already described above. Consequently, the method may also be applied to and make use of suitable manufacturing means such as: means for thermoplastic formation of the micro-reservoirs (this may be a hot embossing tool for example); and/or means for ablative formation of the micro-reservoirs (e.g. a laser machining device); and/or means for additive formation of the micro-reservoirs (e.g. a 3D-printer). All of these means, which may also be used in combination, can be used/controlled according to the design parameters calculated with the computer-implemented method.
In other words, said series of m different dental appliances may be produced using dedicated manufacturing means, in particular as detailed above. Moreover, by applying the method, each of the dental appliances may be fabricated according to a specific set of m different design parameters using said manufacturing means.
For each appliance of the series, the generation of the respective specific micro-reservoir arrangement (in 2D or 3D) can comprise locating the respective micro-reservoirs in a specific ROI that has been specified beforehand. The computer-implemented method can thus deliver a digital data set specifying the micro-reservoir-arrangement, e.g., the pattern of arrangement (and hence spatial density) of the micro-reservoirs and/or specific geometrical design parameters, such as a spatial density and/or an average depth and/or a respective volume, of the individual micro-reservoirs of the arrangement for each appliance of the series. Furthermore, the digital data set can also comprise a patient specific location, defined as the ROI, on the respective dental appliance to be fabricated with the method.
These data sets can then be used for fabricating the different appliances, in particular using an ablative process such as laser ablation and/or thermoforming and/or an additive process, for defining the micro-reservoirs in or on the core, in particular in a core foil from which the core is thermoformed.
Following this approach, one embodiment of this method proposes that the digital data set (which specifies the m different numerical values for the at least one agent release parameter) comprises: (i) a set of patient-specific values, each being based on the specific medical need of a single patient, in particular as specified by a treatment instruction for that patient; and/or (ii) a subset of N treatment-specific-values, each based on a specified dosage of the at least one agent to be delivered to a particular patient within a specified time interval.
Such values, for example a total daily dosage to be delivered to a particular patient over a duration of several weeks, may be laid out in a treatment plan for that patient (for example by a doctor treating the patient). For example, by wearing (and reloading) a first dental appliance according to the invention and produced with the computer-implemented method daily over a first period of time, the patient can safeguard that he receives a desired first dosage. After some weeks, the patient may switch to a second dental appliance of the series which offers a lower second dosage of the agent, and he may wear and reload this second appliance repeatedly over a second period of time. Following this concept, the dosage delivered to the patient can be accurately controlled stepwise with minimal effort for the patient, as he only needs to wear/exchange the right appliance designed and produced for the dosage to be delivered within a specific time interval. In this first scenario, a single patient can thus alter the dosage delivered to his mouth by changing the appliances (taken from said series) which he wears on his teeth, and thus conveniently follow a treatment plan that has been recommended by a doctor, for example.
In a second scenario, the dosage to be delivered to a number of m patients can be specified and the method can help in rapidly delivering custom-made and personalized dental appliances for each of those patients that meet the requirements concerning release rate and dosage with respect to a particular agent to be delivered to a specific patient.
The computer-implemented method proposed here thus uses input data such as patient-specific treatment instructions or treatment plans to derive a suitable (digital) data set of design parameters that can then be used to fabricate a series of dental appliances, which can deliver the agent of interest at the desired dosage to a specific patient during the time interval, in which the patient is wearing the appliance in his mouth (e.g. for several hours over night).
In the following, the process for fabricating dental appliances as described herein, which may be part of the method described before, will be detailed: For example, the fabrication process may be characterized in that a core of the dental appliance is first formed as a core foil, a multitude of micro-reservoirs is/are defined in an outer surface of the core (foil) using: (i) an ablative process, preferably an ablative laser-process, which removes the material of the core at the location of each micro-reservoir; and/or (ii) a forming process, such as hot embossing; and/or (iii) an additive process, for example molding or 3D-printing of an additional outer layer of the core. Of course, it is highly advantageous if the micro-reservoirs defined by that process have features as described before or as specified in the claims directed towards a dental appliance.
The final dental appliance may then be obtained by thermoforming the core (foil) with the already pre-formed micro-reservoirs. Additionally, the final dental appliance may be trimmed in size afterwards, as is known in the art.
Furthermore, as has been explained in detail before, the micro-reservoirs may be filled with a common filling material that is capable of absorbing and releasing an agent such as a flavor molecule or a drug. This may be done prior or after thermoforming of the appliance.
In addition, a cap layer may be deposited onto the core that covers the micro-reservoirs. This may also be done either prior or after the thermoforming of the appliance. As mentioned before, the cap layer may close the micro-reservoirs and/or it may form a diffusion barrier (thereby slowing down diffusion) or it may even be a layer that is impermeable for the agent (thus preventing any diffusion through the cap layer).
Finally, for each micro-reservoir, a corresponding release hole may be formed in the cap layer. This may, preferably, be done using an ablative laser process. This approach is particularly suited when the cap layer is impermeable for the agent.
The laser cutting of the release holes may be done by considering dedicated alignment marks/fiducials; the latter may be patterned together with the micro-reservoirs into or onto the core foil, more precisely into a master foil from which pieces may be cut out to serve as the core foil. Using this approach, each release hole can be accurately positioned over the respective micro-reservoir.
The micro-reservoirs may be patterned into or onto the core with a constant depth and/or volume, preferably such that each micro-reservoir produces the same release-rate and/or release-dosage of the agent in an oral cavity when fully loaded with the agent. Preferably, the multitude of micro-reservoirs may be only defined in at least one spatially limited region of interest (ROI). The at least one ROI may cover less than 10% or even less of an outer surface of the final dental appliance, for example.
Finally, the invention also aims at improving the ease of use of the dental appliances described so far. For this purpose, a method is proposed for reloading a dental appliance (which may have features as described before) with a releasable agent such as a flavor, a drug, or an antimicrobial agent.
The method is characterized in that the dental appliance is immersed in a reload-liquid containing the agent. Different from the state-of-the-art, however, the reload-liquid is heated to an elevated temperature of at least 55° C., while the dental appliance is immersed in the reload-liquid.
An electrically heatable reload-station which provides an immersion basin for taking up and heating up the reload-liquid may be employed. The electrical heating itself may be implemented by resistive heating or by applying electrically induced ultrasound (ultrasonic waves) to the reload-liquid, to name two possible implementations.
Due to reasons of health protection and effective regulations, the agent can only be contained in the reload-station at a maximum concentration that is not harmful to the patient. This maximum concentration thus normally limits the speed at which the reloading takes place. In other words, the time required to fully reload the micro-reservoirs of an appliance will be limited by that maximum concentration. The proposed approach has the great advantage of significantly reducing this time, because the diffusion of the agent into the reservoirs, will be accelerated as compared to diffusion at room temperature, in particular when employing a cap layer in the dental appliance.
Examples of the present invention will now be described in more detail with reference to the accompanying drawings, where features with corresponding technical function are referenced with same numerals even when these features differ in shape or design:
As the micro-reservoirs 3 have been patterned in the outer surface 24 of the foil 14, the micro-reservoirs 3 of the final appliance 1 are facing the gums and inner oral cavity of the patient, when the patient is wearing the dental appliance 1 on his teeth. As illustrated in
The micro-reservoirs 3 in
In the example of
Compared to the example of
The difference between the design of
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In the more sophisticated design of
As
In summary, it is proposed to accurately control the formation and geometry of a multitude of micro-reservoirs 3, which are actively formed in a core 4 of a dental appliance 1 during the fabrication of the same, preferably within a limited region of interest (ROI) 13. This approach allows accurate control of the rate at which the micro-reservoirs 3 release the agent 7 into the mouth of a patient and the total dosage that will be delivered to the patient by the appliance 1. The approach may be carried out using a computer-implemented method that enables rapid fabrication of a series 30 of such appliances 1, which are each personalized to the specific needs of a single patient or a group of patients.
| Number | Date | Country | Kind |
|---|---|---|---|
| 22156802.5 | Feb 2022 | EP | regional |
This application is a 371 National Phase of PCT/EP2023/052198, filed Jan. 30, 2023, which claims priority from European Patent Application No. 22156802.5, filed Feb. 15, 2022, both of which are incorporated herein by reference as if fully set forth.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2023/052198 | 1/30/2023 | WO |
